Friday, 16 June 2017

Using a Prototype

It's a Learning Curve

Way back in April, I mentioned that a friend had commissioned me to create a ring from a stone found in some jewelry she inherited. Time went by, as it does. The Creative Jewellers Guild <> Show & Sale on Mother's Day took up quite a bit of time, as did my love-hate relationship with our vegetable garden. I have, however, been making progress, slowly, on the project. One thing I was sure of was that I would need to play with a prototype to be sure of creating the ring. Malachite is way to soft to being messing with it.

Question: Can I Build What I Designed?

I had suggested various designs and my friend/client liked "D" the one in the center. Having the shank come up over the malachite will offer protection but I have not made such a piece before so I needed to experiment. That story will unfold below.

So, Not This Way, I Guess

In April, I pulled a round (well, almost round) agate from my stash and tried setting it on a shank of round sterling wire. I filed and bent the ends of the wire to make them rise above the stone.

As you can see, it became an interesting ring but I learned a few things (the whole point, right?) that sent me back to the bench in search of a better solution.

Using A Tumbled Agate as Stand-in

This tumbled agate is less symmetrical and a bit bulkier than the malachite but I felt it would serve my purpose much better than the round agate.

I created this bezel for it (those are temporary felt pen fitting marks on the stone and silver).

Creating the Shank

If you are not making a lost wax casting, you have two choices for making a ring shank. You can use wire (round or half-round) or you can cut a ring blank from a sheet of sterling (or gold, if you are a big spender!).

For this ring, I am cutting from sheet. This is a piece of sterling, scored to mark the cutting line and positioned on my bench pin for sawing. I bet only the sewers among you will recognize that round, white object as a seamstress's wax, removed from its plastic holder for ease of use here. It works just as well for lubricating a saw blade as it does on sewing thread.

Measure Twice: Cut Once

My plan was to use two layers for the shank — one to form a ring and a second that will provide "arms" to rise over the stone. My experiment with the round wire shank taught me how very hard it is to size and round up a ring that is open. I think the two layer option will give me more control over that. 

Here, I am about to cut the second strip of silver, having carefully measured both with that super accurate inch/millimeter ruler.

Joining Them Up

In this photo,I am starting the process of marrying up the layers. The inner ring has been soldered shut and rounded on a steel mandrel. While it was still on that mandrel, I partially wrapped the outer ring over it. In this photo, I soldered them together where they meet. I quenched and picked the ring, then put it back on the mandrel to forge the remainder of the outer ring into place.

The second photo shows the ring with its outer layer forged into shape and held with binding wire for a second soldering operation.

Binding wire it great — so long as you remember to remove it before putting your piece into the pickle pot. Just by being there, iron will plate your silver with copper.

Assembling the Parts

With the two-part shank married up, I put it on the horn of my mini anvil to check that the the bezel-mounted stone would fit properly into the arms. Kinda important ;-)

So far, so good. When the piece is a bit complex, it is reassuring to see that the parts will fit together.

Right: the flame approaching the ring for the final soldering operation.

I am holding the ring in a third hand (cross-lock tweezers clamped into a flexible stand). My soldering station is super safe: a large ceramic floor tile on the bench, topped with a metal tin from a discarded toaster-oven. A heavy metal solder block holder, on legs, on top of that holds my charcoal blocks. Behind that assembly, I have a firebrick (which also provides a perch for a ceramic solder tile when I am not using it). I may burn myself one day but I'm sure not going to set fire to the shop!

Experiments Complete

Above you see both rings on a plastic ring measuring mandrel. I think I am ready to start making up that malachite ring, using the two layered system for the ring shank.