How low to go on temp.

Just wonder how low is an aceptable temp for fiberglassing? Monday is  high of 74 low of 36. It looks like 30' 40's and 50's at night straight into May for me. I really want to get moving on this project but don't want to screw it up by epoxying in cold temps.

Maybe I'll try to get a sheet on the bottom side of the deck tonight. low of 55 and doesn't really get cold till tomorrow night.

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RE: How low to go on temp.

Do the work during the warm part of the day and don't worry about the lows. The warm temps will get the reaction going, the reaction will make its own heat and proceed on until it gets so cool that the air sucks the heat out of the reaction.

At that point it will shut down until it warms up again above 60 or so and continue until it gets too cold again. As long as it warms up over 60 each day you're fine.

You might want to keep the epoxy & hardener indoors to allow you to start as soon as you're ready without having to wait for the chemicals to warm up.

Have fun,



RE: How low to go on temp.

   You should be fine with those temperatures. My shop was ~55 all winter when I was doing structual fiberglassing. I am waiting to do my fill coats and finish work until its warm enough to work outside beause at 55 degreees is not practical to put 3 fill boats on in one day due to extended cure times.

If you are doing a clear finish be careful the pollen doesn't get onto the surface before its cured.

RE: How low to go on temp.

   I had the same issue when I was building, outside using MAS epoxy with the slow hardener.  I asked MAS and they said as long as it doesn't get much below freezing at night it's fine, so you should be OK.  It takes a bit longer to cure at lower temperatures. 

RE: How low to go on temp.

   I remember using one of those electric oil filled radiators to slow done the cooling of my garage.  I would also micro wave my epoxy briefly to warm it up, so it would flow better & so I could mix it easier.  I would just pour a little into the paper or pastic cups I was using (it may have been old yougert containers) and but in the microwave for  12 sec or so. I would only warm it enoughf to flow better.

Others have used spot lights to warm the boat.

RE: How low to go on temp.

   Lazlo nailed it, but you kno what - run a spaceheater at night. Won take much to keep it 60 or above. when you go to work,  shut it off.  At months end its chump changeon the e- bill.  However - make sure of two things:


1. you have a smoke detecter in th event of ____ happens.

2. its clear of hanging drapes, a nearby whatever


they are safe but ive seen two in ten years flame out and die.



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