Last edited by sparkles; 15-02-2012 at 07:22 PM.
You had me all excited there. It's one of my favourite subjects.
Sorry to disappoint you Dennis. I'm not very good at this and posted it in the wrong place! What I wanted to know was whether a ring stretcher would stretch heavy rings - 2mm to 4mm thick. I guess it would work but just wanted to get some advice before I splash out and buy one.
Here are some notes on the subject. If I have left something out and others donít chip in, please let me know :
1. To be comfortable, rings are usually no more than 2.5mm thick, or they are obtrusive and splay the fingers. Also thicker material is far too difficult to bend to a round shape, even with a dedicated ring bending tool.
2. Ring stretchers will certainly stretch the material you mention, provided it is annealed frequently enough, but that is a matter of experience. The sticking point is the solder joint, which gradually opens when stretched and if stressed, will suddenly give way. So a reasonable amount to stretch a silver ring safely is 2.0-2.5 English sizes.
3. The ring stretcher will also reduce plain bands, using a suitable hole found on the top and reverse of the carousel below. The planisher which does this, will also conveniently flatten small pieces of sheet if you take away the carousel and substitute a metal block. Substitute a flat doming plate and you have a device for closing short pieces of tubing.
To stretch a ring, use the lever gently or you will overshoot the mark. Keep checking with your ring stick as you go, because the calibrations on your stretcher will probably not correspond. While doing this the ring is rotated frequently to keep it round and also flipped over several times or it will end up slightly conical.
For myself I find it convenient to make rings slightly undersized and then stretch them as required. You soon learn how to get a good round shape without the use of a hammer.
There are also parallel ring stretchers which are more expensive and more complex, but I donít think you need them. Dennis
Dennis, in the last photo, is that a bezel block. So, could you use a ring stretcher as a sort of press?
The thing at the bottom of the ring stretcher comes down firmly when the lever is pulled. I have called it a planisher, because it will flatten metal on a block, but yes it is a small press. I have called the thing in the third picture a doming plate, but it is just a flat doming block, rather than a cube. Dennis.
Thanks for the advice. Cooksons also contacted Durston for me and they assure me it will be OK too but it's good to know there are other uses for it.
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