Treating transom

[dynamic37]

I have a 12 foot Eurovinil inflatable that was in need of a new transom. I have made a replica of the old transom. I used good quality plywood, but not marine grade. The question is how to treat it. I am planning to use epoxy to waterproof the transom and finish with two component polyurethane boat paint.

The transom is fairly thick. The main part is 24mm, and the bottom part is 48mm (two pieces of plywood laminated with epoxy).

I started with a fairly thin epoxy solution so it would fill the wood grain properly.

Question 1: Should I use fiberglass cloth on the whole transom, or is it good enough to just use epoxy? I think the transom is strong enough as it is, since the old transom was only treated with laquer.

Question 2: According to the factory, the bottom cloth (the "floor") of the boat is not glued to the transom, but fastened with screws. From what I have understood, there is a piece of plywood that covers the PVC from the "floor" so the PVC is screwed between this plywood and the transom.
I am afraid this will lead to water entering and destroying the transom. Wouldn?t it be better to glue the PVC to the transom?

Any feedback greatly appreciated.

The old transom

The new transom (this side has been treated once with epoxy, but not the thick part at the bottom)

This is how the factory told me the bottom PVC was fastened

 

[kandil]

Re: Treating transom

Hello and welcome to iboats this a nice job you did with the transom it will be best if you can cover the whole piece with fabric and FG maybe not the grove part and then you have to paint it to water proff it. but you could just paint it and I would use the screws again just pilot hole the holes with a Small drill bit so you don't split the wood and use some good 3M sealant on the screws good luck

 

[dynamic37]

Re: Treating transom

Thank you for the reply.
Just a few questions:

1. What is FG?

2. Acording to some service paople at the local Zodiac store, I will risk the whole floor PVC falling off the transom if I do not glue. It is because of the weight of people pluss the movement from the outboard and the sea, they said.

I am thinking that the weight is on the wooden floor boards that are not actually touching the bottom PVC (they are wedged in between this material and the tubes). Any thoughts on this?

 

[oops!]

Re: Treating transom

hi.....fg is fiberglass.

the epoxy coating you are using is plenty good......the best water penetration barrier with epoxy is 4 coats.....as for the fiber glass....i would use a thin veil woven cloth for that ...(the stuff you get in wallmart or home depot in small packages) do not use chopped strand matt.

im not a inflatable guy......but i think you could ude the standard rule of thumb with your boat........replace what was there.
that means.....as far as the joint....just duplicate what the mfgr's did

 

[dynamic37]

Re: Treating transom

Thanks.

I have decided to go for no fiberglass except all around the edge (it will probably help close the exposed laminate to the elements). The only reason I wanted FG was for strength, but I think the transom is plenty strong enough.

I finally managed to find some images of Eurovinil boats showing how the transom is put together (had to do the search in italian). The photos are not my model, but it looks like it is the same construction. The extra plywood is thinner, so I might go for the kind of plywood they use in concrete construction. I think it will fight the elements pretty good. Only problem is design. I am painting the transom black, and the other plywood is dark brown.