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So, here I am attempting to doing a full bottom job on my 35' boat. Bit of a jump into the deep end of the pool for me, but how else is a bloke gonna learn, right?
Anyway, much has been going on in life on the hard stand. Hull mostly freed of decades of over painted antifoul, numerous pot holes badly filled dug out and a number of larger osmosis blisters found. Anyhow, I digress from the subject matter...

I ended up dropping the rudder myself and what an interesting experience this was. Never have I done this before and now I know how these heavy rudders actually stay in a boat. Mine anyway!
Got it all apart in pieces and now I find that there is a crack developing along the seam where the two half shells of the rudder meet. Water had also been absorbed and after grinding/sanding it to bare glass, discoloration and possible glass rot was found.

Now I prefer to do things right first off, but I think I would be over my head as a first project to 'split' the rudder halves, dig out the existing foam, fix up any fiberglass and rebuild with expanding foam injection?! I mean I'm great at taking things apart and by my calculation, that is half the job done, but who knows right? The other option would be to dremel around the seam to open up a way to dry/drain the innards, then fill the gap with thickened epoxy, slap over a layer of epoxy and bi-axial cloth, fair and barrier coat. Done! Not the most elegant solution, but would it work?

Like I said, I'm a novice here, so any advice on how to proceed is muchly appreciated.

I better try and figure out how to get some pictures up for you, so you can make better sense of my ramblings. 
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Oh, and after sanding, the extent of it?!

Now, there are some darker spots under some of the glass and I think it may have been affected by moisture and rot, but I'm not sure. I tried sounding it out, but I'm getting sooo many different sounds coming from different spots around the rudder, I'm not sure what to make of it.

Anyway, that's the rudder itself. I still have to clean up the steering gear and most importantly figure out how these bearings go??? 

Any help is totally valued here!

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Split it, fix it properly.  Lots of load there, not a good place to be half-assing with epoxy filler.   How else do you know if the foam is still correctly supporting the framework at the bottom of the post and the shaft is corroding just past where you can see it entering the glass.  Wouldn't be fun if it turns out the internal support structure is shot inside your nicely refinished rudder.

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Yep, suppose you're right. I feel like I'm opening a can of worms though. Not sure how to proceed and not sure if I can actually do this job?

Some of the foam is buggered I believe, discoloration would be an indication?

Any hints on how to proceed with this job, like cutting a sizable hole in the side and dig out and inspect, or split along the seam?

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Split along the seam. Forget the Dremel by the way - get an angle grinder with several thin cut off wheels. Goes through glass like butter. Get a white bunny suit too.

Mark the centerline / seam with tape before cutting. Wipe off dust frequently as you cut. The foam may be semi-intact and hold the 2 halves together. You might have to use a reciprocating saw to cut the remnants of the foam apart. Careful you don't cut into the stock or steel work inside.

To glue the 2 halves together with thickened epoxy and tape the seams with a few layers of biaxial. It is not that hard. If you run out of confidence then having a yard do the final re-assembly should only be a few hours work. Taking it apart and rebuilding the inside if required is a lot more time. Tell them you will do the final fairing and sanding; just have them do the glassing.

And that is the fattest rudder I have ever seen. I know it is to hide behind the IOR bustle but it must have a stall angle measured in megaparsecs or something

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17 minutes ago, Zonker said:

megaparsecs

Quote

A megaparsec is a million parsecs (mega- is a prefix meaning million; think of megabyte, or megapixel), and as there are about 3.3 light-years to a parsec, a megaparsec is rather a long way.

things you learn on SA :D

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Haha, yep megaparsec phat, that's to counteract the effects of the blooper!!! :D

As to the rudder, suppose I'll have a go at it! I am thinking of leaving the trailing edge in tact and cut down 4 or 5 inches in. That way It might be easier when putting it back together with the foam and all?!

Bunny suit, tick,

Angle grinder, tick

Rocky music for inspiration to actually go the big cut!!! Still looking.

Thanks so much all of you, this info is exactly what I need and Zonker, you're right, can always ask a yard to fix up my handy work. Good advice!

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1 hour ago, lahana said:

Yep, suppose you're right. I feel like I'm opening a can of worms though. Not sure how to proceed and not sure if I can actually do this job?

Some of the foam is buggered I believe, discoloration would be an indication?

Any hints on how to proceed with this job, like cutting a sizable hole in the side and dig out and inspect, or split along the seam?

You could be, but would you be comfortable with that can of worms opening itself underway somewhere?  I think that could be a lot less comfortable.  Holes cause headaches, a nice clean cut will be much easier.    Buy a diamond cut off wheel for your angle grinder(the metal ones with diamond grit, sold for cutting metal) Cheap ones are only about 15$, and they stay the same size until worn out.  Much safer(no exploding zip disks for you) easier to cut a consistent depth with too.  Watch for any signs of touching metal(sparks, resistance, noise change).  Don't try to cut too deep in one cut, mask the two halves(I would separate port and starboard) with two strips of masking tape, one on each side leaving about a 1/8" gap between, cut down the gap.  Cut all the way around but don't worry about trying to cut deep on the first pass.  Score it only, Then on your second pass, cut full through the glass into the foam(again not worrying about trying to get too deep, or even about holding a super consistent depth.  Focus on keeping the cut straight and square)  Last cut, cut as deep as you can with the disk, witout touching the rudder with the arbor(center spinning metal bit).

If you are uncomfortable taking a grinder to it, you can do it with an oscillating tool and a carbide toothed blade.  It will be slow, but some find it less stressful. 

Once you have cut all the way around, try prying the halves apart.  GENTLY.  I like the red richards cheap painters prybars for this.  They are very thin but stiff.  Get several.  They are handy for many boat jobs too.  

l  If they won't separate, you have two choices, sawzall(a blade with low set(how far the teeth spread to either side is good, think metal blades not rough wood blades) this reduces damage to the glass as you cut.  I am partial to the Milwaukee torch and the Diablo carbide(My favorite), or a wire saw.  Like the ones you see in emergency survival kits.  Useless for trees, but surprisingly handy on foam in a pinch.  I would pick one up just in case, but follow grinder with sawzall.  Not knowing what is inside you will be exploring.  Relax, don't rush.  It's just like docking a boat, if things go wrong and you're just easing up on the dock you can stop and re-evaluate with a little bump, while the guy coming in full tilt is gonna be paying for expensive repairs.  You'll know if you hit metal if you are being observant.  If you feel like it isn't cutting in one area, stop, work another area and come back.  Don't force it through anything.   

Also buy a cheap thin stainless metal ruler, you can use this to probe the cut if you are unsure if you are hitting metal.  You will hear a distinctive noise if it is hitting the metal. 
Last look up rudder guts pictures before you start, a half assed mental map is better than nothing.

 

I strongly suspect you need at least some new foam.  Foam is easy :-). 

If you feel overwhelmed just remember that you can always hire a pro for glassing it back together.  The cleaner the edges of your seam, the lower your bill and the more they will like you.   Don't be tempted to grind your edge bevels with the halves separated.  Just don't do it.  You lose your reference faces and it makes glassing the seam much harder since the bevel doesn't line up perfectly.  Get foam dealt with, then grind bevel.  For bonus points make permanent marker lines across the cut onto both halves after removing the masking tape, but before splitting.  This makes reassembly easier. 

Lastly, good you have a full suit.  Don't forget to tape the cuffs.  For cutting and grinding I prefer the breatheable vs the waterproof.  Wear nitrile gloves, at least two pairs. Tape the cuffs on the first pair, replace the outer pair when they get torn(easier than getting gloves on sweaty hands and keeps dust outside where it belongs.  Do your lungs a favor, shave the day you go to cut and grind.  buy a good fitting 3M hal mask, and a pair of 2297 filters.  These filters don't look like much, but they are p100(best dust filtration) with an organic vapor lining, and breathe like you are wearing nothing.  North etc have too much resistance and you get dust around the edges. 

 

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Jgbrown, thank you so much for all the helpful hints, tips & tricks. I’ll be going at it in the coming days when the weather allows. I’ll be using a grinder, I feel more comfortable with the one I have than having to spend more on buying a multi-tool. :unsure:

As for the trailing edge, I’ll  be going in a few inches on one side, clamp on a strip of wood as a guide for the grinder. Now, where is that Rocky soundtrack! LoL

And yes Fleetwood, I’ll be documenting it.

:rolleyes:

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Also, check out Boatworks Today where the tackle exactly what you're doing.  I did a rudder repair on my big boat (26.5') a couple of years ago, but it was just grinding out a couple of blisters (that sounds perverted), drying over the winter with heat, then reglassing the ground out areas. 

When I pull the boat out of the water this spring, I'll have another look at it to see how it's holding up.

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Yep, had a look at Andy’s videos and I do like the idea of getting some air behind the skins to seperate them from the foam, before doing the cutting. What’s a few more holes right? ... Right?? :unsure:

I’d like to know more about how the putting it all back together process is done? The foam, putting the half’s back together, maybe a layer of biaxial right around? I mean, I’m a whiz at the “taking it apart” as mentioned, but the second half of the job is still a bit of mystery.

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1 hour ago, lahana said:

Yep, had a look at Andy’s videos and I do like the idea of getting some air behind the skins to seperate them from the foam, before doing the cutting. What’s a few more holes right? ... Right?? :unsure:

I’d like to know more about how the putting it all back together process is done? The foam, putting the half’s back together, maybe a layer of biaxial right around? I mean, I’m a whiz at the “taking it apart” as mentioned, but the second half of the job is still a bit of mystery.

How much glass is it currently made out of?  What direction do the fibers go?  As you cut(and especially after foam removal) you may find clues.  This will determine what repair is after.  If you take two nice and clean shells, with clean cut edges(and save a nice bit of the original foam too if you want extra points) and a nicely cleaned shaft to a FG shop they'll be able to put it back together well, the bit of foam is just so they can get a rough idea what weight of foam was used originally.  Usually people bring in half mangled bits with extra damage.    If the rest of the shell is good you can focus on repairing the seam to start with, once you have the seam done and the rudder nice and fair again, then you can think about skinning it with something all over, that way even if you screw up, you've already got a complete shell and can simply grind off and try again. 

A possible scenario could be: rudder cleaned out, shaft inside, outside repaired, mount the whole thing in a jig to keep the shaft and framework true to the rudder, then drill holes in the top, fill it with the correct pour foam and repair the holes after.  Everyone has their own methods, that is outside of my experience so I will leave that to cleverer people than me. 

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It's a fat IOR era rudder. If they used directional glass I would be (somewhat) surprised. Probably mat and woven roving and a final layer or two of mat in a mold.

I've never had a zip disc explode more than once. And I've bought them by the stack of 25 at Crapadian Tire. Never tried a diamond disc; does it cut faster or smoother or just doesn't explode?

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16 hours ago, jgbrown said:

You could be, but would you be comfortable with that can of worms opening itself underway somewhere?  I think that could be a lot less comfortable.  Holes cause headaches, a nice clean cut will be much easier.    Buy a diamond cut off wheel for your angle grinder(the metal ones with diamond grit, sold for cutting metal) Cheap ones are only about 15$, and they stay the same size until worn out.  Much safer(no exploding zip disks for you) easier to cut a consistent depth with too.  Watch for any signs of touching metal(sparks, resistance, noise change).  Don't try to cut too deep in one cut, mask the two halves(I would separate port and starboard) with two strips of masking tape, one on each side leaving about a 1/8" gap between, cut down the gap.  Cut all the way around but don't worry about trying to cut deep on the first pass.  Score it only, Then on your second pass, cut full through the glass into the foam(again not worrying about trying to get too deep, or even about holding a super consistent depth.  Focus on keeping the cut straight and square)  Last cut, cut as deep as you can with the disk, witout touching the rudder with the arbor(center spinning metal bit).

If you are uncomfortable taking a grinder to it, you can do it with an oscillating tool and a carbide toothed blade.  It will be slow, but some find it less stressful. 

Once you have cut all the way around, try prying the halves apart.  GENTLY.  I like the red richards cheap painters prybars for this.  They are very thin but stiff.  Get several.  They are handy for many boat jobs too.  

l  If they won't separate, you have two choices, sawzall(a blade with low set(how far the teeth spread to either side is good, think metal blades not rough wood blades) this reduces damage to the glass as you cut.  I am partial to the Milwaukee torch and the Diablo carbide(My favorite), or a wire saw.  Like the ones you see in emergency survival kits.  Useless for trees, but surprisingly handy on foam in a pinch.  I would pick one up just in case, but follow grinder with sawzall.  Not knowing what is inside you will be exploring.  Relax, don't rush.  It's just like docking a boat, if things go wrong and you're just easing up on the dock you can stop and re-evaluate with a little bump, while the guy coming in full tilt is gonna be paying for expensive repairs.  You'll know if you hit metal if you are being observant.  If you feel like it isn't cutting in one area, stop, work another area and come back.  Don't force it through anything.   

Also buy a cheap thin stainless metal ruler, you can use this to probe the cut if you are unsure if you are hitting metal.  You will hear a distinctive noise if it is hitting the metal. 
Last look up rudder guts pictures before you start, a half assed mental map is better than nothing.

 

I strongly suspect you need at least some new foam.  Foam is easy :-). 

If you feel overwhelmed just remember that you can always hire a pro for glassing it back together.  The cleaner the edges of your seam, the lower your bill and the more they will like you.   Don't be tempted to grind your edge bevels with the halves separated.  Just don't do it.  You lose your reference faces and it makes glassing the seam much harder since the bevel doesn't line up perfectly.  Get foam dealt with, then grind bevel.  For bonus points make permanent marker lines across the cut onto both halves after removing the masking tape, but before splitting.  This makes reassembly easier. 

Lastly, good you have a full suit.  Don't forget to tape the cuffs.  For cutting and grinding I prefer the breatheable vs the waterproof.  Wear nitrile gloves, at least two pairs. Tape the cuffs on the first pair, replace the outer pair when they get torn(easier than getting gloves on sweaty hands and keeps dust outside where it belongs.  Do your lungs a favor, shave the day you go to cut and grind.  buy a good fitting 3M hal mask, and a pair of 2297 filters.  These filters don't look like much, but they are p100(best dust filtration) with an organic vapor lining, and breathe like you are wearing nothing.  North etc have too much resistance and you get dust around the edges. 

 

No current rudder problems but learned much from this.   I am impressed, but not surprised, by the level of expertise on this site.   Your a goodun' JGB. 

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58 minutes ago, Zonker said:

It's a fat IOR era rudder. If they used directional glass I would be (somewhat) surprised. Probably mat and woven roving and a final layer or two of mat in a mold.

I've never had a zip disc explode more than once. And I've bought them by the stack of 25 at Crapadian Tire. Never tried a diamond disc; does it cut faster or smoother or just doesn't explode?

Think you’re right re the matting, the outer looks like a chop strand of sorts. As for the grinder discs, the metal ones are thinner and I would presume cut neater with less catching. Just a bit more accurate to control and last longer.

I am actually now thinking of jumping in and getting a multi tool as their blades are even neater and finer. I mean, the budget was blown long ago, shortly after I bought a boat! :huh:

jgbrown, I’m glad you told me about keeping some foam for weight analysis, I would not have thought of that.

think I’ve got half a plan now, cut along the seam till a few inches from the trailing edge, around 45deg cut aft towards the flat side surface on one side, then straight edge a few inches in from the trailing edge to join up the previous cuts.

I figure I wouldn’t be able to take the shaft out cleanly if I only cut out a large section of one side like in the Boatworks Today videos.

sail69, you’re not wrong there!!! 

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Any advice on the foam used to fill a rudder shell? Would you fill/foam into the 2 halves, then clamp together and seal the seams as described above? Not sure you would want to use an expanding foam on the closed up shell, as you may not know if it completely fills, or over expands.  Mine seems to have a filler type material. I just cleaned up around the shaft over the winter, but know I have to open it up like lahana is undertaking. 

Just reading this thread has me looking forward to it now. Thanks for the inputs. 

Bill

N22 rudder repair 1 excavated.JPG

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16 hours ago, Zonker said:

I've never had a zip disc explode more than once. 

I've never had one explode more than once either. But I've had several explode once. :)

The diamond dust wheel cuts a little slower than a carborundum disk, but stays the same diameter and is a bit easier to control. With one on a skill saw, you can cut through 2" G10 pretty quickly. It will make a bunch of fine dust though.

For filling a metal post rudder, I've wondered if foaming epoxy wouldn't be the best repair (though not the cheapest). It would not absorb water, and it's much harder than foamed urethane. With a metal rudder post going into the top, water will get in eventually, virtually all of them get soaked over time. Foamed epoxy might seal it out, or at least tolerate the intrusion better.

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1 hour ago, DDW said:

I've never had one explode more than once either. But I've had several explode once. :)

The diamond dust wheel cuts a little slower than a carborundum disk, but stays the same diameter and is a bit easier to control. With one on a skill saw, you can cut through 2" G10 pretty quickly. It will make a bunch of fine dust though.

For filling a metal post rudder, I've wondered if foaming epoxy wouldn't be the best repair (though not the cheapest). It would not absorb water, and it's much harder than foamed urethane. With a metal rudder post going into the top, water will get in eventually, virtually all of them get soaked over time. Foamed epoxy might seal it out, or at least tolerate the intrusion better.

I've always liked the idea of foaming epoxy for rudders.  Would work well if you have a mold or in this case, a shell.  Definitely wouldn't use standard foaming PU.

Sicomen supplies it in various densities, but may be hard to source in North America.  Pro-Set makes a foaming epoxy as well; https://www.compositesworld.com/products/pro-set-two-part-expanding-epoxy-foam May be easier to source.  Places like Jamestown Dist sell Pro-Set products.  While I don't think they list it on their site, they may be able to acquire it.

Pro-Set claims it has a density of 15-19 lb/ft3 Which makes for a dense foam, but that is what you want in a rudder.  Many rudders are built with 8 lb foam, but I would want 16 lb.  My guess is this is more cost driven than anything since a sheet of 16 lb foam gets quite expensive.

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From what I have seen after drilling a hole near the bottom of the rudder is that the foam there was very, very light. It was dry though and that, along with a friends suggestion made me think that there might be a horizontal plane somewhere along the rudder stock. The greying from the inside of the glass and the rust leaking out of a crack near the top of the rudder, but not down lower seems to suggest this. My guess would be near where the “bulge” starts, around two thirds up.

My mate also suggested that if it all turns south, we can always build an entirely new rudder out of a foam block, instead of rebuilding the two half shells. Suppose we’ll only know once I get to it with the grinder. Could be a big day coming up!

Still looking for the “eye of the tiger”! :huh:

One thing I’ll be doing before getting cut’n is measure the “approach of the rudder stock to the actual rudder blade. That way, if I butcher it, we can rebuild within specs. ;)

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On 5/3/2018 at 4:31 PM, Zonker said:

It's a fat IOR era rudder. If they used directional glass I would be (somewhat) surprised. Probably mat and woven roving and a final layer or two of mat in a mold.

I've never had a zip disc explode more than once. And I've bought them by the stack of 25 at Crapadian Tire. Never tried a diamond disc; does it cut faster or smoother or just doesn't explode?

the not exploding is good.   Smoother definitely, speed it's a wash.  Faster in a cut?  Hard to say, my first cheap diablo one was about the same speed, the old masonry ones I experimented with were a lot slower(Enough that I switched back to zip disks).   But staying the same size and not changing out discs, probably a lot faster overall.  The best ones are not diamond dust in a sacrificial metal like you find in a masonry blade, but instead are a straight steel blade with proper diamond chips on the outside.  I have ordered the two top current ones from a test I was reading(Lenox Metal Max and Milwaukee Steelhead) the steelhead is supposed to be significantly more aggressive but slightly less smooth on steel which sounds ideal on glass.  @DDW was your experience with masonry or the new generation of steel cutting ones?

@lahana Do yourself a few favours: 1.  Buy good blades.  I am partial to Fein or the Imperial bi-metal blades for general purpose.  Buy one bosch carbide tipped blade for glass only(They work great on metal too, but it blunts the edge enough to be noticeably slower on glass after).   Fein makes a fiberglass specific blade but it's 140$ for ONE BLADE. :blink: I considered buying one for about 30 seconds before I realized how much my brain would explode the first time someone used it on metal and wrecked it. 

EDIT: I just went to amazon to look up the bosch blades for you(I bought 6 when they first came out, still have 2 left, in the same time frame we burned up a few dozen of the non-carbide imperials I had bought before).  It looks like Imperial has released a carbide edged one, so I would go with them instead.

https://www.amazon.ca/Imperial-IBOAT360-2-Universal-Fitment-Titanium/dp/B071R6N7YP/ref=sr_1_1?ie=UTF8&qid=1525484917&sr=8-1&keywords=bosch+carbide+oscillating+tool+blade

Thin is better in a zip disk, but the thinner they are the more sensitive they are to damage and wear from the side, so be very careful to cut true, and you get what you pay for in zip disks.  Either way wear your faceshield!  I have a nice little scar from the time I didn't and one went bang.  Chewed up my safety glasses too. 

Also check the expiry dates when you buy them. 

EDIT: The expiry date check is just to buy the newest ones they've got. I like to grab new ones from a fresh box  too so I know they haven't been getting bashed about at the store.  Don't buy them at Canadian tire, do yourself a favor and buy some decent disks from KMS or similar(I like Klingspor).  I know several shops are caring the diablo diamond blades like I bought, so far quite happy even though it's a little wobbly in deeper cuts(a known issue), I will be upgrading soon.  If you have no zip disks, I would strongly consider buying a nice one once since it will do metal/glass/etc and for about the price of a pack of decent disposables. 

 

 

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Thanks for the info jgbrown, I am located Down Under, so our hardware stores differ slightly, but I'm set for the big reveal today. Still looking for the soundtrack to get me started though. LoL

Anyway, I've decided to start with a few holes and some air pressure to separate skin from foam. See where it lifts and start cutting along the seam. I may do this in two sections (top/bottom) to see if there is any structural bond between the two halves I have to consider. We'll see.

Pics will no doubt follow...

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She's not giving up her secrets easily!!!

Spend a good portion of the day trying to split the rudder. What a job, think she's not finished with me yet!

First I drilled some holes and blew some compressed air in. It all looked promising as the surface rose and cracked free in places, except it also blew out the seam along the trailing edge in a place, but then I couldn't continue the split even with hammer and chisel. Just as well I'm doing this job, it would have been a weak-spot where water could have seeped in, if I didn't have found out about it here.

Anyway, carefully aligned and marked the direction of the shaft and noted it on the rudder. That way I would be able to align it when re-assembling it. So far so good.

Now, a few light runs along the taped seam with the cutting blade and it was clear there were other forces at play and not only glass. The glue they used to bond the two halves is a bit brittle, very hard and varying in thickness. Carefully moving ahead not to hit steel anywhere. Stop, inspect and then go deeper with the grinder again. Figured I'd sneak up on her that way. In parts, water was oozing and with it some green foam bits. Still, so far so good!

Now I got to go around with chisels and try and prey open the two half's. Not much give, so I escalate and use more force and stop worrying about nice neat edges. Weges, shovels and blocks of wood are employed and gloves are off. I'm starting to find out where the shaft and wings off it are and mark them on the outside for reference. The saw worked quiet well, pushing it, using it as a splitting tool as well as saw through foam and glass. A few hours later and this is as far as I got...

I'm not sure how I'm going to go tomorrow, but I suppose it is just going bit by bit and 'working' the wedges around.

 

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I'm guessing that the top skin at least has had it, after I'm finished with it. I'm looking at retaining the halves though, in case I do have to make a complete new rudder from the stock alone. They would be good enough to get a mold off.

Was going to put up a couple more pics, but looks like SA won't let me tonight, till someone else posts here?!

Anyway, hope someone has any ideas for me and on the flip-side helps someone else out as well.

Cheers!

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Maybe a wood saw (keyhole saw) with a stiff blade to cut remaining foam/glue? I would not be surprised if the glue wasn't just polyester resin.

Why did you sand all the paint/gelcoat off the whole rudder?

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1 hour ago, Zonker said:

Maybe a wood saw (keyhole saw) with a stiff blade to cut remaining foam/glue? I would not be surprised if the glue wasn't just polyester resin.

Why did you sand all the paint/gelcoat off the whole rudder?

Dropped the rudder during a hull prep for barrier coat, rudder had a bit of pox previously that was badly fixed. Putty was falling out and gel coat in general was spent. Not much difference sanding it neatly, or going at it with a abrasive flappy disk on a grinder for the roundings and doing the flat surfaces with soft sanding disk. Down to the glass, I could see better just what was going on. 

The rudder wasn’t going to be taken out in my earlier plans. Only after the crack developing on the leading edge, did I pull it out. Boat has been out of the water for over a year now and amazingly a number of osmosis blisters have come to the fore because of it drying. That’s another thing I have learned, even if there is no indication of bulging or sound of full delamination of blisters, after extensively drying out, blisters can break through (even gelcoat) by themselves and leak.

Its  a journey of discovery,... for both the hull and myself. :wacko:

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14 hours ago, lahana said:

I'm guessing that the top skin at least has had it, after I'm finished with it. I'm looking at retaining the halves though, in case I do have to make a complete new rudder from the stock alone. They would be good enough to get a mold off.

Was going to put up a couple more pics, but looks like SA won't let me tonight, till someone else posts here?!

Anyway, hope someone has any ideas for me and on the flip-side helps someone else out as well.

Cheers!

I don't see any hash marks across the cut, just add a few lines across the whole thing after removing the tape. It will make alignment nice and easy.  I don't like the look of the amount of flex you're getting on the wedges, I'd step back from pushing those for a bit and keep working on getting the foam to cut now instead of putting any more force on that, still with a reciprocating saw and a wire saw now possibly.  The skins still look reasonable enough to use, maybe with a few repairs after putting back together, but that could still save a lot of time over making a new foam blank and glassing over it, are there many bad areas in the glass itself?  I also wouldn't leave it wedged overnight to that much of a bend.  The glue kind of looks like filler, if you take a chunk out and break it instead of cutting, do you see any fibers in it?   If you want to make a mold you'd probably be better served by taping that seam up again and making the mold now rather than later.  This might be a good time to discuss with a FG repair shop, to get their in person input on mold vs re-using skins, and a price either way from them just to give you a frame of reference.

 

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On 5 May 2018 at 12:04 PM, lahana said:

Thanks for the info jgbrown, I am located Down Under, so our hardware stores differ slightly, but I'm set for the big reveal today. Still looking for the soundtrack to get me started though. LoL

Anyway, I've decided to start with a few holes and some air pressure to separate skin from foam. See where it lifts and start cutting along the seam. I may do this in two sections (top/bottom) to see if there is any structural bond between the two halves I have to consider. We'll see.

Pics will no doubt follow...

Where abouts down under?

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1 hour ago, jgbrown said:

I don't see any hash marks across the cut, just add a few lines across the whole thing after removing the tape. It will make alignment nice and easy.  I don't like the look of the amount of flex you're getting on the wedges, I'd step back from pushing those for a bit and keep working on getting the foam to cut now instead of putting any more force on that, still with a reciprocating saw and a wire saw now possibly.  The skins still look reasonable enough to use, maybe with a few repairs after putting back together, but that could still save a lot of time over making a new foam blank and glassing over it, are there many bad areas in the glass itself?  I also wouldn't leave it wedged overnight to that much of a bend.  The glue kind of looks like filler, if you take a chunk out and break it instead of cutting, do you see any fibers in it?   If you want to make a mold you'd probably be better served by taping that seam up again and making the mold now rather than later.  This might be a good time to discuss with a FG repair shop, to get their in person input on mold vs re-using skins, and a price either way from them just to give you a frame of reference.

 

I've been trying to sneak up on it and work gently, but I'm not battling foam, the shaft and the welded on wings coming from it are glued well. I've been pulling out chunks of bonding paste and solid resin. Even a hand saw doesn't bite into some of this stuff. A reciprocating saw would, but they are not long enough to get to the offenders. 1st I thought I got the side where the shaft was bonded to prior to sticking the two sides together (had a 50/50 chance there), but now it looks like I got lucky as it's bonded to the bottom half (port side) of the rudder.

As for the bending of the glass, I'm trying to only mess up the one side as that can be easily rebuild and glassed afresh. But I'm expecting to have to rebuild the whole lot if I don't have much more luck with getting these two halves apart. I'll give it a couple more hours of work, after that there'll be drastic measures to free the shaft. Worst case scenario, but at least the new rudder may be a few inches longer. ;)

Here some more pictures that may help explain better.

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DSC06001.jpg

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3 minutes ago, Rushman said:

Where abouts down under?

Vic

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6 minutes ago, lahana said:

I've been trying to sneak up on it and work gently, but I'm not battling foam, the shaft and the welded on wings coming from it are glued well. I've been pulling out chunks of bonding paste and solid resin. Even a hand saw doesn't bite into some of this stuff. A reciprocating saw would, but they are not long enough to get to the offenders. 1st I thought I got the side where the shaft was bonded to prior to sticking the two sides together (had a 50/50 chance there), but now it looks like I got lucky as it's bonded to the bottom half (port side) of the rudder.

As for the bending of the glass, I'm trying to only mess up the one side as that can be easily rebuild and glassed afresh. But I'm expecting to have to rebuild the whole lot if I don't have much more luck with getting these two halves apart. I'll give it a couple more hours of work, after that there'll be drastic measures to free the shaft. Worst case scenario, but at least the new rudder may be a few inches longer. ;)

Here some more pictures that may help explain better.

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Oh that does make more sense now.

I'd still try one of these:

https://www.amazon.ca/UST-20-02117-02-Wire-Saw/dp/B00O3OQ1TI?th=1&psc=1&source=googleshopping&locale=en-CA&tag=googcana-20&ref=pd_sl_xv5f1usws_e

They're shit and you might wear out a couple, but if they'll bite they go over stuff fairly well when you're in a pinch like this.  How deep is the cut, 12" recip saw blades are pretty handy.    Another not so fun trick is to get a bandsaw blade cut it in a section and wrap the ends around a couple dowels to saw with.  Narrow blade, low set, fairly high tpi.  

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1 hour ago, lahana said:

Vic

Which part?

A mate has a business doing glass work in Carrum Downs

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7 minutes ago, Rushman said:

Which part?

A mate has a business doing glass work in Carrum Downs

That's just down the road from me. I'm at at Mordy. Could you PM me your friends detail? I might need his services. :unsure:

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2 minutes ago, lahana said:

That's just down the road from me. I'm at at Mordy. Could you PM me your friends detail? I might need his services. :unsure:

I dunno about him, but I always charge a bit less when someone gets input from me ahead of time on how they can tear something down so as not to create a bigger headache later.  I find they are way less likely to be useless when it comes time for paying, and also thoughtful enough to try to plan to make my life easier.  So getting him to have a look now is a good move!

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2 minutes ago, jgbrown said:

I dunno about him, but I always charge a bit less when someone gets input from me ahead of time on how they can tear something down so as not to create a bigger headache later.  I find they are way less likely to be useless when it comes time for paying, and also thoughtful enough to try to plan to make my life easier.  So getting him to have a look now is a good move!

Good advice, thanks.

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Well, that did it!

Finally, FINALLY! The shovel put it over the edge! Anyway, another few hours today and we now know what's what. Top of blade was soaked, bottom not to bad. The amount of pure resin, bonding and general god knows what in this rudder is amazing. Definitely heavy build and the stock is in decent condition. A few more years though and I think she would be feeling the effects of having moisture in it.

The bottom shell is still in good nick, but I had to crack the top to get her to open up. All in all, I'm glad I did what I did and now just going for a big clean up, digging the foam and bit's n'pieces out best I can, then figure out what my next move is. Think I'll try and salvage as much of the shells as I can, repair/reinforce the top?!, build up some stringers or whatever supports are called and give it a go with foam and epoxy 416 mix. Then either a layer of biaxial along the seam, or cover the whole rudder with it? Then a fairing job, barrier coat and anti foul. Back in business... Please say it's so!

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The  Proset or Sicomin epoxy foams are a big improvement on the polyurethane, I usually leave a vent or 2 or 3 depending on size and orientation, these allow expansion and reveal completion, if there's a mid height baffle plate then maybe two stages, serious external clamping is good, 4x2s with threaded rod is 1 way. Might be easier cheaper to reinforce interior of shell but lams do more work on outside and you can tape seams. Epoxy is good. I just had a heat reaction from an epoxy bog in this new rudder that created some foaming,  there wasn't enough pressure in it though to fill all the voids, reusing the old shell saves a lot of money and time. There's a discussion about sealing the top at the post here also. I am curious if the Walabot would work for inspection.

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Awesome info, thank Bruno!

Yes, I think I will try and retain both halves of the shell and maybe place some biaxial on the inside to fix and strengthen, particularly on the half I had to “work” hard to pry off. 

I’m trying to figure out how to build a jig so I can safely take out the entire stock, clean out and prep the shells and then put the stock back in its original alignment. Probably will glue and laminate it to one side and then foam and glue the other half on. Then either another full cover with biaxial, or just strips over the seam.

Could you point me in the right direction of where you saw the article on how to seal the top of a rudder please?

Thanks again! 

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How are the welds for the webs attached to the rudder stock? Any significant corrosion. Use a jeweler's loupe or 8x magnifying glass if you can. Also check the stock for crevice corrosion in the top 5-10 cm where it enters the rudder.

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7 hours ago, Bruno said:

Thanks Bruno, will have a good look at it. Really appreciate all the help you guys are handing around. Much appreciated.

On 5/8/2018 at 4:02 PM, Zonker said:

How are the welds for the webs attached to the rudder stock? Any significant corrosion. Use a jeweler's loupe or 8x magnifying glass if you can. Also check the stock for crevice corrosion in the top 5-10 cm where it enters the rudder.

SO far it looks A-ok, I haven't been able to take the stock out to have a look at the other side yet. I first have to figure out a way to be able to replicate correct alignment of the stock before I can remove it from the bottom half. But glad you reminded me to do a close inspection. Might even run some die over the welds.

 

On 5/8/2018 at 11:27 AM, Rasputin22 said:

Looks like that green foam that florists use to stick flower stems in. Really tough stuff an perfect for a rudder!

Should I start flirting with the local florist, or keep buying flowers for my wife? Think it'll be cheaper, either way, if I buy a new rudder. LoL

 

Thanks all, keep it coming.

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For alignment, don't discount that you can use a blob of kitty hair or tiger hair body filler to locate the stock back relative to the skins. 

Basically chew out a few areas of the foam, excavating style...  then mix up a blob of the goop with a piece of packing tape on the web of the stock so it doesn't bond to it.  That sets your depth and location to key back together.

Cheers,

Zach

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19 hours ago, Zach said:

For alignment, don't discount that you can use a blob of kitty hair or tiger hair body filler to locate the stock back relative to the skins. 

Basically chew out a few areas of the foam, excavating style...  then mix up a blob of the goop with a piece of packing tape on the web of the stock so it doesn't bond to it.  That sets your depth and location to key back together.

Cheers,

Zach

Thanks Zach, that's what I had envisaged. The stuff you describe we're not familiar with down under, but we have similar. I was actually thinking of mixing it myself with epoxy and chopped strans mix. There is a LOT of resin and bonding all throughout the rudder, it'll take me a while to get all that sorted. Think the grinder will make easier work of it than the multi tool, but I'll keep updating. Crap weather last few days and I'm not hacking at it inside the shed. 

 

In the meantime, I've started to do some quadrant cleaning. The existing olive paint was flaking off and I also wanted to have a closer inspection for cracking etc. Found some elongated through holes, where the bolts fit, to hold the two halves together. I think an option is to bore out and fit with new, thicker bolts. Could this have some adverse efects though?

Also looking to re-paint, or may even go the full hog and have them electroplated?!? I'm mainly looking for a lighter colour that will show up cracks easiest. Any suggestions ya'all?

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Occasionally cleaning stuff like this up with a grinder...  You can put one disk facing upward, and one disk facing downward with a few sandwiched in the middle to stiffen up the pack. No backer pad, so you can grind the underside of stuff.  The guard on and grind top and bottom in and out to blow the foam, resin, and other crap out of the way on the underside of the armature web.  Looks weird, but grinding steel welds with a metal grinding disk nobody cares if you use the top or bottom, but a grit disk looks strange rigged that way, under side of hatches on deck and deck recore lets you grind the underside of the bevel for new core.  Keep your fingers and toes attached please. 

  A multi-tool or sawzall can cut a groove to get the disk into and get started.   I've got a 5 amp cheapo grinder, that you can hold on tight enough to stall.  If you've got a router foot switch, or make a light switch box with a power plug beside a light switch you can add a bit of safety back to the ordeal.  But doing it that way turns an all day job with a multi-tool into a dust storm that gets finished up quickly.

If you've got an air compressor, a right angle grinder with Roloc grinding disks helps for the detail work.

The kitty hair should be available at an auto parts store along side the bondo and body fillers.  Basically just long-strand fiberglass milled into a polyester resin in a quart can...  Catalyzes with cream hardener.  Grab a can of it and a can of regular bondo.

I use both quite a bit for taking off shapes, as a 3/8ths thick blob of it cataylzed slowly on top of a piece of painters tape or mylar makes a perfect copy of the radius you are aiming to extend.  Blob of it around 4 inches long,  ground to fit your hand after it kicks off turns into a hand sanding tool that lets you work a little easier.  Makes for some lazy sanding, but on stuff that has a lot of shape it beats what you can do with 40 grit paper stuck to a stir stick.  

Bondo isn't all that strong, so you can use it as a temporary tack weld if for a jig and fixture.  Basically rough in a 3x3 to hold your rudder on the table top mix up a softball size blob of bondo and spread it thick over your jig and drop the rudder skin down onto it.  In ten minutes you've got a female holding jig that doesn't rock all over the place, that you don't have to shim, and can hammer it loose. 

Painters tape works, as a release agent...  but if you are doing any gluing work sometimes just leaving the bondo to kick off and grab a hold of the skin isn't terrible either. 

Another that you will want to know, is you can take 1/2 inch plywood and rough shape it to the U of the front of the rudder and pack the opening full of regular bondo to take off your lines.  A piece of sticky sandpaper stuck to the rudder, lets you sand it and putty a second time for a perfect fit without spending a lot of time working it down with a jig saw to make a template. If you work it till you get a sharp edge, you can even pull your filler with it so long as you work clean enough to make your transitions between the tapers.  Over fill, and tilt the U until it makes contact as tight as it'll go, and pull up until it stops...  Then switch to the next size.  Takes a few minutes, but if you get your first pull clean you don't over-fill everything and have to sand for a year to get back down to the correct shape. 

If you turn the guides upside down on the same spot and they don't fit, you've got something that isn't round and the centerline of your rudder is off center, with two different radius on each side of a flat spot.  That doesn't necessarily make one low, just that one can be high. I like to glass rudders with the leading edge held vertical where I can walk around them.  Wooden ones you can clamp right to the studs of the wall in the shop.  Glass ones takes a bit of jig-work to hold vertical.  Peel ply helps.

If you have an air compressor, an autobody air file makes real quick work of working down the leading edge and dealing with getting the taper back trued up.  Get your vertical reference points figured out before you address your horizontal ones.  Vertical first you get your radius in the correct spot, and the maximum draft of the rudder profile can't be higher than the maximum...  Beating it down smooth on the horizontal plane with a grinder and DA doesn't take the high spots out of the vertical plane and gets you adding filler to things that, while they are low spots... Wouldn't be if the taper was true, and once you putty up...  You end up far from symmetrical.  If you can hang it somehow from the ceiling this gets easier so you can see both sides from the front like the water will.  You can do the same work with a 16 inch hand board and 40 grit.  Gist being going that way is a can of cheap spray paint, hit the spot being picked on until the spray paint disappears and then DA 40 grit until the paint is gone around it and re-check. 

Most folks have trouble working raw glass fair, and will grind low spots into stuff around high spots.  Throwing a coat of Interlux 2000 on and coming back the next day sometimes is a solution just to have something to look at.  Doesn't take a whole lot of material, and can solve the issue of sanding different colors harder than others, and gives you something to write on... 

Look into how to "Winding Sticks" work.  If stuff isn't doing what it is supposed to sticks longer than the plane you are working to fix they will be out of alignment.  Bright light, and an eye looking for gaps will show you the high spots.  Your Rudder profile gauge can fits both side, but would show you aren't symmetrical if you had one showing the cross section that slip fit and checked both sides at the same time.  Basically, still fucking high compared to the rest of the blade... 

Rolling a florescent light bulb across the blade vertically can show you some of the higher high spots, as it'll wobble.  Profile gauge can fit, but it is still going to be high if you putty up everything else to sand out into that area, and when you get it primed up and really look at it you'll see a pancake flat spot 12 inches wide around it...

Where your blade has a hard break, and fattens up to its root...  its going to be a pain in the ass to keep it low enough there that you can true up the rest without wanting to putty up and fatten the leading edge all over the place. If you deliberately keep it low  and don't putty up the 2-3 inches beside that hard break, until the rest of the blade is done...  You can come back with a smear of putty and finish it.  Otherwise every sanding cycle that you don't take it "ALL" back out of there will give you a reading to add more material at the top.

The lazy way is to leave the transition point low and spot fill when you are in 80-120 grit everywhere else...  Might not be dead nuts perfect in the transition, but you'll have better performance from having a symmetrical blade below it. 


Cheers,

Zach

 

 

 

 

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Hey Zach, can't thank you enough for all the info. You went above and beyond with your post. I had to read it a couple of times to get all the info out of it. It'll help a lot with this job. Cheers!

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7 hours ago, lahana said:

Thanks Zach, that's what I had envisaged. The stuff you describe we're not familiar with down under, but we have similar. I was actually thinking of mixing it myself with epoxy and chopped strans mix. There is a LOT of resin and bonding all throughout the rudder, it'll take me a while to get all that sorted. Think the grinder will make easier work of it than the multi tool, but I'll keep updating. Crap weather last few days and I'm not hacking at it inside the shed. 

 

In the meantime, I've started to do some quadrant cleaning. The existing olive paint was flaking off and I also wanted to have a closer inspection for cracking etc. Found some elongated through holes, where the bolts fit, to hold the two halves together. I think an option is to bore out and fit with new, thicker bolts. Could this have some adverse efects though?

Also looking to re-paint, or may even go the full hog and have them electroplated?!? I'm mainly looking for a lighter colour that will show up cracks easiest. Any suggestions ya'all?

 

 

 

 

Couple quick notes:

After you are sure the aluminum is in good condition, I would have it sand blasted and powdercoated, it's not terribly expensive and lasts much better than paint. 

 

Stick to the polyester resin if you're going to make your own mix.  It's easier to buy premade filler in a can, and is much faster curing(useful to have both options) but is harder to catalyse larger batches accurately.  Epoxy and the normal chopped strand you can buy doesn't work, the binder won't dissolve so you are left with liquid epoxy with a bunch of short stiff fibers.  Polyester resin will dissolve the binder.  I like to mix up the quantity I think I'll need with the fibers first(and use a lot less fiber than you think, it will expand a lot and absorb resin), let it sit overnight, then mix again in the morning  before adding micro-balloons or cabosil after it has finished dissolving the binder.  Done this way the filler consistency stays the same as long as you keep it covered.  If you try to mix it all at once it is harder to get the fibers evenly mixed, and you will probably overshoot on the other additives.  It's easier on your drill too. 

Make sure you keep a note of how much resin you started with, and the total volume of filler. For example(and these are not recommended numbers, just round numbers for an explanation) if you were to start with 10 liters of resin, and after making filler you have 20 liters of filler, then when you fill a container to catalyse, you would use just over 1/2 the amount of catalyst as if it were straight resin at the same temperature(the reason for the little bit extra is because it seems to me that the filler absorbs some of it, so it reacts more slowly than an equivalent volume of straight resin, if you are near the low end of the range for your temperature this can be enough to cause issue so a little extra is cheap insurance, don't do this if you are catalysing near the top of the range though).     This is more accurate than the usual eyeball method of adding creme hardener to pre-made filler. 

If you make your own filler, remember that just like when glassing, the surface will be slightly tacky for a while unless you inhibit the air.  This is handy if you are building, less handy if you are sanding and didn't inhibit the air from getting to it while it cured.

I don't like bondo brand fillers, I've found them inconsistent and unreliable, not sure what you have down their for brands, but if you are trying to make your own filler and not using a pre-mixed system like west($$$$) then I would do the following:

Buy one can of each;

long strand reinforced filler(this is basically chopped strand).

Short strand reinforced filler(this is basically milled fibers as near as I've been able to tell, finishes fairly smooth but a bit slower sanding than sanding filler).

Sanding filler(aka bondo), I like the evercoat brand, but anything will do. 

Use the long strand filler in a can as a comparison while you make your own.  If it's the first time, go slow, add chopped strand fibers, let it sit overnight, see how it's changed, add some more, once you think you are close on the amount of glass you see in the long strand filler, add your bulking agents to get the consistency right.  I like to keep the mix just a little on the stiffer side of what I plan to use, it's easier to add a little resin if you have a need for some extra stiff stuff for positioning than it is to add more filler to stiffen it. 

In areas where long strand filler has being used, or for filling surface defects on bare glass for the first pass I prefer to use the short strand filler vs sanding bondo, it sands reasonably well, tools reasonably well and is stronger and more like the existing surface so I always seem to get a more consistent sand, and more glass is better for durability, it's a nice middle ground. 

I don't like to fill over interprotect.  I will sometimes use a very thin coat of unwaxed gelcoat and a little styrene added for smoothness to even out the colours a bit if needed, mist it with unscented cheapest hair spray to inhibit air(stay away from anything that says extra hold, waterproof etc) then wash with hot water and soap in the morning, and scuff the surface lightly even in the low spots before continuing with filling and sanding. 

EDIT: Oh also, buy a pack of the super thin stainless filler applicators, and a pack of the cheapest translucent plastic ones.  Keep a bucket of acetone handy when working, as soon as you are done applying, wipe the tool and put it in the bucket.  Any buildup on the edge will create marks and lines in your surface.  The metal ones are great for exact feather edges and consistent work, the plastic are handy to cut for making tools for specific tasks. 

Also for inside cornes, buy some cheap wooden dowels in various sizes, cut the end off so it's a clean cut, then cut a curve out of either side with a jigsaw and sand. Very handy for radiuses.  I'll try to snap a photo of one later. 

 

 

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So, I'm back and laden with goodies!

Well, some stuff for the rebuild anyway. 

jgbrown, thanks also so much for the great info. I think I found some long stran bog in an automotive body repair store, will study up on it and report back.

Found a pretty severe Concrete/Fiberglass grinding disc, so hope to make a little quicker job of digging out the shells with it. 

Had a few days away from the rudder, but hope to be able to get stuck into it again near the end of the week.

I've also looked into the powdercoating and see that it's the way to go. Thanks to you all for pointing me in the right direction.

More updates with pics to come!

Cheers!

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I would stay away from powdercoating. It looks nice at first, but eventually peels off and leaves lots of corrosion behind. And it will hide any cracks in the metal. The olive paint might have been a chromate type paint which is a good protective layer for aluminum.

Marine aluminum is just fine kept unpainted if you keep standing salt water or salt crystals off of it. 

The elongated holes are difficult - too close to the edges to drill larger size. Elongation suggest that maybe the bolts were loose at some point. I would consider drilling a second set of holes further inboard or outboard of the existing ones. Drill one hole from the mating surface, clamp halves together, use a transfer to punch to mark mating point, unclamp, and drill second half. You can't get a drill in the space when the halves are together, thus this method.

And use nylock nuts on the bolts too.

 

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There is no force on that radial drive to elongate the holes. Also no apparent deformation around them. My guess is they were that way to begin with - drilled a bit off location and then corrected. 

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13 minutes ago, DDW said:

There is no force on that radial drive to elongate the holes. Also no apparent deformation around them. My guess is they were that way to begin with - drilled a bit off location and then corrected. 

maybe get a machinist to bore them out larger, and insert a bushing?

 

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Hmm, I agree that it doesn't look like deformation of the surrounding material but the pic is pretty blurry. 

He needs some special bolts - 2nd row, far right column. Or maybe far left column.

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Haha, yep Zonker, think you nailed it with the row 2nd row RH one! I'll head down to the hardware store tomorow, hope they have it in left hand screw, as I only have a left hand wrench here. Choices are limited down under. :-)

I had a good dig at the skins this arvo, was using a concrete/fiberglass disc and it actually worked like a treat! A bit hard to get into the smaller radi, but it cut easy enough through the resin only areas and neatened up the glass mat surfaces. I was rather amazed how "gentle" it was on the glass?!? I'm trying to leave some of the areas that molded around the stock for reference, but much of it is cracked and will be replaced by thickened epoxy down the road. The to has some structural ribs in it and I'm not sure if I'll have to rebuild these, or get away with using a denser foam?

As for the elongations in the quadrant, the bolts weren't loose, but suppose they may have been done up in the 32 years afloat, if that was the cause. I haven't worked much with cast aluminum, are there any special considerations when drilling? Wouldn't think so, but I might as well ask. 

There is also another option for coating. Anodizing seems to toughen the surface, protect from corrosion and becomes part of the structure, so corrosion can't start below it. I'll have to look into this a bit further though.

Anyway, her some pics.

Cheers!

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Oh yes DDW, I had a closer look at the quadrant again. Doesn't seem to have been chewed out and deformed at all. Would have thought I'd see some shiny bare alu, but it may also be just one per quadrant halve for ease of alignment?

Raz'r, that could also be an option, but I'm starting to lean towards just pumping it full of Duralac paste and see how that suits her?! I'll do a dry fit and see if there is movement at all. As mentioned earlier, it may also be part of the manufacturing to help with alignments, or it's just an apprentice mark. LoL

Thanks guys!

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Nothing special about drilling cast aluminum. Currently I am having a fight with my daughter who spent 2 years in the Oz education system and wants to call it Aluminium...

Back to drilling - using aluminum cutting/tapping fluid is nice for thick materials like this. In a pinch kerosene is not a bad substitute for the proper stuff if you have some on hand.

Anodizing is very nice but may be overkill for something that has managed for 32 years so far.

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I'd guess on the bolt holes that they were drilled separately, then when put together some misalignment noted and one side elongated to get the bolts through. The fasteners Zonker references are great if you can find a source! Since it has held for these many years, I'd just put it back together. There should be no axial loads on the radial drive. Drilling them bigger when you are that close to the edge could be trouble. If you have access to a mill you could end mill them straight and bigger, offsetting to the middle - but I'd leave it alone as I don't think it's broke.

The anodizing to use in salt water is Mil Spec type III hard. It will not improve the appearance of those as all the imperfections and old corrosion will show through. And in fact little corrosion pits and imperfections/inclusions in the casting will also show and not be perfectly anodized, this is were new corrosion would start. Type II anodize is mostly ornamental, for lawn furniture and such, though it does help a little. That's what you typically see on masts and booms, because its rare to find a Type III tank big enough. Fittings from Harken and Antal are Type III hard. On old cast aluminum like that, I'd use a chromating primer and 2 part PU paint and call it good for the next 30 years. It will look better and last at least as long. 

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Yep, not worried about looks with this thing down in the bowels of the boat. Just interested in giving it some protection from salt water and grease while I’m at it. Speaking of “at it”, fit the replacement steering cables, would it b an idea to use plastic coated wire to reduce wear on the channels on the quadrant and sheves? Or is it going to corrode underneath where you can’t see it?

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If you're cutting and drilling a lot, I really like the wax in a caulking tube style lubes.  Toolsaver etc.  Doesn't get all over the show like liquids, never spills does seem to help bit/blade life, swipe the bit over the end once in a while and it keeps aluminium etc from building up.  Cleans up with mineral spirits.   I've got a tube that was my great uncles, it's about half used up now.

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For machining aluminum, WD40 is one of the best liquids you can use. I don't know why, and it isn't much good for anything else, but it works great for machining aluminum.

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11 minutes ago, DDW said:

For machining aluminum, WD40 is one of the best liquids you can use. I don't know why, and it isn't much good for anything else, but it works great for machining aluminum.

To be fair, it is a good water displacer (go figure). A shot of it on your boat or garden tools before storage will keep them rust-free..

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It's just a mixture of Stoddard solvent and light oil according to the MSDS. I like the smell of it myself. I buy it by the gallon. 

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5 hours ago, DDW said:

For machining aluminum, WD40 is one of the best liquids you can use. I don't know why, and it isn't much good for anything else, but it works great for machining aluminum.

Interesting, I used to use it on blades but found we got more buildup and oily mess than with the wax type lube, I even use the wax on the chop saw we use for cutting extrusions.  My favorite for smell is rapid-tap when it's getting smoking hot, probably bad for you, but reminds me of being a kid messing about in the basement with my dad's tools.  It also seems to work well as a cutting oil with just a drop or two.    

For spray lubes I've started buying the Starrett branded one just because it's cheaper than WD-40 and smells decent. 

Have you tried Sprayon's version of WD-40?  I'm going to test out Wurth's one this year and see how it compares, the sprayon one was much better than the WD-40 but a PITA to find here. 

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Yeah Stoddard solvent/mineral spirits are pretty close to Kerosene chemically so that's why they both are OK drilling/tapping etc aluminum.

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That green colored aluminum may have been treated with Alodine.  It's a chromate conversion coating that can be used as a primer or alone.  It can be applied in various ways including brush, doesnt need a big tank like anodizing.  I think it was originally developed for aircraft.

Paint application is all about surface prep.  I helped put in a powder coating line at a company I used to work for.  Previous to the powder coat line we used lacquer paints and solvent wash, the paint could get damaged by your fingernail and we were getting about 24 hours salt spray resistance.  The powder coat line had a three stage cleaning process with iron phosphate coating as one of the stages.  We ran a few test coupons and intercepted them after the cleaning/prep but before they went through powder coating.  I gave those coupons to the wet paint shop and after painting they passed over two weeks of salt spray.  Same paint as before, just prepared better.  I became a surface prep believer

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Could you split a piece of thick walled fibreglass tube and glue it in where the stock exits, one piece on each side. Get tube with a 3mm gap, then when its all glassed back together flow 5200 in between the glass tube and the stock. 5200 is the only thing i can think of that reliably adheres to ss and glass.

Sorry if this has been discussed upthread, to time-poor to read.

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So I've been thinking about the quadrant coating and may just go with the simplest option. Seeing it will spend its life reasonably well out of the weather and reasonably dry (if it gets swamped, I think I'd have other more pressing issues at hand), I'm thinking of just applying a good amount of wax over the bare aluminum. My close second choice would be to paint it with a zinc phosphate primer, what is used in the aviation industry instead of zinc chromate these days. That is if I can find a place that sells it...

As for the rudder rebuild, that is progressing... slowly, but a plan is hatched and I will be taking pictures for you guys. 

Anyway, I have already learned a heap from all of you and hopefully some of it may help someone else as well. That's what this section of SA is all about, but titties, that's another thread. :-)

Next part for me is trying to figure out the foam aspect of the rebuild, what system to use, how it's applied, density of the foam etc.

Any hints?

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19 hours ago, jgbrown said:

Interesting, I used to use it on blades but found we got more buildup and oily mess than with the wax type lube, I even use the wax on the chop saw we use for cutting extrusions. 

Wax out of the tube works ok on a circular blade, which has enough centrifugal force to fling off the buildup. For drilling or especially milling, you can end up with a wad of chips and wax which you are recutting and are obscuring your view. I even use it with the cutoff blade in the lathe.

With aluminum, one of the main jobs of the lubricant is to keep from developing the dreaded Built Up Edge, where material sticks to the rake of the cutting tooth. WD40 seems to do that really well with aluminum - not so well with other gummy materials like titanium. 

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On 5/2/2018 at 10:52 PM, lahana said:

Oh, and after sanding, the extent of it?!

Now, there are some darker spots under some of the glass and I think it may have been affected by moisture and rot, but I'm not sure. I tried sounding it out, but I'm getting sooo many different sounds coming from different spots around the rudder, I'm not sure what to make of it.

Anyway, that's the rudder itself. I still have to clean up the steering gear and most importantly figure out how these bearings go??? 

Any help is totally valued here!

1094.jpg

216.jpg

There never was any structure across that seam.  The structure is elsewhere. Odds are you could get another forty years out of it if you just painted it and splashed it . 

If you want to feel like you did something good, lay some fresh glass over that seam.

( note: I would do the following as part of a normal bottom Job  and probably not even bother to itemize it on the bill... or maybe charge $25 to $50 )

it is already sanded pretty well.

If you have some good quality ISO resin it would be fine.

offs are I would use a few squirts of West System as my resin 

i would use 1.5 ox chop strand may 

I would tear three strips .... no scissors as I wouldn’t want any sudden edges

the mat strips would be three widths 

the length would be a couple inches longer than the crack , three inches then four inches.

the width would be about an inch and a half ,.... a little wider and a little wider than that 

I would probably brush on a couple extra layers of the West resin after the glass layers kicked.

 

problem solved... maybe 15 minutes of my time including set up and clean up.

 

as the rudder is showing zero signs of any actual failure, the repaired rudder would be stronger than the one that made it through the last forty years.

 

oh yeah... the extra resin is so, before applying fresh antifoulant, you can rough up the surface without destroying the structure of the band aid 

 

My apologies to those contributors whe spent so much effort trying to describe unnecessary and extensive solutions to the non-existent problem!! 

 

 

 

 

 

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10 minutes ago, Gouvernail said:

There never was any structure across that seam.  The structure is elsewhere. Odds are you could get another forty years out of it if you just painted it and splashed it . 

If you want to feel like you did something good, lay some fresh glass over that seam.

( note: I would do the following as part of a normal bottom Job  and probably not even bother to itemize it on the bill... or maybe charge $25 to $50 )

it is already sanded pretty well.

If you have some good quality ISO resin it would be fine.

offs are I would use a few squirts of West System as my resin 

i would use 1.5 ox chop strand may 

I would tear three strips .... no scissors as I wouldn’t want any sudden edges

the mat strips would be three widths 

the length would be a couple inches longer than the crack , three inches then four inches.

the width would be about an inch and a half ,.... a little wider and a little wider than that 

I would probably brush on a couple extra layers of the West resin after the glass layers kicked.

 

problem solved... maybe 15 minutes of my time including set up and clean up.

 

as the rudder is showing zero signs of any actual failure, the repaired rudder would be stronger than the one that made it through the last forty years.

 

oh yeah... the extra resin is so, before applying fresh antifoulant, you can rough up the surface without destroying the structure of the band aid 

 

My apologies to those contributors whe spent so much effort trying to describe unnecessary and extensive solutions to the non-existent problem!! 

That would have been food for thought and probably a good way to go about it in hindsight, but there was no way of knowing what was going on inside the rudder and what the extent of damage was, without opening it up. The rust flowing from the seam on the leading edge was a warning sign. I will be feeling a lot more comfortable with more work and knowing what's going on, than just laminating over something that could be well on its way out!

One of the reasons I like to do things for myself, I know it'll be done right, even if its not the right way to go about it.

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8 hours ago, lahana said:

So I've been thinking about the quadrant coating and may just go with the simplest option. Seeing it will spend its life reasonably well out of the weather and reasonably dry (if it gets swamped, I think I'd have other more pressing issues at hand), I'm thinking of just applying a good amount of wax over the bare aluminum. My close second choice would be to paint it with a zinc phosphate primer, what is used in the aviation industry instead of zinc chromate these days. That is if I can find a place that sells it...

As for the rudder rebuild, that is progressing... slowly, but a plan is hatched and I will be taking pictures for you guys. 

Anyway, I have already learned a heap from all of you and hopefully some of it may help someone else as well. That's what this section of SA is all about, but titties, that's another thread. :-)

Next part for me is trying to figure out the foam aspect of the rebuild, what system to use, how it's applied, density of the foam etc.

Any hints?

You can still buy zinc chromate, they sell it as the primer for outdrives/outboard engines.  It's not even particularly expensive, Moeller brand is one option. 

 

5 hours ago, DDW said:

Wax out of the tube works ok on a circular blade, which has enough centrifugal force to fling off the buildup. For drilling or especially milling, you can end up with a wad of chips and wax which you are recutting and are obscuring your view. I even use it with the cutoff blade in the lathe.

With aluminum, one of the main jobs of the lubricant is to keep from developing the dreaded Built Up Edge, where material sticks to the rake of the cutting tooth. WD40 seems to do that really well with aluminum - not so well with other gummy materials like titanium. 

That makes sense re: milling, but that's outside my normal scope of work, always wanted to play with one though.   I've never had a problem with it when drilling, or with sawzall, jig saw, die grinder bits, countersinks etc which are bad for that buildup, being able to leave a bit extended and just touch it with the bit speeds things up vs grabbing a bottle.    The one I use liquifies very quickly in use, but because it is up the flute on a bit, it doesn't seem to sling or get anywhere else, or hold the chips in place any more than a pour/spray liquid.  Ditto on sawzall/jigsaw, because it only liquifies on the teeth in contact with the metal, as you progress through the cut and use more of the blade you can effectively add lubricant as you go without re-applying.  It also never leaks in a toolbag or box in in the bilge.   

 

 

 

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