I've been making polyhedral dice sets (with epoxy resin) for just under a year, and today I tried casting with jesmonite for the first time.
I used a small jar mold instead of a dice mold to try it out. It's about 75 degrees today, low humidity. I filled my mold with water, measured the water, and put the amount into the jesmonite calculator (www.jesmonitecalculator.com). The mold held 25 grams of water, but I entered 30 so I could have a bit extra in case of any problems.
The calculator said to mix 37.5 grams of powder with 15 grams of liquid. I measured precisely, then began mixing by hand.
Almost immediately the mixture was super thick ... like, very difficult to mix thick, and certainly difficult to pour (extremely slow moving). I tried the entire process the separate times, measuring, double checking, mixing both by hand and with a whisk attached to a drill, and got the same result.
Can anyone help me figure out what I'm doing wrong? Happy to answer any questions for clarity ... thanks in advance!