Had a chat with an old timer at NAPA that made me paranoid about primer thickness.

He said he's seen guys lay it on too thick and then the paint blisters months later, and I realized I've been rushing that step for the last 2 years. Any of you ever had a job come back because of a primer issue?

2 comments

2 Comments

the_avery1d ago

Thick as mud more times than I can count" is exactly the kind of thing that worries me... because I've actually seen it go wrong firsthand. Not with my own work, but a buddy of mine laid primer on heavy and had it shrink back weird after a few months, leaving a ghost of the sand scratches visible. You say blistering is from moisture or grease, and you're mostly right, but thick primer can trap solvents underneath if it skins over too fast... then months later when that panel heats up, you get that micro-blistering that looks like a rash. I think a lot of guys get away with it because their primer is thin enough that it still breathes, but it's not a rule you can count on.

xena11d ago

Oh come on, "paranoid about primer thickness"? You've been doing it wrong for two years and nothing happened, right? That old timer probably still thinks you have to sand between every single coat like it's 1975. I've laid primer on thick as mud more times than I can count and never had a single comeback. Blistering is from trapped moisture or grease, not from primer being a little heavy. If your paint is blistering months later, you had bigger problems than primer thickness, like not cleaning the panel right or shooting in high humidity. People blame primer way too much when the real issue is they rushed the prep or the paint itself.