Im new to the whole epoxy resin scene so i figured id do some ding work to get used to working with it. the first few i did were nice, very clear, and rock hard. the last one i did didnt set right and is still gummy. its certainly deepr than the others dings, but everything else was the same. could it be an error in the mixture? any advice?
im about to glass my first entire board with epoxy and am trying to avoid disaster. thanks a bunch.
jrz.
your mix of epoxy:hardener was off.
it’s too cold.
if it’s the first one, clean it all of with some denatured alcohol and try again.
if it’s the second one, put a hot lamp over it and see if that helps things along.
so what is the ideal temperature for epoxy resin?
you might not have mixed thouroughly either. I always use 2 cups/buckets to avoid pulling some unmixed product off the sides of the container.
take bucket one, measure and stir.
transfer to bucket 2, continue to stir and dump
70-degrees +
i needed to patch a big ding in advance of a cold front swell, but i waited too long and the front had already come through. temps were down to about 50-55, so i took my desk lamp (which gets very hot) and set it up over the repair. i had actually done two repairs on the bottom in different places. the one under the light cured in a couple hours (just as it should), while the other one was still very gooey. i then switched the light onto the other ding, and an hour later it was cured solid.
you might not have mixed thouroughly either. I always use 2 cups/buckets to avoid pulling some unmixed product off the sides of the container.
take bucket one, measure and stir.
transfer to bucket 2, continue to stir and dump
hi, allan. yeah, that was part of my thought process in #1, but i didn’t really explain the details. every bit of epoxy needs to be mixed with hardener, or else it will never set up. so, whether there wasn’t enough epoxy to go around, or it just wasn’t mixed thoroughly, the result will be the same gooey mess.
ahhh, so as opposed to throwing a little extra catalyst in like with PE resin to help expedite the process, i need to really ensure that 2/1 ratio?
the gooey ding has now been sitting for over a day or so, can i heat lamp it, or dig it out and go fresh?
thanks for the help, this site is amazing.
Humidity isn’t your friend, either.
If I have to do an epoxy repair in the winter, I lay it down, tape a sheet of plastic tightly over the repair, and then - like Soulstice - set a halogen shop light 8 or 10 inches away. Finished nice & fast, and with the plastic, usually no sanding, either 
I make a square of plastic & tape the perimeter on 3 sides. Work out all the bubbles & tape down the 4th side. Then, pulling tight, enough tape to cover the whole thing. Even on flat spots like the bottom, it will work.
BTW, the plastic trick also works to turn lam resin into sanding resin, if that’s all you have for a polyester repair. All you need to do is keep oxygen off it while it goes off - plastic is just as good at that as wax is Plenty tack-free for sanding…if you have to sand at all. On rail repairs, where you can get really tight taping, sanding is almost never necessary.