Is there anything in particular or special that I need to know or do to the scrap before, during, or after
there are all sorts of things that you can do. I’m not even going to
scratch the surface. I make wire every day, and though I do make
sheet, it tends not to be of the same quality as that from the
bullion dealers. Wire I can make to a very high standard, so I’ll
focus my advice on that.
Make sure your metal is very clean before you melt it. If you are
working to a hallmarking standard, add a small amount of higher carat
material (eg. fine silver, 22ct gold) to ensure that the fineness of
the metal is high enough. You should have removed any solder before
melting up, because it lowers the carat of your metal, and ruins the
working properties of the metal.
Melt your metal in a crucible with a low-oxygen flame. I often add a
well-mixed paste of charcoal, borax and water before I add the metal
- this serves to remove some of the base metals, and if you intend
to roast the metal for a long time like this, ignore the advice
above about adding finer metal.
Then, using casting sand or similar, make a one-use ingot mould. I’m
usually working with a lot less than an ounce of metal. I use a
rectangular piece of steel to push a depression into the sand, then
pour straight into that. That gives it really neat sides, and I much
prefer the open method to using steel ingot blocks or an open iron
mould. The resulting ingot will look a bit like a loaf of bread, but
tiny.
Pickle and clean the ingot, then hammer the top side and end surfaces
to compact them. Anneal and pickle. Then either hammer the ingot into
shape, or use a rolling mill with holes for square wire. If you only
have a flat roller, it might be too time consuming to make your own
wire - does anyone else have a good method?
Any “feathering” on the edges of the metal should be filed off, and
if you see this feathering every time you roll the metal, it may be
too far gone, and need to be melted up again - the feathering can
get worked into the structure of the wire, causing it to flake or
break when you try to bend it.If you have round or half-round
rollers on your mill, set them so they will just touch the metal,
and roll your square wire through 4 times, one for each surface (you
only need do it twice if they are fully round rollers). This removes
the flange left by the square rollers, and softens the edges very
slightly - I actually think this is better than true square wire,
because it’s a lot less likely that you’ll unevenly round off the
edges while working with it. If you are making round wire, continue
this process to soften the edges further - this makes it much easier
to draw it through round holes.You must have a draw plate.
Unless you want to do it like the ancients did (if you do, email me,
and I’ll send you the link for a journal article. Draw plates are
fairly similar. Don’t try to draw more than 3mm wire by hand, as it’s
more effort than the metal is worth, and less than 0.5mm can get very
annoying. Once you have your wire, it will be curved. Straighten it
with one of two methods. For round wire only, you can twist it - 8
turns left, 16 turns right then 8 turns left again to bring it back
to it’s original shape. Do this while keeping the wire tense, and it
will be very straight. The alternative, for anytype of wire, is to
clamp it in a vice at one end, and hold it in tongs at the other end.
Then, carefully move your torch flame up and down the wire, while
keeping it tense. It will gradually straighten AND it will be
annealed. Always pickle and polish and clean the wire before use, and
it will look as good as anything from the bullion dealer.
Hope there aren’t too many typos; got to get to work now! Comment and
abuse to the usual address