Getting ready to paint my sons 71 truck. What reducer do I need for hot weather (eg. slow, medium, fast). I screwed up when I painted my 56. Bought all my supplies in the winter when it was cold weather, then had a delay and wasn't able to paint until the following summer after the tempature got hot.. I experienced alot of "solvent pop" and ended up having to sand and repaint the entire front clip. I was told I used the wrong reducer. Tempature in TN is in the low 90's. Appreciate some help. maybe even an explanation on why different reducers are required for different temps. Thanks!!

Hump

 

Get the slowest they have, too slow is better then too fast. I normally use slow even with temps in the 70's around here, and just allow good flash times between coats and good set time between base and clear. Too fast a reducer or activator, as well as putting on heavy coats without good flash time between is a cause of solvent pop. If possible I'd try to avoid painting when its hot and humid (high humidity can lead to other problems as well. Thankfully we don't get a lot of days like yours, but did spend a weekend in the garage a few years back in that sheet, and it was miserable, and we got close to that weather this week with plenty of humidity. Trying not to drip sweat on what your painting, or mark up the base taping a two tone, with sweaty hands. Add to that not expecting those temps and I didn't buy the slowest activator, and got some pop on the hood and roof and ended up repainting them. Maybe you can go to the weather site and check the forecast, and kind of plan to paint when it looks like you will have reasonable temps and realitively ow humidity. I like painting early am if possible, critters seem to be stiller, not trying to fly to the flourescent lights, and the sun is down. I find myself checking the weather online sometimes when getting set to paint, Some have an hour by hour forecast with a graph of temp and humidity, often its the other way around here, when is it likely going to be warm enough.
The slower the reducer, the longer the top of the paint will be allowed to stay open to allow solvent to escape, and think a slower reducer also produces a smoother laying paint. but in cool weather, may run or slide easier. I never use a fast reducer, and try to go a bit slower reducer for the temps. The only place where a quicker reducer may be benefitial IMO is when spraying a flattened or semi gloss paint job. They often have a temp range printed on the reducer.

 

[quote=Sore Knuckles;6415392]Getting ready to paint my sons 71 truck. What reducer do I need for hot weather (eg. slow, medium, fast). I screwed up when I painted my 56. Bought all my supplies in the winter when it was cold weather, then had a delay and wasn't able to paint until the following summer after the tempature got hot.. I experienced alot of "solvent pop" and ended up having to sand and repaint the entire front clip. I was told I used the wrong reducer. Tempature in TN is in the low 90's. Appreciate some help. maybe even an explanation on why different reducers are required for different temps. Thanks!!Hump quote]

Slow for warm weather ,,,most likely you had moisture popping ,rather than solvent ...use pleny of flash time in between coats & watch for blushing ..A good dryer is very important ...Humidity will kill you without it ....

Too fast a reducer will cause dry spots & orange peel from poor flow