How is it formed?

Hello there

A friend has asked me to try to replicate a copper ring he has had
for many years. It is now a beaten up old thing with a split in it
but I can’t fathom out how it was formed.

The ring has been made from a triple helix of copper strip. It is
just a band approx 4mm wide with no stone or other detail. It is
soldered in one place which suggests it was made from a strip of
twisted strips but the puzzling thing for me is that the cross
section is like a marquise shape - oval with points top and bottom.
(apols for my ignorance - I don’t know any other technical name for
this shape.) The ring is nicely rounded on the outside and curved but
less deeply so on the inside. It doesn’t have any core. Surely if it
were forged round without any internal support it would just end up
flat? Well that’s all I’ve managed to produce so far - quite a nice
flat ring band of twisted copper strip but not what is wanted!

Please can anyone help me here or direct me to somewhere that will
describe the process for me?

Thank you
Collette (UK)

Hello Collette, Could you not file the inside curve of the ring much
like a comfort fit band is made? It does not have to be flat in
order to emery and then polish it.

Have fun.
Tom Arnold

A link to a photo would help a lot. If I understand you properly, a
possible method would be to create the triple helix on a low melting
point core, form the whole to the required marquise shape, bend it to
create the ring and then heat it to melt the core out before
soldering it up.

You could use lead as the core, or, even better, Wood’s Metal (its
the stuff that melts in boiling water). Take care to not allow the
core to stick to the copper.

I hope this helps.
Regards, Gary Wooding