Rock Castings

[Anonymous]

What's the best way to make rock castings? The ones I want to cast offer a particular challenge I think because they are surrounded by dirt, and I want to cast the dirt as well to maintain the natural look. I think it I use the latex it will soak into the dirt and won't be of any use.

[Tracklayer]

Hello banini_jeque. I've always used aluminum foil to make my rock molds by crinkling it up, uncrinkling it, forming it into the shape I want, filling it with plaster of paris then pulling the foil away after a couple of days and wa la. Then I sand, file, spray paint and texture them into the way I want them. It's a lot cheaper than buying a bunch of rubber molds...

Tracklayer

[Anonymous]

Yeah that would prolly work huh. I really like the way these rocks I found look though. One idea was using plastic sandwich wrap and putting latex behind it to hold the form, but I'm afraid that it will distort the details of the rock too much. I dunno though I guess I should just try it.

[Anonymous]

well, the rocks I want to cast have cracks in them. I didn't really want to make a junkyard though.

[selector]

For banini, if there was a way to SPRAY an initial, thin layer of the mold rubber over the are you wanted to model, or cast, and then do several more sprays until you get a layer thick enough to pour an amount that you could use to peal the whole thing off the surface, you would have a super-detailed mold. I am not an expert in this by any means, so I am winging it here. But maybe you could spray a light film of canola oil over the surface first to prevent your first spray coat (paint-like) from bonding with the granules of sand? I dunno.

[Anonymous]

Another challange I face is that the stuff I want to cast is vertical, so whatever I put on it is just going to slide, and I don't want to go spraying oil around in a nature area, although that probably would work if it was flat.

[selector]

Okay, understood. I think you're hooped if it is a vertical surface. Sorry.

Tommyr, yeah, you're right. I responded to this before I got the gist of the other material, and I was really responding to Tracklayer. I agree with his underlying principle, but felt that it was too hasty to jump on the wolfman. I was wrong..hasty myself.