I must note that for like $10-20 you can easily make a curing box
Go to home depot/lowes or whereever. You're looking for the 1/2" or 3/4" rigid foam insulation in 8'x4' sheets. They'll even cut it for you!
I wanted a taller one, so I got 2 sheets. the sides are 4' tall and 2'8" wide. The bottom and top are 2'8" wide. Duck tape the whole thing together. With leftover scrap make a shelf over the heat source so drips do not hit it. The sheets can easily be cut by scoring with a utility knife and breaking along the edge (put the piece on a table with the scored part on the edge and just push down quickly. Should break cleanly.
Duck tape it into a box shape. Make sure it is sealed pretty well. Cut a hole in the top for a thermometer (I used a candy thermometer for like $1.50). Make one wall a door by making a duck tape hinge. With leftover foam you can even make the door seal better by making a dovetail style seal. Cut a hole for a cord in one wall and put your heat source inside under the shelf you have made. You can use 100watt lightbulbs (or 300 watt or even a small heater if you're careful). Since the heat source is seperated by the shelf the heat should be relatively even throughout the curing box and since the temp is higher than normal the cure should be pretty rapid. Cover anything that might get resin on it in plastic since polyester resin can eat through some foams.
Using this method I get the inside of mine up to 130-165 degrees and cure 24 hour epoxy for another layer in less than an hour and fully cured in less than 4 hours.
I must note that be VERY VERY careful to make sure it doesn't get too hot inside. The adhesive of some duck tapes will turn to goo at higher temps and the shelf will fall. The foam insulation can take quite a bit of heat, but make sure the heat source is not aimed at a close wall nor close to the wall. The foam might deform a little, but this is mostly a problem with the door. I secure the door shut with more duck tape (with an end folded over so i can grab ahold of it) along the side and top. Always be aware of potential fire hazards. Know where your fire extinguishers are. Some resins are flammable (I think polyester resin is) and so I'd be careful about heat sources near it. It also cures plenty fast so I wouldn't worry too much about more heat if you're using polyester resin.
WARNING!
This is a huge one. The foam insulation is flammable. DO NOT OVERHEAT IT! The ignition point is much higher than what you'll be putting in the box (unless you're ruining pieces anyway and crazy to boot...the point is over 500 degrees F for the insulations I've looked up). Put the heat source on a board to keep it off of the foam as well.
I suppose I could make a tutorial if there is much interest.