Could 3M dry guide coat trapped in the surface of the filler have caused my problem?
The reason I ask is that after 8 days of drying in 90 plus daytime shop temperatures and 72 hours under a lamp to keep the surface at about 120, I went out wiped the area down with solvent, then waited 3 hours, in 90 degree temp and very low humidity, I sprayed epoxy primer, not reduced, and got the same result, beading of the primer on the surface of the filler. Grrrrrr!
Today, I sanded out the problem area filler, refilled the area, sanded to 320 then rubbed the dry guide coat on. That's when it hit me. This could have been the problem. I had been racking my brain trying to figure out what had contaminated the surface of the old filler and when I rubbed the guide coat on, the filled area took on the same mottled appearance of the old filler.
I've since sanded the area with 400 and will wait overnight before spraying primer again.
I've used this guide coat throughout this project and never had a problem so I'm still puzzled.
Any thoughts?