Convergent Series

learning, using & teaching metal clay, and other aspects of life

Making My Ring Come Out the Size I Wanted.

Posted by C Scheftic on 2011/09/16

Given how many pieces of various sorts I have made out of the different metal clays over the years, relatively speaking I have not made many rings. What’s the difference? I do make rings for myself; I will teach others how to make them; I may give the occasional one as a gift; but, at this point at least, I rarely make rings to sell.

Sizing is an issue for any ring-maker. Since metal clays shrink as they sinter into a more-solid metal form, however, size is a detail that really matters when making rings. (This is one reason why I would never use a mix of clays for a basic band ring. If I can’t be sure of the shrinkage, I may have to spend more time post-fire in resizing it. Using “fresh” clay is a simple way to reduce the chance of that! That’s also why I held off posting this item until I could write the two entries that preceded it this month….)

When I do make rings, I often start by making a flat piece that will become my ring’s band, firing that, then shaping, sizing, and adjusting the resulting piece of metal as needed, all before adding the top and re-firing. While that method does require two firings, there are several very simple ways to test and adjust the ring band before proceeding. The already-fired band won’t shrink any more, so I can be pretty sure what size the ring will come out to be before I start on its decorative top.

The recent class I took at the Valley Art Center with Gordon Uyehara, however, used a different technique. We formed the clay around a ring mandrel, let that dry, then added the top, and fired everything at once. It’s a hold-your-breath situation waiting for the rings to come out of the kiln, to see what size you end up with. Yes, there are methods for adjusting size, if necessary, to make rings larger (relatively easy with a simple band) or smaller (can be trickier, depending on the ring, and does require yet another firing, whether in kiln or via soldering). Personally, I find it more thrilling to have the ring go into the kiln and come back out the right size in the first place, but I was happy to venture down the other route for that one day.

Also, while I’ve used both PMC and Art Clay for rings with the double-fire method, I’ve only used PMC-brand clays for band-rings made the way we did at that workshop. (Why? Because I’ve only done them that way in workshops, specifically, in ones where the clay was included in the class price.) For Gordon’s Pearl Box Ring class, however, we could bring whatever clay we wanted. Since he works mostly with Art Clay, that’s what I took. If I had questions about working with it on the ring, I could get help from someone with lots of experience using it. Here’s what happened with sizing (sorry, but rings require simple math):

  • My goal was a size 8 ring. Anything from 7.75 to 8.25 would be OK. A little smaller would be tolerable. But 8.5 would be bigger than I wanted, and I did not want to have to do anything to reduce the size afterwards.

  • Gordon reported that Art Clay says to make a ring 2 sizes larger, to account for shrinkage.

    • Thus I should make it a 10, so it’d shrink to an 8.

  • But, he added, since you’re covering your ring mandrel with a teflon strip or another easy-release surface, you should figure that adds about a half-size. Position it 1.5 sizes beyond your goal.

    • If I made it on the mandrel mark of 9.5 then, with wrap, that would give me the 10 that would shrink to an 8.

  • With rings, I always try to “work-harden” them a bit after they’ve been fired. The “99.9% pure” fine silver of regular metal clay comes out of the kiln annealed (i.e., soft). Fine silver will always be softer than sterling or Argentium silver (and even those are not necessarily the strongest choices for rings). But any form of silver will harden up, at least to some extent, if you “work” it for a while: hit it (gently…) between two hard surfaces (e.g., a between a hammer or mallet and ring mandrel or a steel bench block), to “re-align” the silver crystal structure. But, in my experience, that hitting tends to increase the ring size at least a little. (If a ring comes out to small, that’s one of the easiest ways to size it up as needed!) In the end, I chose to position mine only 1 size larger, and use the work-hardening, along with a little reshaping, to get it back up where I wanted.

    • I built it on the mandrel at 9. I had some moderately heavy teflon wrapped around it so, per Gordon’s logic, I guess that took it up just a tad above 9.5.

  • It came out just a tad above 7.5.

    • Once I finished hardening and reshaping the band, it ended up right at 8, maybe a hair over that. Perfect!

Why did I reshape the band to no longer be the perfect round I had out of the kiln? (The round band is shown in the first photo with this post, above. The slight change should be just visible in the second photo above.) Because I find that round rings with heavy tops tend to topple over on my finger. The thing that really controls the ring size you wear is rarely the space where you’re wearing it! In most cases, it’s the knuckle the ring must pass over to reach that spot. (And the extra size of the knuckle often helps to keep the ring from just falling off the finger.)

With an oval band shape, you can make it a bit smaller than you think you need, turn the ring sideways to put it on, then straighten it back up to wear. Or, with a squarer band, the sides of the band and the sides of your finger are fairly well matched up, so the ring sits in place as intended.

(If I’d made this in my studio, rather than in a class, I’d’ve taken the extra time to add a few embellishments to the top. In the workshop, we didn’t have that much extra time, and I wanted to wear mine home. But, at least, I got the “fronds” to sort of sprout from the space where I set the pearl, so I’m OK with it as it is.)

What’s your favorite “tip” for making metal clay rings, using whatever method you prefer?


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