HI,
Trying my hand at rock molds with a box of scenery products I was gifted years ago. The hydrocal was tightly closed but only half full. I mixed up three batches of varying consistencies given I am new to this. The castings released easily and have great detail but even a couple of days later they feel damp. Some 'ring' when snapped with a finger, others don't Is this typical or should I toss them and get some fresh supplies?
Thanks
Tim
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Give the castings a few days to dry. You can install them if they are slightly damp if you set them in plaster or Sheetrock mud. If you want to use glue they need to be really dry. Really dry makes a sharp snapping sound when broken.
George
Did you shake the container before you poured it? The contents settle and can separate. If they're real thick rock castings, they can take a while to fully dry. You can try setting them in front of a fan or something a little warm, like a heater vent to see if they dry out some more.
If you use too much water vs hydrocal, the casting will remain moist for several days. I found that "wet" castings tend to break more easily when removing them from the molds. It will be fine, but you just need to let it dry longer before handling it. Try using the exact amount of water/plaster specified by the manufacturer. It will seem too thick at first, but it will soften if you mix it well.
Bob
Hi, Thanks for the advice! The directions were vague - no ratios given - but from what you all say my situation is normal. I'll try setting a few from the first day with plaster tomorrow and see what happens.
Tim
The first of the now free videos at the top of the page is Rich Melvin on Hydrocal.
Yeah...back when I was young and skinny! 
CLICK HERE to go to the videos!
Rich Melvin posted:Yeah...back when I was young and skinny!
CLICK HERE to go to the videos!
Wait, you're fat? I don't believe it. Surely you jest.
Hi,
Thanks again, here's photo of my first attempt. The piece in front is next up for some detail. Trying to break up nightlines in the corner.
I've made several rock castings using hydrocal, and they would dry completely within 24 hours. I had success using a ratio of 4 parts water to 10 parts hydrocal by weight.
Well, here's the follow-up photo. Pretty happy with the way it turned out. Thanks for everyone's advice!
Very nice
Looks great Tim. I put off working on the scenery for my layout because I thought it would be difficult. Once I finally got started it wasn't as bad as I thought.
John
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