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Searched the forums and couldn't find an existing post so I thought I'd ask the question: Can existing keel bolts be cutoff, have extensions welded on and then refit the keel? Presumably the existing keel bolt is 304 SS. 

 

 

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1 hour ago, Issywa said:

Searched the forums and couldn't find an existing post so I thought I'd ask the question: Can existing keel bolts be cutoff, have extensions welded on and then refit the keel? Presumably the existing keel bolt is 304 SS. 

 

 

Yes.

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I would think that you would drill new bolt holes and epoxy in new bolts to the lead or cast iron and prepare new holes in the bilge sump. That way you know all the metal is solid and your vessel safe(at least in that regard).

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2 hours ago, Issywa said:

Searched the forums and couldn't find an existing post so I thought I'd ask the question: Can existing keel bolts be cutoff, have extensions welded on and then refit the keel? Presumably the existing keel bolt is 304 SS. 

 

 

I prefer contact adhesive, but pva will do in pinch

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Seriously, yes you can but the risk level is high. SS is not easy to weld properly and even if you do find someone who will certify their work, why would you? The cost of welding, machining etc is not going to be inexpensive, just get new bolts and do a first class job on a vital structural component.

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49 minutes ago, Controversial_posts said:

This all seems like overkill.  Just cut the bolts off flush, & a couple tubes of 5200 should do the trick…

With a few tech screws to hold the keel in place while the 5200 cures, right?

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4 hours ago, Caecilian said:

I prefer contact adhesive, but pva will do in pinch

PVA sucks. It creeps and fails by creep rupture. I make up hot hide glue and add a little piss. That makes it waterproof. Much better.

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1 hour ago, fastyacht said:

Why would anyone use 304 for a keel bolt?!!

I would think 316 would the the ideal choice.

I wouldn't recommend cutting and welding new ones on. You're going to have a hell of a time welding new ones onto the old stubs in a way that's even remotely close to the tensile strength of the original bolt. Furthermore, welding right up against a block of lead isn't my favorite idea.

This is one area that I'd have a specialist company do the job. The loads are extremely high, lead isn't exactly the most friendly thing to work with (beyond the obvious issue of toxicity) and the price of failure is very high.

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Just now, JM1366 said:

I would think 316 would the the ideal choice.

I wouldn't recommend cutting and welding new ones on. You're going to have a hell of a time welding new ones onto the old stubs in a way that's even remotely close to the tensile strength of the original bolt. Furthermore, welding right up against a block of lead isn't my favorite idea.

This is one area that I'd have a specialist company do the job. The loads are extremely high, lead isn't exactly the most friendly thing to work with (beyond the obvious issue of toxicity) and the price of failure is very high.

Not even 316. If you need to be stainless steel, it *must* be 316L. Normal 316 is not restistant enough to chloride attack.

But frankly, all this stainless is merely for being cheap. Silicon Bronze is the only truly appropriate material for keel bolts in most circumstances. I know--you can find plenty of successful stainless steel usage. But to me, it was all obviously a cost issue. As long as you don't end up with a crevice corrosion issue occurring, all good.

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1 minute ago, fastyacht said:

Not even 316. If you need to be stainless steel, it *must* be 316L. Normal 316 is not restistant enough to chloride attack.

But frankly, all this stainless is merely for being cheap. Silicon Bronze is the only truly appropriate material for keel bolts in most circumstances. I know--you can find plenty of successful stainless steel usage. But to me, it was all obviously a cost issue. As long as you don't end up with a crevice corrosion issue occurring, all good.

That makes sense. I would think Titanium would also be a very good choice (good tensile strength, very good corrosion resistance), though it's probably even more expensive than silicon bronze.

Most boats I see use stainless though, and it seems to hold up reasonably well for a reasonably long time.

One thing that I do have against stainless is that it is very prone to galling. I can't say I've ever had a keel nut seize to a keel bolt, but I've had it happen on lots of other stainless hardware in other applications. 

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Yep. Galling sucks and is an endemic problem with stainless steel but not bronze. You *must* use thread treatments with stainless on stainless but can still go badly.

Titanium is troublesome everywhere except on carbon fiber laminates. It is too noble and too hard. It also isn't particularly good in cold temperatures--not that that is an issue in a bilge. (it is HCP crystal structure which has a ductile t brittle transition temperature range). Every piece of titanium I've had on my bicycles has failed. There is this absurd beliefe that it is "stronger than steel" so it can be the same diameter. NOPE. haha.

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1 minute ago, fastyacht said:

Yep. Galling sucks and is an endemic problem with stainless steel but not bronze.

Titanium is troublesome everywhere except on carbon fiber laminates. It is too noble and too hard. It also isn't particularly good in cold temperatures--not that that is an issue in a bilge. Every piece of titanium I've had on my bicycles has failed. There is this absurd beliefe that it is "stronger than steel" so it can be the same diameter. NOPE. haha.

Definitely a very different material, but quite useful for many applications. In any case, I don't see a huge advantage to using it in a keel over something else.

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35 minutes ago, JM1366 said:

One thing that I do have against stainless is that it is very prone to galling. I can't say I've ever had a keel nut seize to a keel bolt, but I've had it happen on lots of other stainless hardware in other applications. 

That's why they invented anti-seize compounds.

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22 minutes ago, SloopJonB said:

That's why they invented anti-seize compounds.

Yes, and they work fantastically well when people use them. I know this may come as a complete shocker, but there are a lot of morons in this world, and the rest of us have to live and work with them.

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Gorn FRANTIC,

 

Do you think that we should give AS a ring so GRS can improve his report on keel failures ?

 

After all he could learn a few thinks on this topic and pad out his report by a few more pages.

 

Pulpit

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2 minutes ago, pulpit said:

Gorn FRANTIC,

 

Do you think that we should give AS a ring so GRS can improve his report on keel failures ?

 

After all he could learn a few thinks on this topic and pad out his report by a few more pages.

 

Pulpit

On that subject, what ever happened to the investigation on the Ker coming back from Tas when the keel fell off? 

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10 minutes ago, pulpit said:

Gorn FRANTIC,

 

Do you think that we should give AS a ring so GRS can improve his report on keel failures ?

 

After all he could learn a few thinks on this topic and pad out his report by a few more pages.

 

Pulpit

 

6 minutes ago, Hitchhiker said:

On that subject, what ever happened to the investigation on the Ker coming back from Tas when the keel fell off? 

Hitchhiker,

who knows with AS, I'm shore it will pop up when it's to their advantage and it will be back dated to suit their needs as well.

 

Pulpit

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Interesting comments..... 

This is a J44 that I am contemplating buying and the PO had the keel bolts cut and extended. I'm trying to get more details but as I currently understand, the existing keel bolts were cut to remove the corroded bits and then extended. Possibly with couplers, but still awaiting more info. 

Currently "Boatless in Seattle" but I'd hate to be "Keel Less in Seattle" - that might make for a really bad hair for the Admiral.....

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25 minutes ago, Issywa said:

Interesting comments..... 

This is a J44 that I am contemplating buying and the PO had the keel bolts cut and extended. I'm trying to get more details but as I currently understand, the existing keel bolts were cut to remove the corroded bits and then extended. Possibly with couplers, but still awaiting more info. 

Currently "Boatless in Seattle" but I'd hate to be "Keel Less in Seattle" - that might make for a really bad hair for the Admiral.....

Either include the cost of a full keel job in your offer or run - fast.

"I'm contemplating buying a Ferrari that had a broken frame repaired by welding in some rebar - will that be O/K"?

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We did a keel bolt "replacement" on a catalina 27 by sistering existing bolts with new machined rod held in with half-round bar insterted in a transverse hole drilled through the fin. Red loctite, safety wire, epoxy to seal, and offset from originals in the bilge enough to not affect laminate. Originals stayed in place.

 

HW

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2 hours ago, Issywa said:

Interesting comments..... 

This is a J44 that I am contemplating buying and the PO had the keel bolts cut and extended. I'm trying to get more details but as I currently understand, the existing keel bolts were cut to remove the corroded bits and then extended. Possibly with couplers, but still awaiting more info. 

Currently "Boatless in Seattle" but I'd hate to be "Keel Less in Seattle" - that might make for a really bad hair for the Admiral.....

yeah sleepless is the right mode of being here.

What else has been "repaired" on this J44?

RUN!!!!

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6 hours ago, fastyacht said:

Not even 316. If you need to be stainless steel, it *must* be 316L. Normal 316 is not restistant enough to chloride attack.

But frankly, all this stainless is merely for being cheap. Silicon Bronze is the only truly appropriate material for keel bolts in most circumstances. I know--you can find plenty of successful stainless steel usage. But to me, it was all obviously a cost issue. As long as you don't end up with a crevice corrosion issue occurring, all good.

For sea water contact there's hardly any significant difference between 316 and 316L for both crevice corrosion and corrosion fatigue except where larger sections are welded, then granular effects from carbide precipitation is reduced with lower carbon content, and that encourages chloride related crevice corrosion. There's a lot of of confusing information around regarding 316L.

316 Keel bolts are at high risk if they can get wet. There's not only the risk of crevice corrosion but also a much lower S-N curve for fatigue cycles to failure if the surface is wet.

Duplex SS is much better such as 2205,  Monel and S Bronze are good.

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15 hours ago, Issywa said:

Searched the forums and couldn't find an existing post so I thought I'd ask the question: Can existing keel bolts be cutoff, have extensions welded on and then refit the keel? Presumably the existing keel bolt is 304 SS. 

 

 

If you have a steel keel the bolts are threaded into the keel 

unscrew them and replace 

in its a lead keel the bolts are J shaped and are removed with a torch

A new bolt fitted .,,then lead melted into the old bolt cavity 

I have never heard of keel bolts being welded 

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19 hours ago, Issywa said:

Searched the forums and couldn't find an existing post so I thought I'd ask the question: Can existing keel bolts be cutoff, have extensions welded on and then refit the keel? Presumably the existing keel bolt is 304 SS. 

 

 

Understanding that I am being rude.... Only a fool would ask this question.  This is coming from a guy who spent some time sitting on an over turned big boat that lost its keel bulb. 

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10 hours ago, Haligonian Winterr said:

We did a keel bolt "replacement" on a catalina 27 by sistering existing bolts with new machined rod held in with half-round bar insterted in a transverse hole drilled through the fin. Red loctite, safety wire, epoxy to seal, and offset from originals in the bilge enough to not affect laminate. Originals stayed in place.

 

HW

Sounds like barrel nuts.

SuperDealStuff (12) Cross Dowels/Barrel Nuts - 1/4-20 20mm X 10mm  Zinc-Plated CNC

I saw some pics of a big keel being redone that way in Turkey - everything was on a huge scale but it looked a lot better than the normal J-Bolt procedure.

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12 hours ago, Haligonian Winterr said:

We did a keel bolt "replacement" on a catalina 27 by sistering existing bolts with new machined rod held in with half-round bar insterted in a transverse hole drilled through the fin. Red loctite, safety wire, epoxy to seal, and offset from originals in the bilge enough to not affect laminate. Originals stayed in place.

HW

That is one of the two standard fixes for the questionable original Catalina 27 keelboat setup with dissolving steel keelboats, based on my thoroughly faulty memories of my own Catalina 27 and my time in one of the Catalina 27 owner's group. Owners did the bore-in-from-the-sides solution with fat barrel nut type fittings roughly the diameter of the bore holes and possibly bedded in with epoxy if memory serves.  Catalina Direct provided the alternative light weight solution with some lag bolts sistered in next to the rotting original J-bolts.  The lagbolts had what my classy British friends would characterize as Big Fuckoff Threads but I still wouldn't go offshore at all with that.  Here's the Catalina Direct link and the caveat:   

Important safety message: It is critical you understand that the retrofit lag bolts will not be as strong as the original bolts once were. The original bolts were first bent in a "J" shape, then cast into the molten lead. Don't expect to add this kit to your boat, then sail it to the Bahamas! If the original keel bolts are degraded, the boat is not and will not be as seaworthy as it once was.  Your sailing should be limited to inland waters and light air.

Bolt Retrofit Kit For Lead (catalinadirect.com)

Not exactly an AABC recommendation with that lag bolt fix, eh?  

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On 10/12/2021 at 3:09 AM, Sail4beer said:

I would think that you would drill new bolt holes and epoxy in new bolts to the lead or cast iron and prepare new holes in the bilge sump. That way you know all the metal is solid and your vessel safe(at least in that regard).

are you thinking keel bolts are just sitting in the lead casting as lead and stainless bond so well?

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10 hours ago, hokie said:

Maybe talk to the yard that did the work? Seemed like a reasonable solution here: Keels on post

Quote

 grind it to a tip or point, do the same with the new all-thread and then put them tip to tip and fill the space with weld for a full bond weld

How do they keep the two sections straight during the weld process? Tap w/a hammer and eyeball???????

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1 hour ago, Sailabout said:

are you thinking keel bolts are just sitting in the lead casting as lead and stainless bond so well?

There is not exactly a lot of information from the OP as to what the deal is. Speculation is fun but pointless without more data.

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4 hours ago, Sailabout said:

are you thinking keel bolts are just sitting in the lead casting as lead and stainless bond so well?

hopefully it is cast iron and not lead, but I believe this is not an uncommon way of connecting the keel bolts. The alternative and better way I have heard of is to have a bend piece of stainless rod cast in the keel. A keel bolt replacement to a lead keel seems incredibly difficult to do well.

I would actually stay away from a design that has its bolts sitting in lead.

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15 hours ago, SloopJonB said:

Sounds like barrel nuts.

SuperDealStuff (12) Cross Dowels/Barrel Nuts - 1/4-20 20mm X 10mm  Zinc-Plated CNC

I saw some pics of a big keel being redone that way in Turkey - everything was on a huge scale but it looked a lot better than the normal J-Bolt procedure.

Close, but through-drill instead of tapped, and a flat on the bottom to accept washer/nut. So it was a rod with two threaded ends, instead of a length of all-thread. Was also reasonable beefy, in the range of 70mm dia drill hole IIRC.

 

HW

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8 hours ago, AnotherSailor said:

I would actually stay away from a design that has its bolts sitting in lead.

That would really narrow your choices.

Like by about 85%.

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So the saga comes to an end. After speaking with several folks involved with keel manufacturing, metallurgy and welding, I've decided to pass on the boat unless the owner elects to remedy the keel boats by installing new ones recast into the lead keel. 

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On 10/12/2021 at 1:17 AM, Issywa said:

Interesting comments..... 

This is a J44 that I am contemplating buying and the PO had the keel bolts cut and extended. I'm trying to get more details but as I currently understand, the existing keel bolts were cut to remove the corroded bits and then extended. Possibly with couplers, but still awaiting more info. 

Currently "Boatless in Seattle" but I'd hate to be "Keel Less in Seattle" - that might make for a really bad hair for the Admiral.....

If you are willing to sail that boat, I have a nitroglycerin delivery job you may want to look into. Also I have a airplane for sale with corroded bolts holding the wings on, I was too cheap to buy more bolts, so I just got myself a Harbor Freight welder and added a few threads to them. BTW, the nitro delivery truck rides on retread tires.

That boat is worth whatever J-44s sell for minus whatever it costs to put new keel bolts on or get a new keel. Here is a general warning: The current boat market has brought out huge numbers of sellers that think ANYTHING that floats is worth huge $$$. I wasted a lot of money looking at a boat that not only was not in the amazing condition the broker was describing, it was beyond economic repair :(

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On 10/13/2021 at 10:28 AM, AnotherSailor said:

A keel bolt replacement to a lead keel seems incredibly difficult to do well.

I would actually stay away from a design that has its bolts sitting in lead.

 

Or just good old way with apertures on keel. Though I don't know if it is impossible to do such thing in modern narrow and tall keel.

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Yes, you absolutely can do this.  I had this done to my UN30 at the same yard as did this J/44.  They do what is called a full bleed or full penetration weld that is actually stronger than the bolt itself.

It is a technique utilized when the bolt is corroded/pitted/ect. above the sump, meaning something was in that bilge that damaged the bolt from the nut up. in my case it was from a steal lifting eye that should have been stainless.

 When you pull the keel you notice that the bolt length that had been within the fiberglass, below the bilge and encapsulated within the thick fiberglass, is not showing any corrosion issues.

I actually lift my UN30 (5000lbs) off it's trailer and into the water regularly off two of these bolts and when it was done the welder showed me welded rod that he attempted to break with a long breaker bar on nuts.  The bolt itself twisted with zero damage to the full bleed/penetration weld. 

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3 hours ago, Ballard Sailor said:

Yes, you absolutely can do this.  I had this done to my UN30 at the same yard as did this J/44.  They do what is called a full bleed or full penetration weld that is actually stronger than the bolt itself.

It is a technique utilized when the bolt is corroded/pitted/ect. above the sump, meaning something was in that bilge that damaged the bolt from the nut up. in my case it was from a steal lifting eye that should have been stainless.

 When you pull the keel you notice that the bolt length that had been within the fiberglass, below the bilge and encapsulated within the thick fiberglass, is not showing any corrosion issues.

I actually lift my UN30 (5000lbs) off it's trailer and into the water regularly off two of these bolts and when it was done the welder showed me welded rod that he attempted to break with a long breaker bar on nuts.  The bolt itself twisted with zero damage to the full bleed/penetration weld. 

Though you wouldn’t be lifting a 44 into the water by the keel bolts on a weekly basis. 

You have certainly shown that there could be more to the story though as the Poster has declined the boat, I guess I will stop typing.
 

 

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7 hours ago, Ballard Sailor said:

They do what is called a full bleed or full penetration weld that is actually stronger than the bolt itself.

These two aspects are not the whole story of welded connection strength over the life of the connection.

What about:

  • Fatigue
  • Hardness
  • Heat affected zone
  • Corrosion
  • etc

?

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When I brought my boat, my criteria was pretty simple.  If the keel bolts are good, I’m good to go!  I arrive to the boat.  It has everything I’m looking for!  It has a sprung vang, and a line adjustable spinnaker pole ring car!  So, he has the sails laid out.  I can fix that, whatever it is!  He finally take me below.  The keel studs are shinning like mirrors!  In my mind I said “ Fuck”, I had no way out of this deal!  I bought the boat, and have been more than happy for almost 10 years now!

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3 hours ago, fastyacht said:

Wtf is with this "full bleed" bullshit? It is a full penetration weld. If blood is involved you must be making swords or something.

And I thought this crowd would go off about the full penetration....

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21 hours ago, Ballard Sailor said:

They do what is called a full bleed or full penetration weld that is actually stronger than the bolt itself.

Yeah, no. A full pen weld on a s.s. bolt that gets salt water on it regularly would scare the shit out of me. 

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On 10/12/2021 at 11:46 PM, bstrdsonofbtl said:

How do they keep the two sections straight during the weld process? Tap w/a hammer and eyeball???????

Yes believe it or not that's how a lot of welding is done. To weld two rods end to end, you would typically grind the end of each rod to a 45 degree point. You would then use a piece of angle iron or other jig that would keep the two pieces of rod relatively straight end to end. This would be clamped in place. 

You have to be very careful with the weld....... if you keep too much heat on one side it will pull the rod to that side regardless if its clamped or not. Good welders know all the tricks. 

That being said, I wouldn't repair a critical component like keel bolts in this fashion. Especially if the person doing the welding is just your typical boat yard hack. 

Its not the strenght of the weld, its the heat affected zone/corrossion resistence that would be compromised.  

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Oh yeah. Lots of 316 stainless steel these days is actually 316L (L = the low carbon variety that can be welded properly).

But 316 bolts on a 20 year old boat could easily be plain old 316. And maybe 2 year old bolts too. I've not seen 316 bolts specified as 316L (though again, they might be)

When you weld 316 you get a heat affected zone (HAZ). The weld itself stays stainless (stainless filler rod). But a short distance away from the weld, you'll get a section where the cooling rates cause areas that are no longer very stainless. And that is where you'll get corrosion and cracking.


Stainless steel is also one of those metals that really moves around when welded. Even with dogs/jigs it is hard to keep it straight.

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Quote

 

 jig that would keep the two pieces of rod relatively straight end to end. This would be clamped in place. 

 too much heat on one side it will pull the rod to that side regardless if its clamped or not.

Good welders know all the tricks. 

 

Lol...my question was semi-retorical. I worked in the fab plant at RMB for 25 yrs, 15 as a welder. 

I would like to see the methodology used. Is welder running in a circle around said keel while welding or doing one pass one side then one pass other side, rinse repeat?

Jig holding replacement bolt section in place but prolly still need to put on a nut and wail away w/a dead blow while it glowing hot.

Quote

Stainless steel is also one of those metals that really moves around when welded.

Cro-mo bike frames also "walk" all over the place unless you weld in a proper sequence. Still need to be cold set. Aluminium way less fussy if you get them to the surface table for alignment in a timely manner. Let them set for a couple days though and there'll be trouble! Buckled scandium d/t's and the downhill bikes, just forget it. You'll never get the twist out.

 

 

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On 10/14/2021 at 3:06 PM, Ballard Sailor said:

Yes, you absolutely can do this.  I had this done to my UN30 at the same yard as did this J/44.  They do what is called a full bleed or full penetration weld that is actually stronger than the bolt itself.

It is a technique utilized when the bolt is corroded/pitted/ect. above the sump, meaning something was in that bilge that damaged the bolt from the nut up. in my case it was from a steal lifting eye that should have been stainless.

 When you pull the keel you notice that the bolt length that had been within the fiberglass, below the bilge and encapsulated within the thick fiberglass, is not showing any corrosion issues.

I actually lift my UN30 (5000lbs) off it's trailer and into the water regularly off two of these bolts and when it was done the welder showed me welded rod that he attempted to break with a long breaker bar on nuts.  The bolt itself twisted with zero damage to the full bleed/penetration weld. 

This dound ctazy. There is a binch you arrnt tellimg us.

For indtance, how get threads pitched properly

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On 10/15/2021 at 4:22 PM, Zonker said:

Oh yeah. Lots of 316 stainless steel these days is actually 316L (L = the low carbon variety that can be welded properly).

But 316 bolts on a 20 year old boat could easily be plain old 316. And maybe 2 year old bolts too. I've not seen 316 bolts specified as 316L (though again, they might be)

When you weld 316 you get a heat affected zone (HAZ). The weld itself stays stainless (stainless filler rod). But a short distance away from the weld, you'll get a section where the cooling rates cause areas that are no longer very stainless. And that is where you'll get corrosion and cracking.


Stainless steel is also one of those metals that really moves around when welded. Even with dogs/jigs it is hard to keep it straight.

The HAZ zone can be eliminated with a post weld heat treat and minimized by using a ELC electrode.  Small diameters are very hard to keep straight. The larger the diameter the easier it is to keep straight. 

Also several have mentioned 45 degrees we only use that for a single bevel. A dual bevel is usually 25 degrees. 

In short yes this is possible but it is totally not practical. I welded the 4' (foot) long SS ACME thread back together on my boat 5 years ago. This ACME thread is what lowers the 800 pound dagger board on my old Dehler 25. The ACME thread was post weld heat treated afterwards in a vacuum furnace environment. Retail cost for the heat treat alone was $800. Fortunately I had connections.

JJ

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1 hour ago, johnsonjay17 said:

The HAZ zone can be eliminated with a post weld heat treat and minimized by using a ELC electrode.  Small diameters are very hard to keep straight. The larger the diameter the easier it is to keep straight. 

Also several have mentioned 45 degrees we only use that for a single bevel. A dual bevel is usually 25 degrees. 

In short yes this is possible but it is totally not practical. I welded the 4' (foot) long SS ACME thread back together on my boat 5 years ago. This ACME thread is what lowers the 800 pound dagger board on my old Dehler 25. The ACME thread was post weld heat treated afterwards in a vacuum furnace environment. Retail cost for the heat treat alone was $800. Fortunately I had connections.

JJ

So for mortals it would be cheaper to just have a new one machined?

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4 hours ago, johnsonjay17 said:

The HAZ zone can be eliminated with a post weld heat treat and minimized by using a ELC electrode.  Small diameters are very hard to keep straight. The larger the diameter the easier it is to keep straight. 

Also several have mentioned 45 degrees we only use that for a single bevel. A dual bevel is usually 25 degrees. 

In short yes this is possible but it is totally not practical. I welded the 4' (foot) long SS ACME thread back together on my boat 5 years ago. This ACME thread is what lowers the 800 pound dagger board on my old Dehler 25. The ACME thread was post weld heat treated afterwards in a vacuum furnace environment. Retail cost for the heat treat alone was $800. Fortunately I had connections.

JJ

Agree. The welding could be done but you'd have to deal with the HAZ and if it's 50mm above the lead or cast iron acting as a giant heat sink good luck with that.

Keeping it straight isn't that big a deal, I've done similar welds lots of times.

Can this be done? Sure. But. I wouldn't do it on my own boat and I definitely wouldn't do it for anyone else. Wouldn't want to have to think about it in the years to come and wonder...

FKT

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3 hours ago, Ishmael said:

So for mortals it would be cheaper to just have a new one machined?

If you asked me to machine you 4' of ACME profile thread into a 316 shaft, you'd think $800 was a bargain. And that's without knowing the shaft diameter or TPI count.

I've got a lathe that could do it. I just know what an absolute prick of a job it'd be.

FKT

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19 hours ago, Fah Kiew Tu said:

If you asked me to machine you 4' of ACME profile thread into a 316 shaft, you'd think $800 was a bargain. And that's without knowing the shaft diameter or TPI count.

I've got a lathe that could do it. I just know what an absolute prick of a job it'd be.

FKT

True on the 4' threaded shaft that is why I welded it. But not true for some specialized bolts. By the way the machine shop quoted me $1,200 to make a new one. Since I ran a shop that welded and did heat treat it was a no brainer for me. And worse it was actually not ACME but a metric version. The boat was made in Germany. 

JJ 

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