3
So apparently modern car primers don't need 24 hours to cure like the old stuff
Was talking to a PPG rep at the shop last Tuesday and he showed me their test results. Their new urethane primer was fully sandable in 45 minutes at 70 degrees. Blew my mind because my old mentor always made me wait overnight. Anybody else still stuck on old curing times?
3 comments
Log in to join the discussion
Log In3 Comments
miller.avery6d ago
Man I learned that lesson the hard way on a customer's truck. Laid down some of that new stuff, followed the instructions to the letter, and had fisheyes showing up in the basecoat two days later. Had to strip it back down and start over. These fast cure primers are fine for small touch ups or spot repairs where you know the surface prep is absolutely perfect, but for a whole panel or a full job I still give it at least a few hours if not overnight. That time savings ain't worth the risk of a comeback.
5
aaron8966d ago
Learned that one myself on my own truck, had to drive around with a primer patch for a week looking like a rolling billboard for bad decisions.
5
brooke716d ago
Call that rep back in six months and ask how many of those "45 minute" jobs came back with adhesion problems. I've been spraying since 2003 and I've seen this exact song and dance before. That fast cure stuff works great when everything is perfect - 70 degrees, low humidity, clean metal, proper activator ratio. But the real world has moisture in the air, dust in the booth, and panels that got wiped down but not etched right. I had a buddy try that fast cure on a quarter panel last summer, sanded it after an hour, looked great. Then the clear started lifting three weeks later. The old timers weren't stupid, they knew chemistry takes time.
1