One more thing to worry about

[PonoBill]

I noticed my epoxy is being a bit more random on when it kicks, even though I'm warming the resin in a water bath to 85F and heat the shop to 70F. Today when I was weighing out a batch I hadn't put the part B close to my weighing area. When I returned from fetching it, the resin weight had increased by about five grams. WTF?

I took my little WEST scale apart and found a drop of uncatalyzed resin had found it's way under the scale rail and turned to goop. Weight on the rail would slowly compress it, but it took a while.

One more thing to check every now and then. I cleaned it all up and we're back in business. Today's mix went off like clockwork.

[supuk]

I have noticed resin increasing weight when warmed in the microwave for some odd reason. if I mix 6-700grams it will always increase by 3-4 grams when it comes out. its no issue with that quantity especially with RR.

[Night Wing]

Small un-noticed details have a bad habit of messing things up no matter what field of endeavor. These details are the gremlins of "Murphy's Law". 

[PonoBill]

I know what you mean SupUK--I've seen it too. I suspect the microwave drives out some moisture that the resin picks right back up. I can't think of much else that would account for it. I weigh the resin before I nuke it, then stick it on the scale and watch it do it's thing. Add hardener to the proportion for the initial weight. The saving grace is that its RR, which is super forgiving. I was probably off by ten percent with the recent scale fiasco, and while the time was variable, the stuff still kicked hard. I've pulled sticky cloth off a board two days after it was supposed to kick, but never did.

I quit using the microwave. I have a hotplate so I just stick a pan full of water, heat it to 80F and stick the jug in it.