Every proper fire needs a good ring of stones around it to keep things contained. So, we broke into the scrap chunks of foam to make some rocks.
First up we cut / broke scrap foam into pieces that were roughly the size we wanted for the stones.
After sorting the pieces into similar shapes we roughed up the surfaces to be glued. Next we glued the pieces together using Gorilla Glue White glue. This glue works well on pink foam, just remember Gorilla glue requires moisture to cure, so each piece was wiped with a wet cloth to start with.
After applying the glue the pieces were held together using clamps. You can also use wooden skewers inserted through the layers to hold things together, but they will make sanding and shaping more difficult.
Once the glue cured it was time to shape our rocks. Shaping was accomplished mostly with an orbital sander with some heavy (60) grit sand paper. Make sure to do this in a well ventilated area, and to wear a mask. Do not breathe in the pink foam dust.
When shaping rocks, make gouges with the sander, round off any square edges, and generally just play around until you have something that looks like a rock.
There’s really no reason to worry about smaller gaps and holes in the foam, they will either be filled in by the finishing steps, or remain and just add imperfections to the stone surface, which adds character.
Once the shaping and sanding was done it was time for a protective coat. There are many commercial “hard coat” products on the market that can be used, but a tried and true home haunter favorite is “Drylok” masonry sealant. That’s what we used.
We applied a generous coat of drylock to the face of all of the stones. There was no reason to do the back side as these stones are going to be mounted later to the fire framework that will support the cauldron for the cauldron creep.
Once the Drylock coat was finished it was time to add some detailing. These rocks were to be placed around a fire pit so we wanted them to look sooty and ashen.
Using cans of black, white and grey spray pant we applied light texturing by holding the can a few feet from the rocks and applying light mists of paint spray. It takes some practice to get the technique down, but if something looks too dark or too light go back over it with some other colors. They are rocks, there’s always variations in colors.