It is about 98 where I am, in the shade. The heat index today is about 105. My shop is under my house and the temp is about 88. I glassed the underside deck of my night heron hybird and had no problems with the MAS epoxy.  I had no blush issues to worry about. If it is in the upper 90's where you are working that might be a bit too warm. 

Mark 

Chris

I built thru the winter in Michigan.  The MAS system worked as low as 55 degrees and I also did some work in early summer with the shop at 89degrees with 70 percent humidty.  Never any blushing problems.  At 89 degrees you have to be a little quicker getting the epoxy mixed and onto the boat.  I did have one batch get hot in the cup and I stopped and threw out his batch.

Rod

Thanks guys,

  Since it's gotten dangerously hot around here I decided to put off the glassing until it cools off next week. Thankfully there's some small projects on a Pocketship that can be done indoors for the rest of this week. Been a long time since I felt a heat index of 108.

   Chris

When putting epoxy over bare wood, it is most important that the temperature be falling and the wood needs to be as warm as the temperature of the air when you start. Do it in the evening. Otherwise, the subsequent moisture coming out of the wood will be a problem. For me, the epoxy saturates better and is easier to work with when the air is warm, close to 90 degrees. Beware, it will set quicker. I don't epoxy if it is really humid or rainning and I would advise against ever doing the wood sealer coat outside because of the fluctuating air moisture content & pressure.

Dripping sweat on the bare wood will leave little circles.

Lew

I think lew was referring to the offgassing of the wood as it warms up, but he is correct that glassing (especially) should be done as temperatures fall if heat's an issue.

I did glass our Prams in high heat and humidity. Small batches, work quickly, biggest fan(s?) you can find to blow some of the heat off. If necessary keep a cold water bath around for the mix. Don't mix in an icy bath (gets funky), but once mixed, if you can keep the epoxy cool, it'll go further. The reaction is heat-based so if you can pull heat out of the mixed epoxy, you delay setup.

correct,

Lew

I have just completed the glass work inside my Skerry in an unairconditioned garage in Southwest Florida.  I waited till 5PM each day when the temps began falling and worked till 10 or 11PM.  Still hot as Hades but I had no problems.  Mix small (8OZ) batches and pour onto the cloth and spread with a squeege.  You would think that it would cure completely in that temp in 24 hours, so recoat the next AM and there will be no outgassing because you're recoating only what you did the night before.  Then at 5pm coat everything else as temps again are falling.  You only have to worry about out gassing with the initial coat of epoxy or epoxy/glass.