Is there anyway to tell if there's already a barrier coat?

[ForeverDes]

I'm stripping my boat to repaint, and I think there could already be a barrier coat under the soft bottom paint. The soft paint comes off pretty fast with a random orbital sander and 80 grit paper, but the layer under that is very hard. I've stripped some of the topside paint down to fiberglass, and whatever is coating the fiberglass on the bottom is much much harder, and in pretty good shape, with no cracks, flakes or loose patches (So Far).
Of course, if I can get by without applying new barrier coat, I'll save considerable $, and not stripping that very hard layer would save me considerable time as well.
So, how can I tell if it's a barrier coat?

[Rumrace]

Year and brand if you mean vynlester. Not all skins are equal and hand laid on on glass are so thin and inconsistent they become brittle and a second coat gives you a fresh skin to paint on. If you have any pox the barrier coat is non existent or took a hit and was repaired poorly.

[JimsCAL]

If the paint on the bottom after stripping off the sofft bottom paint is in good shape - well adhered, not peeling, smooth, etc. I would just sand it put on fresh bottom paint.

[ForeverDes]

Originally Posted by Rumrace

Year and brand if you mean vynlester. Not all skins are equal and hand laid on on glass are so thin and inconsistent they become brittle and a second coat gives you a fresh skin to paint on. If you have any pox the barrier coat is non existent or took a hit and was repaired poorly.

It's a 1959 Boat, made long before vinylester. No pox, blisters, flaking, chips or cracks, whatsoever, so far.

Originally Posted by JimsCAL

If the paint on the bottom after stripping off the sofft bottom paint is in good shape - well adhered, not peeling, smooth, etc. I would just sand it put on fresh bottom paint.

That's what I'm hoping as well. It was on the The Great Lakes its whole life, hauled in the winters, so it's always had a chance to dry out between seasons, if any water penetrated, so I was concerned no one ever bothered with a barrier coat.

[ForeverDes]

By the way, when I say barrier coat, I mean an epoxy coat over the fiberglass gelcoat. I never considered vinylester a barrier coat, although I see how it could be phrased that way.