When using a guide coat to identify imperfections, what is the best practice for removing any residual guide coat before applying additional filler or glaze? Is there any risk of surface contamination if you apply body filler directly over remaining guide coat? Do most people sand the low spots or just use compressed air and/or wax and grease remover before reapplying filler. I'm just wondering if guide coat (spray or dry) has caused any issues or top coat reactions for anyone. Thanks in advance for any feedback.

-David

I use dry guide coat and just blow it off well before the next coat of filler. It is a good idea to scratch up any low spots to improve adhesion, but the guide coat itself is compatible.

Thanks very much Chris. I was also able to find some additional information on this topic I thought I would share here:

https://m.youtube.com/watch?v=upka-Sic0KM


From the comments:

Premium Powdered Guide Coat is not charcoal. It is a combination of pure carbon and other items to give you an even spray and will not stain or cause a mess that would come with using charcoal on a repair. Charcoal can leave behind residue that may seep through paint and clog sandpaper. Charcoal can have other contaminants in it that could cause fish eye and other possible imperfections in your final paint job. Premium Powdered Guide Coat has been formulated and tested to make sure these issues do not occur.

I also learned that cheap black lacquer paint can contaminate filler and should not be used as a substitute for guide coat. Although, I know many do use it.

https://m.youtube.com/watch?v=TjKoRI7nG0M


Thanks again!

-David

I always sand off as much as possible.

JCCLARK wrote:I always sand off as much as possible.

X2

A folded piece of sandpaper, light finger pressure to reach the lows spot, a quick back and forth will remove remaining guide coat. You are applying more filler anyway so no damage done.

X3
Jay D.