Transom Thickness

Filling in my stern drive hole.

Core in transom is about 1 3/4" and outside glass is almost 1/4". Inside I've sanded the glass off down to the core already.

Rest of transom is wood and solid so going to keep it wood for now. When I have to replace the transom at some point in the future I'll switch coring.

Whats the better option to get the core thickness?

(4) 1/2" ply and sand it down til its level with the transom core

(3) 1/2" ply (1) 1/4" ply I don't really want to use 1/4"

(2) 3/4" ply and (1) 1/2"?

 

I don't think the exact layering of the ply is going to amount to much. I would suggest beveling the existing glass with a 1:12 bevel (3" per side bigger for 1/4") and starting with the biggest piece of glass first. Also make sure the core ply has 'drank' enough resin before the glass goes on so it does not pull it all out from the glassing.

A buddy redid their whole transom, ply portion was 2x 3/4" + 1x 1/4" bonded with epoxy. I was given the extra 3/4" ply for bringing resin and helping with the lam, which got me through a job I needed in my boat with still some left over.

 

I beveled 4" around not sure if over kill but was planning on 5 - 6 layers in and out of 1700 depending on how flush it came out.

I just wanted to get the core as close as possible so I had flat surfaces to glass. But if you used 1/4" is ok I don't mind doing 2 layers of 3/4 and 1 of 1/4 that should be pretty close.

 

It depends on whether you need any strength, but I'd prefer to use less pieces, so 2x 3/4 plus 1/4". If it needs strength; I'd decore the old wood and leave the core in the middle if it exists or decore in a fashion that provides best strength and I'd only use epoxy for keyhole repairs.

 

Well guess maybe I should post some before and after. So I can feedback on how bad I did LOL. Gotta lean somehow.

Spent couple hours yesterday getting the core cut out to the funky shape of the out drive and laminated them together. Should be cured today so gonna give it a go today after work to at least get the core glued in and hopefully one side glassed. I doubt I'll have enough time or energy to try to glass both sides.

Going with epoxy because I have no idea what was used on the transom. It was re-done before or at least the out drive was changed I uncovered some plugs for different shield bolts while grinding away.