Casting A Small Resin Figurine

In this video I use a Platinum Silicone rubber to make a mold of a small, detailed figurine. Then I cast copies of it in urethane resin.

When molding a figurine in silicone rubber one of the most important aspects of the job is properly orienting the model in space. Doing so insures that you will make a clean casting with no bubbles and minimal parting lines. I positioned this model so that the sprue location would be very easy to clean up yet fill the mold rapidly and completely. Only two vents were necessary to let the air out of the cavity. Before pouring the mold I used a vacuum chamber to de-gas the silicone rubber.
The rubber mold is a one-piece cut mold. I used the absolute minimum amount of cutting to free the model from the rubber, making sure that the mold remain in one piece.
When casting with urethane resin is it it is important to measure and mix the resin properly according to the manufacturer's instructions. I use a pressure pot set to between 50 and 80 psi to compress the resin while it is curing. This helps to eliminate bubbles in the casting. But the most important way to make sure you get bubble free castings is to properly place air vents so that the air rises naturally out of the cavity as it fills with resin.

Thanks to Maria for sending in her fairy figurine. Check her work out at:

Thanks to Silpak.com for providing the Silicone rubber used in this video. It is a platinum rubber with a soft Shore rating of 20. Product number R-3700-20. Silpak has been my material supplier for almost 30 years. Check them out and be sure to tell them I sent you!

TIME STAMPS
00:00 Molding and casting a small figuring in urethane resin.
00:46 Correctly position the model in space.
03:12 Building a mold case.
05:50 Sprue and vent the model.
11:13 Assemble the model and mold case.
13:41 Pouring the silicone rubber.
14:12 Opening the case and cutting the mold to free the model.
19:13 Mixing and pouring the resin.
22:21 Removing the mold from the pressure pot and inspecting the casting.
24:21 Trimming the sprue and vents.
27:41 Strategies for correcting the flaws in the casting.
29:13 Evaluating the 2nd casting. Looks great!

Here is a list of suppliers for the rubber, resins and waxes I use in my videos:
https://www.dropbox.com/s/kz6mhmf7v5v...

Do you have a project to suggest for the channel?
Here’s a .pdf with everything you need to know:
https://www.dropbox.com/s/pjb0l6fr7zj...