Caulking Problems

[Leviathan]

Hello All,

First post here. I have a 1965 AYC carvel planked yacht. Recently I inadvertently caused a lot of damage to my yacht by sailing in rough seas. The boat had been sitting in a very hot dry boatyard for several months. I got an unexpected notice from the boatyard, that I needed to move my boat out of the yard as other boats were coming in. I found a slip a couple of hundred miles south, and took the trip on short notice. I had expected to take on some water, as I knew the planks had dried out. The weather forecast called for 15kts of wind, which turned out to be 30kts. The boat pounded hard, and I started taking on inordinate amounts of water that could not be managed by my bilge pumps.

I was forced to abort the trip, and return to port on anchor as there was no space left at the boatyard. Upon exterior inspection I found a multitude of open seams. But more surprisingly I found broken scarf joints in the planking. My boat has plank joints which are scarfed diagonally between the frames, and are glued together with a non-epoxy glue. 11 of these scarfs joints separated on the starboard side, which was the side facing the sun while at the boatyard.

The yacht takes on zero water under the waterline, but the topsides have now been severely effected by this 40 minute excursion.

My question is, has anyone here ever had this type of problem? Are there any recommendations on how best to solve it?

Thanks

[wizbang 13]

Re: Caulking Problems

When you say” scarphed diagonally”… not sure what you mean?
Where are you, how old de boat?
sound like re gluing these scarphs and perhaps gluing or bedding butt blocks behind dem

[Peerie Maa]

Re: Caulking Problems

Do you mean scarf joints like this one on a Narrow boat?



I can only suggest that you fit butt blocks behind the scarfs, well fastened and caulk them.

[Leviathan]

Re: Caulking Problems

There are no butt blocks behind the scarfs, and there is no way to install butt blocks because the boat has a very robust ceiling. To do that would involve the total demolition of the yacht.

Unlike the photo posted by Nick, my scarf joints are straight diagonal, without the vertical tabs. As previously mentioned, my boat was built in 1965 and I'm now in Mexico. There is zero love for wooden boats in Mexico, it is literally "casting pearls before swine."

[wizbang 13]

Re: Caulking Problems

Well that is a carp way to join planking .
I think no miracle cure .

[Peerie Maa]

Re: Caulking Problems

There are no butt blocks behind the scarfs, and there is no way to install butt blocks because the boat has a very robust ceiling. To do that would involve the total demolition of the yacht.

Unlike the photo posted by Nick, my scarf joints are straight diagonal, without the vertical tabs. As previously mentioned, my boat was built in 1965 and I'm now in Mexico. There is zero love for wooden boats in Mexico, it is literally "casting pearls before swine."

I would be very surprised if a yachts ceiling is structural. Bite the bullet and fit butt blocks, You can always patch the ceiling with pieces scarfed back in. Glue rarely reglues a fractured glue joint, it needs clean wood to bond to.

[Gordon Bartlett]

Re: Caulking Problems

If I really couldn't get behind the joint, I would consider cutting the scarf out completely, then scarfing in a short plank to rejoin the cut ends. Make the new scarfs in the more traditional manner with the angle running from inside to outside, rather than from top to bottom. And definitely use epoxy for the scarf joints. If the new plank is left extra thick during it's installation, it could be easily faired to the hull's surface after the epoxy hardens.

[Slacko]

Re: Caulking Problems

A skilsaw or multitool could clean out and widen the joint so that epoxy could be goodged in there, but a butt block behind as well would make it a much more secure joint.

[Pelirrojo]

Re: Caulking Problems

If you want to fix it right you need to pull either the plank or the ceiling. If you want to make it able to go to weather bend make patches of either 1/4 or 1/2 ply coat them with tar and screw them on with either # 8 or # 10 stainless screws spaced about an inch apart. To be clear the second is very much a temporary fix and only should be used as to get you to a better place to properly repair the planking.

Nicholas

[Ian McColgin]

Re: Caulking Problems

For a repair that works with the planking and can be done from outside, I used to cut away the wood taken up by the broken scarf. Then bevel each end 8:1, easily done with a Japanese style pull saw (to make kerf guides for the bevel) and a slick. Make a plug to fit and epoxy with a few screws at the ends.

Hard to do in water but also impossible if you're baking one side all day long day after day so finding a working place matters.

[Leviathan]

Re: Caulking Problems

Hello my Friends,

Thank you all for your responses. This yacht cannot be torn apart by demolishing the interior to install butt blocks. If any of you actually saw the interior, you'd all understand why. I don't think butt blocks are actually necessary, as the planks have not sprung. The frames are 8" apart and the scarf joints are diagonal, and extend only between the frames. The breaks are only hairline cracks, the worse one is barely wide enough to put a very thin knife through it. The planking is nearly 3" thick, and will most certainly swell up when hydrated with sea water. Unfortunately, the former owner painted the boat with epoxy based paint which maybe the root cause of the problem, and may inhibit hydration?

My plan was to try and re-glue the broken scarf joints using a hypodermic needle and west systems epoxy. Any thoughts on that?

[sp_clark]

Re: Caulking Problems

Unfortunately, the former owner painted the boat with epoxy based paint which maybe the root cause of the problem, and may inhibit hydration?

Would do that, yes. Why epoxy's so popular for constructing new craft. Worth the expense as long as it's done right.

My plan was to try and re-glue the broken scarf joints using a hypodermic needle and west systems epoxy. Any thoughts on that?

How thick is your planking?

You may have limited success with a hypodermic as the epoxy in between the scarf-jointed plank ends will inhibit a proper bond with fresh stuff. Besides, being cracked, the joints are contaminated already & need to be cleaned well before any further insult's imposed on 'em.

Better proposition I'd think would have you routering out the scarf seams to at least half the depth of the planking then "injecting" fresh epoxy to saturate the newly-exposed end grain of the planking, soon to be followed with suitably thickened epoxy to fill the routered seam gap.

Don't go all the way through though 'cause then there's nothing holding the epoxy back from simply running down in the inside of your planking.

This kind of thing is common for decks and hulls but instead of thickened epoxy a wood spline is epoxied in place into a saw kerf that 'freshens' the joint surfaces. In your case the scarfs aren't long enough to deploy a circular saw for the kerfing, why I suggest a 1/8" router bit.

Find a good source for carbide 1/8" diameter router bits or better yet up-twist carbide end-mills. Notorious for being easily broken but superb for the operation being contemplated. End mills are tougher than single-edge router bits and don't clog as quickly from the stuff being removed. The up-twist are essentially self-cleaning but be prepared with proper PPE 'cause you'll be getting all the dust they kick back into your face.

And don't force 'em. They'll do the job but if you force the feed they'll break well before they dull.

Or haul your boat out & strip off the epoxy paint.

But that won't do much for the epoxified scarfs, will it?

Can you post a pic or two of one of your scarfed planks that's popped? That'd be of help knowing what it is your facing.

[Leviathan]

Re: Caulking Problems

Well I'm afraid I don't have the gonads to do such aggressive things to a yacht that I consider to be a national treasure of the United States The trees used to build this yacht were 1500 years old before they were cut, and then the wood was dried for 30 years before being used to build this vessel. If I do something so aggressive that turns out to be wrongful, this yacht is irreplaceable.

[Ian McColgin]

Re: Caulking Problems

A few years after I started using the method I sketched in #10, WoodenBoat published a description of what Gannon & Benjamin called the "hide a butt" to repair/replace rotten plank ends. It's essentially the inside version of what I did on over a hundred rot repairs.

You might use power tools to fashion the insert but it's really as fast to do by hand. The faying surfaces need to by good with clean thin glue lines.

[wizbang 13]

Re: Caulking Problems

A little bit of epoxy is not a good thing . That includes epoxy “paint”
The national treasure is sixty years old .
How pretel were these planks kept tight originally? Reef the buggers out and recaulk them then. Or slap a dynel patch on the top

Three inch thick planks PLUS a structural ceiling?
…. and paint her white.