Has anyone worked much with the stuff outside of art class? We picked up four of the cheap 2' x 2' plastic ceiling tiles from Menards and I am going to build a frame around them so we can cast our own tiles. I will grease the molds with coconut spray, reinforce the tiles with mesh drywall tape in the plaster and then paint the surface after it dries. I'm looking for input on how thick to make them and the drying time needed. Thoughts? Hoping to have this and the crown molding done by xmas.
I haven't used it for any building projects but have done a lot of casting and molding with it. It sets up firm enough to remove from your mold pretty quick - maybe 10-15 minutes, but I would let it cure for 24 hours before you get too rough with it. 2x2 might be asking a lot, even if you reinforce it. How thick are you planning on? They will get heavy quick as your thickness increases, and will be pretty weak if left too thin. I would consider some more substantial reinforcement than mesh.
If you can find something like the product below and embed it in the plaster you can make this pretty thin.. Real plaster dries fast and is hard as a rock pretty fast! I have mixed this in a metal can and it got so hot I couldn't hold it for long.. You have to work fast.. Great for drywall repair too! BOEN 9.5 in. x 150 ft. EIFex Mesh Non-Adhesive EIFS Stucco Mesh-EM-95150 - The Home Depot
Whatever you use as a mold release should be washable so you can paint it.. Drywall compound shrinks, dries sloooow and cracks.. Plaster is much harder, dries fast and shouldn't crack! Avoid having to sand as this stuff doesn't sand very well.. All my drywall has hard plaster skim coat on it..
Seems that Murphy's oil soap is pretty popular straight up with a thin coat.. Washes off then can be painted.. Mold Release Materials - Studio Operations and Making Work
I was a model maker in the aircraft industry, although it was 25 years ago. Johnsons paste wax for release agent, apply to mold and buff out , you will get a lot of parts without reapplying. Burlap for strength, put a layer of plaster in the mold then dip the burlap in the plaster and smooth onto back of tile. 1/2 inch thick when hardened will be very strong. Air bubbles will be your biggest enemy, we used to use a vacuum chamber to "suck" them out before pouring. Pour slowly so you do not trip air in the details. Be patient, mixing and not getting lumps will be key.
Ok, I have made my prototype! I set up a makeshift tile studio in the garage loft, even fired up the USSC King and had a nice fire whike I was out there. Image below is of my form, which is a store bought plastic tile with a plywood bottom (leftover bead board from a previous project) and 2x4 sides. I coated this with original Murphy's oil soap. Below is the form filed. I filled halfway, eliminated bubbles, added the mesh tape and them finished filling to the desired thickness. You will notice the tile isnt level, I need to shim my work surface. And here is the finished tile. Seems pretty strong-- I carried it from the garage loft into the house so the old lady can have a look when she gets home.
Yes very cool!!! Any idea of the cost savings? I assume that's why you're making them and not buying.
I won't know for sure until I make a full bag's worth of (level) tiles but I am estimating costs at $2.50 per tile compared to $13 or so at the store for the plastic cheap looking ones.
That's awesome. I'd be curious how much one weighs too. Seems like a very plausible project. I myself would rather make stuff then buy it. Good job on you.
