Is this paint - or flowcoat?

[Ceirwan]

The removal of some deck bits and subsequent filling of the holes, plus just general wear & tear requires me to renew some or all of the non-skid on my MGC 27.

At some point in the past someones done a very good job of it, but its now starting to wear thin in places, which is quite visible when the deck is wet.
However its hard to tell what they've used to actually do it, it seems a lot tougher than regular paint and also easier to keep clean, so I'm wondering if they've rolled on some kind of flow coat mixed with a non skid aggregate to get a more 'original' look.

What does everyone reckon, is this just a good 2 pack paint with non skid added to it, or is it flow coat with the same?
I've attached some photos below.

I bought some non skid flow-coat from East Coast Fibreglass, but having done a test patch on some wood, the non skid is far to aggressive, so if I did go the flowcoat route I would have to mix myself.

 

[Spyro]

Try a bit of acetone on it. Flowcoat shouldn't be affected.

 

[Ceirwan]

I used some acetone when cleaning up the gunk left from removed hardware, and it wasn't effected.

However I wouldn't necessarily expect to see it start lifting paint either?

 

[eilerts]

Hard to tell, despite a lot of good photos. In the 4th photo there is flaking, that is rather typical for polyester flowcoat if the surface is not well prepared. But the layer also looks a bit thin for flowcoat.

Perhaps it helps to peel of a flake and see how brittle it is. I believe flowcoat will be more brittle than paint. I would also guess that paint softens at a lower temperature than flowcoat when heated.
After years in the sun, there may no difference.

 

[Ceirwan]

Hard to tell, despite a lot of good photos. In the 4th photo there is flaking, that is rather typical for polyester flowcoat if the surface is not well prepared. But the layer also looks a bit thin for flowcoat.

Perhaps it helps to peel of a flake and see how brittle it is. I believe flowcoat will be more brittle than paint. I would also guess that paint softens at a lower temperature than flowcoat when heated.
After years in the sun, there may no difference.

I might experiment with some flow coat and various non skid particles.
My experience with non skid paint has been that it usually has a matt rather than glossy effect (which makes sense given its purpose) and that it holds the dirt.

Whatever is on here is excellent in terms of grip and how easy it is to clean, just starting to wear a bit thin.

 

[William_H]

As I understand it flow coat is really made for painting onto the inside of a molded hull to smooth out the roughness of the GRP on the side away from the mold. This would be done when GRP is still green (not hardened fully) so there is a good chemical bond. So flow coat is essentially just polyester resin with pigment. It is not the best at sticking to any other surface. I would suggest a 2 pack polyurethane paint with something like International Intergrip in or on the paint to give non skid. Very hard and good adhesion. If acetone or similar will not soften the paint that is there I suggest it might be polyurethane paint. ol'will

 

[davesparkes]

It looks as though the original gelcoat finish has been painted using KiwiGrip or similar?

Cheers,
Dave

 

[davesparkes]

https://www.pyiinc.com/KiwiGrip/

 

[Ceirwan]

Thanks, but its definitely not Kiwi-Grip.

Kiwi-grips non skid texture comes from the roller, this stuff has particles in it. Having used Kiwi-grip on the last boat I wouldn't use it again, messy to apply, hard to get a consistant finish and holds the dirt. Also found it didn't stick so well, perhaps because its water based?

I'm fairly convinced its flowcoat now with a non skid added, but I'll try some GRP friendly pain stripper on an unobtrusive section of it.

 

[eilerts]

I see that I missed the last paragraph and the real question.
I would definitely go with PU paint and not polyester flowcoat. The latter is very unforgiving when it comes to pretreatment. As mentioned above its main use is to seal fiberglass laminate. It is basically gelcoat with wax added. Painting flowcoat on unknown substrate is risky.
Epoxy topcoat is another alternative. Some epoxies are formulated to be tolerant to difficult and even contaminated surfaces.

Doing some test is a good idea. You should check how good the old stuff stick to the original gelcoat and what pretreatment you need to do for the new paint.
How about this test: glue a short stick of wood vertical to your old paint, let it cure and break it loose. Does the paint follow and how hard is it to break free the stick? Unfortunately, I have no decision rules to help interpret the result. I guess if the stick breaks, you are fine, if a larger flake follows, you are in trouble.