Hello
I bought a rock mold from Woodland Scenics and I was wondering if there is a alternative to using Hydrocal as if you make a lot of rocks it could get to be pretty expensive.
Billy
Regular plaster of paris. I get mine at Wal-Mart.
[#ditto] Have always used plain old Plaster of Paris
Me three! (cheap is good) Mix your plaster into the water. Not the other way around. This will cut down on air bubbles. Lightly spray your mold with “wet water” before you pour in the plaster.
I second the second. I tend to use Plaster of Paris for casting molds. However…if you buy a hundred pound bag of Hydrocal it becomes cheaper than PoP. Now that sounds like a lot but when I was using the hardshell method with paper towel strips I used it up fairly quickly.
Tilden
PofP sets up pretty fast, but that is one more reason I use it.
If you add a teaspoon or two of vinager to a gallon of water and use that to mix your PoP it slows the curing a bit.
Or casting plaster in five pound cans from art suppliers.
Mix in some filler like Vermiculite ( soak it first ).
I’ve used plaster:
Wolfgang
I use pop as most here seem to. I find that soaking the mold in warm water makes it more flexible when it comes time to remove the casting. I also use the really wet stuff I get on top of the mix to prewet the mold, I then seems to pick up all of the detail.
Dave
I use hydrocal. Caboose hobbies sells it in a 10 lb bag for under 10 bucks. Seems to last a long time. The Woodland scenics milk carton stuff is several times more expensive. Hydrocal dries hard and strong.
Joe
Thanks for the info everybody this helps me get steered in the right direction
Billy
Other than price, what are the other differences between Plaster of Hilton (sorry about that) and Hydrocal?
The Hydrocal I get (Scenic Express, I think) says “Lightweight Hydrocal” on it. Is is significantly lighter than PoP?
Does one pick up the details of a fine-scale mold better than the other?
How about setting time and ease of use?
Is one more brittle than the other after it’s out of the mold?