I dunno, can you count to four (or three) hardener pumps after taking a short break? I think you would have to make a very “hot” mix, with more than just an additional pump of hardener, especially when starting with 8 pumps of resin.
It may have been the exothermic reaction wait time, especially if the hardener to resin mix was rich.
In the old poly-resin days, with far less pot life, I’m sure folks enjoyed a steaming, Ow-too-hot-to-hold, soon-to-be hockey puck of poly resin, even when it didn’t eat through the mixing pot.
If it wasn’t way too much hardener/too long a wait I’m gonna lay melted pot blame on the cheap Dollar Store knock-off Solo cup. Do you and Doug shop at the same Dollar Store?
Although. . . . . you say “pumps”. Have you cleaned those pumps, and checked the (5/1) calibration anytime recently? At any time?
To clean the pumps West recommends that the resin pump be flushed with a solvent, they suggested alcohol. To clean the hardener pump flush with hot water (the hardener is water soluable), then flush with alcohol.
Good opportunity to check the pumps calibration while you are at it.
Unless mixing a really rare big batch of epoxy I only use two sizes, and two varieties, of mixing pots. For “larger” batches, Chinet Crystal 9oz cups. “Larger batches” usually meaning 4 – 5 pumps each, especially is I am mixing in flyaway thickeners.
https://www.walmart.com/ip/Chinet-C...uS7UT2Rbwxi-guNwi6RoCUcEQAvD_BwE&gclsrc=aw.ds
Yes, we set out the finest crystal in my shop. Those Chinets are transparent, which is nice for mixing different epoxies and additives, not too static-clingy with silica or graphite powder, reusable at least with the same mix over a few days. Don’t squeeze to hard, they become brittle.
And, for wee amounts of one of the G/flexes or etc, 30cc/1oz graduated medicine cups.
https://www.amazon.com/Disposable-M...pY2tSZWRpcmVjdCZkb05vdExvZ0NsaWNrPXRydWU&th=1
200 each for $9 quickly pays for itself in less wasted resin, especially pricey G/flexes. Trying to mix small amounts in larger pots I have a habit of making too much epoxy, especially 50/50 G/flex.
I don’t even use the graduations; it is easy to eyeball 50/50 G/flex 650 mixes nozzle dribbled into the cup. With thickened G/flex 655, in the toothpaste tubes with a toothpaste consistency, is even easier to swipe off a pea sized Part A dab on the edge of the cup, where it clings, as you squeeze out an equal pea size dab of Part B alongside and mix.