Looking for advice from the painter crowd on Humidity and priming of raw (new) steel with the typical automotive primers, is there issues with trying to lay down some primer in high humidity? I forgot the name of the product but its a typical high build sandable automotive grey primer all we have been having the past 2 months have been rain, and today was no different..seems like 3" of rainfall in just the past few hours what say you?
Biggest reason I have a window AC unit for the shop. Not to cool the shop (crazy insulation, so it stays pretty cool) but to decrease the humidity in the shop.
Im well insulated, but i dont think that helps much with the amount of precipitation we have had..its just crazy wet up here I have a humidistat in the shop..im afraid to look at it should i just go for it? does primer behave badly in high humidity?
I say this...heat the garage and dry it out. That way you have no issues. It was a bigger problem in the days of lacquer primers but trapping moisture is never good. I forgot what your exhaust plan is but with temps near 60deg you should heat up fairly fast. Get some air movement to go with that heat and you'll be fine. You have a propane torpedo heater, right? And a wood burner too?
Oh hey thats a great idea.. I could fire up the wood burner..and paint in my shorts the humidity is up around 78 to 80% at this point even with my over head fan on all week so the possibility of trapping moisture in the primer is a concern?
I think I'd be more worried with top coat. We've primed near 80% humidity before. Never noticed an ill effect. Highlander has a great point/thought though. Dry it out some with the wood heat!
You want it warm anyways bro. You're probably shootin a "4 to 1" type of urethane primer, right? 4 parts primer, 1 part hardener (catalyst). That shit doesn't really like cool temps and it may "skin over" and trap solvents if it's not warm enough. 65 degrees MINIMUM. It's what, 55 outdoors right now?
Yeah boss, yer right. The Temp. sure did drop after that front went thru..and its not warming up again up here until next week..than it will go from 55 to 85! I was able to shoot it in my shop in the winter , but temp. was my only issue, and that was an easy one with my wood burner. Shit now most of my dam wood is wet guess its time to go score some propane
If you are priming bare metal, make sure that your Primer is Direct to Metal, otherwise, give it a good coat of Epoxy Primer . After 2 hours, pour on the 2k primer. Humidity doesn't play a big role in priming. Air flow, temperature and dry time are the important factors. Air flow across the car will "wick" the moisture out. I hope this makes sense. Good Luck, VR&C.
Back in the day when I was shooting laquer I always ran the heat to burn off the moisture. I ran it up to 80 or 85 degrees and I didn't run exhaust fan till all primer or paint was on the vehicle. Then I'd give it about 5 or 10 minutes and hit the exhaust fan. If you run the exhaust while you're still spraying then you are sucking humidity right back into the shop.
I pulled off of it guys, after the weather went thru, the humidity went up to 100%..at 62 degrees. and i didnt feel like heating up my shop to sweat like a june bride while priming.. thanks a ton for all the advise and ways to work it maybe tomorrow
i have found that urethane paint and primer actually dry faster in higher humidity. never can get it to really flow.
They say the dumbest question is the one never asked, so, excuse the dumb question from a guy that has never painted with anything but a rattle can: Hopefully I'll be painting my car soon and I live in really high humidity area between the Pax River and the Chesapeake Bay. I've noticed water based paints being used more lately and wonder if that would be a good way to go in high humidity. After all if your spraying water...
bare medel MUST have etch primer sprayed on first. then a 2K primer over that. its Fin primer humidity will only effect the flash time in between coats. spray it on let it tack (when you toutch it with your finger its sticky like tape) and spray another coat or just read the proper flash times for tempitures on the applacation guide that you can ask for if your buying quality primer at a REAL paint shop. no need to get tec. with primer your sanding it after just get proper flash times and your golden dude
with the newer paints, it is more important that the air in your spray hose be dry. use a water separator and a inline dessicant dryer.
use an etch primer first (the transparent green stuff that stinks), let it flash and then 2K urethane primer. If you have bare metal it has flash rust on it whether you see it or not, and really should be etch primed, its designed just for that. You can use epoxy over the metal then prime but it doesn't adhere nearly as well as etch primer, and etch is much more forgiving to apply..
Progress is good. Doing the same thing myself now. Media blasted, 2 coats Epoxy, Filler, 2 coats of Epoxy, 2 coats of high build 2k Primer sanded to 220 grit. Only a few small imperfections that showed up blocking the 2k. I need to work on those and shoot on more 2K then paint. Never done any of this before temp was around 80 degrees not sure on humidity but its all pretty forgiving so far since it gets sanded on anyway. Primer is very easy to shoot comes out thick and orange peely but sands easy.