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Sim
09-08-2012, 02:47 PM
Hi,

I'm new here and just finding my way round, so please excuse me if there's a similar question elsewhere.

I'm currently making a ring out of silver PMC. I need to set stones in that can't be fired with a torch (I have no access to a kiln, and I'm just a hobbyist). I've got some silver bezel strip to make a rubover bezel, but it's not quite as neat as I'd like. I'll practice of course. I don't have, and can't get, a collet making plate.

What other options do I have for setting a square, unfirable stone in PMC? I can't find a 5mm square silver collet. Can I use other any white metal? I know platinum doesn't bond well with silver, but does anything else? Is it possible to form a collet with PMC and set the stone afterwards...? Can you anneal PMC so it rubs over...? Or does anyone have any tips for making a square rubover collet with the bezel strip? I just want to make sure I'm not missing any obvious tips.

Or, of course, are there any other square settings I can use that I've not yet heard of? I don't want claws, I want it to be solid.

Thanks in advance,

Sim x

mizgeorge
09-08-2012, 03:20 PM
There are a number of ways of doing this, but the best option would be to make the whole thing in sterling. Much cheaper too!

Sim
09-08-2012, 04:20 PM
It's a gift, and he doesn't want sterling. So a no-go, I'm afraid!

Kwant
09-08-2012, 06:01 PM
Here is a link to a site where indeed you can get a 5mm square collet. http://www.goldschmiedebedarf.de/product_info.php?products_id=13570 this is for a faceted stone with a culet, which is what I am assuming you are attempting to set.

You could of course make your own from silver sheet (I use both 0.3mm and 0.5mm) with an internal wire support for the stone, filing off the corners at a slight angle removes the problem of creasing or ugly corners. Square stones are not the easiest to set and even with the above ready made collet it would still be tricky.

Sim
09-08-2012, 06:17 PM
Ah, thanks so much. Yes, that's what I'm trying to set. I might get those as back-up...! I do intend to stick with this attempt at making them, though. Can you explain to me in more detail what you mean about filing off the corners? Thank you!

Oh! And they can be soldered to silver clay?

Many thanks!

Kwant
09-08-2012, 06:20 PM
Give me a few minutes and I will draw something to explain more clearly.

http://farm8.staticflickr.com/7270/7747953228_33f12d5cd0.jpg (http://www.flickr.com/photos/12340604@N02/7747953228/)
filing corners on square setting (http://www.flickr.com/photos/12340604@N02/7747953228/) by kwant (http://www.flickr.com/people/12340604@N02/), on Flickr

This is exaggerated, but when you rub over the sides they make a neater kind of mitre. Sometimes there will be a little bit of a gap but this is preferable to a crumpled corner.

Sim
09-08-2012, 06:30 PM
Very much appreciated!

ETA: ah, I see now. I did wonder if you meant just at the top, but couldn't be sure. That's brilliant, thanks!

Dennis
09-08-2012, 09:34 PM
If you once return to the idea of making your own rub over collet, then give up bought bezel strip and cut your own from 0.4mm fine silver sheet. you will find straight away that it is much easier to use.

Going on with this idea, for a square stone you can make a piece of right angle metal in one go, and cut it up to make two useful lengths. Then join the L-shaped pieces to make a square for your stone. The easy way is to fit a shorter L inside a longer one.

I personally prefer to check each right angle on a piece of 1.0mm graph paper as I go along and once soldered correct any small error on a square mini triblet (mandrel). Then as Kwant suggests you can make a wire bearer, or make a second square to fit inside, but not as tall.

Of course if you want a tapered collet You simply do as above, but taper the edge of one L before fitting it into the other. Try this with copper first and you will see that the top and bottom of your collet will need filing flat, so allow extra height for this waste.

Finally most beginners are disappointed in the finished result, because they have pushed far too much metal over the stone. you only need a third to a half of a millimetre of extra height.

Welcome to the forum, Dennis..

Sim
10-08-2012, 09:10 AM
If you once return to the idea of making your own rub over collet, then give up bought bezel strip and cut your own from 0.4mm fine silver sheet. you will find straight away that it is much easier to use.

Going on with this idea, for a square stone you can make a piece of right angle metal in one go, and cut it up to make two useful lengths. Then join the L-shaped pieces to make a square for your stone. The easy way is to fit a shorter L inside a longer one.

I personally prefer to check each right angle on a piece of 1.0mm graph paper as I go along and once soldered correct any small error on a square mini triblet (mandrel). Then as Kwant suggests you can make a wire bearer, or make a second square to fit inside, but not as tall.



Thanks so much for this. Another thicko question though: When you say L-shapes, is that like a net of a half-box shape? So when it's all 'folded' into shape, it's like a square cup? I'm not sure if I've understood correctly. But I'm ever so grateful to you :Y:

Dennis
10-08-2012, 02:43 PM
Yes, what you are making is a piece of square tube. When you make the two halves , they each look like the letter L seen end on.You can either join them by fitting a smaller L inside a larger L with longer arms, which is easier. Or you can turn the Ls with their points uppermost and rub them on a flat sheet of abrasive paper until you have mitered edges which will come together like the corners of a picture frame.

In either case it is useful to have some calipers to check the lengths are correct and some squared paper, as mentioned above to check the right angles. Dennis.

caroleallen
10-08-2012, 04:01 PM
If it helps, Bellore do 5mm square tube in silver.

Sim
11-08-2012, 07:02 PM
If it helps, Bellore do 5mm square tube in silver.

Thanks Carole! I'll certainly bear that in mind.

Dennis, after a day or so of trying to understand what you meant, it dawned on me while looking at my garden table. The two L shapes means I only have to make two bends, not fiddling around with 4 on one strip. So it will look like a b/q joined at the fat bit. I'm not the sharpest tool on the workbench ;) Thank you, that will definitely help!