You know those adorable concrete mosaic kits that they sell in all the big-box craft stores, the ones with all the stuff that you need to make one concrete mosaic, handprint optional, to put in your garden path in the spring? The ones that look really fun to make, and you’re pretty sure that the grandparents would just adore one made by your kids?
Yeah, you can make dozens and dozens of your own concrete mosaics for the same price as one of those mosaic kits, and even more cheaply, if you use found and natural objects for the mosaic tiles, and recycle plastic packaging for the concrete molds.
Seriously, the only material that you need to buy to make concrete mosaics is the concrete. And yes, you can buy fancy-pants mosaic concrete if you want to spend the money, but you can also head on down to your local mom and pop hardware store and just buy yourself some…concrete. That’s it. Whether it’s called concrete or cement, it’ll work, and it’s cheap, so I’m telling you right now to spring for the more expensive, higher-grade concrete. If you buy the cheapest concrete you’ll find yourself out in the yard for half the day sifting all the pebbles out of your concrete, and you just don’t need that kind of hassle.
You can also substitute cement mortar for the concrete, and frankly cement mortar is my favorite, because it doesn’t have the pebbles to sift out.
Before you spend money on concrete, it’s worth trying to Freecycle some–people rarely purchase just the right amount of materials for a particular project, and even a quarter of a bag of concrete is going to do you just fine.
To mix the concrete, get out an old bucket, an old cup, and a paint stirrer. Measure out an amount of concrete that will fill your mold (Do you know how to fill a mold with water and then pour it into a measuring cup to find the volume? Science in action!), and just enough tap water, a little at a time, to give the concrete a brownie batter-like consistency. This is actually the only part of the project that’s messy, since concrete mix is dusty, so do this on the porch.
While you’re Freecycling your concrete, see if anybody has any concrete mosaic molds that they’re looking to get rid of, but take-out containers, deli containers, silicon cake molds, and any crap plastic packaging that you’re stuck figuring out how to recycle also make perfect molds for mosaics. If you’re worried that your mosaic will stick to the mold (it probably won’t), grease it up a little first with cooking oil, lotion, or whatever you’ve got handy.
Scoop concrete into the mold, overfilling it slightly, and lift the mold up and thump it down a few times to release any air bubbles from the mix. Use your paint stirrer like a straight edge to scrape the concrete nice and flat and flush with the edge of the mold.
For mosaic tiles, take a walk around your house and gather up all the little loose bits and detritus of daily living, from beads and buttons to nuts and washers to game pieces and LEGOs. Your kids don’t play Hungry Hungry Hippos anymore? Take the marbles! They’re tired of making friendship bracelets? Grab the pony beads!
Thrift store plates, smashed to smithereens, also make excellent mosaic tiles, as do river rocks.
This is a really, really simple mosaic, basically the simplest there is and thus an excellent introduction to the art and a good project for beginners, so we’re not worrying about grout or any other nonsense. All you have to do is push each mosaic tile into the concrete until it’s flush with the top of the mold. As you can see from the photo, kids can do this, and you can do this at your living room table. It’s simple.
Slide your concrete mold somewhere out of the way (don’t try to carry it around yet!) for a few hours, then go over each mosaic tile with an old toothbrush to brush away any concrete bits. Later, when you’ve reached the curing time listed on your bag of concrete, go over the tiles again with a damp cloth to clean them off and shine them up. Give away your mosaics for Christmas, and plant them in your garden in the spring. Finally, you’ll have a nice place to stand while you admire the basil!