Thanks.
The process is actually very simple and easy, it’s just time consuming and takes some practice. I can put together a complete materials list and detailed directions if anyone is interested, but I don’t want to bore those that aren’t. Here is the Cliff Notes version.
Develop a floor plan. Build a frame. Cut/form Styrofoam and/or foam rubber into desired shapes. Hot glue them into the frame. Mix Elmers glue and grout, and apply 5-10 coats with an old crappy paint brush. Paint with non-toxic water based polyacrylic craft paint. Seal with 5-10 coats of non-toxic craft store all purpose sealant (like Mod Podge). Let dry completely between all coats.
Practice by first making a small rock out of a chunk of scrap Styrofoam – maybe golf ball sized. Practice the grout/glue step until you get comfortable with it. I didn’t, because I’m a bonehead, and I learned some hard lessons.
If you want a little more detail, read on. If not, you might want to skip the rest.
Develop a floor plan. This can change as you go, but it’s best to have at least a general idea of how you want the finished product to look, and what features you want to include. Take careful measurements of the inside of your enclosure, and remember that each piece will grow slightly with each layer of grout. Take this into account when making cuts.
Build a frame. I built a 3 sided frame out of 1/8” particle board, which is the same material peg-boards and most office clipboards are made of. It’s available in 2’x4’sheets at Home Depot for a less than $5 a sheet. I will use plastic sheets or plexiglass for future versions though, because I’m afraid that if the frame gets wet accidentally and is not completely sealed, it will weaken or warp and ruin the piece. I used my wife’s hot glue gun, wood glue, and some rectangular pieces of scrap wood for supports. Slide the frame into your enclosure to make sure it fits. Do this periodically during construction, or you might wish you had.
Carve the Styrofoam or foam rubber into the shapes you want, and dry fit them into the frame. When you have them where you want them, hot glue them in place.
Mix and apply grout. I mixed my grout with Elmers glue instead of water. Wallpaper glue works also, but you must make sure it is non-toxic. Grout and water simply didn’t set up very strongly for me, but with the glue added, it sets up almost rock hard. The proper glue:grout ratio is something you just need practice to get right. I never really measured it, I just mixed until it was not too thick, not too soupy. Apply a coat of grout, and let the piece sit until it’s dry. Repeat this step until the piece is completely covered to your satisfaction. It might take 6-8 coats, maybe more. Depends on how thick your grout mixtures were. You can also add non-toxic polyacrylic paint to the grout mix to make it any color you want. You only need to do this for the last few coats though. You can make some pretty cool looking rocks by making several small batches of different colored grout, and then applying them while the piece is still wet. The colors blend and give a really cool effect.Experiment with your golf ball sized rock.
Paint/seal. Paint with non-toxic polyacrylic paint. It can be brushed on, or dabbed on with an almost dry sponge. It can also be diluted and sprayed on with a cheap dollar store spray bottle. Dilute the sealant until it’s the consistence of milk, and either brush it on or use a cheap dollar store spray bottle to apply it. It can be tinted with paint, or left clear. It just depends on what you want it to do at this point. Apply as many coats as needed until a drop of water beads up on the grout surface and doesn’t get absorbed.
Pretty easy.
MZ
