An alternate method is to use the bezel formula to determine what length of strip is needed to fit the stone. First, add the oval length + oval width and divide this by 2, to get the aproximate average diameter. Then (diameter + thickness of metal) x 3.14 will give you the length needed to make the bezel.
Since ovals can be a variety of proportion, it may not always fit exactly but this approach should get you very close. Bend the strip with half round/flat pliers or ring bending pliers, solder it closed and then adjust and refine the shape to fit the stone.
I know the math and have applied it upon occasion, but as your bezel thickness increases, it doesnāt work as well and I fall back on just wrapping the bezel material around the stone, marking the overlap, cutting, filing, soldering and adjusting as needed with simple tools. I have mentioned all of this before, but I forgot to mention that I have an old Kagan roller that works great to stretch a bezel that is a little tightā¦Rob
For me, this has been one of the big advantages of owning a pulse arc welder. I set a lot of larger, oddly shaped cabochons.
First, larger bezels tend to pop open when soldering the ends together. After I shape and cut the bezel around the stone, I tack the ends together with a couple of small welds. Then I solder the bezel ends together with hard solder and donāt worry about anything pulling apart.
Then I do what Rob talked about, tack weld the bezel to the baseplate.
Before that, I do final shaping of the bezel around the stone, using the stone like a custom shaped bezel mandrel. I put a bit of dental floss in between the stone and bezel. Then I tack weld the bezel with the stone still in there to the base plate. That way I guarantee a perfect fit. I can pull out the stone with the dental floss and solder like usual.
I didnāt mention this technique before, because itās such an expensive solution, but if you set a lot of oddly shaped larger cabochons itās a game changer.
If you donāt have a PUK, Orion or laser welder, be sure to anneal your bezel after shaping and before soldering. That will help relax the metal and help it to keep its shape while itās being heated.
Hi Jeff, thanks for this tip! I just got orion 1500s and have been playing around with it and figuring out how to use it, and when to use it in my making process. This was so helpful!
One quick thing to add to this tip of welding your bezel in place with the stone in the bezel before soldering. Donāt weld more than you have to. Otherwise youāll make extra clean up work for yourself. I try to weld the bezel in place every 5-15 mm or so. Welding is just to hold the bezel in place before soldering.
round pliers and half round ones are great to haveā¦ I have bothā¦use them to shape ring shanks also but carefullyā¦
Iāve make a bezel out of both sterling and fine silver and gold, by using a very thin paper strip and measuring the total diameter of an oval or irregularly shaped stone, with the ends soldered together on the SNUG sideā¦the bezel strip or wire can be initially made in a rough oval shape and pushed over the stone to just slightly stretch it out into the final shape using a burnisher or even a wood dowelā¦ the total length of the bezel has to be done very carefully when first cutā¦if itās soldered on to a flat surface, you donāt need to take anything more into consideration. If its soldered on to a curved surface with the curve side outward, you need to take into account the curvature and make the bezel a little longer, since the top end of the bezel will flare out, making it more difficult to fit the stone snugglyā¦ Iāve done that with all of the oval stones that I have set, even small ones without having to use anymore tools. This technique is primitive but effectiveā¦If the bezel doesnāt fit, you can just make another one and save the bezel strip for a smaller stone.
I donāt have an arc welder, so Iāve used hard solderā¦ everything Iāve made was with a propane air torch.
PS: Jeff youāve been a great moderator. All of the discussions that youāve moderated have been very well thought out and provide a wealth of useful information to people who have asked questions. Thanks to everyone who have contributed. You are the ones that bring a lifetime of experience to the table.
Steve
regarding using a piece of paper to measure the circumferenceā¦i also use waxed dental floss or i run wax over unwaxed dental flossā¦the wax makes it stickyā¦then mark at the overlap.
Thicker bezels have to be a bit longer than one measured with a thin strip of paper passed tight around the stone. This is basic geometry. The same applies to making a ring. There is both an inside and outside circumference. It is the inside circumference that fits the stone or your finger. To get that circumference, you need a bezel strip or ring blank that is something like the average of the inside and outside circumference. This is pretty much idle talk. I just wrap the bezel material that I am using around the stone, shape the bezel around any corners if the stone isnāt round or oval, mark the over lap, add a little to be removed when filing the bezel strip ends, solder and then fit it to the stone. We have discussed a number of different ways to get it to the shape needed to fit the stone. Pliers and mandrels work well. If the bezel material is thin or fine silver, you can just push it over the stone and manipulate it with your fingers, a bezel rocker or other smooth tool. If the bezel is too big, make it smaller. If it is too small, you may be able to stretch it the same way that you stretch a ring by hammering lightly on a mandrel. I have already mentioned using a Kagan ring stretcher. If you are a lapidary, you can adjust the stone to fit the bezel. I usually design a piece around the stone, but sometimes I design the stone around the piece. After you make a lot of bezels, this process just becomes second nature with each of us finding our own way of doing it. As is the case with much of what we do, there is no one right way. The real trick is to solder the formed bezel to a back and have it be the same shape as the stone when you are done. Make sure that it is annealed before you solder it to the back. Have you ever watched wire move around when you anneal it. Use hard solder as you will likely have additional soldering steps. Donāt do too much finishing on the bezel end joint until after you do any additional soldering as these additional firings may pull solder out of the bezel end seam. At the same time, if the bezel end seam will be hidden by the addition of other pieces to the bezel, finish the end seam sooner in the construction of your piece. This has been a great discussion as making bezels is an important skill to learnā¦Rob
unto each their own, as long as it works! great tips everywhereā¦ once someone finds their own technique that works, they can refine it to work even betterā¦ thanks
sorry about the mistakenly deleted postā¦ was trying to edit itā¦ Rob you are an expertā¦ your input is always valuable to both beginner and advancedā¦ thanks for your contributions.
Darn - what a good idea to use the welder for stitches. Iāve been doing stitches for so long, it never occurred to me to look at the PUK on the next bench. duh! Thanks. Judy