Originally Posted by Randy
I've been doing a fair amount of epoxy lately and have been complaining to myself about how slow it kicks off but I'd rather that than the pot meltdown.
I bet you were coating with it. There are ways to speed it up, like faster hardener, warming the resin before mixing or warming the piece you're applying it to before applying. When I coat bare wood, I warm it with a heat gun before coating. Besides faster cure, you expand the air in all the wood cavities and it will contract
again after the coat is on, creating a vacuum that sucks the epoxy in deeper. It also prevents the little bubbles that are the result of expanding air when it warms up from curing epoxy.
Someone wrote about putting epoxy in a bucket of water
. I have seen buckets of ice used for that but you could use hot water for faster cure just as easy.
I have noticed that the more filler is added, the quicker it cures. That one wasn't described in any literature that I found. If I need a lot, I spread it out on a piece of carton for better cooling
. If it's just a bit, I spread it over all the sides and bottom of a mixing cup to increase the surface area.
What unbusted experienced is caused by exothermic heat of course but as he did many similar batches and this problem only occurred with one, there was something different to that one batch. I am not surprised if contamination speeded up the curing process after I saw epoxy cure in a new but cheap
throw-away cup without hardener. Contamination of epoxy is a big problem and a lot of users make many errors. Solvents have negative impact as do your finger prints. Always use clean or new mixing cups/sticks, a new throw-away brush, sand the piece you're working on and use a vacuum cleaner afterward without touching it or wiping with solvent. No tack cloths either.
When I started working with epoxy I made all those errors. As I did more projects and read more documentation
, I changed my way of working and it is now close to how a surgeon operates. Prepare, work clean and fast and clean up fast when something didn't go as planned. It is actually faster and the results are much better. Every joint I make now is stronger than the material and that was often not the case when I just started.