Originally Posted by leeave96
My Boys and I need to paint a wooden garage and here it is in December. We are looking at outdoor temperatures between 40 and 60 degrees through out the next few days. The building is already primed and ready for top coat, but the temps have fallen as per above. I've got Valspar exterior paint and the can says you can paint down to 35 degrees, but I'm a little worried even 45 or 50 degrees might be to cold for latex paint. BTW, the siding is T111.
Any tips, advice or suggestions for cold weather painting would be most appreciated.
The best advice one could give for painting latex in cold temps is to wait until they're warm temps.
Given the temperature range you've described, you'd probably be OK to go ahead and paint latex with few problems...However, surrounding air is not the only temp you need to be concerned with. In order for a latex coating to coalesce properly, air, product and surface
temps need to be above 35 degrees - during application and the critical few hours after. That means if the temp drops rapidly or frost settles during this dry time, some funky things can happen to that film. Evidence of a coating that has not coalesced properly may be splotchy appearance and premature chalking, little to no stain resistance, diminished flexibility that could result in peeling (which would only be a problem if you were to paint over a wildly expanding substrate such as, say T1-11 siding).
I sometimes kinda resent manufacturers that market exterior products as low temp - not because they don't work, but because they know their market will always push the limits of what's printed on the can. When we used to say "do not apply below 50 degrees", we knew people would be painting into the low 30's. Surprisingly, there really weren't that many problems doing that. But, now if we say "may be applied down to 35 degrees", how far do you suppose some will push this particular envelope?
Coalescence issues are not easy to repair. If you experience problems, an existing coating that hasn't properly coalesced really doesn't provide a solid foundation for a new application of paint or primer next season if it's needed.
As I said earlier, you'd probably be OK - but I'm always overly-cautious with temp-related concerns, and I HATE to paint things twice. Good luck and I'm sure you're gonna hear some opposing view points on this thread.