Arctic1

Keel Bolt Questions

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Hi I have 1 inch keel bolts and the washers have started to dig into the wood, and the hill to keel join has developed a bit of a smile, i have bought large flat silicon bronze plates 4mm thick, i was going to put the plates under the washers to help spread the load, and then tighten the bolts,  couple of questions....

1) is 4mm thick plate thick enough? It was the thickest i could easily purchase, the plates are 100 x 100

2) is there any issues with having two washers?

3) what torque setting should i torque them up to? Its a full lead keel and the boat is wood cold molded double diagonal planked, the keel is about 900 kg

thanks in advance :)

0554F8AE-8506-4BCF-9BBE-BE9989D07606.jpeg

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Assuming there is more than one keelbolt, remove the nut and have a dig around the bolt to ensure there is no rot. Then put a little thickened epoxy around the bolt and push the bronze washer down onto it until it squeezes out, maybe with a little clamping force from the nut. When it has cured tighten that fucker up as much as you can with a socket and cheater bar. The epoxy will stop the washer cupping into the divot already created. 

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Thanks, I will do that, however what about stopping the epoxy bonding to the bolt? 

Cheers :)

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Put some mold release on the bolt threads and underside of the washer.  Might as well use your backing plate as the washer.  Mclube works as mold release.  Or use shortening, nature's mold release.

You could double up the backing plates to get more thickness.  Not as good as solid since they can slide as they flex, but better than nothing.  It should be a lot better than it was.  Round the corners so they don't concentrate the stress as much.

Keel bolt torque is usually based on the bolt diameter.  One would think there'd be formula based on the weight of the keel and the compressive strength of the stub, but that does not seem to be the case.  With clearance issues, as much as you can put on it might be the best you can do.

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Bolt torque is based on the bolt diameter, thread count and material, not so much what it is fastening.

There are myriad torque tables on the Interweb - look up the specs for your bolts and use them.

DO NOT put a piece of pipe on a wrench and "tighten them until the suckers scream". That's a good way to get stripped or galled threads or even snap one off.

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3 hours ago, xyzzy said:

Keel bolt torque is usually based on the bolt diameter.  One would think there'd be formula based on the weight of the keel and the compressive strength of the stub, but that does not seem to be the case.  With clearance issues, as much as you can put on it might be the best you can do.

Or beg or borrow a torque multiplier like this one -  max torque of 1,110 ft-lb https://www.princessauto.com/en/detail/torque-multiplier/A-p8160665f

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Washers spread out a load in a roughly 45 deg angle from the underside of the nut to the material underneath. So... a 4mm thin washer really only spreads out the load about 5.6mm further out from the edge of the round washer ... But better than not doing it!

Let's eyeball the round washer at about 60mm diameter.

Area under = pi x 30^2 = 2827 mm2.

New 4mm plate - now compressive area goes to 60+5.6+5.6mm in diameter. Area under = pi x 35.6^2 = 3981 mm2 or about 40% more compressive area.  Not as bad as I would have thought.

Isn't eyeball engineering fun?

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Ok. What if its a thicker washer or the washer hasn't seen enough load to warp it? Surely at that point its spreading the load over the whole surface of the washer?

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There are some really knowledgable experts that say you should never need to torque the keelboats. You are applying forces and stresses that ripple through the keelson down to the leaded keel. I am thinking your boat is older than 30 years. Good chance they need a good looking at. You can not tell the condition from around the nut to several mm down.

Mine for example... quite similar to your vintage and build.

17266802535_0520448e76_o.jpg

17060967557_bc0ae24051_o.jpg

I would proceed with caution. The one you posted appear to be stainless. Stainless does not last forever. You might be experiencing bolt separation on your boat  (thus the smile) in addition to crushing of the keelson. I would suspect if one bolt is jacked, the rest may be too. I am willing to guess the keel is J bolted in. You should be prepared for an earnest discussion on your boat and your absolute willingness to address it. . Ask me how I know this...

Bigger questions are:

How old are the keel bolts?  

Where has the boat been kept and how long have you had it?  (Some marinas have dirty power lines in the water and zincs are often not enough. A bad marina or a previous boat owner could have done her wrong a while back. Moreover a dirty power line dropped from another boat or poor electrical box in the water next to your boat could cause enough galvanic corrosion to dissolve (ionize) a bolt(s) over a winter.) 

When was the last haul out and is it out of the water now?

Are you prepared to cut the keel off and do a proper fix if broken or will you be willing to sister in new ones in rather than cut the keel off?

A proper keel repair in the states with the mobile guy who has the tools will run in excess of $5,000.  If you have the yard do it.. over 10k.

 

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Hi thanks please see answers below:....

There are some really knowledgable experts that say you should never need to torque the keelboats. You are applying forces and stresses that ripple through the keelson down to the leaded keel. I am thinking your boat is older than 30 years. (Its 39)

 

Good chance they need a good looking at. You can not tell the condition from around the nut to several mm down.

 Mine for example... quite similar to your vintage and build.

I would proceed with caution. The one you posted appear to be stainless. ( they are silicon bronze)

Stainless does not last forever. You might be experiencing bolt separation on your boat  (thus the smile) in addition to crushing of the keelson. I would suspect if one bolt is jacked, the rest may be too. I am willing to guess the keel is J bolted in. (Maybe, i susbwct they would have been cast into the lead or bolted in pockets)

You should be prepared for an earnest discussion on your boat and your absolute willingness to address it. . Ask me how I know this...

Bigger questions are:

How old are the keel bolts?  39 years

Where has the boat been kept and how long have you had it? Marina, i have had it 2 years

 

 (Some marinas have dirty power lines in the water and zincs are often not enough. A bad marina or a previous boat owner could have done her wrong a while back.

 

Moreover a dirty power line dropped from another boat or poor electrical box in the water next to your boat could cause enough galvanic corrosion to dissolve (ionize) a bolt(s) over a winter.) 

When was the last haul out and is it out of the water now? 2 years and yes out now

 Are you prepared to cut the keel off and do a proper fix if broken or will you be willing to sister in new ones in rather than cut the keel off? Yes

A proper keel repair in the states with the mobile guy who has the tools will run in excess of $5,000.  If you have the yard do it.. over 10k.

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If they are si

31 minutes ago, Arctic1 said:

Hi thanks please see answers below:....

There are some really knowledgable experts that say you should never need to torque the keelboats. You are applying forces and stresses that ripple through the keelson down to the leaded keel. I am thinking your boat is older than 30 years. (Its 39)

 

Good chance they need a good looking at. You can not tell the condition from around the nut to several mm down.

 Mine for example... quite similar to your vintage and build.

I would proceed with caution. The one you posted appear to be stainless. ( they are silicon bronze)

Stainless does not last forever. You might be experiencing bolt separation on your boat  (thus the smile) in addition to crushing of the keelson. I would suspect if one bolt is jacked, the rest may be too. I am willing to guess the keel is J bolted in. (Maybe, i susbwct they would have been cast into the lead or bolted in pockets)

You should be prepared for an earnest discussion on your boat and your absolute willingness to address it. . Ask me how I know this...

Bigger questions are:

How old are the keel bolts?  39 years

Where has the boat been kept and how long have you had it? Marina, i have had it 2 years

 

 (Some marinas have dirty power lines in the water and zincs are often not enough. A bad marina or a previous boat owner could have done her wrong a while back.

 

Moreover a dirty power line dropped from another boat or poor electrical box in the water next to your boat could cause enough galvanic corrosion to dissolve (ionize) a bolt(s) over a winter.) 

When was the last haul out and is it out of the water now? 2 years and yes out now

 Are you prepared to cut the keel off and do a proper fix if broken or will you be willing to sister in new ones in rather than cut the keel off? Yes

A proper keel repair in the states with the mobile guy who has the tools will run in excess of $5,000.  If you have the yard do it.. over 10k.

If they are silicon bronze then they might be ok. Moreover torquing on bronze isn't the recommended as the threads are less robust than say new stainless.  

Very few people ever made cold molded boats with silicon bronze and more often used 316 stainless. A full keel boat does give you security where keel bolts are concerned. Since you are willing to take a look I might suggest you could partially drop the keel to take look at the threads anyway for your peace of mind. 

There might be places where the deadwood is attached by keel bolts to hull that do not bite into the lead. Take note of those spots by using a tapping method. In fact you can tap every one of those keel bolts with a small ball pin hammer and listen to it ring. A more dull ring or even a thud may indicate an issue with the bolts. It may not be scientific as a close inspection but has proven as an indicator for a millennia. The smile is indicating that the developing loss in the shear strength needed in the keel should be taken seriously and not with just some epoxy encapsulation methodology. 

Could you post a photo of the boat and keel as it is currently and include the smile too so we have a reference to how the keel lays against the hull. 

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Hi thanks

I am down there tonight so will take a photo, the hull to keel join wasnt weeping, but there was a crack at the join

the boat is double diagonal kauri glued construction, with a full lead conventional fin keel, its not a full keel. 

Its not common in new zealand to use stainless steel on a wooden boat with lead keel due to the risk of crevice corrosion 

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45 minutes ago, Arctic1 said:

Hi thanks

I am down there tonight so will take a photo, the hull to keel join wasnt weeping, but there was a crack at the join

the boat is double diagonal kauri glued construction, with a full lead conventional fin keel, its not a full keel. 

Its not common in new zealand to use stainless steel on a wooden boat with lead keel due to the risk of crevice corrosion 

The construction method you have was developed here in Alameda, CA.  There are numerous boats like yours here although the Kiwis developed it into a fine art.  My boat is one of the first to use this construction methods in 1967, the leaded section a top secret creation from Boeing. Ron Holland and Peterson used the construction  methods when making their 1970s designs. In New Zealand - the boat design is known a Chico - first in double diagonal laminated Kauri and then later in fiberglass.

Note the trailing edge of the keel  - it is wood.

21131263612_b5008d7c07_b.jpg

21141758825_0fd4d5d89a_b.jpg

I am guessing your boat is much like this except 900 kilos lighter in lead. Most IOR boats had stainless j bolt keels including mine. The shear strength of stainless is higher than bronze..  When I retrofitted I used 1.25" silicon bronze bolts. I am guessing a keel bolt repair was done by a prior owner since it is bronze and the bilge is quite clean indicating someone cared for the boat. 

 

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21 hours ago, Alcatraz5768 said:

Ok. What if its a thicker washer or the washer hasn't seen enough load to warp it? Surely at that point its spreading the load over the whole surface of the washer?

Not really - unless the washer is infinitely stiff or the material the washer is sitting on is very soft. In the real world, the washer does deform locally and stress is concentrated pretty close to the bolt head. Think of it this way - what if the washer was 1m x 1m? Hopefully you wouldn't argue that the load at the edge of the washer pushing down is the same as right under the bolt head. Yes, a stiffer/thicker washer spreads out the load more (think of a 1m thick washer now). In real life washers are not that thick so pressure is not evenly distributed.

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26 minutes ago, Zonker said:

Not really - unless the washer is infinitely stiff or the material the washer is sitting on is very soft. In the real world, the washer does deform locally and stress is concentrated pretty close to the bolt head. Think of it this way - what if the washer was 1m x 1m? Hopefully you wouldn't argue that the load at the edge of the washer pushing down is the same as right under the bolt head. Yes, a stiffer/thicker washer spreads out the load more (think of a 1m thick washer now). In real life washers are not that thick so pressure is not evenly distributed.

I agree with you but how do you define "thick"?

Diameter of the bolt? Diameter of the fastener? Difference between the diameters of the two? Something else?

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5 hours ago, IStream said:

I agree with you but how do you define "thick"?

Diameter of the bolt? Diameter of the fastener? Difference between the diameters of the two? Something else?

 

5 hours ago, Zonker said:

Not really - unless the washer is infinitely stiff or the material the washer is sitting on is very soft. In the real world, the washer does deform locally and stress is concentrated pretty close to the bolt head. Think of it this way - what if the washer was 1m x 1m? Hopefully you wouldn't argue that the load at the edge of the washer pushing down is the same as right under the bolt head. Yes, a stiffer/thicker washer spreads out the load more (think of a 1m thick washer now). In real life washers are not that thick so pressure is not evenly distributed.

In this case the boat is made of wood which is quite soft (kauri) so much softer than a thick bronze washer, I see no reason the washer won't spread the load over the whole area, in fact I have often seen keel bolts after an impact where the whole washer has pulled down into the keelson. I agree if we are talking a flat penny washer, however even with these, after they yield initially, as seen under most deck fittings, they then gain an enormous amount of strength and will then spread the load over the whole area, whilst not being the best shape. 

To this end, my keelbolts will be fully threaded bar either in 316 or galv 8.8 steel, and potted in resin to spread the load through the whole timber structure, not just the loaded nut and washer. 

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Thanks for the advise everyone so far, i found some 60 mm 3 mm thick silicon bronze washers to go over the 4mm plates so will use both.

i dont think the keel bolts should be fairly good, the antfoiling had just cracked along the join when i hauled her out, that coupled with the fact that the washers on the top are digging into the wood is the reason I want to make sure everything is tight.  The washers just seemd undersized to me.

so i will follow what is suggested on here, remove the existing washers, check the wood around the bolts, fill with epoxy, cure, then put the washers on and torque up to the correct torque specified for thread blot size and material.

Are the keel bolts normally glued in during construction for a wooden vessel of this age (39 years) or would it be normal practice just to have glued at the hull to keel join? I do have some concern that tightening them may result in breaking some glue join? Thats assuming i will be tightening them more than they already are. 

I have another question about paint but will start a new thread for that

Black jack there are heaos of Chicos around nz they are very popular, mostly glass ones, they all had teak over ply decks though which caused allot of issues on ones which hadnt had them removed.  

My boat is an Alan Wright tracker. 

http://sailboatdata.com/viewrecord.asp?class_id=6695

one of the few wooden ones

3E5FE7C7-DE15-45E0-B94C-D22488CD8D0F.jpeg

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My impression is that most keelbolts are oversized, when new, for the loads they encounter and are in fact sized to survive their environment long enough that something else fails first.

Torques specs are generally intended for metal stackups and the application of a preload (elastic elongation) to the bolt such that it will never encounter a greater load in service.

Torquing large keel bolts on a wooden boat to a torque table value scares the livin' shit outa me for fear of crushing the wooden layup.

My gut feeling, assuming that someone with real experience cannot be found, is to tighten to snug plus a little and keep an eye on the smile. Yeah, that's pretty vague, but crushed wood has very little strength.

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On 7/20/2018 at 5:51 AM, Black Jack said:

There are some really knowledgable experts that say you should never need to torque the keelboats. You are applying forces and stresses that ripple through the keelson down to the leaded keel. I am thinking your boat is older than 30 years. Good chance they need a good looking at. You can not tell the condition from around the nut to several mm down.

Mine for example... quite similar to your vintage and build.

17266802535_0520448e76_o.jpg

17060967557_bc0ae24051_o.jpg

I would proceed with caution. The one you posted appear to be stainless. Stainless does not last forever. You might be experiencing bolt separation on your boat  (thus the smile) in addition to crushing of the keelson. I would suspect if one bolt is jacked, the rest may be too. I am willing to guess the keel is J bolted in. You should be prepared for an earnest discussion on your boat and your absolute willingness to address it. . Ask me how I know this...

Bigger questions are:

How old are the keel bolts?  

Where has the boat been kept and how long have you had it?  (Some marinas have dirty power lines in the water and zincs are often not enough. A bad marina or a previous boat owner could have done her wrong a while back. Moreover a dirty power line dropped from another boat or poor electrical box in the water next to your boat could cause enough galvanic corrosion to dissolve (ionize) a bolt(s) over a winter.) 

When was the last haul out and is it out of the water now?

Are you prepared to cut the keel off and do a proper fix if broken or will you be willing to sister in new ones in rather than cut the keel off?

A proper keel repair in the states with the mobile guy who has the tools will run in excess of $5,000.  If you have the yard do it.. over 10k.

 

Still one of the scariest keel bolt pictures I’ve seen!! A good reminder to all. 

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5 hours ago, Arctic1 said:

Thanks for the advise everyone so far, i found some 60 mm 3 mm thick silicon bronze washers to go over the 4mm plates so will use both.

i dont think the keel bolts should be fairly good, the antfoiling had just cracked along the join when i hauled her out, that coupled with the fact that the washers on the top are digging into the wood is the reason I want to make sure everything is tight.  The washers just seemd undersized to me.

so i will follow what is suggested on here, remove the existing washers, check the wood around the bolts, fill with epoxy, cure, then put the washers on and torque up to the correct torque specified for thread blot size and material.

Are the keel bolts normally glued in during construction for a wooden vessel of this age (39 years) or would it be normal practice just to have glued at the hull to keel join? I do have some concern that tightening them may result in breaking some glue join? Thats assuming i will be tightening them more than they already are. 

My boat is an Alan Wright tracker. 

http://sailboatdata.com/viewrecord.asp?class_id=6695

one of the few wooden ones

3E5FE7C7-DE15-45E0-B94C-D22488CD8D0F.jpeg

sharp boat. I like it.

Keel bolts are not generally glued in to the hull. Most boats of the era are j-bolted in. Meaning the bolt is shaped like a captial J with the hook part cast into the leaded keel. The visual part is threaded and set into the hull where the washer and threaded nut is applied. There were some folks who used double ended threaded rods but which added additional expense for most builders and new buyers.  Then semi permanent goop is placed around the keel and sealed. a thing layer of epoxy and tape to seal and fair the joint often happens and then the boat is painted and dropped back into the water.

The process you just described may not your real solve your problem. It only makes a hard plug around the top of the keel boat for aesthetics and visual top down inspection. Once again, the boat is 39 years old. Take the time to drop the keel enough to do a good inspection. While the keel is dropped build a sleeve that works for the keel bolt and the hole that it fits. (or pour and fill the without sleeve) Pour the epoxy and let it cure overnight. Fair or re-drill the hole in the morning.

What you will accomplish by doing this is a full inspection of the keel,  a renewed keel joint without a smile and full confidence in the bolts themselves as well as solve the issue of an ugly hole where a questionable bolts that begs to be torqued. If the bolts aren't bad the whole process can be done in 2 days provided you have a sling to lift the boat overnight.

If you proceed with the proposed plan of others, that encapsulated keel bolt and keel very well may be a pain in the ass to pull in the future. 

One other thing to consider... the keel bolts in your vessel may be in fact replaced threaded lag bolts which work well. The torquing of them might prove ill advised.

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2 hours ago, mad said:

Still one of the scariest keel bolt pictures I’ve seen!! A good reminder to all. 

Yeah, now I’ll have nightmares again...

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Dropping the keel is a pretty big undertaking and should not be taken lightly. A lot of keels your vintage were bedded on epifill because it was a bit flexible and could be broken in the future. If it's just a small crack, proceed as per your description, bigger washers, glass around the joint, will be fine. 

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Bump - as you seem to move on from this discussion and are talking paint.

On 7/21/2018 at 1:50 PM, Alcatraz5768 said:

Dropping the keel is a pretty big undertaking and should not be taken lightly. A lot of keels your vintage were bedded on epifill because it was a bit flexible and could be broken in the future. If it's just a small crack, proceed as per your description, bigger washers, glass around the joint, will be fine. 

What Alcatraz suggests is deferred maintenance. Many people chose it. While the easy route it is not the safest. Your boat is 39 years old. If you sail off shore, with non sailors swimmers or children - the liability is compounded.

We lost a wonderful IOR boat off the coast of California because the owner decided deferred maintenance on his keel. It nearly killed everyone. The boat went down in 30 seconds. Most people will say they hit a container or a whale broke their boat. These boat owners report that so insurance pays them despite the truthful and real neglect of not securing the keel when they were in the yard patching a smile.

https://www.pbo.co.uk/expert-advice/how-to-check-keel-bolts-28039

42709013995_5f47bc9655.jpg

Here is a photo of a bronze keel bolt nut. It was only after the nut was removed the fracture in the nut was reveled. This most likely  occurred when someone torqued the nut in the yard sometime during a yard visit.

43565837502_4d181b04bf.jpg

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Looking at the pictures the OP posted, there isn't much room to put a thick or double washers on. There is barely a thread above the nut with the existing washer. What you would need is a flange nut - probably hard to find in bronze this size, though not that hard to make. 

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This technique is about sealing leakage.

As an inspection technique, it would behoove one to pay close attention to what the cuttings look like.

If they're just dry wood or resin, this might work quite nicely. The depression in the wood from the original washer could be filled and a larger load spreader plate installed.

If they're WET wood, you might have a serious problem. The wood may have become saturated and spongy.

If there's a lot of rust, then the bolt still must be inspected.

Gougeon doesn't speak to depth of cut. My guess is to drill until the cuttings are clean and dry.

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Using this method it seems the nuts and washers would be superfluous, particularly on a new build, if you could sufficiently abrade the surface of the bronze then the washers and nuts would just be there for peace of mind more than anything else

also it seems if repairing by this method that tightening the nuts afterwards isnt going to do much. I guess if its a repair the bond between the bolt and epoxy may not be that good

6 hours ago, Feisty! said:

This technique is about sealing leakage.

As an inspection technique, it would behoove one to pay close attention to what the cuttings look like.

If they're just dry wood or resin, this might work quite nicely. The depression in the wood from the original washer could be filled and a larger load spreader plate installed.

If they're WET wood, you might have a serious problem. The wood may have become saturated and spongy.

If there's a lot of rust, then the bolt still must be inspected.

Gougeon doesn't speak to depth of cut. My guess is to drill until the cuttings are clean and dry.

 

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Progress update for anyone interested.  I a tough time trying to remove the first bolt, I put a 750 mm power bar on it but couldn’t get it to budge, so ended up needing to apply heat to it with a MAPP gas burner, that did the trick and freed it up.  I then removed the paint around the bolt where the washer was going to go and sanded it back, saturated the whole area with evedure, i then covered the square washer and bolt with mold release and spread thickened epoxy into the depression created by the previous washer. I put the new washer on and tightened the nut and let it set over night, next day pulled apart and it looked good.  

So so far so good. However a couple of problems i had putting things back together.

firstly the washers i had weren’t quite thick enough, the one i pulled out was 9 mm, so i have had to use 1 x 4 mm thick square plate large washer, and then two round 3 mm thick washers, this means there is one thread left on the top of the nut.

secondly it was my first time using loctite, i coated the entire threads of the nut whoch was a mistake because i believe it was too much it started to cure as I was doing the nut up as the nut was sticking then freeing with more presure, i dont have a torque wrench but did it up as hard as I could with the 750 mm power bar.  Later i read that the loctite is only supposed to go on the last few threads of the stud.  Now I am worried I didn’t get the nut tight enough because having too much loctite was making it harder to do up. So my option is live with it and assume its tight enough (the nut made an impression into the bronze washer so it is pretty tight) or I could put the blow torch back on the nut, remove it and do it again. 

Are there any engineers here can give me a tip? I was using the high strength red permanent loctite, is a lower strength ok? It a 1 inch bolt.  The reason i coated all of the thread of the nut is because i though i needed the whole lot coated to act as a lubricant and prevent galling when tightening. How can i lubricate the nut and use loctite? 

FD7AC365-AE48-45B5-B323-57194787B87B.jpeg

D68F6944-BA4F-43C7-B6C5-9DC797244FE6.jpeg

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Also I highly doubt with a 750 mm power bar that I could apply enough pressure to crush any timber the combined thickness of the keel + floor + plus hardwood timber on top would take allot of force to crush more than i can apply with the power bar.

i emailed the designer about what torque settings to use, Alan Wright he is one of NZ most successful crusing boat designers, he said back in his day they didn’t measure the torque, they would just do them up until it felt right, so I think the 750 mm power par should be about right, a 500 mm torque wrench does  210 nm, im guess with 750 mm im getting close to 300 nm, my only worry is that with the loctite on the threads arent really lubricated. 

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On 7/25/2018 at 3:14 AM, Black Jack said:

Bump - as you seem to move on from this discussion and are talking paint.

What Alcatraz suggests is deferred maintenance. Many people chose it. While the easy route it is not the safest. Your boat is 39 years old. If you sail off shore, with non sailors swimmers or children - the liability is compounded.

We lost a wonderful IOR boat off the coast of California because the owner decided deferred maintenance on his keel. It nearly killed everyone. The boat went down in 30 seconds. Most people will say they hit a container or a whale broke their boat. These boat owners report that so insurance pays them despite the truthful and real neglect of not securing the keel when they were in the yard patching a smile.

https://www.pbo.co.uk/expert-advice/how-to-check-keel-bolts-28039

42709013995_5f47bc9655.jpg

Here is a photo of a bronze keel bolt nut. It was only after the nut was removed the fracture in the nut was reveled. This most likely  occurred when someone torqued the nut in the yard sometime during a yard visit.

43565837502_4d181b04bf.jpg

That nut looks too yellow to be silicon bronze?? Maybe they used the wrong metallurgy? 

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I would not use red loctite in that application - in fact I would not use loctite at all. If you do use it, I'd use blue. You should not have trouble with it curing in the time it takes to run the nut down and tighten, unless for some reason this is taking an extraordinarily long time. I'd use a lubricant like grease or perhaps even Tefgel, if you were worried about them turning on their own, witness mark the nut so that you can see if it has turned. They are not subject to vibration like the nut on an engine. 

If you use loctite, you cannot later check the torque of the nuts or tighten them. If you are doing several or all of them, you are going to want to go back and retorque them all in series when you are done. 

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Locktite is fundamentally to secure threads against vibration or rotational loosening so it is pointless on a keel bolt. I put anti seize on mine to prevent galling.

Tightening them "until they feel right" or "until the suckers scream" is not the way to do it.

Rent a torque wrench and tighten them properly to the torque specified for your bolts - there are myriad torque tables on the Interweb.

The correct torque depends on the bolt diameter, material and thread count.

You can look it up. ;)

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1 hour ago, SloopJonB said:

Locktite is fundamentally to secure threads against vibration or rotational loosening so it is pointless on a keel bolt. I put anti seize on mine to prevent galling.

Tightening them "until they feel right" or "until the suckers scream" is not the way to do it.

Rent a torque wrench and tighten them properly to the torque specified for your bolts - there are myriad torque tables on the Interweb.

The correct torque depends on the bolt diameter, material and thread count.

You can look it up. ;)

Here is one http://www.engineershandbook.com/Tables/torque3.htm 

However all the tables I've come across specify dry torque values.  You will probably want wet torque numbers, which will vary depending on the lubricant and I've never come across one of those on the internet.

However there is a discussion of this on another website: http://www.cruisersforum.com/forums/f55/keelbolt-torque-discrepancies-lubricated-dry-more-less-35429-2.html 

I've cut and pasted an excerpt from post # 25 there:

"...WITH CLEAN DRY THREADS.
Now the correction factors... for:
SAE20 motor-oil, copper-graphite anti-seize, WD40: 0.80
SAE40 motor-oil, zinc-anti-seize: 0.75
SAE30 motor-oil, molybdenum grease, graphite: 0.70
never-seize and other specialized products: 0.45 (!!!!!!!!!!)..."

Assuming this is correct, for something like Tefgel, you would take the dry torque value of about 250 ft-lb for 1" silicon bronze and multiply by 0.45, so about 115 ft-lb.

The post also mentions that the correction factors were obtained from a publication called something like "Handyman-in-your-pocket"

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Heat it up to free the loctite and back the nut off. Lubiricate the threads as has been said and crank that nut up as tight as you can with that powerbar and it will be fine. All the torque guides will be assuming you are bolting steel structures together so are essentially useless for this application. 

I will be using the gougeon method for my boat, and boring around the keel bolts was always standard practice, although it sucked dick. 

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Thanks Everyone for the helpful answers, i will remove the loctitie, clean the threads and re use with some lubricant, I dont have tefgel handy, but do have some duralac, can duralac be used for the same purpose? Cheers

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44 minutes ago, Alcatraz5768 said:

Heat it up to free the loctite and back the nut off. Lubiricate the threads as has been said and crank that nut up as tight as you can with that powerbar and it will be fine. All the torque guides will be assuming you are bolting steel structures together so are essentially useless for this application. 

I will be using the gougeon method for my boat, and boring around the keel bolts was always standard practice, although it sucked dick. 

The torque tables I've used assume nothing about the material being bolted, only the bolts size, thread count and material. You need to have the specified torque to provide the necessary stretch for that size bolt. The best way to measure torque is to measure actual bolt stretch with a dial indicator but that is obviously impractical on a keel bolt.

Torque is torque - it doesn't care if it's fastening steel or aluminium or fiberglass - that should be factored in when the sizes of bolts are selected during design.

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5 hours ago, SloopJonB said:

The torque tables I've used assume nothing about the material being bolted, only the bolts size, thread count and material. You need to have the specified torque to provide the necessary stretch for that size bolt. The best way to measure torque is to measure actual bolt stretch with a dial indicator but that is obviously impractical on a keel bolt.

Torque is torque - it doesn't care if it's fastening steel or aluminium or fiberglass - that should be factored in when the sizes of bolts are selected during design.

I get what you are saying, however if you torque up a 1" bolt to the 'specified' torque, but in the process crush the keelson, or the core material in your layup, who is winning?

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Then your backers are too small.

I find they usually are - mere washers on keel bolts are way to skimpy for my taste - I back up deck hardware with more substantial bits than most keels have.

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In theory you might crush things, but not a chance on mine, its pretty solid and over engineered. I reckon i would need to get a 2 metre powerbar before anything was at risk of getting crushed 

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9 minutes ago, SloopJonB said:

Then your backers are too small.

I find they usually are - mere washers on keel bolts are way to skimpy for my taste - I back up deck hardware with more substantial bits than most keels have.

Ok

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You don't have any more thread to allow for a thicker washer. Our steel square washers we use in AU house construction are 16mm bolt - 5mm washer. 25mm bolt - 6mm washer.

Most backing plates have traditionally been 6mm(1/4") flat aluminum plate, nowadays its 6mm G-10 fibreglass plate. Round washers love to crush wood fiber. Square ones not so much. That is why the spec them in timber houses.

4mm should be adequate as long as you fill in the crushed area. A little car wax is good mold release. Definitely use  something. I've snapped many screws that got a wee bit of epoxy on their threads.

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Unfortuantly the wngineering supply company only had 4 mm plate for the square washers, and the bolts are only threaded at the top so this means i need to pack them out using two off the shelf round flat washers which are 3 mm thick each

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Torque tables for bolts are a rule-of-thumb thing assuming average material, lubrication, and conditions. The clamping force can vary widely depending on these factors, and cannot be accurately determined without testing. I'm not sure any figure - even one quoted from the builder - would be authoritative. The theory behind bolted connections is to preload the bolt to a value higher than any load it will see in use, this makes it immune from fatigue. I.e., "tighten the shit out of it with a 750mm breaker bar" is likely as good a guess as any. 

On the washers, two 4mm washers stacked are 1/4 the strength, and 1/8 the stiffness, of one 8 mm washer. But probably better than what you had there before.

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So you're saying that when you put a cylinder head or main caps on an engine you can just tighten the bolts until they feel right?

None of that inaccurate Ft/Lbs, Inch/Lbs stuff - guessing is just as good?

Sorry DDW but you just provided "Internet Wisdom" with that post.

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Not at all what I said. When Ford or Toyota specs those bolts, they are very well engineered and characterized. Even on a popular series production boat, the entire run is a prototype run for Ford, and they are highly unlikely to have done any such engineering. 

The torque table out of Machinery's Handbook will give you a reasonable figure for ordinary steel bolts in an ordinary situation, clamping steel connections. How that relates to silicon bronze bolts clamping timber is a very long stretch. 

By the way, a good experienced mechanic can tighten the head bolts or cap bolts on a normal engine by feel and it will be fine. A good mechanic would not do that if there were specs and the tools were available. Sometimes, they aren't. 

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I believe frp compressive strength varies from 15,000 to 25,000 psi.  1 in and bigger bolts develop huge clamping forces.

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Torque tables are available for different materials, thread counts and diameters. Note that what material is being fastened is NOT listed.

image.thumb.png.95bcd6438946bda30052b66bcf13b218.png

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The torque tables are good, but wet torque values are pretty much guesswork ranging from 40 to 80% of the dry value.  Im wither going to do them with a torque wrench up to 210 nm, and then once all are tight tweek each ome with the power bar, or just forgo the torque wrench and use the power bar, it will achieve around 280 nm max.  I doubt i can over tweek it without a much bigger power bar, tge wood is pretty substantial and load is spread with quite a large washer

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Many of the keelbolts of that era were monel, do a spark test or have a look for greenish oxidation. If so dont worry about them too much and you can just use stainless plates or even high carbon steel (thats all my boat has which has lasted fine). Not much load on a tracker. 

 

Black Jack you totally wrong about 3 skin cold moulding btw.

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They do have greenish oxidation on one, i thought they would be silicon bronze, either way silicon bronze is close to monel in the galvanic series.  The keel floors and keel and planking is all very much over specced on the tracker too. The planking is two layers of 1/4” so pretty substantial for the size of the boat 

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11 hours ago, SloopJonB said:

Torque tables are available for different materials, thread counts and diameters. Note that what material is being fastened is NOT listed.

And, since the material that is being clamped can vary widely in properties, that is a problem. Those guides are meant for clamping hard materials like steel. Under those conditions it will produce a clamping force appropriate to the fastener size, disregarding design specific conditions, i.e. it is safe for the bolt. Clamping a piece or two of hard metal there is no concern about damage. Torquing a 1-8 bolt to 265 ft-lbs will produce something like 20,000 lbs clamping force. Also 20,000 lbs on the washer, and 20,000 lbs on the end buried in the soft lead (whatever that looks like - commonly just a J bend). This is timber, and cross-grain at that it appears. 

Using such a table for keel bolts is not authoritative as I said, because that is not it's intended application, and this application differs significantly. Blindly following a table off the internet is not the correct answer, and it's not engineering.

If the keel bolts and nuts are monel, you need to worry a bit about galling - worse than SS. Less of a problem if silicon bronze.

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Foot Pounds - probably the most fundamental unit of torque.

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13 minutes ago, SloopJonB said:

Foot Pounds - probably the most fundamental unit of torque.

But not Ft/lbs.

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 I like to work in metric, anyhow the bolts arent j bolts they have nuts and washers at the other end sealed in, it was common when constructing these boats to sit the hull on top of the keel and then drill from the top down and secure them at the lower end via pockets in the lead.  Mine varies slightly to the attached plan, the origonal design calls for two 1/2 inch keel bolts and 4 7/8 inch, however mine has two 1/2 inch and 3 1 inch. 

162945E8-CF70-45F9-8535-F7C871E4F6AA.jpeg

A851C928-65F6-4D46-B4FD-B98EC531AD87.jpeg

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Having done over 20 full keel off repairs, and being taught by some of the best timber boatbuilders in the world (imo), just get the powerbar and crank them up. 

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1 hour ago, weightless said:

But not Ft/lbs.

????

That's a standard abbreviation.

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The SI units of torque are Newton-meters, abbreviated as N•m.

The SAE equivalent is Foot-Pounds, often abbreviated as Ft•Lbs but should really be Ft•Lbf, as a pound is a measure of mass whereas a Newton is a measure of force.

SlapJon is running on about Ft/Lbs, which would be feet-per-pound and has no bearing on this topic or any other of which I'm aware.

 

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1 hour ago, Moonduster said:

as a pound is a measure of mass whereas a Newton is a measure of force.

A pound IS a unit of force.

A slug is the unit of mass in imperial.

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I love it when engineers have a pillow fight. 

Slide rules at 10 paces!

 

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12 minutes ago, 12 metre said:

A pound IS a unit of force.

A slug is the unit of mass in imperial.

12 - you realize your talking to Moon - FFS! :rolleyes:

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I own a high precision slide rule. It's about 6 feet long. 

Arctic1, I like the detail on that design. Never liked J bolts much. 

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It can be confusing ... let's review

In the Imperial Measurement System, a pound is a unit of mass.

In the Gravitational FPS System, a slug is a derived unit of mass, in standard gravity, that is accelerated to 1 ft/sec2 when one pound-force (lbf) is exerted upon it. A pound-force ought not to be confused with a pound.

The SI system of measure resolved this duality/paradox through use of the kilogram and Newton as units of mass and force, respectively. The SI system has since become the standard bearer of measurement; the Imperial and FPS units are now derived in terms of their SI equivalents. In those derivations, a Pound is exactly 453.59237 grams; it is a unit of mass.

A SlugJon is a buffoon who, generally, cannot be bothered with accuracies and, specifically, cannot distinguish between ft•lbf and ft/lbs. He freely admits to being "opinionated [and] deeply suspicious of those who have [...] the answer". Likely a result of this self-professed paranoia, when faced with facts, his recourse is to make ad hominem attacks as if still on the grade-school playground of his continuing juvenile existence.

 

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8 minutes ago, Moonduster said:

It can be confusing ... let's review

In the Imperial Measurement System, a pound is a unit of mass.

In the Gravitational FPS System, a slug is a derived unit of mass, in standard gravity, that is accelerated to 1 ft/sec2 when one pound-force (lbf) is exerted upon it. A pound-force ought not to be confused with a pound.

The SI system of measure resolved this duality/paradox through use of the kilogram and Newton as units of mass and force, respectively. The SI system has since become the standard bearer of measurement; the Imperial and FPS units are now derived in terms of their SI equivalents. In those derivations, a Pound is exactly 453.59237 grams; it is a unit of mass.

A SlugJon is a buffoon who, generally, cannot be bothered with accuracies and, specifically, cannot distinguish between ft•lbf and ft/lbs. He freely admits to being "opinionated [and] deeply suspicious of those who have [...] the answer". Likely a result of this self-professed paranoia, when faced with facts, his recourse is to make ad hominem attacks as if still on the grade-school playground of his continuing juvenile existence.

 

Oh! Hard punch! Cites and everything! 

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24 minutes ago, Raz'r said:

Oh! Hard punch! Cites and everything! 

A double semicolon attack with duality paradox!

 

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I recommend: image.png.e73e7601f595fb84a3e0af915aa07058.png

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47 minutes ago, SloopJonB said:

I recommend: image.png.e73e7601f595fb84a3e0af915aa07058.png

Oh! The fabled “brush off”. Will Moondust recover from this unanticipated response?

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There's nothing from which to recover.

But a post that says "ignore" is inherently contradictory, either ignore or don't. I'm guessing he's pretty ignorant.

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On 9/4/2018 at 2:42 AM, Gutterblack said:

Many of the keelbolts of that era were monel, do a spark test or have a look for greenish oxidation. If so dont worry about them too much and you can just use stainless plates or even high carbon steel (thats all my boat has which has lasted fine). Not much load on a tracker. 

 

Black Jack you totally wrong about 3 skin cold moulding btw.

Enlighten me about my ignorance on 3 skin cold moulding. I would like to know what i am missing.

And again...

Why would one retorque 40 year old invisible to the eye keel bolts siting in similar vintage deadwood in a boat that has an unknown marina history, groundings and possible collisions which have direct and indirect consequences to your keel safety.  When one does torque old keelboats, they are without a doubt are tightening the unknown and quite possibly allowing further ingress for structural weakness, adding stress cracks in compression and further shorting the safety margins of the vessel. Whether you want to admit it or not, you are taking a short cut, possibly not doing your complete due diligence and getting emotional reassurance and conjecture from people far away who also do not know the boat. In reality - the option of doing nothing but watching is as valid as torquing on some nuts to estimated specs in an speculative composition.

I bring and challenge this topic in respect for our own safety and security as as most of our boats are going beyond the intended service life. The patchwork of their repairs and unknown histories should give us pause. When I want a diagnosis for a structural issue i would rather have full knowledge of my boats condition rather speculate before putting trials and eventually lives on the line.

 

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On 7/20/2018 at 7:00 PM, Black Jack said:

The construction method you have was developed here in Alameda, CA.  There are numerous boats like yours here although the Kiwis developed it into a fine art.  My boat is one of the first to use this construction methods in 1967, the leaded section a top secret creation from Boeing. Ron Holland and Peterson used the construction  methods when making their 1970s designs. In New Zealand - the boat design is known a Chico - first in double diagonal laminated Kauri and then later in fiberglass.

Note the trailing edge of the keel  - it is wood.

21131263612_b5008d7c07_b.jpg

21141758825_0fd4d5d89a_b.jpg

I am guessing your boat is much like this except 900 kilos lighter in lead. Most IOR boats had stainless j bolt keels including mine. The shear strength of stainless is higher than bronze..  When I retrofitted I used 1.25" silicon bronze bolts. I am guessing a keel bolt repair was done by a prior owner since it is bronze and the bilge is quite clean indicating someone cared for the boat. 

 

Chicos were designed by Gary Mull if thats your boat and its not double diagonal as we know it, looks more like its strip planked

Double diagonal was first used in NZ in the late 1800's by builders like Arch Logan who in turn developed it from Scottish boatbuilding heritage. At that stage the planking was riveted together with layers of calico soaked in red lead between them. Usually three skins, one at 45, one at 90 and the last on the other 45.  Over the years the method developed and became lighter  boats benefited from the advantages of rigid monocoque  construction and the superior qualities of Kauri, resulting in some of the worlds most advanced and fastest yachts of the day. Eventually with the advent of modern glues the method developed to its zenith in the 1970s with the boom in boat building and availability of good timber, since then it has been in decline. It remains the one of the best methods of wooden boat construction and we have countless 2 and  3 skin boats still sailing, some from over a 100 years ago. It may well have had a strand of development in your area but Ron Holland would have grown up immersed in its knowledge and traditions.

 

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4 hours ago, Black Jack said:

 

Enlighten me about my ignorance on 3 skin cold moulding. I would like to know what i am missing.

And again...

Why would one retorque 40 year old invisible to the eye keel bolts siting in similar vintage deadwood in a boat that has an unknown marina history, groundings and possible collisions which have direct and indirect consequences to your keel safety.  When one does torque old keelboats, they are without a doubt are tightening the unknown and quite possibly allowing further ingress for structural weakness, adding stress cracks in compression and further shorting the safety margins of the vessel. Whether you want to admit it or not, you are taking a short cut, possibly not doing your complete due diligence and getting emotional reassurance and conjecture from people far away who also do not know the boat. In reality - the option of doing nothing but watching is as valid as torquing on some nuts to estimated specs in an speculative composition.

I bring and challenge this topic in respect for our own safety and security as as most of our boats are going beyond the intended service life. The patchwork of their repairs and unknown histories should give us pause. When I want a diagnosis for a structural issue i would rather have full knowledge of my boats condition rather speculate before putting trials and eventually lives on the line.

 

Why ever retighten a bolt of any kind?

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3 minutes ago, Gutterblack said:

Double diagonal was first used in NZ in the late 1800's by builders like Arch Logan who in turn developed it from Scottish boatbuilding heritage. At that stage the planking was riveted together with layers of calico soaked in red lead between them. Usually three skins, one at 45, one at 90 and the last on the other 45. 

Wow - I had no idea it was that old.

Did they use thin, wide "veneers" like recent boats? In other words was epoxy the only real change in modern times?

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4 hours ago, Gutterblack said:

IMG_7245_2.jpg

This is copper riveted to plank framed boat with layers of veneer. It is a mechanical bond rather than a chemical bond. There is some nuance and the veneer is clearly laid upon the planks . Furthermore this boat is a full keel boat. Not quite the same although outwardly they do look similar.  Further this is a different boat build than the OP... In many ways apples and oranges comparison.

The modern method of cold molded construction with epoxy started in the US and really got going here in Alameda/Oakland, CA. Barney Nichols and other bay area notables were some of the first to use multilayer veneer epoxy technique and ply which they began in the the Kaiser ship yards during the war effort.

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5 hours ago, SloopJonB said:

Why ever retighten a bolt of any kind?

Sure. Ever tighten a bolt that was fractured, stripped or embedded in questionable materials?

Just because something can be torqued does not mean it should be torqued after the application was first applied.

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5 hours ago, Gutterblack said:

Chicos were designed by Gary Mull if thats your boat and its not double diagonal as we know it, looks more like its strip planked

Double diagonal was first used in NZ in the late 1800's by builders like Arch Logan who in turn developed it from Scottish boatbuilding heritage. At that stage the planking was riveted together with layers of calico soaked in red lead between them. Usually three skins, one at 45, one at 90 and the last on the other 45.  Over the years the method developed and became lighter  boats benefited from the advantages of rigid monocoque  construction and the superior qualities of Kauri, resulting in some of the worlds most advanced and fastest yachts of the day. Eventually with the advent of modern glues the method developed to its zenith in the 1970s with the boom in boat building and availability of good timber, since then it has been in decline. It remains the one of the best methods of wooden boat construction and we have countless 2 and  3 skin boats still sailing, some from over a 100 years ago. It may well have had a strand of development in your area but Ron Holland would have grown up immersed in its knowledge and traditions.

 

I never said my current boat was totally cold molded but I did have one of Barney Nichols cold molded epoxy boat built in the mid 1950s. Saw the plans of his builds, talked to Myron Spaulding before he passed several years ago on the subject and know a lot about boat construction through my research of a book I have been working on and off for the last few years about west coast boat development and design.

As a reminder - Holland was an apprentice here in Oakland under Mull who was an apprentice under Nichols. Holland got to see first hand how the technology was changing. 

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39 minutes ago, Black Jack said:

This is copper riveted to plank framed boat with layers of veneer. It is a mechanical bond rather than a chemical bond. There is some nuance and the veneer is clearly laid upon the planks . Furthermore this boat is a full keel boat. Not quite the same although outwardly they do look similar.  Further this is a different boat build than the OP... In many ways apples and oranges comparison.

The modern method of cold molded construction with epoxy started in the US and really got going here in Alameda/Oakland, CA. Barney Nichols and other bay area notables were some of the first to use multilayer veneer epoxy technique and ply which they began in the the Kaiser ship yards during the war effort.

I was showing you the history of 3-skin, there are two diagonal inner skins and one fore and aft on Rawhiti . All before modern glue but the principle is the same, when resourcinol, aerodux and epoxy came along then they changed it to the 45/90/45 or 45/45 method.

In 1960 or thereabouts the builders of three skin boats discarded details like rebates in keelsons and made them far more similar to cold molded dinghy hulls and that is pretty much the same method used in the OP's boat 

As for Ron Holland, hes a great mate of an old boat builder I know, and Ron did his apprenticeship here in NZ I think with Jim Young but will check

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3 hours ago, Gutterblack said:

I was showing you the history of 3-skin, there are two diagonal inner skins and one fore and aft on Rawhiti . All before modern glue but the principle is the same, when resourcinol, aerodux and epoxy came along then they changed it to the 45/90/45 or 45/45 method.

In 1960 or thereabouts the builders of three skin boats discarded details like rebates in keelsons and made them far more similar to cold molded dinghy hulls and that is pretty much the same method used in the OP's boat 

As for Ron Holland, hes a great mate of an old boat builder I know, and Ron did his apprenticeship here in NZ I think with Jim Young but will check

That would be super. I love reading how one thing leads to another when intelligence in design and true craftsmanship really come together.

One thing for sure - the Kiwis can build a fine cold molded boat that lasts. Kauri wood or not!

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10 hours ago, Gutterblack said:

IMG_7245_2.jpg

Wow - over 100 years ago.

Epoxy & staples replacing red lead and copper rivets seem to be the only significant changes since then.

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Was the red lead like a kind of glue? Whenever I see the word I think of anti-corrosion paint on steel. 

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More of a wood preservative I think. AFAIK there were no waterproof glues of any sort 100 years ago.

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The linseed oil keeps the water from penetrating, the lead kills all living organisms. 

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