Interior Plywood surface repair Qs

a previous owner ( twice removed) put stick-on vinyl square tiles over what I assume to be water damage that delaminated the first layer of the plywood. I removed the tiles and discovered this


I have tested the ply and both the surface and interior is now dry, after I checked and refurbished ALL the previous water ingress points.

note that I have to do some external hull repairs using full epoxy ( west Systems) - so have ample supplies of that and fiberglass fabric

I want to get your advice, to discover IF I am on the right track re repair - or if there is a smarter way do doing this,

My question start

1) shall I carefully peel off the loose layer pieces/patches entirely - and if possible reapply with epoxy and good pressure with appropriate clamps ? NB : I note that some small gaps in the surface layer fully visible elsewhere ( no photo as yet) appear to have been filled and patched with some form of thickened epoxy, and had some form of peel ply and surface clamp to make it conform to the surface - these have not re lifted

2) should I also map out a full coverage patch ( all of the panel visible) and then epoxy ( 2 pack west systems) to/over the original ?

3) I note that in one corner (only so far) the Laminex/Formica (Blue) will move in under pressure, so I'm thinking that I will need to remove the whole blue panel there and then patch and reapply.

advice - opinions please - or even if there are better forums in which to ask this question.

PS the hull is structurally all polyester resin/fiberglass over Airex foam, so this ply is mostly cosmetic

 

If only the first layer is delaminated, you can glue a thin plywood over it. They also make self-adhesive veneer that works well.

 

The most significant word in gonzo's post is "If". Do a really thorough investigation before anything else.

 

There is a good chance that wasn't marine grade plywood to begin with. Many boat interiors are treated just like house interiors. Direct water contact isn't expected to happen. That is to say, less expensive options are often used. If you are secure in your inspection and repairs of any leaks, you may choose to not go overboard (enjoy the pun) with a fully waterproof repair. I wouldn't use particle board or OSB, but a good cabinet grade plywood would give you over a decade of great performance. In fact, the resin filled gaps you're describing might be the inner plys of a low grade cabinet plywood.