When I recently came across a photo of a round black concrete tray, I knew I had to make a DIY version. Sometimes when I tackle a project, figuring out how to do it is harder than actually doing it. I’ll have a picture in my mind of exactly how I want it to turn out, and then I’ll do a bunch of planning to try to turn that into reality in a way that I can show other people how to replicate. That’s easier said than done sometimes. In this case, I wanted a round, matte black concrete tray, with straight, non-tapered sides.
As you can see, I figured out how to bring my vision to life, and I’m happy to share a tutorial. Once you know how to do it, it’s not hard at all!
This is one case where the image in my head and the reality don’t quite match, but that’s because the reality is even better than I had pictured.
It’s a very distinct possibility that this concrete tray is going to inspire many more black concrete projects. I love how the black concrete looks like lava stone.
What else should I made from black concrete?
There are a couple of secrets to getting the look of this concrete tray, but the first one I had to crack was the molds. The perfect molds turned out to be cake pans. Pie pans and plastic plant trays might also work, but for straight, non-tapered sides, metal cake pans are the best mold I found. You definitely don’t want to use tins you’ll want to use for baking, though, so do what I did and hunt for the perfect molds at dollar store and thrift stores. If you want your tray to look like mine, you’ll need two pans that differ in diameter by half an inch (be sure to measure the actual pan size, not including the handles or rim).
Another piece of this puzzle was getting the right color concrete. I wanted black, so I bought “charcoal” powdered concrete dye, and added the amount recommended on the package. And then I added a lot more, to get it as black as I could. My concrete still dried less dark than I would have liked, so I figured out how to make it darker.
Maybe I could have made another concrete tray and added more black pigment, but the first tray I made broke because I tried to remove it from the mold too early, so I used it to experiment with finishes to darken the concrete. The finishes I settled on are some of the same ones that people use to finish concrete countertops, so they’ll help protect the tray from stains, too.
Round Black Concrete Tray
Concrete – My favorite material to use for this kind of project is this quick-setting cement.
Concrete pigment – I used this powdered pigment.
2 cake pans – I used one 8-inches, and one 8 1/2-inches in diameter.
Acrylic fortifier for concrete
Mineral oil – You should be able to find this at any drugstore.
Howard Feed-N-Wax, or other beeswax-based finish. See notes on Step 6.
Sturdy stir stick
Weight, like a brick or heavy books
1. First you need to prepare your cement molds. I used two cake pans, one 8-inches, and the other 8 1/2-inches in diameter. Spray the interior of the bigger one and the exterior of the smaller one with cooking spray, then use your fingers or a paper towel to evenly spread the oil all over the surfaces of the pans that will be touching the concrete. Set aside.
2. Mix up the concrete. The 10 or 20 lb size of the concrete I recommend comes in a plastic bag inside a bucket, so you can use the bucket itself for mixing. I used about 2.25 lbs of concrete, and also added an acrylic fortifier to help strengthen the concrete. (It’s probably not necessary, but I haven’t tried this project without it.) Follow the recommendations on the packaging for the amount of water to add. My package of pigment said to mix it with the water, so I mixed the water, acrylic fortifier, and dye before adding it to the concrete. I started with the amount of dye recommended by the package, but that wasn’t dark enough, so I ended up adding a lot more. Be sure to work quickly and mix thoroughly. Keep in mind that the concrete will lighten as it dries, but you can also darken it up a bit with a finish.
3. Scoop concrete into the largest cake pan and shake/tap it to release bubbles. Other ways to release bubbles in the concrete are to gently tap the work table it’s on with a mallet/hammer, or operate a vibrating tool like a hand-sander on the table. Press the smaller cake pan into the center of the concrete, doing your best to keep the edges even. Put something heavy on top like a brick, then put the tin someplace level and leave it alone while the concrete sets.
4. After the concrete has cured for at least 24 hours, remove it from the pans. You may need to press or tap pretty hard on the back of the bigger pan to separate it from the concrete, but be careful not to break it!
5. If the edges of your tray aren’t as even as you would like, you can sand them. I used a mouse sander and hand sander with 80 grit sandpaper, then 120 grit. You should definitely wear a mask and eye protection.
6. Sealing is optional, but it’ll give you a darker finish and help protect your tray from stains. I experimented with a bunch of different sealing options, and the one I liked the best was food-grade mineral oil, and then a wax. Put some mineral oil on a rag, and spread it all over the surface of the concrete until it all looks shiny. Let it soak in, then repeat. I did 4 or 5 coats, letting it soak in from 5 minutes to overnight. It will go from shiny to matte after it has all soaked in, but you don’t need to wait for it to all completely soak in before adding another coat.
After the last coat of mineral oil has soaked in, spread a coat of wax over the concrete, and let it soak in. The easiest wax to find is probably Howard Feed-N-Wax, and the finish over the mineral oil is really nice. I tried a couple of different waxes and mineral oil combinations, and the only ones I didn’t like were when I did just the waxes without the mineral oil. That left a white, waxy residue in some cases. The other waxes I tried were a 50/50 combo of beeswax/paraffin wax I had left over from making a waxed canvas tote bag, and a beeswax/olive oil wood polish I made a while ago. If you want a food-safe finish you can eat off of, the Howard Feed-N-Wax is not recommended, but either of the beeswax mixtures should work. You could also use a finish meant for concrete kitchen countertops, like this beeswax-based one or this sealer.