Recommended fiberglass replacement - transom

[77mutiny]

Hey everyone, i'm getting ready to put the new transom in my 77 bayliner mutiny 17ft runabout.
Let me preface my question by saying that i've searched the previous threads a bunch, but it's always hard to try to assume that something that worked for one boat will work for yours. But thanks for all the help from the boat pro's on this site.

So, it was either a 3/4 or 1inch transom, it was too rotted to pull out in one piece, i had to chip it all out. I plan on using west system epoxy, and marine plywood to replace. There will be a 90 horse johnson outboard going back on it.
I've sanded the transom down, and a couple inches on the sides to adhere the glass, i plan on using wood flour to make peanut butter to seat the transom.
i need to know what should i put between the wood and the transom, it is a little bittle "wavy" from sanding, not too much though.
and the what type of glass is recommended for transom? biaxial, woven ect ect?? I'll probably put two or three layers......
And if i get marine plywood, should I coat it with anything before i lay the glass over it?
Thanks in advance everyone.

 

[oops!]

Re: Recommended fiberglass replacement - transom

thata a lot of questions....but here goes !

for the hull thats wavy....use peanut butter...(use the search if you dont know what it is) or two lavers od 1.5 oz chopped strand matt......

that will "fill the voids"

do this just before you install the new transom ....that way you will get a chemical bond .....using epoxy....it will last forever.

the fav cloth around here is a bi ax product called 1708......

one layer covering the transom will do......2 is super strong and waterproof.

3 is way over kill.

it is standard to coat the ply all over....the edges and back and front....

you want to protect the transom from any chance of water getting in behind the glass......

 

[77mutiny]

Re: Recommended fiberglass replacement - transom

got it, thanks for the quick response, since i'm using peanut butter for the seating, i'll just go that route for the "waves".
So how many layers of epoxy should I coat the ply with before i glass it in?

 

[oops!]

Re: Recommended fiberglass replacement - transom

try to get 3 coats on it....i read a chart that showed 3 is allmost 5 times the protection as 2

 

[77mutiny]

Re: Recommended fiberglass replacement - transom

should i drill a couple of holes in the ply to allow the peanut butter to escape when i clamp it in to the transom?

 

[oops!]

Re: Recommended fiberglass replacement - transom

i would pre drill all thru hulls.....like the tie down eye hooks....this will allow any exess to squeeze out......it will also allow you to use a full bolt thru the transom to squeeze it togeather......

if you use peanut butter.....make sure the mix is flat......if you glob it on then apply the transom....there will be air between the hull and the transom....

really coat the inside "touching areas" with epoxy....make sure you get a good bond

 

[iwombat]

Re: Recommended fiberglass replacement - transom

On those thru-holes. Pre-drill them oversize. Then, fill them back up with peanut butter and drill them the correct size.

Ta-da! Waterproof holes.