PDA

View Full Version : Join The Strip Club



Dennis
28-03-2011, 05:23 AM
When mounting round stones of 5.0mm or more it is time to give up tubes and use strip. But not the stuff you buy which is flimsy and usually much too wide. Join the club and cut it from a sheet of fine silver, say 0.5 mm thick. The width needed for most cabochons is 1.5 to 2.5 mm, just enough to engage the curved part of the stone.

If you can find a cheap set of twist drills, going up in half sizes to 10 or 12 mm, their shanks will provide an ideal set of mandrels for making bezels (and incidentally jump rings). Measure your stone with callipers and wind your strip around the relevant drill shank or one slightly smaller. Once cut and soldered its size can gradually be increased by either forcing it up a tapered triblet, with your fingertips, or by light taps all round with a hammer. The fit should be snug but the stone should still pull out with Blu Tack or a wax cone. Shallow cabochons can be made more prominent by adding a jump ring or washer to raise them, but this does not necessarily have to be soldered in
.
For faceted stones the bezel will be the same depth as the stone, measured from table to culet, but you also need a bearer. This can be a second tube fitting closely inside and soldered to support the stone at the correct height for setting. A more professional option is to raise some spurs inside the first tube, using a scorper, to support a washer or jump ring, which is then soldered in place.

For a splendid finish it is also worth considering setting from behind. Make one tube so that it will admit the stone and add a narrow domed washer to the front. Adjust the window so that it will only just retain the stone, and polish. Push the stone in from behind and then add an inner tube with its back end made flush and slightly bevelled. Then close the back of the outer tube around the bevel.

These are quick fixes, but I do think that faceted stones are more elegantly fitted into tapered collets. This does away with the need for bearers, although setters often cut a slight ledge with a burr or graver to steady the stone. For small stones you can use tubing and coax it into shape in a collet block, but for larger sizes I prefer to make a cone shape out of sheet first and then perfect it in the block. Dennis.

Below: My box of drills.
Bezel made from sheet.
Set from behind.
Cone shaped collet.

MuranoSilver
29-03-2011, 08:44 AM
Thanks Dennis!
Now I have to buy a collet block #-o lol
Beautiful pieces (as always) have you a pic with that last stone set?
Looks gorgeous :Y:
Nic x

Inanegal
29-03-2011, 08:57 AM
Hi Dennis,

Thanks for the excellent tutorial and great photos.

I especially like your 'Cone Shaped Collet' design. May I ask if you have any tips for shaping the bottom of the collet where it joins the ring shank? I always find this very difficult and wonder whether there are any clever ways of doing it...

Best wishes

Nina

Dennis
29-03-2011, 09:36 AM
Thank you Nic, nice to have you back here. I knocked the ring up on Sunday morning just for this thread, and then found my CZ selection a bit low, so I'll get a bigger stone today and post the result.

Hi Nina, it is a perennial problem to fit any collet to a shank. Briefly the answer is to use a round file with the same diameter as the shank. For shanks made of flat strip the curve goes the other way and having filed the shape roughly, I wrap abrasive paper around a mandrel until it ends up the right size and use that.

Kind regards to both, Dennis.

Inanegal
29-03-2011, 09:56 AM
Thanks for the advice, Dennis.

Nina

caroleallen
29-03-2011, 04:16 PM
Lovely work as usual Dennis. Good to see you back Nic. I've been wondering where you were.

lorraineflee
29-03-2011, 04:19 PM
Lovely work as usual Dennis. Good to see you back Nic. I've been wondering where you were.

What she said!!!

Lorraine

jille
29-03-2011, 04:32 PM
Dennis thanks for taking the time and trouble to write this, it's invaluable to a beginner like me

ps_bond
29-03-2011, 05:14 PM
I knocked the ring up on Sunday morning just for this thread...

Thank you Dennis - your method is far more efficient than mine of "meaning to get around to photographing..."

Mia
30-03-2011, 09:20 AM
Thanks for the info Dennis. I am attempting some simple bezel settings using 0.5 ss strip. Should I be using fine silver ? I was advised to cut my own strip from sheet because commercial bezel strip is flimsy as you say but I thought fine silver would be just as flimsy because it is soft.
I have practiced with copper which worked out fine, but on my first attempt with silver I melted the bezel strip when attaching to the back plate ! Given the price of silver I have gone back to copper & gilding metal for more practice.
Also, I have been given a pretty cabochon which is trapezoid shape. I am not confident about the corners. I was thinking if I lightly cut a mm or so at each corner it would rub over without creasing - wishful thinking?
Regards, Mia

Dennis
30-03-2011, 10:45 AM
Dear Mia,
If you use 0.5mm sterling silver strip, you will probably need a punch and a hammer to set your stone. Fine silver can be pushed over by hand and as its melting point is slightly higher than sterling, it should not give you any trouble. However, flimsy strip will heat up much faster than a thicker base, so to begin with try heating through mesh from underneath, or at least keep the flame moving and avoid concentrating it on the strip.

If you can post a pic of your cabochon, I and no doubt others will tell you how to do it. Kind regards, Dennis.

Fraser
30-03-2011, 10:47 AM
I set a lot of stones, particularly large cabochons, and find britannia silver the best for bezels. I order strips from Cooksons, usually 0.4mm thick, and in different widths for different stones. It is softer than sterling, but not as soft as fine silver, which scratches too easily. It is more expensive than sterling however.
As regards sharp corners, I file down slightly the height of the bezel at the corners, but do not make a sharp nick. I then use a setting tool that has a flat curved end (sorry do not know the name) and roll the metal down, always working from the corner point outwards. (I hope this makes sense). The whole length of the bezel should be chamfered slightly along the outside of the top edge also. After setting I use an agate burnisher to smooth the bezel further.
I would like to try adding gold bezels to silver sometime. Can anyone recommend the best carat and thickness to use for gold bezels?

ps_bond
30-03-2011, 10:48 AM
You could notch the corners, that works - but there is another way, described here (http://gemstone.smfforfree4.com/index.php/topic,1738.0.html); that'll leave you with a continuous bezel, no notches (although note that the excess material is removed by filing the corners!). If you do notch, as you close the corners over it can be a good idea to run a fine sawblade in the notch to widen it for the next bit of closing.

With the working away from the corners method - which incidentally is the same as I use when hammer setting thicker bezels - the metal has more room the move, so the extra is better concealed midway down the long sides of the setting.

These can all be further neatened & tarted up with judicious use of a flat graver by bright cutting.

Have you got access to a copy of Cogswell, Mia?

ps_bond
30-03-2011, 10:53 AM
I then use a setting tool that has a flat curved end

A bezel rocker?
http://www.cooksongold.com/images-prod/999_AJG_.jpg


I would like to try adding gold bezels to silver sometime. Can anyone recommend the best carat and thickness to use for gold bezels?

My preference would be to stay away from 9k for bezels - I can't stand the spring-back on the stuff! The 18k 0.3mm strip from Cooksons works well for that style of setting.

Fraser
30-03-2011, 10:57 AM
Yes Peter, that's the one! And your linked tutorial shows the method I am describing.

Dennis
30-03-2011, 05:21 PM
Hi Mia,

You are now well provided with advice on setting multisided cabs, so I should like to go back one stage to what I think is much more difficult: making a bezel with corners.

1. When you start this by cutting and filing a groove, you will lose some of the internal width of your bezel . In theory this is equivalent to the depth of the groove, but ultimately takes accuracy and experience to compensate for.

2. As an amateur I prefer to get each corner made and lightly soldered before going on. This helps to keep it stable while I fiddle with the next one.

3. In closing a corner you may sometimes find that you have not filed it sufficiently and you might have to pass a saw into it, or worse, open it again. In attempting this be sure to re-anneal, or the bezel will break apart.

4. Having made the last corner, I also prefer to complete the bezel with a final join along one of the straight sides. This gives me a further chance of adjustment before I cut off the unwanted surplus.

5. If after this you attempt any further changes in shape, you will alter everything and may at best have to cut it open again , or at worst start from the beginning.

Finally I urge you to get plenty of practice before going on to precious metals. Dennis.

Mia
30-03-2011, 09:58 PM
Thanks for that link Peter. I have bookmarked it so that I can keep going over the instructions. I have found that I am very much a visual learner with these things even though I spend my days buried in books !. I have not seen Cogswell although it has been recommended here before. I would be happy to make the purchase provided it is well illustrated, I find jewellery making books that are very "wordy" frustrating because I am always asking questions and they simply can't talk back.

Mia
30-03-2011, 10:09 PM
Hi Dennis,
Thanks for taking the time to give me more info on making a bezel with corners. I always appreciate your advice here when I'm lurking even though I don't always thank you. I have made some bezel strip with 0.5mm copper and I managed that ok but the cabochon was quite large - about 40mm I think. I am keen to get more practice. How easy is the copper to manipulate for smaller stones ? Is gilding metal any more user friendly ? Having this little chat today has put me in the mood to get out into the garage and get creating !

Dennis
31-03-2011, 10:57 AM
It should be ok Mia, because when you annael copper it goes dead soft. I don't know about other base matals, because during my early days silver was not as expensive. If you have access to a rolling mill you can always reduce some to 0.4mm. Dennis.

sga
31-03-2011, 12:15 PM
I just started setting bezels a few weeks ago and found this really helpful, thanks Dennis.

Edited to say: I mean bezel setting, setting bezels would be silly, where would it end ;-)

Dennis
31-03-2011, 10:14 PM
I do worry that what I suggest won't work for you, So please speak up if you think it's rubbish.

I note that Fraser uses Britannia silver for his bezel strip, and must agree that for very large stones it can be hard to keep the bezel in shape when soldering it to a base. But for rings and pendants using fine silver, which I have watched over a long period, I have not noticed the bezel deteriorate out of proportion to the rest of the piece. Dennis.

jille
01-04-2011, 07:26 AM
Oh so that's why I was having trouble with larger bezels, I couldn't understand how they were out of shape after soldering. So next time I'll try Britannia silver.

Dennis
01-04-2011, 01:44 PM
What I would really suggest Jille, is that you fix any really large bezel to its base with three or four tiny spaced out drops of superglue, with the stone in place. You can dispense the stuff nearby from the dropper type bottle and then work some into place with the end af a saw blade.
Once this has set, extract the stone with Blu Tack or a wax cone and solder as usual.
More often than not the solder joint will be complete, but you can easily add a little more and reheat a second time, because the glue burns away cleanly.

If you have not seen it, you might also like to look at this http://www.cooksongold.com/forum/show-tell/3431-super-superglue.html
Kind regards, Dennis.

jille
01-04-2011, 04:46 PM
thanks Dennis, I love those earrings