Vodkaman Posted December 6, 2010 Report Share Posted December 6, 2010 Beware of old plaster. It has been a while since I made a PoP mold, so long that I had to look up my notes for the mix ratio. The mold is for another project, nothing to do with fishing, but the information is relevant and serves as a warning. I have never had a problem mixing plaster before, other than when experimenting with mix ratios. When mixing the plaster, the texture felt very gritty and lumpy with very small lumps. The mix seemed thicker than normal and I still had a lot of plaster left to add from my tried and tested ratio. I bottled out and added more water and poured. The mold is fairly large, requiring about 1.25 liters. The plaster never set and remained like a heavy sludge. After two hours I dumped it. I went back to my notes to check, no problem. I then decided to do a small test cast, this time sticking to my notes. Again the mix seemed very thick. After mixing, I reached for my mold container (about 5 seconds) and went to pour. The plaster had set and I could not pour. But, after another ten minutes, I could still dent the surface with my finger (not just my nail). Something was very wrong. I then Googled the problem and discovered that indeed, the plaster can go off in time, re-hydrating itself, plus Indonesia is a humid climate and I bought the plaster two years ago. I would guess that the plaster could be baked to remove the water and make it good again, but I do not possess an oven, strange, but Indonesians do not cook with ovens. Plaster is so cheap anyway, why mess about with it, I will buy more tomorrow. My next bag of plaster will be stored in a sealable plastic container. Be warned. Dave Quote Link to comment Share on other sites More sharing options...
