Crushed Cement Cups

Happy Crafty Monday!

As promised, I have an exciting new project to share with everyone today.  Small cement planters that look like crushed plastic cups!

Last March I was visiting a close friend in Munich when I spotted a video on Instagram about how to use a crumpled solo cup to make a small cement planter. I showed it to my friend and a day later we were in the German version of Home Depot buying cement. We had so much fun that I knew I just had to try and recreate this project once I got home.

I took a bunch of progress photos which I’ll show with the instructions below. But I also tweaked my technique as I went and I didn’t necessarily capture all of my final recommendations in these photos. I’ll make sure to point out when my recommendations differ from what the photos show, and you may need to use your imagination.

Materials:

1. Cement – I used Cement All by Rapid Set. It’s available on Amazon but a LOT cheaper at a Home Depot or similar store.
2. Plastic Cups – I used 16oz, 12oz and 8oz for various jobs.
3. Plastic Spoons
4. Duct Tape
5. Latex gloves
6. Sandpaper
7. Water

Process:  

1. You’ll need two cups for your mold.  I used 16oz cups for the outside, and while I originally used 8oz for the interior (shown in the photos) I found that if you are careful you can use a 12oz and then you have a much larger area for your plant and you use less cement. I am much happier with those planters, and so are my plants! I did make one 8oz planter which is adorable, but tiny and not very practical.
2. Cover the exterior of your large cup in duct tape.  This is because when you start squishing and crumpling the cup, it might split or crack. It also helps the plastic to hold the crumple once filled with cement.
3. Crumple your cup. Feel free to really squish it, every wrinkle will add detail to your finished planter and make it look more interesting.
4. Let your cup pop back out to it’s full shape, while retaining the crinkles and indents.
5. Double check that your interior cup can still fit without hitting any of the sides. This is especially important when you are using the 12oz cup inside. You may need to smooth out some of the larger indents.
6. Put on your latex gloves and start measuring your cement and water. You need 4 parts cement powder to 1 part water. I usually used the large 16oz cups for mixing in, and a smaller 8oz cup for measuring approximate amounts, measuring up to a specific line along the side of the cup.  It doesn’t have to be super precise.  
7. Start mixing. I found it was easiest to measure the water into my mixing cup first, and then add the cement powder a bit at a time. It will often feel like there’s too much powder but just keep mixing and it will all absorb the water, I promise.
8. Once mixed, pour your cement into your mold. Because we are using plastic cups you don’t need any non-stick layer for the cement to release. Fill the mold about 1/2-2/3 of the way up. If you start inserting your center cup and there isn’t enough cement you can always add more, but you can’t really deal with overflows.
9. Start inserting your center cup. I found if you use a stack of them it helps them hold their shape, and gives you a larger area to hold. This step is where I learned the most as I made my planters. You want to beware of pushing down on your center cup and then letting it rise back towards the surface. That will cause the cement to stick on the sides of the two cups, so your finished edge will have a sort of lip along the inner and outer edge, which just means more sanding and not as nice a finish. However if you only ever push down then the top surface of the cement will be flat or slightly convex, which is a much nicer edge. Here’s what happens to the wet cement when you let your center cup rise up after pushing it down, and what the final edge looks like with those lips, vs the nicer flat edge you didn’t need to sand.
10. Here’s another step I tweaked. The original video I saw recommended taking duct tape and using it to tape the center cup down. However, this is where I found it is almost impossible to get it taped in place without it rising up a bit and giving you that ugly edge. Instead I used a bit of my cement to fill one of the smaller center cups, and make a cup shaped cement weight. I would drop that into the center cup in my stack, and it would hold the cup down. If you push your cup part of the way and then drop the weight in it will help it sink down slowly and evenly without rising back up and messing up your edge. If you plan on making more than one of these planters, I found it was a worth while step to take, making this center weight. But beware, you must make this weight first, so it is already hardened when you drop it in, and can therefore slip right out when you are done.
11. When your cup has set, you can remove the center plastic cup by slipping the cement weight out, and then crumpling the cup towards the center while gently twisting and tugging.
12. Now you just peel the outer cup off. First, remove the duct tape. Then cut the rolled plastic edge, and from there you can start peeling the cup away. You can do this as soon as your cement feels solid and is still warm to the touch, but beware it won’t have it’s full strength yet so be a bit careful. If you are using the 12oz cup you might want to give your planter an hour or two to set before you try to remove the mold, since the walls are thinner. I broke a few because I was too impatient.
13. Sand any rough edges, or unsightly bumps with your sandpaper. Make sure your planter has had time to properly set first, I’d wait at least 24 hours to be safe.  Then just add soil, your favorite plant, and enjoy!

The cement is porous, so it will absorb water from your soil. You might find that you need to water your plants a lot. I found the plants that are happiest in the long term are super drought resistant plants like jades and other succulents which can survive their soil being sucked dry by the cement. It is one reason I didn’t bother trying to add drainage holes. If you are worried that the cement might get so wet it would damage the surface your planter is sitting on, you could try dipping the base of the planter into colorful latex paint. Wouldn’t a row of these dipped in bright rainbow colors look so cute along the windowsill of a children’s room?!

Also as you can see from some of the past photos, when you use an 8oz cup inside a 16oz cup, you get an edge that is approximately 1/2 inch thick. But if you use the 12oz cup you get the nice thin edge you see here, which is closer to a 1/4 inch thick. It is still structurally sturdy, but you use less cement, the thinner edge is more elegant, and you have a much bigger interior space for your plants. You can also see that for the larger inside cup you do sacrifice a bit of the crumpled look, since your crumples can’t be as exaggerated. So you’ll have to decide what’s more important for you.

I hope you have enjoyed this tutorial, I really loved how my planters came out, they are all lined up on my windowsill at work! If you give this project a try I’d love to see the results. And follow me on Instagram for more projects like this, @the3Rsblog.

Ciao, Allison

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