Copper / Silver bangle: Join first, or form first?

I want to make a bangle out of copper, with a silver lining. Simply =
because=20
copper tends to stain the skin.

One approach could be to create two bands, one of copper, one of silver,=20
with the tolerances so snug the silver band fits inside the copper band.

Or I could take two flat bars (0.25mm thick for example) of each =
material,=20
join them together (solder?) and then form the bangle.

So wht I want to know is which approach is best. Join and then form the=20
bangle, or form two bangles and then join.

hello michael, this approaches have been tested only on gold and silver
bangles/rings or different gold colors.but i think it will do even with
copper.
you can do that by forming the two shapes on the anvil, when you have
reached the desired shape you have now two rounded closed and soldered
silver and copper bangles and the two bangles fit *perfectly,after
cleanning the joints clean them by pickling and then roughly sand them
thorough, now fit the silver bangle into the copper bangale (stretch it
up if necessary). before you solder dip the object in lite boric acid
solutes in alcohol, flux them and solder. (beware from little gaps
between the two pieces, this will prevent a hard unnecessary extra work
later !).after the solder is done, pickle and finish it usualy by
filing and polishing. if you like it as an "open bangle" you can saw
it afterward in the solder joint..
another approach is to use a sheet of pure silver a little wider and
longer then the copper and to "wrap" the silver edges on the copper
from below,if its an "open bangle" and you dont solder the edges, the
silver layer might get open if you try to spread it.
And last nice approach is just to finish the two pieces thorough
separately. and then nailing them with silver or copper nails,in this
way you dont need no solders at all.,and the bangle will be much more
elastic and springy if its an oepn bangle.=20

Hope its useful,

Redsmith

"Michael" wrote in message=20
...

...So wht I want to know is which approach is best. Join and then form =
the
bangle, or form two bangles and then join.

I would go with the latter. I've done this with rings in the past and =
it=20
always worked out fine. If you've got a bangle mandrel, you should be =
able=20
to get fairly close dimensionally - close enough that it might take a =
couple=20
of saw cuts to get it bang on at least. Then insert the silver lining and=
=20
solder in eight places, away from the bangle joins. Good polish and =
you're=20
done, should look good.


John

On Wed, 07 Sep 2005 08:07:48 -0700, in |=07=F5 "Michael" =
wrote:

I want to make a bangle out of copper, with a silver lining. Simply =
because=20
copper tends to stain the skin.

One approach could be to create two bands, one of copper, one of =
silver,=20
with the tolerances so snug the silver band fits inside the copper =
band.

Or I could take two flat bars (0.25mm thick for example) of each =
material,=20
join them together (solder?) and then form the bangle.

So wht I want to know is which approach is best. Join and then form the=
=20
bangle, or form two bangles and then join.



The answer to that, for me, would depend some on the way you're attaching=
the
two together, plus whether the inner and outer layers are the same =
dimensions.
If you're planning to completely solder the two together, and both pieces=
are
the same length and width, then I'd say it would be a lot easier to sweat=
solder
the two together while they are both nice and flat, and can be fitted =
very
easily. Expansion and contraction from heating shouldn't alter the fit, =
and you
should be able to quickly produce a single blank which is a nice solid
bimetallic strip, copper on one side, then silver on the other. As a =
solid
piece of metal, even though two pieces, it would then not be difficult to=
wrap
the two around into a bangle. This saves the whole bit about having to =
make two
seperate bangles closely fitted, and as two closely fitted bangles, you'd=
still
have to perhaps wrestle with problems of the outer bangle expanding away =
from
the inner one while soldering or other thermal warping problems getting =
in the
way of a good fit while soldering, either from different rates of =
expansion
between the two metals, or if you got one hotter than the other one. So =
if the
two pieces are the same size initially, I'd solder them flat. I'd also =
leave
the two blanks slightly oversize in both width and length when soldering.=
That
would give you room to trim up the ends, which will distort slightly on =
bending
and shaping. And any edge distortion caused while bending could also =
then best
be cleaned up after bending it around.

Now, if the inner layer is smaller or larger than the outer layer (wider =
or
narrower, then bending the two together will cause distortions that you =
might
not want. If the inner layer were wider, it's edges would flare during =
bending
into a bangle, for example, and if that was not desired, then making the =
two
pieces seperately and fitting them would be preferred.

Also, if you're attaching the two layers with something other than =
solder, such
as rivets, then also you'll probably need to form them seperately and fit=
them
together.

Peter

Michael wrote:
I want to make a bangle out of copper, with a silver lining. Simply =
because=20
copper tends to stain the skin.
=20
One approach could be to create two bands, one of copper, one of =
silver,=20
with the tolerances so snug the silver band fits inside the copper =
band.
=20
Or I could take two flat bars (0.25mm thick for example) of each =
material,=20
join them together (solder?) and then form the bangle.
=20
So wht I want to know is which approach is best. Join and then form the=
=20
bangle, or form two bangles and then join.
=20
=20
=20
=20
Can you post some more information?
such as the proposed bangle width in the thickness you specify,Also=20
wether its to be flat or curved in section?
and wether its an open type ie cuff fitting or a closed circle?Because=20
how you make it will largely depend on the design.
Peters general reply covers a no. of ways to achieve what you want.
Having made lots of bi and tri metal bracelets both open and closed=20
Ive had to use different ways to get the different layers to lie tighly=20
against each other after bending.
=46or example,
if you take say a 1/4in round copper rod, form into a circle and=20
solder shut.
Its much easier then to make an interference fit lining as a flat=20
insert then dess up to fit the bottom half of the copper than to do it=20
before you make up the copper circle.
Say you wnted to use 1/4 wide by 1/8in thick copper as an open cuff=20
type, then you use 1mm silver sweated along its length, clean up then=20
use a soft plastic or leather mallett on your smiths stake to form into=20
the cuff shape,.Needless to say you need to ensure your stake is free of=20
marks and highly polished otherwise youll mark the silver in the process.
this shape is normally like the letter C
you will learn a lot by trying this! for example where to start bending=20
first. Also if you aiming for a specific wrist size youll need to make=20
it a shade larger as you can always make it smaller but NOT larger.
you will find if you try to sweat the 2 .25mm strips together you will=20
have difficulty keeping them dead flat .As once soldered any uneveness=20
cant be removed. Also the bi metal strip will become very much stiffer=20
to form into the shape you desire.
You may need to use thicker siver ,say 1mm with 1/2mm copper.
Much easier to manage and little erxtra in cost.
Mor info is really needed to give a considered and specific reply.