Copper Models Patching

Jewelry Discussion
1

I’m in the process of creating some metal master models for casting.
These models are etched and engraved. Under even the most controlled
situations etching can produce some surprises. I need to patch a
pinhole hear or there and in the areas where a line or edge was
lost, I need to build this back up and re-sculpt it.

The dilemma is that the material I use to fix these imperfections is
going to determine what type of molds I have made from the models. I
need to choose between vulcanized molds or silicone. Even though I
will lose some size, I preferred vulcanized rubber because it is
stronger, but if I use wax as my patching agent, then I will have
to go with silicone, which may break down in a few years causing me
to have to pay for new molds for all of these models again, and
there is quite a few. I also tried using soft solder, but it didn’t
allow me the control I require.

So the question: what do any of you on-list suggest I use as a
patching material for copper models?

Thanks all for reading.

2 
    So the question: what do any of you on-list suggest I use as a
patching material for copper models?

How about a two-part liquid metal patch like JB Weld? Or you could
try lead/tin electronic solder with a soldering gun.

James in SoFl

3 
    So the question: what do any of you on-list suggest I use as a
patching material for copper models?

The perfect material for this is an epoxy material called J. B.
Weld. It’s carried in nearly any well stocked automotive or
hardware store. Once cured, the stuff can be worked like metal, and
will withstand pretty significant temperatures.

Ron Charlotte – Gainesville, FL
@Ron_Charlotte1 OR afn03234@afn.org

4 
what do any of you on-list suggest I use as a patching material for
copper models?

The traditional method and still the best, is to drill out the
imperfection, thread the hole and screw in a threaded copper rod. If
you make the thread on the copper rod slightly on the large size by
wedging the die open slightly in the diestock and, after screwing it
into the hole and cutting it off flush, you gently tap it with a
hammer to spread the top a bit, it can be finished so as to be
virtually unnoticeable.

Virtually every bronze sculpture is ‘repaired’ in this way as it has
always been almost impossible to make large castings with no
imperfections. You will see this technique has been used on even the
most famous old bronze statues if you look closely enough.

Best Wishes
Ian
Ian W. Wright
Sheffield UK

5 
So the question: what do any of you on-list suggest I use as a
patching material for copper models?

I would drill out the pin hole to the size of a copper or silver
wire that I had on hand, insert the wire, and then solder it in place
with silver solder. Then I’d cut off the protruding wire and refinish
the area. Sometimes you can even just do this by riveting it in,
without using any solder at all. I think it is worth it to be able to
make a vulcanized mold.

M’lou Brubaker, Jeweler
Goodland, MN
www.craftswomen.com