Building a Clay Warming Oven
Updated: Feb 11, 2022
You can now watch this as a Youtube tutorial!
I've been sculpting a lot lately, and I continually run into the issue where my clay is cold and hard when i'm ready to start. It always takes a while to warm up the clay to start with, but I always run into frustration as my clay always cools off again before I'm done with it! I have seen other artist do it, so I wanted to build a Clay warming oven so that I can keep my clay ready to go for the whole time I'm working. This blog post will take you through why and how I built mine, and my review of how it works!
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Now my preferred clay has a lot to do with the decisions I made through this whole process, so Lets start there:
My favorite clay is Monster Clay, It's an Oil/Wax hybrid clay. When it's cool it can be handled and carved like Wax, when warm it's soft and easy to form. Usually oil clays leave a residue on your hands when you work with it. It makes me want to wash my hands every 5 minutes- that is really irritating to me. Monster Clay hardly leaves a residue so I can keep working for hours. And the last cool feature is that you can be heat Monster Clay up to a liquid state that can be poured into a mold. The 5lbs kit of Monster Clay comes in an oven safe container which I used to calculate the dimensions that I'll make my oven. Even though my focus is on monster clay, this idea for a clay warming oven will work for Chavant, Plastilina, Sculptex and other Oil based clays.
You can buy Monster clay here: https://amzn.to/38MUMiF
I wanted to make an oven that could keep my clay warm, but not too warm. Liquid monster clay is great to pour into a mold, but isn't useful when it comes to blocking out shapes. I have a little toaster oven that I used to use with polymer clay, but I've found it gets my clay too warm. If you heat up monster clay too hot and fast the components can separate and there just wasn't a temperature on the dial that was low enough to not make my clay instantly a liquid. It also wasn't big enough for the volumes of clay I want to work with. the oven safe container would barely fit in the thing and then it was too close to the heating elements and could melt.
I started out with research, I wanted to see how other artist solved this problem. I here are the ones I found helpful:
I liked the simpleness of the cardboard box method, but I wanted something a little more substantial (and a little less an eye sore!) I really liked on the 2nd blog that he used foam because that would hold the heat much better. So the search began for the perfect box.
Storage cube: https://amzn.to/39WHSzO
I wanted to find a wooden storage cube, but they were mostly sold out and more expensive than I wanted. I found this Way Basics Eco cube on Amazon and decided to try it out. It's made from Recycled paper board, it's lightweight and 100% recyclable which always makes me happy! So while it is sort of made of carboard, it looks so much better than just a box.
Aluminum reflector socket: https://amzn.to/2Wm8QNe or from your local hardware store
Insulation foam: From your local hardware store. I had been gifted some 2" thick from a friend, but I reccommend getting 1"
Aluminum foil: From your local grocery store
Tape or glue: I used scotch tape, but you can also use spray glue like the blogs above: https://amzn.to/2WpJ8aL
Lightbulb: an LED bulb won't work here, get the old kind
First task was to locate the top piece before assembling to cut a hole in the top.
Trace your reflector socket and then draw your cut line 1/4" -1/2" inwards so it has a lip to sit on. Cutting the hold would have been done really easily with a drill and jig saw, but I just went at it with a utility blade. Working slowly and carefully I removed layer by layer until I broke through. Not the most effective, but it worked!
To help clean up the inner edge I use my finger and wood glue to fill in the gaps. When this dried it was very hard and a little pokey, so I used sandpaper to finish it off.
I assembled the rest of the box according the the instructions, it was really easy and didn't require any glue or tools.
The next step I took was to line the inside with insulation foam. This took a little extra time because I only had 2" insulation foam on hand. I used the full 2" on the bottom and back of the box, then cut it in half to just have 1" on each side. I couldn't figure out a good way to add the foam to the door, so I just left it off. Each peice of foam was a good fit, but still had a bit of wiggle room, I knew adding the foil would add a little bulk.
I wrapped each of the foam pieces in Aluminum foil, making sure that the shiny side would be the side to show in the oven. I simply folded the foil around the foam and taped it into place. You could glue it into place with 3M 77 general use spray adhesive like some of the other tutorials did. I didn't want to use that because my infant daughter was in the room with me.
The taped worked just fine though, I don't see any reason why I would need to take it any further. The Foil ended up adding more bulk than I thought it would, so it made for a tight fit putting the foam back in the box.
I taped some more foil onto the door, I made sure to tape all the way around so the foil wouldn't catch and rip on anything.
Added more to the top too, just in case. I didn't worry about making it perfect, as long as it was mostly covered I was happy.
Here's a picture of how the clay fit inside! My clay warming oven is done.
How it works
It actually works really well! Almost too well, because it was warm enough to melt my clay to liquid! with a brand new tub of Monster clay that had been sitting in a 65 degree room, it took
15 minutes to start softening the top layer, and in 1 hour there was a sizable liquid puddle.
It's still getting a little hot for my taste, and I won't be usually using it to heat up a brand new tub of clay. I like to process my clay first into about golf-ball-sized lumps to make it easier to handle. So a real use scenario would involve me using one of my other tubs and fill it with about the amount of clay I need immediate access too. So I tried that next:
You could say that my oven was "preheated" at this point, maybe it had cooled off a little while I had the light off and the door open, but I digress. I checked on my clay again in 15 minutes and it was already pretty liquid. Some of the larger chunks were still cool so I kneaded my clay together for a minute or two until it was a homogeneous temperature.
I was curious so I turned off the light and left the clay in the oven to see how long it would stay warm. I came back in an hour and it was still warm and at a really good working temperature! So my oven works really well, I can simply manage the temperature by switching on and off the light, but with how long it stays warm and how quickly it gets to a good temp it won't be too difficult.
I did use a 75 watt bulb, so I wonder if getting a lower power bulb would work better. I'll have to try that out sometime! Thanks for reading through my blog and hope it helps you make your own clay warming oven!
UPDATE: From a recommendation from a YouTube comment, I ordered a lamp dimmer https://amzn.to/34PXAPs (paid link) it works perfectly to let me dial in the temperature and keep the clay the temperature I want.