How to Cast Rock Molds

Moisten mold with soapy water and shake out any water right before

 pouring each mold. The molds must be supported and level.

 Pink foam works great, it’s for support not looks.

 

 

 

 

 

 

 

 

 

 

 

I like to use a small square plastic bucket and a flat wooden paint mixing stick for mixing the Sheetrock 20 drywall material with water. I mix as much as I want to lift with 1 hand. I have also used a plastic flat bottom drink pitcher; the handle makes pouring easy. (Like the ones you see at the hospital)

After pouring the mix into the molds you must continuously tap them with a stick or somehow vibrate the mold vigorously for about 15-min.

Allow walls and Tunnels to dry over night

 

Some of the rock molds you may want to trim to fit a specific location. About 4 hrs after pouring, gently remove rocks from molds.

1st loosen all around edges then all around again before peeling out of mold.

The rocks are much easier to trim and shape while soft.

The portals and walls trim better with a thin zipsaw or belt sander after 72hrs.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rinse everything off in a large bucket use this same bucket for cleaning the molds, sticks. Do not poor this water down the drain, allow time for it to settle, then scoop the water of the top. This mix could clog your drain and hurry.

If something cracks or breaks you can moisten the crack and dust with the dry mix put together and allow to dry.

Even the small pieces can be used on the layout. The scrap material can be added to the molds after pouring to fill the mold and eliminate waste.

The molds should be placed directly into a bucket of water to soak. After 5-10 min. Brush them out a stiff brush rinse repeat several times them remove any loose bristles.