Sign in to follow this  
DrewR

Winch pads, UHMW or Delrin?

Recommended Posts

I need to raise my primaries about an inch. I know this has been discussed before but since the search function sucks (I did use it) I'll ask again.

 

McMaster has 'short rods' which are up to 6" widths 1" thick in both Delrin and UHMW (and PVC and etc. etc.), which would be better for winch pads? The winch bases are 5 3/4" so a 6" round pad would be ideal, I'll chamfer the top and I think I should be good to go. I know both are slippery, but that shouldn't be a problem to me.

 

I read their whole spiel on plastics but they don't mention UV resistance which I'm thinking might be important. My outboard rail bracket for instance is slowly chalking away. It may have been Delrin.

 

I could lay up some teak and cut circles but getting the 6" chunk of plastic the right thickness seems the easy way to go.

 

Suggestions welcome.

Share this post


Link to post
Share on other sites

Why do you want "bearing" type plastic for winch pads? If you want plastic pads I'd think manufactured glass (G10?) would be a better choice. Pre-made teak is the easiest choice but then you have varnishing down the road.

Share this post


Link to post
Share on other sites

I don't neccesarily want bearing type plastic, but it is readily available in 6" x 1" disks and cheap. G10 in 1" thickness is not cheap and I cannot find pre-cut disks, My shop and tools are currently in a storage unit along with my teak stash, If my shop was in place, I would have already made them out of teak, I have a ton and all the tools to do it.

 

I have access to a machine shop at work and can use the Bridgeport and other tools, but we don't have a woodshop, unfortunately.

 

I'm just trying to do this cheaply and quickly. Too many over rides this season with the new self tailers. I just spent a week on the boat and the risers are a tad too low, 2 or more wraps pushes the line down and leads to overrides, the lead is just a RCH too low.

 

Over the winter I plan to fab correct ones so I guess the UV protection is not so important but the strength is.

 

But like so many things I plan to do, if it works it is likely to stay in place for longer than intended.

Share this post


Link to post
Share on other sites

In that case I'd use Delrin.

Share this post


Link to post
Share on other sites

Starboard? Or use teak...it doesn't need finishing at all.

Share this post


Link to post
Share on other sites

Go with black if aesthetics allow. It'll tolerate UV better.

Share this post


Link to post
Share on other sites

Starboard is UV stable, relatively inexpensive and easy to machine.

 

If a canted pad were useful, casting a pad of filled epoxy might be an alternative.

Share this post


Link to post
Share on other sites

If you're going with Delrin, you need to get a version with UV stabilizers. Their design guides aren't real bullish for outdoor exposure, but if it's black and only for a couple of years you should be fine.

Share this post


Link to post
Share on other sites

Practical sailor did a test on compression recently. Nothing good to say about starboard in compression.

Share this post


Link to post
Share on other sites

If you didn't know, McMaster also has technical information about materials, available via the same search engine as you find the things you're looking for. A search for 'plastics' gets a link to 'about plastics' and eventually this:

 

j03-aboutplastics-genpurpd1-gis.png?ver=

 

Share this post


Link to post
Share on other sites

Practical sailor did a test on compression recently. Nothing good to say about starboard in compression.

 

That was at MUCH higher compression loads than we are talking about here (backing plate failures around the bolts). This is also supported on both sides. It should be well within limits.

 

My main concern would be getting the sealant to bond. Try flame treating the plastic (Google) before applying the goop of your choice (something weak like butyl).

 

On easy way to get a disk is a hole saw, or even a fly cutter. Any machine shop should have both. The hole in the center won't matter. Just sayin'.

Share this post


Link to post
Share on other sites

 

Practical sailor did a test on compression recently. Nothing good to say about starboard in compression.

 

That was at MUCH higher compression loads than we are talking about here (backing plate failures around the bolts). This is also supported on both sides. It should be well within limits.

 

My main concern would be getting the sealant to bond. Try flame treating the plastic (Google) before applying the goop of your choice (something weak like butyl).

 

On easy way to get a disk is a hole saw, or even a fly cutter. Any machine shop should have both. The hole in the center won't matter. Just sayin'.

 

 

UHMW cuts beautifully with a fly cutter in a drill press. I was surprised since it is so abrasion-resistant. Black lasts much longer than white in the great outdoors.

 

I used starboard for mounting bases for my foot blocks, no issues with it at all after 9 years. Epoxy held two thicknesses together long enough to shape and machine it, after that the bolts take the load.

Share this post


Link to post
Share on other sites

Issue with thermoset plastics is creep. You might need to tighten bolts periodically, like when you have the drum off for servicing. Keep an eye out for sealant failure due to wiggle. Otherwise, UV stabilized UHMW or HDPE is fine. Personally, I like phenolic for this application. Phenolic don't creep.

Share this post


Link to post
Share on other sites

There you go - Tufnol.

 

Back to the future.

Share this post


Link to post
Share on other sites

So many of the mentioned polymers have crap for compressive strength. Do your research. As what'll happen when that winch gets used for a dock line?

And if you go with some variety of composite (my vote), paint it.

Share this post


Link to post
Share on other sites

^^ In 12 years I've never relied on the winches to tie docks lines. I've used the cleats for the main security and the winches occasionally for secondary springs lines. But all the primary loads are on backed up cleats. I live on a mooring and dock to get fuel and water mostly.

 

I bought black Delrin 1" disks from McMaster. I took the path of least resistance. Should have them today or tomorrow. If they compress or UV away I am out $70. The only teak ones I could find came in 2 sizes and were tapered and not what I wanted. About the same money.

 

My guess is they will outlast my ownership of the boat.

Share this post


Link to post
Share on other sites

The black Delrin will work fine. I used on my last boat and it held up for the 6 years we had it and is still working now. the Delrin has a compressive strength far higher then teak. You can shape and sand the Delrin and to get a good finish you can scrape the surface with a utility knife blade and it will remove the fuzz. and sand scratches. If you want to protect the pads from the sun make winch covers that extend down to cover the pads and they will stay looking like new for many years .

Works the same on Delrin

Share this post


Link to post
Share on other sites

There you go - Tufnol.

 

Back to the future.

Works a treat. ;) I've fabbed a number of kitchen & bath countertops from a phenolic material called PaperStone -- not sure if they are still even in business. (Yoop - they seem to be. At least their website is up.) Anyway, when you buy that shit in 5 x 12' slabs, you end up with quite a stack of remnants. Rupture=24ksi; elasticity=1700ksi; compressive=45ksi. Awesome for deck coring, winch pads, mast steps, and so on.

Share this post


Link to post
Share on other sites

Great ideas, but with a packed up shop it's hard to pull off with just my Leatherman. Black Delrin 6" disks X 1" thick arrived yesterday, they look perfect. Winches are anodized black so with hope the pads fade to a similar patina.

Share this post


Link to post
Share on other sites

Did you ever consider just molding the winch bases with epoxy and filler (see the Gougeon Brothers Book on Boatbuilding for a complete DIY method). It results in a lighter, stiffer base that you won't have to ever worry about or retighten. Awesome material. Easy to use. High compressive strength. Can be cast at an angle. It's what I've used many times.

Share this post


Link to post
Share on other sites

The black Delrin worked excellent. I spun them on the lathe at work to exact size of the winch base so it looks like it's part of the winch. Very happy with the results.

Share this post


Link to post
Share on other sites

$30 ea for a 1" x 6" black Delrin. The winch base was 5 7/8" (from memory). I stuck it on the lathe at work and spun it a bit and it looks like a million bucks.

 

They have varying sizes and thickness disks as well as flat plate.

 

Until the Delrin chalks up, the winch and the new base looks like it was made as one piece. I forgot to photo it.

Share this post


Link to post
Share on other sites

$30 ea for a 1" x 6" black Delrin. The winch base was 5 7/8" (from memory). I stuck it on the lathe at work and spun it a bit and it looks like a million bucks.

 

They have varying sizes and thickness disks as well as flat plate.

 

Until the Delrin chalks up, the winch and the new base looks like it was made as one piece. I forgot to photo it.

 

Bad journalist. No biscuit.

Share this post


Link to post
Share on other sites

 

$30 ea for a 1" x 6" black Delrin. The winch base was 5 7/8" (from memory). I stuck it on the lathe at work and spun it a bit and it looks like a million bucks.

 

They have varying sizes and thickness disks as well as flat plate.

 

Until the Delrin chalks up, the winch and the new base looks like it was made as one piece. I forgot to photo it.

Add to Post

Bad journalist. No biscuit.

 

 

This better? (I'd like my biscuit, please):

 

post-10747-0-59341200-1472942272_thumb.jpg

Share this post


Link to post
Share on other sites

Looks great. Looks like you added an overdrive to the winch transmission. ;)

Share this post


Link to post
Share on other sites

Homebrew epoxy and G10 are not great for this application as they are not UV stabilized and would need to be painted. My choice would have been Starboard, but I think $30 for a piece off the shelf that requires virtually no shaping or finishing and is pretty good for UV is the right solution.

Share this post


Link to post
Share on other sites

Starboard is a UHMWPE and will creep under load. It is definitely not what you want under a winch. You want something with high compressive strength....Like WEST System epoxy/filler. A simple coat of paint will protect it for a very very long time.

Share this post


Link to post
Share on other sites

It's pretty flush, it's not cantivelered as far I can see. I just have the very large flat washer it had before and I added 1" longer bots. I'll keep an eye on it, and since its a J/35 all of the screws are easy to see and get to. Backing plates I can do without a problem if it seems like I need them (if the washers or glass under deforms I'll make a backing plate, but so far, only 3 races, one in high winds, it all seems good). It's dry plywood under the glass and no signs of moisture ingress.

Share this post


Link to post
Share on other sites

I didn't mean that the spacer is cantilevered, I meant that the assembly is pretty tall, which puts the winch drum high above the deck. When the sheet pulls against the winch drum the winch drum torques on the deck, and the torque becomes greater as the drum height becomes greater, so the backing needs to be stronger.

 

Anyway, it sounds like you are already keeping an eye out for deformation, which was my intent.

Share this post


Link to post
Share on other sites

In my experience the backing plate issue can get overstated. I had a Columbia 43 years ago that had big two speed S/S Barient primaries. When I went under the deck I saw that they only had standard washers with lock washers - not even fender washers let alone backing plates.

 

The boat was 35 Y.O. at the time, had raced on the East coast, gone to L.A. via Panama etc. and there was no sign there had ever been any problems with the winch mounting - no leaks or distortions or compressions of the glass etc.

 

I suspect backing recommendations are a bit like anchors - some safety factor one-upmanship redoubled a few times over the years ends up with "strong like tractor" installations becoming the base line.

 

I've never personally seen a situation with inadequate backing causing a problem other than crushed plywood - where chains mounted on a ply bulkhead with only small washers backing the bolts..

 

I do like to put nice custom polished backers on my hardware though - cheap insurance, looks nice & tech-y and reassures people.

Share this post


Link to post
Share on other sites

Diarmuid's post gave me an idea: why not in Corian or some of that other kitchen counter shit? Remnants, like the man said; cheap, easy to source

And about as heavy as you can get. All the plastics are heavy. Teak is so much lighter

Share this post


Link to post
Share on other sites

 

Diarmuid's post gave me an idea: why not in Corian or some of that other kitchen counter shit? Remnants, like the man said; cheap, easy to source

And about as heavy as you can get. All the plastics are heavy. Teak is so much lighter

 

 

Especially once it sheds that heavy varnish.

Share this post


Link to post
Share on other sites

IF I had my woodshop set up, I probably would have made new teak pads 1" or so taller. As it is, my shop packed up is in a storage unit, post divorce blues, so I'm left to mail order and tools I can finagle time on. So the pre-made 6" Delrin pads about an 1/8" oversize that I could spin down to the correct size seemed to be a fast and cheap way of getting it done, and it was. Less than one week from concept to installation and their first race (trial by fire). ~$70 with shipping and 15 min on the lathe. And the results exceeded expectations.

 

Sometimes you gotta play the cards you was dealt and get creative.

  • Like 1

Share this post


Link to post
Share on other sites

I know this is an old thread, but the manufacturers typically use polystyrene, which has an amazing ability to handle pressure without cracking. You can also cover it with an epoxy paint.

Share this post


Link to post
Share on other sites
On 8/15/2016 at 3:09 AM, IStream said:

Go with black if aesthetics allow. It'll tolerate UV better.

Yes....i have good luck with black 

do not use wood.

 

Share this post


Link to post
Share on other sites

Bumping this, as I have a similar project on the burner. Need bases for Lewmar 40s, about 6" x 1.5". Currently thinking about casting them out of thickened epoxy in a cake pan. My previous plan was to do basically the same thing, but with a few layers of biax on the outside. Another idea would be to do biax with a core of end-grain balsa or something.

Here's a wacky idea that I had: wet out a long 1.5" strip of biax. Put it on top of a 1.5" strip of some kind of light, flexible foam and roll the whole thing up like a roll of duct tape to make what would essentially be a GRP spiral with the foam serving as a separator. GRP top and bottom to finish off.

Or how about this: GRP molded around a disk of some low-density home despot foam. Drill winch bolt holes slightly oversize and glass in five GRP tubes with an ID of what I need for the bolts.

Any thoughts? I'm sort of bouncing around between ideas here as I don't think I fully understand the forces involved.

Share this post


Link to post
Share on other sites

These are intensely complicated design solutions to the basic problem of creating a nicely-shaped slab. Are you German?

Share this post


Link to post
Share on other sites
15 hours ago, fucket said:

Bumping this, as I have a similar project on the burner. Need bases for Lewmar 40s, about 6" x 1.5". Currently thinking about casting them out of thickened epoxy in a cake pan. My previous plan was to do basically the same thing, but with a few layers of biax on the outside. Another idea would be to do biax with a core of end-grain balsa or something.

Here's a wacky idea that I had: wet out a long 1.5" strip of biax. Put it on top of a 1.5" strip of some kind of light, flexible foam and roll the whole thing up like a roll of duct tape to make what would essentially be a GRP spiral with the foam serving as a separator. GRP top and bottom to finish off.

Or how about this: GRP molded around a disk of some low-density home despot foam. Drill winch bolt holes slightly oversize and glass in five GRP tubes with an ID of what I need for the bolts.

Any thoughts? I'm sort of bouncing around between ideas here as I don't think I fully understand the forces involved.

Compression... on my boat the balsa core is replaced by solid laminate where the winches are. I wish they had done the same for the clutches. They used g10 tubes, but the laminate bent a bit, water got in, and it’s a mess. I will replace with solid under the clutches.

Share this post


Link to post
Share on other sites

I could do solid glass, but if people are using teak for this job, solid glass seems like massive overkill. And fucking heavy.

We're not talking about a grand prix boat here, but still a tight one design fleet. I'm not looking to add 20+ lbs if I don't have to.

Share this post


Link to post
Share on other sites
17 hours ago, fucket said:

Bumping this, as I have a similar project on the burner. Need bases for Lewmar 40s, about 6" x 1.5". Currently thinking about casting them out of thickened epoxy in a cake pan.

I'm in the middle of doing this.  Lewmar 30STs, a little smaller than the 40s.

I got lucky (?) and found that the bottom of a West Marine 2-1/2 quart mixing bucket was just about the perfect diameter for the top of a pad, and had a nice taper.  I taped buckets to the deck where I wanted the pads to go (so that they adopted the slope of the deck at that point), and filled to the level I needed with a succession of partial pours.  WEST 105 thickened with 404 to about a "ketchup" consistency, so that the top ended up level.

When set, they popped out of the buckets easily, and when flipped over I have pads that are level on top, and match the contour of the deck on the bottom.  Prepping them for paint now, will post photos when done if there is interest.

 

Share this post


Link to post
Share on other sites
1 minute ago, fucket said:

I could do solid glass, but if people are using teak for this job, solid glass seems like massive overkill. And fucking heavy.

We're not talking about a grand prix boat here, but still a tight one design fleet. I'm not looking to add 20+ lbs if I don't have to.

how about machined out G10?

If you're building a pad on top of solid glass, sure, it's overkill

if you're talking about a pad hidden inside a cored panel, I can show photos that it's not overkill....

Share this post


Link to post
Share on other sites
Just now, sledracr said:

I'm in the middle of doing this.  Lewmar 30STs, a little smaller than the 40s.

I got lucky (?) and found that the bottom of a West Marine 2-1/2 quart mixing bucket was just about the perfect diameter for the top of a pad, and had a nice taper.  I taped buckets to the deck where I wanted the pads to go (so that they adopted the slope of the deck at that point), and filled to the level I needed with a succession of partial pours.  WEST 105 thickened with 404 to about a "ketchup" consistency, so that the top ended up level.

When set, they popped out of the buckets easily, and when flipped over I have pads that are level on top, and match the contour of the deck on the bottom.  Prepping them for paint now, will post photos when done if there is interest.

 

cool

Share this post


Link to post
Share on other sites

On my boat I cast solid epoxy pads for Andersen 46's that saw tremendous strain at times (overcanvassed fast 40' cat). They were sloped at about 30 degrees so were cast in place with temporary dams made of cardboard/mylar tape, then shaped and sanded to look nice. I think I covered them with a couple layers of biaxial because they were at least 2" thick on one side, and more on the other.

The epoxy was mixed with colloidal silica and milled fibers for extra strength. I've used the same technique for electric windlass mounting pads.

If you cast them, don't use baking pans unless they are silicone. Aluminum ones probably don't have enough draft angle to release easily. Or use a plastic bucket/yoghurt container/something from the grocery store in plastic.

Share this post


Link to post
Share on other sites

Poured one, used about 10% milled fibers, 5% cabosil and 20% glass microspheres. Based on the numbers I've seen, it should have compressive strength higher than teak or the Delrin used above. Still may try to add a couple layers of biax to be on the safe side.

xD7ONsw.jpg

 

 

Share this post


Link to post
Share on other sites

Nice, I may try that. I think I will try to find two containers that nest together nicely and wrap a couple of layers of bi-ax over the inner one and then drop it into the casting mix you mention. Take out some of the dead weight in the interior of the piece and still be stronger due to the inner fabric. 

Share this post


Link to post
Share on other sites

Now that's a great idea, wish I thought of it.

Does anybody have any advice for glassing the part in the picture above? I'm thinking about wrapping piece of tape around the circumference, then putting a maybe 1/2" oversized circle on top. Then back in the mold for a caul with some weights on top.

Share this post


Link to post
Share on other sites

How will the winch be attached to the base and the base to the boat?  Through bolt from the winch all the way through to the underside of the deck?  Doesn't that change the leverage on the bolts quite a bit?

Share this post


Link to post
Share on other sites

That's a great question and I would love to hear others' thoughts on the topic.

Share this post


Link to post
Share on other sites
4 hours ago, xyzzy said:

...  Through bolt from the winch all the way through to the underside of the deck?  

That's how I'm doing mine. 

 

Share this post


Link to post
Share on other sites

That's how it's been done for a very long time.

Seems to work.

Share this post


Link to post
Share on other sites

Something I've found rather handy for making cast epoxy blocks, is to go to the kitchen isle at walmart and stare at the glassware section til you find something the right shape if you turn it upside down.  Walmart is better than your own kitchen, because if you need three of something you can buy three instead of having one that is perfect and making a casting then getting tempted to make a mold off the casting when you discover that bowl was the last one on earth of the right size...

Wax the inside of the glass, mix up your goop and work the air out of it in the glass and let it kick off.  The next day, smack it with a hammer inside a trash can and you've got a part that releases out of the mold easily without care for draft angles, and with no sanding because it is dead slick. 

Just don't cast polycarbonate in a pyrex baking dish on your bbq grill...  Didn't know pyrex exploded if the temperature changes quickly, opened the lid for a peak and when I shut it... CABOOM.  Not a piece of glass bigger than a tooth pick, and a ball of semi-molten plastic that wasn't quite on fire...

  • Like 1

Share this post


Link to post
Share on other sites

That's surprising - I thought the whole point of Pyrex was that it could withstand temperature extremes like that.

Your "Lost Glass" process seems extremely wasteful when there is an almost infinite variety of plastic vessels available that will just pop off the moulded piece ready for use.

Share this post


Link to post
Share on other sites
3 hours ago, SloopJonB said:

That's surprising - I thought the whole point of Pyrex was that it could withstand temperature extremes like that.

Your "Lost Glass" process seems extremely wasteful when there is an almost infinite variety of plastic vessels available that will just pop off the moulded piece ready for use.

I think it's only lost glass when you done fucked up :p I know the feeling about being tempted to make a mold just in case, but then that's a whole lot more work than just buying duplicate cheap bowls if needed.  The nice thing about glass for this is that it is more dimensionally stable.   Also if it's hot enough to explode glass, it's definitely hot enough you'll come back to a puddle of plastic sludge, besides the fact that that that kind of heat isn't great for the strength of the part anyways.

old Pyrex(borosillicate? Not sure about the spelling, like the stuff lab ware was made out of ) withstands many things better, the new stuff can be Ok for slips and drops vs regular glass but is otherwise kind of crap, it's trading on the name now...  It takes more to fail than regular glass, but when it fails, it fails big.  I'll never forget being over for dinner when my mom put a new style pyrex pan with lassagna out of the oven down on the stove top and there was some water on it.  The sudden quench was interesting, nothing for a few seconds while she turned around then a large bang and horrible tiny shrapnel from one end of the kitchen to the other.  Very lucky...

The best IMO was hercuglass, I have one cup from them around somewhere still I think.  I'm still kicking myself for not getting a whole set of mugs and bowls made while they were still at it(IIRC something about replacing sodium with potassium in the outer layer?) Like Gorilla glass but more suited to food.

 

 

Share this post


Link to post
Share on other sites
44 minutes ago, IStream said:

If you really want resistance to thermal shock, you gotta get the Good Stuff: pyroceram.

https://en.wikipedia.org/wiki/CorningWare

Production of the original Pyroceram based version of Corning Ware ceased in 2000[citation needed] and the brand was relaunched as a line of stoneware based bakeware in 2001.[3]

Why they gotta wreck all the good products?

Share this post


Link to post
Share on other sites
1 hour ago, jgbrown said:

Production of the original Pyroceram based version of Corning Ware ceased in 2000[citation needed] and the brand was relaunched as a line of stoneware based bakeware in 2001.[3]

Why they gotta wreck all the good products?

So the bean counters can save $0.02 per unit.

Share this post


Link to post
Share on other sites
4 hours ago, jgbrown said:

Production of the original Pyroceram based version of Corning Ware ceased in 2000[citation needed] and the brand was relaunched as a line of stoneware based bakeware in 2001.[3]

Why they gotta wreck all the good products?

Yeah, then they reintroduced the genuine article in 2008. It's not cheap, never was, but it works great.

Share this post


Link to post
Share on other sites
On 6/22/2018 at 2:20 PM, Rasputin22 said:

Nice, I may try that. I think I will try to find two containers that nest together nicely and wrap a couple of layers of bi-ax over the inner one and then drop it into the casting mix you mention. Take out some of the dead weight in the interior of the piece and still be stronger due to the inner fabric. 

Would you include a “weep hole” in this design?  

Others have mentioned Home Despot insulation foam... would covering that in 3 layers FG and drilling 2x oversized bolt holes filled with epoxy with silica do the job? The foam is easier to shape to, say, a curved surface. Tape sandpaper to the cabin top & go for it.

Share this post


Link to post
Share on other sites
On 6/18/2018 at 6:12 PM, fucket said:

Bumping this, as I have a similar project on the burner. Need bases for Lewmar 40s, about 6" x 1.5". Currently thinking about casting them out of thickened epoxy in a cake pan. My previous plan was to do basically the same thing, but with a few layers of biax on the outside. Another idea would be to do biax with a core of end-grain balsa or something.

Here's a wacky idea that I had: wet out a long 1.5" strip of biax. Put it on top of a 1.5" strip of some kind of light, flexible foam and roll the whole thing up like a roll of duct tape to make what would essentially be a GRP spiral with the foam serving as a separator. GRP top and bottom to finish off.

Or how about this: GRP molded around a disk of some low-density home despot foam. Drill winch bolt holes slightly oversize and glass in five GRP tubes with an ID of what I need for the bolts.

Any thoughts? I'm sort of bouncing around between ideas here as I don't think I fully understand the forces involved.

I needed to raise my new quatro type cabin top winches 1.5" so I had my local mill shop lay up 2 layers of 3/4" PVC cut from 1 x 8 planks, cut into a circle and beveled a 1/2" .  Been on for 7-8 years  I think I paid around $75 for a pair.  PVC also available in 1".  

Share this post


Link to post
Share on other sites

G10.  Laminate two pieces together with epoxy if you need it thicker.  Wear a mask when you grind it.

Starboard is a great product for gutting and filleting fish, but that's about all it's good for. 

Share this post


Link to post
Share on other sites

Thought I'd post an update.  I finished my pads a couple of weeks ago, just in time to bolt everything on and untie for a trip to the Gulf Islands.

I "cast" my pads using West 105 resin, 206 slow-hardener, and 404 high-density filler.  For molds... it turns out that the bottom of a 2-1/2 quart bucket from West Marine was just about the right diameter to work as a winch pad and had a nicely tapered shape.  I taped a bucket on the deck where each winch was going to be placed, and when poured the "bottom" of the winch pad had the same angle (aft and outboard) as the deck at that spot, and the top was level.  Flipped over, worked great.

For the clutch pads I found a couple of $2 rectangular tupperware containers, about the right size and shape and similarly tapered.  I cut the bottoms off, taped them upside-down on the deck at the right spots, and again, the bottom had the right angle, the top was level.  a little shaping with a belt-sander and they're more than good enough.

I did screw up a few times.  First time I poured, I poured full-depth and the stuff got impressively hot.  Hot enough (steaming, boiling epoxy gets your attention!) that I moved the "molds" to a concrete part of the dock, just in case they caught on fire.  I ended up doing smaller pours at successively steeper angles.  First pour about 1/4" deep, with the molds on a level surface.  Scrub off any amine blush, rough up the surface with a sanding disk, wet in a layer of 1-12/oz mat, then next pour about 1/4" deep with the mold propped up to a little angle.  Repeated that sequence until the last pour brought the pour to the final depth, with the mold at the final angle.  IIRC, the winch pads took three pours, the clutch pads took four.

Painted with some Krylon rattle-can all-in-one (primer plus paint) spraypaint, and.... for my 6k(beloved)SB, I'm pretty happy with the result.  The only pain in the ass so far is that I bedded them with butyl tape, and the tighten/clean up the ooze/repeat cycle is a little annoying, but worth it in the long run.

pads-01c.thumb.jpg.4e2f1fdde70912598c7920b340a33ecc.jpg

pads-02c.jpg.1af4e61b490d8480d9ec5e629e2ecf0c.jpg

pads-03c.thumb.jpg.ac544157dd362e2a38e6edb95671fa49.jpg

Share this post


Link to post
Share on other sites

Thanks!

I forgot to add a picture of my super-complex high-tech molds for the clutch pads....  (note the water level...)

 

pads-00c.jpg

Share this post


Link to post
Share on other sites
1 hour ago, Rasputin22 said:

Very nicely done!

Agreed, but are you sure the boat was perfectly on its lines when you poured? They could be a degree off depending on the fill level of your fuel, water, and waste tanks...OCD on that!  :ph34r:

 

Share this post


Link to post
Share on other sites
22 minutes ago, IStream said:

OCD on that!  :ph34r:

Hah!

Actually, I did put a level across the companionway rails, just to see if the boat was sitting level side-to-side.  It was within a degree or so. 

Fore-and-aft, I didn't really care, I was more interested in the lines having a nice straight run from the deck organizers to the face of the drums.  That pretty much determined the height and angle of the pads.  There's no real "straight" lines, fore-and-aft, so no cues that the angle is wrong.  Side to side, yeah, standing at the wheel a difference of few degrees would be noticeable.

What I did find was that my location on the boat affected the side-to-side angle noticeably, so when I did the final pours I left long enough to make sure they set up level.  Two beers at the Woodfire Grill worked out to be a perfect amount of time, as it turns out.

B)

pads-05c.thumb.jpg.4360d2971c0f5e21b25185c267dd0d8a.jpg

  • Like 2

Share this post


Link to post
Share on other sites

Turned out pretty nice!

Consider using some Krylon clear coat on top of the paint.  It seems to help the paint last longer and fade less.  Just match the paint, e.g. krylon fusion black + fusion clear.  Or rustoleum appliance epoxy black and rustoleum clear enamel.

I think you could have placed a level between the anticipated location of the end of the clutch and the drum, then trimmed the boat fore-aft until it read level.

Share this post


Link to post
Share on other sites

This thread has moved from UHWM and delrin to epoxy casting. In which case I have a question. I've been using epoxy for a long time for various purposes, including casting machinable blocks with various fillers.  But UV resistance is a big issue with epoxy and I'd like to avoid regular painting. I've been wondering about adding titanium dioxide, (or aluminum powder, or graphite, or,  or, ) in the mix, or as an outer layer in a casting (like gelcoat on a mold-made boat). Anyone tried anything like that? 

Share this post


Link to post
Share on other sites

I liked using graphite powder in epoxy for the reasons you mention but that works well for rudders and keels. Some of the graphite tends to rub off which is fine for those wet-sanded surfaces.  Titanium dioxide would probably work better otherwise, let us know if you try it.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this