Have a small repair on fiberglass kayak. Will use Gflex 650 epoxy and 4 ounce fiberglass cloth. BUT the air temp will be only 61F during day with low of 50F at night. Doing mid day at 12 noon. So it will still be curing during the night at 50F. No way to heat garage. No space heater. Now it says you can use a hair dryer or heat gun. I have both of those BUT it doesn’t say how long to use the heat gun. I mean use it for 5 minutes? or how long. Holding a heat gun for a long time doesn’t sound like fun. Heat gun low setting is 500F. If too hot I do have a hair dryer, no idea hot hot a hair dryer is. Plus again how long do I hold it to speed cure time. I would like it totally cured in 2 days.
Oh I tried chatting with west systems and the guy didn’t know and said he would find out and email me BUT no email so far from them.
I used a heat gun on a 50 deg day for a small repair (dime size) using polyester resin. I heated it until the surrounding area was warm to the touch. Cured in a couple of minutes but polyester cures faster than epoxy.
The instructions that come with the unthickened G Flex epoxy warns against heating the curing epoxy to over 120 F. A hair drier should apply sufficient heat with less risk of overheating.
There are a number of things you can do to accelerate cure. First, and most obvious, store your epoxy indoors so that it is at room temperature when you mix it. If you can get a hair dryer or heat gun to your kayak, you can use it to warm the surface you are going to repair before you lay on your cloth. When you mix the resin and hardener in your mixing cup, you can carefully warm it while stirring so that it is above room temperature when you apply it.
I would apply a thin layer of G Flex before you lay on your cloth. Warm that with your hair drier until it has cured to a tacky state. Then lay on your cloth and wet it out. After wetting it out, waft the hair drier over it again. If you can, repeat the warming process every hour or so.
I think with periodic careful warming, you will have no problem achieving a hard cure within 2 days at those temperatures.