Friday, February 28, 2014

Playing With Push Molds

My first polymer clay components were all made with textures impressed into them - either commercial rubber stamps or else designs I pressed into them with various tools.  Having created the designs, they were then cut out using cookie cutters or, in one case, the lid from an aerosol can.

So this week, I decided to try making some push molds, using a 2 part silicone compound.
To make molds, you take approximately equal amounts of each color of putty, mix them together and then press your object into the putty.  
In a few minutes the putty hardens into a rubbery silicone mold.  You then remove the object and viola, you have a mold into which you can press your polymer clay.  It sounds easy and fun.

I gave it a go earlier this week, using some buttons that had interesting textures.  But all the molds I made were lopsided.  It turns out that it is a bit tricky to press the button into the molding compound with exactly the same pressure on all sides.  Fellow AJE team member, Kristi Bowman, suggested that I try pressing the molding compound onto my objects, rather than pressing the objects into the mold.

So that's what I tried yesterday.  I used a fun flower shaped magnet and pressed a layer of molding compound onto the flower side.  Then I added more compound and built it up around the bottom and the edges, so it would be thicker, (when I made molds the first time, several were too thin on the bottom and they tore).
  When the compound hardened, I popped out the magnet and this is what I had.
It's certainly better than my first attempts, (for which I have no pictures), but if you look carefully at about the 9:00 position, you'll see that some of the petals have dents in them.  I think this is because I un-molded the magnet too soon and I damaged the still-soft mold while trying to get the magnet out.

Then I went through the same process with a heart shaped faux cinnabar bead.

I'd only worked with light colored polymer clay so far, so I decided to try something darker.  I mixed one part black clay with  three parks purple clay.  The purple was quite bright, so I wanted to mute it a bit.  
I pressed the polymer clay into the molds, popped it out, added holes at the top and placed the shapes on a piece of cardboard.
I placed the cardboard on top of a pizza stone that came with the oven, but you can also use an unglazed tile.  Then I covered it with an small inverted loaf pan and baked it for 45 minutes at 275F.

They came out of the oven nice and firm, but quite a bit darker than I had hoped.  I wanted a muted purple, like an aubergine, but these were nearly brown.  So I used some paints, in many layers, including some brighter highlights. That helped, but it is still not quite what I had pictured in my mind.
Its clear to me that I am still in the practice mode, with lots left to learn.  However, I keep reminding myself that I learn a lot when the outcome is less than what I'd hoped for.  Its a process and I'm learning step by step. And, hey, I burnt my first batch of polymer clay and I've never made that mistake again!

Linda Landig Jewelry – Etsy


  1. Love your experiments Linda! The learning process is good fun... looks like you're having a great time!

  2. So much fun to see you playing with Polymer Clay and I know you're having fun too. Keep it up girl, you'll get it down in no time!

  3. I have been curious about how those mold work for a long time now. Thanks for showing us!

  4. I'm having the same troubles with the browning. SiGH. When one of us finds the secret, it will be a breakthrough. I have used push molds for metal clay and love them. I've been experimenting with using polymer clay to take impressions. I had a problem with using those molds more than twice because they didn't want to release. So I tried cold water and that worked better. For metal clay, we always used oil but you can't do that with poly clay cause believe me, it burns! LOL

  5. I thought I had burnt my molds because they were so brown! I was using a different substance, but they were still brown! I also made the mistake of making some too thin, but others were thicker and work pretty well! I read somewhere to use baby powder to keep the clay from sticking to the molds but I always have baking soda handy from my metal work and use that. It seems to work well! It's great fun experimenting--thanks for the helpful article, Linda!

  6. A couple of tips that might help: make sure you've calibrated your oven using a mercury-type thermometer to check the temperature. Most ovens are not even close to the temperature that the dial indicates. Polymer clay only needs 30 minutes per 1/4" so 45 minutes is overkill and may have darkened your clay (I don't know what kind you are using). The pizza stone may be intensifying the heat-- I cure my clay on simple pieces of cardboard with a deli sheet under the clay (a paper one not plastic!) and only use a tent of aluminum foil to cover light-colored or translucent clay. Before you do a keeper piece, try out small amounts of your blend first so you can see how it will be once it's cured. Lastly, clay usually darkens with curing so add some white to your mix to lighten it.


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