Butt joint floor repairs

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Butt joint floor repairs

Post by APB » Sun Nov 04, 2012 6:09 pm


I have just acquired Enterprise 15905 which is a need of a little TLC. I need to replace a section of the floor up to about 0.5m form the transom and a section of the keel band beneath. I was intending to remove the keel first then cut the sections of flooring out with a jig saw using the side frame a a guide. The replacement floor panels would then be screwed to the underside of the hog and the frame supporting the transom and but jointed on the other two sides. I intend to use West epoxy with the high density filler powder. Is the butt joint likely to be strong enough if I ensure there is enough glue in the joint? It will be firmly secured to a frame on both sides and is not in an area which is going to be frequently stood on. Also I think the existing floor is about 8mm thick and is difficult to obtain so I was intending to use 9mm plywood and sand to tie in with the level on the underside.

Any advice appreciated.




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Re: Butt joint floor repairs

Post by neil » Sun Nov 04, 2012 6:58 pm

I would encourage you to use a scarf joint - greater gluing surface and no hard point to fracture.
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Re: Butt joint floor repairs

Post by kfz » Sun Nov 04, 2012 7:50 pm

How was it originally constructed? I'd just replicate was there before.

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Re: Butt joint floor repairs

Post by Rupert » Sun Nov 04, 2012 7:53 pm

Maybe use 2 pieces of 4mm ply, with the outer piece piece slightly larger than the inner, assuming you are doing the job from the outside.

Otherwise, yes, I have used butt joints (or more often a very steep scarph), but not on anything bigger than a couple of square inches, as they are far more likely to crack.

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Re: Butt joint floor repairs

Post by JimC » Mon Nov 05, 2012 6:03 am

neil wrote:I would encourage you to use a scarf joint - greater gluing surface and no hard point to fracture.
Agree, the "hard point" is the critical part. You have a surface which moves and bends all the time as crew is jumping all over it, and in the middle of it the butt joint introduces a discontnuous point with quite different properties. So its pretty much inevitable that there will be facture and cracking either of the joint or else of the wood each side of it, depending on where the strength is greater.
So what you need to do is make distribute the loads as evenly as possible so the properties of the floor are as even as possible. So a scarf joint is best, seperate veneers with each one larger than the one before is very good, and two layers of ply of different sizes will probably do near the transom.

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Re: Butt joint floor repairs

Post by roger » Mon Nov 05, 2012 7:47 pm

someone was up early Jim :shock:
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Re: Butt joint floor repairs

Post by poacher » Fri Nov 16, 2012 8:24 pm

The epoxy butt joint will be stronger that the origonal ply. It doesn't even have to be a good fit. If you doubt this do a bench test with a strip of ply, you will never break the joint.
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Re: Butt joint floor repairs

Post by Lukey T » Tue Feb 05, 2013 9:21 pm


Did you manage to get this done? Has it worked? As I think I may have a similar problem on a Mirror

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