I got some pinholes here and there after I spray the clear coat on my part after I pull it off the mold and trim it, anyone might know why that happened? Is it because I didn’t sand my part correctly before apply clear coat?
how do you guys prep the surface before applying clear coat?
did you have pinholes before spraying the clear? If you did, spraying clear wont fill in those pinholes, at least not completely.
i always sand and/or dewax the part before applying clear - i use wax mold release and if any is on your part its going to end it tears. but a light sand will help make any pin holes a little more shallow and hopefully the clear will fill them in, light coats and thin it to its manufacturers limit (eg 20-25%) to help it flow.
This of course is assuming the pin holes are on your part before you start spraying.
if you mean pinholes, like “the clearcoat won’t make an even surface on the part”, then its either not sanded well (i use wet 1200 sandpaper , you can also use 1000) or there is residue from either wax or some other polishing paste.
If it’s a gelcoated part straight from the mold, I wetsand with 400. Spray light passes of the clear and keep a toothpick in one hand. As I see a pin hole developing, I touch it with the toothpick for a second. You’ll see the paint flow into most of them. Then, one final coat of clear usually covers up the “blemish” caused by the toothpick.
Maybe it’s because I didn’t sand the part well enough before clear coat and pinholes were cause by the semi-permanent mold release on the part(I think), the toothpick is a great idea to fix the problem.
Are they pin holes or fish eyes? There is a huge difference. Can you not post a pic? No-one can help unless you show exactly what the problem is…