This is a fiberglass hatch (race car) that has a thin layer of gel coat on it. I have scuffed it with 150 grit, and noticed this small indentation where the OEM latch would go. I am not using it. The indent is about 1/32”-1/16” and is structurally supported from the underside (I checked). Can I just apply filler directly into the scuffed Gel coat? It would certainly be convenient. I plan to flow-up with an epoxy sealer coat and HB urethane primer (while still in the cure window). Then block sand the whole panel before base/clear.

Have y’all had good experience with thin layer of filler directly on scuffed plastic?

Should be no problem. We fill stuff like that all the time when we are building our latest kit car project. I prefer to use something like a poly putty such as USC Body Icing. Like it a little better than the standard Bondo style fillers because we can smooth/shape it enough for very little sanding. The Icing also has more flex for adheasion.....

Thanks for the response! I will give it a shot! I’m using 3M’s premium select filler. It does go on much smoother than their typical pink bondo brand, and can leave a glazed surface if applied at room temperature. Next time I’m gathering materials, il try the poly putty!

Thanks again!

Yeah, that 3M filler is fine as well.....

Amateur hobbyist so I don’t have a heated, ventilated area. Something I learned the hard way: warm your filler up while mixing and right before applying if it’s cold out. It’s in the mid 50’s here (we are lucky in LA) and it goes on really course with a ton of pinholes if it’s not warmed to room temperature. Gives you a lot of respect for the chemistry when you realize just how sensitive this stuff is.