The MAS website has some information that may help you, scroll around here:
http://www.masepoxies.com/Epoxy_School_/Tech_Support_FAQ.html##11

Ric

: I am building in an uninsulated garage and will have to heat it to
: do the glassing. I plan to build some kind of tent around the
: kayak to minimize the space to be heated.
: But heating is expensive. How long is it necessary to heat? How
: much should the epoxy cure before I can turn of the heat? I'm
: not looking for a number of hours (Because it varies between the
: different epoxy-brands), more like at which cure-stage I can
: stop heating.
: The temperature is around freezing at the moment. Without the tent
: (which I haven't made yet) I could only get the temperature up
: to around 14 C (~57 F) with a 2000 W electric heater and a 4200
: W propane heater. But that is too expensive for long term use.
: Btw. does anyone have a description or pictures of a tent-frame
: that is easy to make?

: Palle Dam
: Denmark