Introduction to the Lapidary Arts

Lapidary Arts at Nova Labs

On Saturday, March 24, 2018, Nova Labs members met in Blacksmith Alley for the second offering in the Introduction to the Lapidary Arts course series. Christopher J. Evey instructed the class on 3 types of rock saws used to process rough gemstones into pieces ready for shaping and polishing. Carrie Hafer, Brad Clements, Marnie Dollinger, Rob Bowers, and Stacey Lanzilotta attended the class.

Students working at the cutting and grinding machines

Students working at the cutting and grinding machines

Chris began the class by walking through the setup and operation of the Raytech trim saw and the Diamond Pacific Genie Trim Saw Attachment. These saws are used to cut small pieces of rough gemstones and more commonly, cut segments from stone slabs into the pre-forms that will become cabochons. Next, the class shifted focus onto the larger saw, the Lortone Panther, which is a 14 inch diamond saw used to cut flat slabs from large rough rocks. Surprisingly, the saw did not turn on when activated; however, this flaw turned into a teaching moment as the students witnessed how to repair electrical wire connections to this vintage equipment. Brad and Chris successfully rewired and soldered a loose connection to solve the issue and restore power to the saw.

Brad's Oregon Thunderegg

Brad’s Oregon Thunderegg

With the large saw running, the class began to cut some of the rocks they brought to class. Brad cut a beautiful Oregon Thunderegg he purchased specifically for this class. Rob cut a quartz crystal geode acquired during his past vacation. Carrie cut a few slabs from some nice quartzite that she later ground into cabochons.

Throughout the day, Chris made his grinding station available so that student who were not otherwise engaged with using the saws could attempt to stay warm by making cabochons. Stacey, Marnie, and Carrie each made their first cabs during this class.

Rob's Quartz Geode

Rob’s Quartz Geode

The class wrapped up after some additional cabochon instruction and cleanup. The students expressed an interest in more lapidary classes and suggested a course on where to find gemstones and how to identify them. Additionally, all the students voiced an interest in a Nova Labs-sponsored field trip in the local area to collect rocks.

Marnie (Front) and Stacey (Rear) at the Cab Machine

Marnie (Front) and Stacey (Rear) at the Cab Machine

Chris and Carrie discussed potential interest in the purchase of a cabochon grinding machine at Nova Labs. In examining space in the Crafters Cove area of the Orange Bay they thought perhaps a small rolling bench that could fit under one of the wire racks might work to store a grinding machine. This machine would need to be rolled out to the shop in back for use so as not to disrupt other members and cleaned up each time before being returned.  Chris agreed to continue to support investigating and discussing potential lapidary equipment in support of our rock hounds and future classes for Nova Labs.

Carrie's rock slabs and first Cabochons

Carrie’s rock slabs and first Cabochons (photo by Carrie Hafer)

Provided by Christopher Evey

Molding and casting demo by Reynolds Advanced Materials

Cast items on display. Photo by Steven Strasburg.

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 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.

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!

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Here are some more photos from the class. All photos by Andrew Albosta unless otherwise indicated.


Thermoforming at Nova Labs

About a week ago, maker Eric K. demonstrated plastic thermoforming for an enthusiastic class at Nova Labs. He used the thermoformer he built himself and maintains at Nova Labs. You may have seen the video of Adam Savage’s vacuum forming machine, which works similarly, but Nova Labs’ machine is even bigger, with a total forming area of 2 feet by 4 feet!

Here’s some video of the Nova Labs thermoformer in action during the class:

A thermoforming machine has essentially four parts:

  1. A hard surface with many holes on it
  2. A vacuum pump underneath, which (when activated) sucks air below
  3. A movable platform onto which you attach a sheet of plastic
  4. A heating element

To make a part, you first place an object on the hard surface, and then clip the plastic onto movable frame. The frame is lifted so that it’s close to the heating element, where the plastic is then heated until it’s soft and droopy. You then lower the plastic and frame toward the platform and object, and flip a switch to activate the vacuum. The plastic is then sucked onto your object, wrapping around it.

ThermoformingThere’s a lot more to it than that, and Eric did a great job of explaining the ins and outs of using a machine like this. For example, you want the plastic to sag to about the height of the object you’re wrapping. The object itself should be solid, not hollow, or it could collapse and damage the machine.

Eric was also kind enough to bring a number of small wooden objects, and each student thermoformed their own object. He even showed off several parts that he was thermoforming for large drone work.

Removing a thermoformed objectThermoformer controls

This class — and many others like it — was provided at Nova Labs. Check out the NOVA Makers meetup for many more!