Successfully vulcanized parts straight from the Form1

Hey folks-

I decided to see how prints from a Form1 would stand up in the vulcanization process. (I spincast gaming miniatures as a hobby/side business.) I use organic rubber molds and vulcanize them at 320F for 2.5hrs. Now, on paper, it didn’t look like this would work, but it actually worked perfectly. I printed a couple of small parts on Friday and left them in a window until Monday morning so they hardened up a little more. The parts even survived the process. There is a stress fracture in the sprue for the wheels but that was from me pulling it out of the mold with needle-nosed pliers. (The flash on the wheels is because the cavity was not properly vented yet, casts afterwards were perfect.) I plan to try some larger and less flat pieces this weekend!

Joshua - too cool. I have never heard of spin casting or vulcanizing but want to try this! Could you post a short description or tutorial of your steps?

Spin casting is how a lot of jewelry, figurines and other small metal parts are made. Vulcanizing is taking uncured rubber mold blanks, sandwiching your parts between them and then cooking them at 320F and a few thousand PSI for a few hours. The rubber expands and hardens (vulcanizes) capturing all the detail of the master.

I have a couple of videos, geared more towards my customers, but you should get the idea!

This is really fantastic Joshua!

Just to prove to myself it wasn’t a fluke I made a mold of another part. Worked perfectly.

Now that’s *awesome* news!  I thought for sure the SLA material wouldn’t stand up to the vulcanizer temps/pressure!  Are you casting with zinc alloy of some sort?  Now I’m motivated to get my furnace conversion to LP going! :wink:

This is great Joshua, enjoyed your videos too. I wonder if your method could reproduce this fairy sculpt I did awhile back? If you are interested and not too busy let me know your thoughts.


@Clay I cast everything in lead-free pewter.

@Shea I could quite easily reproduce that, but with pewter you aren’t going to get that fantastic surface finish without a lot of polishing.

I have seen Joshua work awhile back while researching the Spincaster and Vulcanizer before I purchased a set for myself. Joshua is actually doing the same thing I am doing, only I plan to make parts for suppliers and he already has an established business of his own and it is quite fascinating if I do say so myself.

Joshua have you tried the I think it is the organic low temp type of molds for your items? and if so how does it or not work?

I have a few more questions if you don’t mind being bothered once and awhile…

There are a number of low-temp silicon molds. Unfortunately I can’t use them. As you can see in my video I have some green silicon molds I get a friend to make for me if parts are really delicate.

I live and do this work in an old warehouse in Oakland, CA. I don’t have a garage or barn so I cook my molds in our warehouse kitchen. The one time I cooked a silicon mold I thought I was going to die. When I opened the mold can there was so much foul outgassing that I got light-headed and almost passed out. I barely made it out of my back room. I haven’t been brave enough to try it again!

I am always open to questions. When I started this I had no one in a similar situation to turn to so I am happy to be that guy for those looking to do it now.

“I decided to see how prints from a Form1 would stand up in the vulcanization process.”

You seem to have trans. resin. Do you try it whit the grey resin?

This is pretty cool.

Awesome work.

Kevin, I do not have any grey resin. Early on as I was learning my way around the machine I had a number of failed prints. Its so much easier to clean the cured bits from the clear than I imagine it is in the grey. I just clean the metal masters instead of the prints and then make production molds from them.


You say you have some failure print. Did you make some mistakes on the supports or something like that or its the form 1 that its not close to the 100% success print? We currently have a jewlery 3d printer . All the supports need to be designed for each piece 8-S.

We are looking for a printer with better results . We sometimes have to restart the same piece 4 times

thx for the fast answer.