Filling wholes left by the removal of seacocks

[david clack]

I have a small clinker doube ended yacht rather like a Scandinavian Tumlare and believing that the fewer holes in the hull of a wooden boat the better have decided to remove the heads. I have taken out the seacocks and am left with the two through hull holes. My question is what is the best way to fill them. The planks are quite narrow, about 4 inches wide by 5/8 ths of an inch Mahogany and I am wary about cutting them further to fit diagonal graving pieces.If I fit backing pieces on the inside will it be o.k.to glue in circular plugs?
Is there danger of the plan splitting over time?
What is the best type of glue to use?
I am concerned that in the English winter I wont get the planks dry enough to use epoxy ( I dont want to let the boat dry out in any case)What would be the best bedding to fit the wooden backing pieces on?
Any advice appreciated.
Cheers David

[Thad]

Circular with backing block is best. If you fasten the plug to the block and the block to the plank you could just caulk with cotton and compound. Epoxy should adhere to damp wood if not wet. Polyurethane adhesives like 5200 will definately work too if the inside surface is clean.

[John R Smith]

I agree with Thad's method on this. Balcotan (glue) will work OK on damp wood, whereas IMHO Sikaflex and 5200 type things don't like damp and will peel off again.

John

[Carlsboats]

I have filled planking holes this big a couple of times. Had good luck by fitting a round plug, then adding a backer block. The block should be as big as you can make it, to give you plenty of room for fastenings. If you can get to clean wood on the inside of the hull, glue as well as screw it down (I like resorcinol for this, as it is really waterproof). If there is any question about the integrity of the glue surface, through bolt the backing block and set it in bedding compound. It is important, of course, for the backer to be shaped to fit tight against the inside of the planking.