Don't know where I got the idea from, but it's cheap and fast. No waiting around for wax to dry etc. I don't do it often tho...
My understanding of gelcoat is that it's a hard protective layer for the composite materials. Otherwise the mat or cloth would become exposed and the part would fail.
That being said, I've never used it, mainly cuz I can't get it at Home Depot
. I've done the below hood and airdam with HD stuff, mat was from Aircraft Spruce. I wonder, is there any reason I should start to use gelcoats?
I still need to color sand the air dam...I made a female mold for the airdam using the same materials (no masking tape tho!).