OK, this project was probably our biggest fail to date. We got some wrought iron legs from my mom that she was throwing away and decided we would make a concrete table top for our patio out back. We had some leftover concrete and melamine board from our concrete desk and my wife had some craft tiles leftover from something a long time ago.
We had a ton of different options with the tiles. Some were rounded and smooth, some were square and smooth on side and rougher on the other. The main thing I wanted was something colorful. We came up with a design that was meant to be sort of like green grass to sandy beach to ocean and there would be little color bits here and there that would be “flowers” in the grass and “crabs” on the beach, and “fish” in the ocean. I build the melamine mold and caulked all the seams on the inside. We arranged the tiles as we liked them in the bottom of the mold since the plan was that the bottom of the mold would be the top of the table. We used a tinu bit of caulk to try to hold the tiles in place so they wouldn’t slide all over the place when the concrete was poured in. We tried to face the smoothest flattest surface downwards in the mold so that we wouldn’t need to do much (if any) sanding of the final table. The design was beautiful.
We mixed the concrete and poured it in and smacked the sides with a rubber mallet to try to get rid of air bubbles. We again made the concrete too wet I think.
We gave the concrete about a week to cure to be safe since we suspected it was overly wet. Then it came time to remove the cast. The side came off pretty easy, but the base of the mold would not budge…I got a putty knife and carefully slide it between the cast and the melamine base all the way along the outside – still didn’t budge. I eventually got some cedar shims that I had and jammed them into the small gap I had created and tapped on them with the rubber mallet again. This worked much better and the mold finally released from the cast. Unfortunately, a decent percentage of the tiles also released from the cast and stuck to the mold =(.
I removed the additional tiles that were definitely not secure and we started to assess our damage limitation options. The caulk had caused the tiles to stick pretty well to the melamine mold. In addition the smooth tiles did not bond with the drying concrete hardly at all. These two things combined made it really difficult for the tiles to stick to the cast and instead we had a bunch of empty spaces on the table. We had some spare black grout from a kitchen backsplash we put in so my wife took that and rubbed it all over the whole surface. We knew this would make the table black (which wasn’t really desirable) but we figured it would also fill in some of the craters. It actually did both things pretty well. You could still tell the craters were there but they were definitely reduced.
Once this was done we applied a bunch of layers of concrete sealant and called it a wrap. Definitely not something we are proud of but it still works pretty well as an outdoor table ;).