In January when I posted Making Things Out Of Concrete showing some of Ben Uyeda’s concrete creations, I mentioned:
“I have long wanted to make some bonsai pots, table lamps and a few other creations locked up in my imagination using concrete, grout or some other cementitious product.”
Since then, I have been on quite a journey that has taken me from here …
… to here!
Ben Uyeda’s ideas expressed so clearly in his videos inspired me to at least try a few things. Along the way, I have learned a great deal from others as well and I felt it would be a good thing to ‘pay it forward’ by sharing some of what I have learned. I hope it will help others who want to make things out of concrete and I also hope that they will leave some comments about what they have made and how. I will be writing this as a series of posts and will include details on how I made the white pot above and some other creations that I hope you will like. I will include as many pictures as I can. In this post, I will share some of my early experiments. In the following posts, I will drill down a bit more and keep them focused on specific molds.
How and where to start?
After watching Ben’s videos, I e-mailed him to ask what mix he was using. Ben told me he was using Quikrete® Countertop Mix so I contacted Quikcrete® with a few questions and they replied to me with some excellent information including a suggestion to try their Non Shrink Precision Grout. I headed down to our local lumber yard and ordered a bag of each. Both mixes are gray in color.
I wanted to try and use re-cycled items for my molds so I visited some of the thrift stores and purchased some old plastic containers (like Tupperware). I also retrieved two plastic salad bowls from our recycling bin, a large and a medium, the kind they sell pre-made salads in at the grocery store. And … a burnt out light bulb!
Note: I know that great molds can be made using urethane rubber. If you want to go down that route, check out Smooth-On. At some point, I will use some of this myself, but I really want to try and use existing shapes to achieve my creative goals.
First attempt at a bowl
I wanted to try both mixes so I started with the countertop mix. I mixed some up and then poured it into the large salad container and then pressed the medium one down into the mix and placed some weights in the middle to hold it down. 18 hours later, this is what came out of the mold.
While the sides turned out very smooth and shiny, the edges were quite rough so I used a file to even them out a bit. It could use more sanding which I now know how to do.
First attempt at a pedestal
Next, I mixed up some of the non shrink grout. The grout can be mixed in a very thin mix, much more pourable than the countertop mix. I wanted to see what a pedestal would look like so I made a small mold out of a plastic container and a piece of plywood and sprayed the inside with Pam® … I had read that it is a great release agent …
Here is the mold. The plywood has been painted and the edges wrapped in electrical tape to smooth them out. The grout is poured into the container and then the plywood piece is pressed down into the container to form the feet. It is held in place with a few weights.
Here is what came out of it. Note the very bubbly finish. It turns out that while Pam® is indeed a good release agent, it is an aerosol and the air in the oil is what caused this finish. I will try this again with the same mold and a different mix (which I will cover in part 2 or 3) and see what comes out. That said, this was a very interesting result. I wanted smooth … I got bubbles … but it’s kind of cool!
First attempt at a light bulb
Next I tried the concrete light bulb idea. It’s pretty simple to do but if you decide to try this, please wear leather gloves while you handle the bulb. I used a pair of cutters to remove the electrical contact on the bottom of the bulb. Then I used some long thin needle nose pliers to remove the inner parts of the bulb. With the contact out, one can pour a thin mix into the bulb. Again, I used the grout and let it harden. The next day, WITH GLOVES ON, I used a hammer and gently broke the glass then picked away at it with a small X-Acto blade to get the glass off.
First attempt at a bonsai pot
Now it was time to try something more substantial. An actual bonsai pot. I created a mold out of some old melamine shelving that I had in my workshop and then used insulating foam for the cavity and for the drainage holes. All inner seams of the box were caulked with thin bead of latex caulking. The foam is glued together with a hot glue gun and then glued to the bottom of the box with the hot glue gun as well. Here is the mold.
This time, I used the Quikrete Countertop Mix. As it is a thicker mix, I had to work it into the mold by pressing it in. It was a very messy job! Here is what came out of the mold.
What I learned and what I want to learn
- ALWAYS wear a dust mask when you are working with the concrete in powder form!
- Playing with concrete can me pretty messy. Plan ahead. Have some plastic sheets to work on and buckets you can use to clean your tools in when you are done. DO NOT clean them in the sink! Very bad idea …
- Take notes on how much mix you need for a particular mold. It is better to mix a bit more cement than not enough. Just have a few smaller molds you can pour the excess into. I’ll show you some neat ones in upcoming posts.
- Why did the bowl turn out so smooth, but not the pot? While the pot looks OK, I really wanted to get to a smooth finish like the white pot I show at the beginning of this post. That said, many people seem to like the rough finish so knowing how to do either is empowering.
- Waiting 18 hours to take things out of molds is difficult! I wanted to do this faster … and I did! I’ll share that gem in part 3 😉
- While the mold for the bonsai pot is not that hard to make, there is quite a bit of prep work (screwing and un-screwing, caulking, gluing foam etc.) and as it is made of melamine (MDF) I know it won’t last long. Maybe two or three uses maximum, then I need to make a new one. And, for every shape you want to make, you need to create a new mold. There must be a better way … and there is … and yes … I will share that too!
- Working with concrete is way more fun than fixing CSS and PHP code on web sites … just a LOT messier!
I hope that this has been helpful to those of you looking to create things with concrete. I’ll be sharing much more in the following posts. Please feel free to leave comments, questions or anything you have to share on the subject. I’d love to hear from you 🙂
Read more in this series:
All photos by Gil Namur – All Rights Reserved