Cabochon ring - what setting to choose?

[Aurarius]

I've got a few small cabochon stones ranging from 4-8mm diameter and I'd like to have a go at incorporating one into/onto a plain ring band. Could someone please advise me (a beginner) what setting I should think of choosing that won't be too difficult?

I thought of a tube setting for the 4mm, but then I can't see any sterling tubing for sale that is exactly 4mm internal diam. Will 3.8mm internal diam. tubing fit? This seems to be the nearest size.

Next option is I've got some fine silver bezel wire and some 0.6mm sheet, but at 3mm high the bezel wire seems a little high for the smaller stones.

I've thought of trying a collet, but without a collet forming block I'm not sure how I'd form the pierced template into a cone shape.

I don't really want to buy a pre-made bezel even though it'd be the easier option; I'd rather do it the long way.

ED. I should perhaps add that the stones are round and translucent.

[Nick martin]

For the tubing, you need it to be a little thicker than your stone.

So if for example you were setting your 4mm stone, then your tubing needs to be say 4.5mm diameter, 3.5 / internal diameter. That way when you cut your seat you'll have 0.5mm of metal to fold over onto your stone.

I find tube setting to be the easiest although in the interests of keeping the back tidy in a ring setting, I Iike to put a circular disc on so that the gems not visible. This part is more fiddly that setting the stone.

Nick

[Dennis]

Yes, Nick has explained tube settings. Essentially, the hole in the tube must be small enough to support the stone and the remaining wall about 0.3 mm thick when prepared with a setting burr. Then you must bevel the outside so that you only have to push over a very thin knife edge about one third to one quarter of a mm tall.

All in all it is better to have a selection of short tubes to match up, because stones of a nominal diameter still vary in size.

As a beginner, it is easier to start with larger cabs and use bezel strip which you cut yourself from 0.4mm thick fine silver sheet. It needs to be only just tall enough to grip the stone, so as to show as much stone as possible when set. I find it convenient to bend it around the stem of the right size of twist drill when starting it and then checking on the stone before cutting and soldering.

Having a small bezel mandrel and some guidance from an elementary text book will be helpful. Dennis.

[Goldsmith]

I would think that the 3.8mm. ID tube could be used, or even the 4.2mm. ID tube. You can open the smaller diameter tube with a bur or file to fit the stones. If the stones are not perfectly round then the 4.2mm. ID tube might be better, the extra 0.2mm. interior diameter of the tube setting would easily close over a 4mm. diam. stone. As for the larger diameter stones make them out of pierced strips of 0.5mm. silver, easily made when wrapped around an 8mm. steel rod or a drill shank. As an aside I would suggest that a good purchase for a beginner is a selection of steel rods in various sizes, good for many jobs such as making jumprings and tubes etc. I even use them for making punches. You can buy silver steel rods in all sizes from here; https://ekpsupplies.com/materials-me...l/cat_141.html

James

[Gemsetterchris]

You could flush set them or even bead set, technically this would be simplest but you would need to be drilling out the hole very accurately to get the stones at a good depth & snugness.
Most likely using a burnisher made from brass or copper to avoid scratching the softer stones if your flush setting.
All really depends what you want to do & the how the cabs have been shaped.

[LydiaNiz]

Personally, I'd make bezel cups and file down the walls if they were a bit high. I can email you my bezel making worksheet if you want it.

[Gemsetterchris]

A quick albeit scruffy knockup using a moonstone, just to give you an idea... course you can make things abit more artistic.

[Aurarius]

Many thanks to everyone for the replies.
On tube settings I hope I have understood this correctly: We're assuming a tube with an initial wall thickness of 1mm whose initial internal diameter is around half a mm narrower than diameter of the stone, or the widest point of the stone if it isn't a true round? The shelf you create should allow about two thirds of the height of the stone, when seated on the shelf, to project above the top of the tube before the thinned rim of the tube is pushed over on to the stone? The top part of the tube is thinned twice, first on the inside to accommodate the diameter of the stone, and then again on the outside to enable the final rubbing over on to the stone? The shelf doesn't have to be literally a shelf created by a vertical-sided burr, but can simply be a taper created, for example, by a round file; the important thing is that it allows the stone to sit level and at the right height?

James, when you mention making jump rings and tubes using the steel rod, am I right in thinking that the idea is you use them for forming bezel strips on and forming wire into jump rings? You also mention their use in making tubes. I'm not sure I've understood that bit. Please could you explain briefly their use in tube forming? (ED: I think I understand now - you just wrap a strip of silver sheet round them to create a small piece of "tube"- we're not talking about making whole lengths of tube?)

Chris, your suggestion about using a brass/copper burnisher to reduce the chance of marking the stone makes a lot of sense, particularly when the worker is a beginner.

Lydia, yes I would really appreciate your bezel-making worksheet, thanks. I'll try and pm you.

One limiting factor in my work at the moment is that I have only a Dremel multitool, and its minimum rotation speed is 10,000 rpm. I find this too fast for a lot of things, to be honest. What sort of rotation speed (or range of speeds) generally is it best to use when burring out seats/cutting bearings? Another limiting factor is that one of my arms is partly paralysed after a road accident many years ago, so holding a workpiece in one hand and working on it with the other can be difficult. I notice I tend to use a vice (rubber-jawed) a lot more than other people. When you are stone setting is the general preference to have both hands free anyway and have the workpiece clamped in a vice/microblock?

[Gemsetterchris]

Look into getting a Benchmate, that'll free up both hands if needed & make things a lot easier for you.

Sent from my HTC Desire S using Tapatalk 2

[Dennis]

You are mainly on the right lines, but if you browse tubes here: http://www.cooksongold.com/category_...=Silver+tubing, you will note that the wall thickness is usually around half a mm.

It is helpful for the future, to make a table of tube dimensions and codes for quick reference. You could also send for the printed catalogue, because you don't always know what's available until you see it. Dennis.