I’m not trying to be critical or suggest you shouldn’t switch, but if it didn’t harden more and adhere that is a strong sign that, regardless of your previous 5/6 positive experiences, this time you may have any combination of the following:
- not had accurate/precise amounts of resin and hardner
- possibly not mixed well/long enough
- the previous surface was contaminated/not bare wood, etc.
What did you use for release agent?
It’s not uncommon for fishing rod builders to run into the exact problem you described when making batches of finish and epoxy, as with those the accuracy/precision needed is greater.
Hines - no offense taken. Totally fair observations/questions.
The previous surface not be properly prepped (it was -- at least the same way I've always done it) would make a lot more sense if the leftover epoxy had hardened but not the epoxy applied to the right. In the past I've found that MG is pretty forgiving in terms of ratio. It's just a simple 50/50 and I use the little measuring deal that comes with it. So it could be an imprecision there, but seems unlikely. I'm paranoid about it not mixing properly, so I go over the time they recommend. But if I had to guess one of the three options you proposed, that would seem the most likely. But this had been bugging the hell out of me, so I decided to run a little experiment. I took ingredients from the same kit that didn't set right in the rifle and set up three samples: (1) just epoxy and hardener, no dye (2) epoxy, hardener, and the same amount of dye I used over the weekend; (3) epoxy, hardener, and the smallest bit of dye I could apply with it actually being there (it wasn't as dark as I intended, but clearly colored). #1 and #3 hardened as I would have expected in 8 hours. #2 is still "gummy" like what didn't set in the rifle. This leads me to think I either used too much dye and it screwed up the ratio in the rifle itself or there's just something not good with the dye and I used so little in #3 it still set. I'm not a chemist, though, so not sure what ingredients in the dye would affect the bonding/reaction?
