There’s lots of ways to mold a cat.

Cast items on display. Photo by Steven Strasburg.

Jay Mazur, from Reynolds Advanced Materials, stopped by Nova Labs on January 25 to lead a demonstration on various types of mold making materials, applications, and techniques. Hailing from Macungie, PA, Reynolds Advanced Materials is a distributor for Smooth-on, a supplier of many different casting supplies to hobby and industrial markets.

Classrooms A and B at Nova Labs were full for the demonstration.

Classrooms A and B were both full of people interested in learning more about what can be done with urethane, silicone, rubber, epoxy, and more. Some of the materials had pot-life (the time you can work with the material after mixing the various parts together) in the two or three minute range, while others remain workable for much longer. A cast of a large silicone dime in Smoothcast 300Q (Q for “quick” apparently!) even had a dramatic reaction going from clear to opaque in a few seconds, surprising everyone in the room. It was pulled from the mold and passed around the room hardly 30 minutes after being mixed and cast.

Pouring high in a thin stream to reduce bubbles. Product was Mold Star 16 Fast – it has a 6-minute pot life and 30-minute cure.

Jay offered tips for working with various products:

The ‘double pour and mix.’ – you start by mixing in one cup, then transfer to another cup to ensure that you can thoroughly stir all the hard-to-reach material at the bottom of the container.
For foams, mixing part B a LOT before you combine with part A will help – you can add a lot of air to part B without worrying about the pot life (one flexibile foam he demonstrated only had a pot life of 50 seconds, so pre-mixing really helps).
You should also keep some clay on hand, just in case the wall around the part you are casting begins to leak.

At the end of the multi-part demonstration, Jay mixed a product called Alja-Safe and had everyone do a life cast of their thumb. After the 8-minute cure time, the same fast-cure urethane used on the dime was used to create reproductions of each person’s casting. At least a few people said that these would be used to create literal USB thumb drives!

For more info, check out www.reynoldsam.com

Prepping the Alja-Safe alginate before each student was able to mold their thumb.

Molding a thumb in Alja-Safe.

6-8 minutes later, each participant could remove his or her thumb

Thumbs ready to be filled.

Round 1 complete, mixing round 2. The pot life of the Smoothcast 300Q was no more than 70 seconds, so Jay had to pour fast.

Red tinted Smoothcast 300Q for the thumbs. Photo by Brian Jacoby

Waiting for the thumbs to cure.

Comparison of the copy to the real deal.

A thumb in SC300Q.

Here are some more photos from the class.

Jay Mazur pouring the first item

A casting made of Dustin Hoffman’s face. The first layer was SC325 with flesh color added. Foam iT!5 was used as a backfill material, and was tinted blue at the request of someone inthe class. The skin-toned first layer was too thin to be opaque.