Homemade silicone molds


This is fairly quick, and only peripherally related to Thermomorph.  At the WOYWW crop I had a look at Shazsilverwolf’s homemade molds.  I used a similar, although not identical, recipe for making my own.

What I used was:

  • Silicone caulk (labelled Bathroom Sealant by Unibond)
  • corn starch
  • baby oil (in lieu of glycerine)
  • acrylic paint (craft grade, so fairly thin)


You can see the selection of items I used to create the molds there to the side.  The amounts I used were equal parts caulk and cornstarch, with more cornstarch depending on the stickiness when it was completely mixed (a bit like the additional flour when rolling out dough in baking – as much as is needed to keep it from sticking to the surface!) and maybe  4 or 5 drops of baby oil.

Once it is firm and doesn’t stick to your hands AT ALL, lightly coat the item to mold with Vaseline.  Press it into the molding material and allow to dry for about an hour. I found with some things I could press then remove the item BEFORE it actually dried and still got quite a clear impression.


As you can see you do, in fact, get quite a detailed impression.


The problem is getting the Thermomorph into JUST the mold area.  It sets quite quickly so you need to press JUST ENOUGH of the Thermomorph as is needed to fill the depression.  Any that squidges out needs to be trimmed off.  And THAT is a bit of a pain for very shallow molds.  I am wondering if rolling the Thermomorph thin then pressing that into the mold, with it thin enough at the edges for easy trimming, would work better.  I also have some proper silicone molds on the way and I suspect those will work better as they are deeper.  The one that I made that worked best was a rose (deep mold)  off a bracelet from Primark.


I would say that one is as quality a result as a commercial silicone mold.  I think it may take a bit more play to get the hang of it, but certainly these molds would work well with the hot glue embellishments or  for air dry or Fimo clay – those would be easier to trim than the quite hard when set Thermomorph is.  It’s a quick process to mix up the mold material and within an hour you can start using it, so it’s pretty close to immediate gratification!  I would stress that this sort of mold is NOT food-safe, so don’t use it for cake decorations for example.

Product Name: Thermomorph
Price: £19.95
Size: 500 grams
Material: Polymorph granules

Thermomorph Amazon page: polymorph
Thermomorph website: Thermomorph

US readers can try this link at Amazon USA instead. 

As an aside, I solved the problem I was having with Safari refusing to load a number of web pages – apparently it’s not just me but a more universal problem with the DNS server  used by my router – the thing that translates what you recognize and type (blog name search, url, whatever) into the IP address of the site and sends you to it.   I was not willing to switch browsers to Chrome (which uses a Google DNS server and which seems to not have this problem) so we just added the Open DNS server to the front of the list in the router so it uses that one rather than the one provided by my ISP. Since doing that, so far I have not had a single page fail to load.  Something to think about if you are getting very slow to load pages, or lots of Server Not Found messages.  It’s unclear to me if it is specifically a Mac/Safari combo problem but if you are experiencing this, you might try changing your DNS server assignment and see if it helps.

5 thoughts on “Homemade silicone molds

  1. Thanks so much for the reply. Well, I tried this yesterday and it was an epic failure. The silicone totally stuck to the gloves (medical type) that I was wearing, and I ended up with more in the mold than in my container. I needed it for several minutes and it just never seem to change texture? Finally I gave up and slapped it in a plastic container and shoved in the item. It did pop out of the container this morning, but there were tons of air bubbles. When massaging the silicone in the water, it looked nothing like your photos! It was real stringy. What brand are you using? I know I bought silicone sealant. Any ideas?

  2. Can I make a larger silicone mold and fill it with plaster of paris??

  3. wahou superbe idée merci

  4. Great info… thanks for your experiments and research!
    Jo x

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