Precious Metal Clay

@marie, any PMC tips you might share?

To start, there a few different brands and they all vary from each other. Most sites will state if you can fire using a torch, and I personally order from Riogrande. Its hard to find good deals on pmc, even on ebay or amazon. I use pmc3, but I've also used Artclay, and I like the Artclay copper clay. The original pmc requires a kiln. Other than that, its just personal preference. I might add the copper clay is more difficult to "cook" than silver clay. In my opinion, pmc3 is sturdier than others and has less shrinkage.

Working with your clay is the easy and fun part. You can use push molds like with polymer clay. You can use items you already have and make molds of them using oven-bake polymer clay, just spray your item before with pam so the polymer clay doesn't stick to it. You can make great organic shapes with it. Working with the clay is all about experimentation, and there's a lot you can do. Pmc3 sells an item which is basically a syringe filled with slip that you can use to connect pieces of fired silver or other pure silver parts together. The opportunities are endless with this. If you want to use cabs or stones be sure they can surive 1500º flame.

Once you are done making your clay piece, let it sit out and dry completely, which can take about a day. Clay you don't use you want to make sure has as little exposure to the air as possible.

To actually 'cook' the clay you will need a soldering block. A soldering block is worth the investment, and Riogrande carries them as well. A safety note: always fire in a well ventilated area since there are fumes released from the bonding process. Take your butane torch and make sure its filled since you will have it on for several minutes. You don't want to use something more powerful than a butane torch since it will melt or overcook your piece (done this before). You want to turn it on, but don't have it on "full blast" unless its a very weak torch. I have mine at like 3/4s power, but every torch is different. You want to hold the torch fairly close, but not so close the flame is touching the piece. The piece will flame, and there will be smoke. Try to keep the flame moving around the whole piece. The point is to evenly heat the whole item, like a kiln, and you don't want one part to get hotter than the others. You will have to do this for several minutes. You are waiting til the item gets "red hot"(more of an orange), and then, depending on the thickness of project, keep the flame on it for another 3-6 minutes for pmc3, and 5-10 for pmc+. Its easier to tell if you've over done it, since the piece will be very shiny. It should be matte. Let it cool when its done. Some people dunk it in cool water to accelerate the cooling process, but I'm not a fan of doing this. With pmc, patience is key. Be sure to let it cool slowly if there's a stone in the piece. The firing process takes experience and practice. If its shiny after or it melted or folded- too hot. If it never got red or orange- not enough heat.

I'm sure I left something out. I'll work on a photo tutorial once I have more time, little busy with the first thanksgiving I have to cook for inlaws!

awesome Marie! Great essay.

Is there shrinkage during firing? If so, is it predictable?

Make sure the stone can take the heat! Then no sweat, and you can do things otherwise almost impossible.

That is something seriously to consider in the future. See that kind of process rather than actual metal-work for me. Thanks for the post.

I want to make myself a ring with a 6x9mm ruby. The silver has a shrinkage of 8-12%. What is the best method of setting this gem?

I personally dug these rubies out of the dirt and had them professionally cut. I'm going to torch fire the silver pcm clay. If I can calculate the shrinkage I'm okay with adding it later. I need to get the mounting space pretty accurate though. The three rubies are visually flawless. I have several pounds of uncut gemstones yet to be cut. I have already sold a loose pair of garnets for a $120 profit. Your comments are full of good information. Thanks. I'm not rushing this project.

These arrived yesterday from metalclays.com:

Ring Maker - 8mm - (9-10 US Size)
Ceramic Shrinkage Stopper, #21( 9-1/4 to 9-1/2 US)

I'll do a test ring in a few weeks. I looked at the rubies
under real good light and they are more pink than they looked
outdoors. Hopefully the heat will make them a deeper red.

The dog and I are headed to a jewely swap meet and make in a few minutes.

So, I made my first silver pmc ring last night. It snapped off on the bottom. It will still work as a 4/5th round. I was shaping too hard. I also designed a pendant. They will get torch fired in a few days. I'm not ready for stone setting yet, but it was a good experience. Pictures at some point. Thanks for the support.