In this question someone living in Phoenix, AZ asks about temperatures and how they can effect your body work and painting.

I’m doing a project outside. I can shade it to get out of direct sun exposure heating up the panel in the work area, but it’s hot outside.

I need to shoot some epoxy and then add bondo … I hear about restrictions regarding the temps being too low for some of these materials, but how about too high?

I’m assuming it will speed up cure times quite a bit for sure.

When does it get too hot to perform body work?

This is an important question for both the professional and the home hobbyist. In most areas of the country you can expect a few weeks in the summer that are better off spent inside an air conditioned building with a cool drink.

Many smaller professional shops consider both the worst days of winter and summer as seasonal times that they just need to close up or reduce the workload. They do this for the benefit of their employees and for the customer.

In addition to the heat comes humidity so for people living in northern areas of the country high humidity can cause blushing of clear coats or other defects but since this person is in Arizona humidity is not a problem.

Most manufacturers will give you a material data sheet that describes what temperatures the product is best used at.

Lower temperatures are a serious concern and you should not paint or use body filler below about 60f ever. In addition you should not try to over compensate for lower temperatures by adding more hardener either in your filler or paints.

Higher temperatures are often just as bad.

You never want to work on a vehicle that is hot to the touch. You never want to apply filler or paint to a vehicle that is or has been just sitting in the sun. You will end up with material that pops off the vehicle 6 weeks down the road or paint that drys like sandpaper.

With that said you can normally work up to about 95f and  in some instances slightly higher but over 100f in any location you are really just asking for trouble.

To compensate for higher temperatures you need to formulate your hardeners and reducers must be matched to the temperature. There are solvents that will evaporate slower and allow the paint to flow but they can only compensate so much. You may also want to use a flow agent.

For fillers you want to apply thin coats and use the normal amount of hardener.  You do not want to use less hardener because of the temperature because hardening of filler is a chemical process it is not the product drying out.

Personally I say go fishing and come back to it later.

When you work in either really hot or really cold conditions you never get the best work and it often wears thin on tempers.