Sir...why do I get those super small pinholes in my gelcoat repair ? I see them after I start sanding. I get the finish the way I want it...and sometimes if you look hard enough, you can still see those super small holes. Thanks for any info sir.

There's actually a couple things that can cause those. Watch how thick you lay it on, building it up to quickly can trap air and high spraying pressures can cause them as well. Moisture in the air lines can also cause a similar affect.

Build up film thickness gradually and try and spray when its cool out if ya can.

Thanks for the response. I'm not spraying anything...just doing little chip/spot repairs...then sanding. Seems common to get these little porosity type holes. Maybe Im not pushing all the air pockets out when I putty knife the small amount of gelcoat filler in ?