Silicon Casting A Wax Model

Lets say you just spent a long time carving out a wax model that you plan to cast in metal, you know that your wax model will be destroyed when you cast it, but you really like and want to be able to save it.  Silicon Casting to the rescue!

 

You will need the following:

your wax model (or anything you want to copy)

A form to hold the liquid silicon

some liquid silicon (I used Dragon skin 10 from smooth on)

A vacuum chamber and pump (this is not needed, but will greatly improve your casting)

DSC_0535

First glue your wax model to the bottom of your form, unless you are going to suspend the item (if you want both sides cast), if you are doing that you will have to cut it in half later, look on youtube for tips on this, I did a simple one sided cast.

The mixing process for the silicon is pretty simple, follow the mixing ratio’s for your silicon.  In my case it was a 1 to 1 mix.  Follow the instructions as each one is a bit different.

DSC_0542

Once you mix it together, give it some time in the vacuum chamber (how long will depend on how long your silicon takes to set up, you don’t want to wait too long and have it harden in the mixing cup!), then pour it slowly into your form, starting from a low point and letting the silicon find its own level. Go slow, and try not to introduce more bubbles.

 

Then back into the vacuum chamber again, to get even more bubbles out.DSC_0544

I also cast a simple silicon disc, just to see what would happen, it came out like a super tough, super stretchy cup coaster.  I might use this technique later to cast gaskets and stuff like that.

DSC_0548

I found that quickly running a torch over the top pops most of the surface bubbles.  Very quickly run it over the top, never stop moving, and only do it once or twice.  Too hot and you will harden the surface.  Keep the torch far away, and move very quickly.  There will be a couple bubbles left, but most will pop before the silicon hardens.

DSC_0553

DSC_0554

DSC_0555

Next melt your wax and pour it in!

DSC_0560

Don’t melt your wax in a mason jar…this jar later broke, use a pyrex jar.

DSC_0564

The blue wax hardening.

DSC_0569

DSC_0570

DSC_0571

Some waxes melt better than others, the blue wax didn’t melt well, but the green wax I had was perfect!

DSC_0572

DSC_0575

DSC_0579

DSC_0580

DSC_0581

Air bubbles from the blue wax, it just didn’t like being melted.

DSC_0582

DSC_0583

You can see that it copies every little detail!

DSC_0585

DSC_0587

I made another one just for fun.

DSC_0588

That’s it!  I recently purchased some food safe silicon, which I am going to use for chocolate casting!  This is a really simple and easy process, I can’t wait to try it some more.