A suggestion......

[oscarvan]

I believe Ed is a member here and my remarks are in NO WAY intended to disparage him or his skills, but after watching the following video I would recommend not "a layer of glass" and some polyester on the plug seam on the bottom, but SEVERAL thoroughly wetted layers of increasing width with several more layers of polyester over top feathered several inches both directions away from the cut. This is a structural issue. The foam plug glued to the bottom of the outer layer, with the fiberglass plug glued on to that with some filler around it is by itself not going to return the strength the original laminate had. It's a sandwich for a reason and the inner layer is as important as the outer layer.... (Think I-beam)

Am I off base here?

https://www.youtube.com/watch?v=20N42OgpTqk

[Boatsb]

That process will not pass many inspections. The seam needs to taper over a longer area and usually an extra layer or two inside are a good idea. It's certainly not the right way to fix the deck under the windlass .

Another DIY turned DIW.

[Photolomy]

I wouldn't describe coosa as "foam". It has quite a bit of rigidity. Nonetheless, yes, I would glass over the cutout piece to tie the bottom skin back together. I wouldn't worry about aesthetics underneath. This is in the chain locker, and even if it extended past the bulkhead, it would still be hidden by the headliner.

I am not sure how much glass he put on the bottom. I am not sure it needs to be as thick as you are suggesting. Given that the original skin is already that thick and the forces on the seam are nothing like they would be if the all the skin was thin.

[rsmith]

I believe Ed is a member here and my remarks are in NO WAY intended to disparage him or his skills, but after watching the following video I would recommend not "a layer of glass" and some polyester on the plug seam on the bottom, but SEVERAL thoroughly wetted layers of increasing width with several more layers of polyester over top feathered several inches both directions away from the cut. This is a structural issue. The foam plug glued to the bottom of the outer layer, with the fiberglass plug glued on to that with some filler around it is by itself not going to return the strength the original laminate had. It's a sandwich for a reason and the inner layer is as important as the outer layer.... (Think I-beam)

Am I off base here?

https://www.youtube.com/watch?v=20N42OgpTqk

Old men with pony tails need to be smacked up side the head

[Pascal]

I skipped thru the video (no time to watch someone talk for 10 minutes about something that could be said in 1 minute ..).

Coosa is very strong and I think an overkill there. I ve used divinicel for core repairs instead. Much better than balsa, lighter and easier to work than coosa or ply. With coosa you way get away without a bottom layer of glass over a small area like this one.

Also I wouldn’t use polyester but epoxy which has much better cold bonding capabilities, important for repairs.

Coosa by itself is very strong and in some applications doesn’t have to be laminated. I have redone my weather board with coosa completely eliminating the stanchions by using coosa vertical posts every 4 or 5 feet. All epoxied together to a coosa base. No glass. Very stiff.

[edward]

Pascal how about a picture ?

[Pascal]

Here you go. It was them capped with a 1x3 mahogany rail

[edward]

Thanks ! Looks great !

[oscarvan]

Old men with pony tails need to be smacked up side the head

Now, now.... let's not be rude. <<After 34 years of corporate hair cuts for a paycheck letting it grow...>>

[Avenger]

Now, now.... let's not be rude. <<After 34 years of corporate hair cuts for a paycheck letting it grow...>>

Ooooohhh, you rebel, you!