Is there a soft wax which I can use to take impressions?
Alma, the very soft waxes, like sculpture wax or the red boxing
waxes are fine to push into a surface like that, but then difficult
to remove.
A method that works well, though, is to use slightly harder, but
still flexible sheet wax, such as the pink or green sheets, or the
harder salmon colors if you warm it up a bit so it's flexible. Then,
and here's the cool trick, put a layer of saran wrap or similar
plastic wrap between the wax and the pattern. Sandwich that with a
rigid hard surface like a sheet of thicker metal, behind the wax
(another sheet of plastic wrap between that back plate and the wax
is a good idea too. Also put something rigid behind your pattern if
it needs it. The squeeze the whole sandwich, pushing the wax into the
pattern. A vise works well enough, or a hydraulic press works even
better if you have one. Doesn't need all that much pressure, but the
presses are good for keeping things flat. What the plastic wrap does
is act as a seperator, so you can peel the wax sheet layer from the
pattern, and then peel the saran wrap from the wax. No sticking, or
at least, much less than if you pushed the wax directly into the
metal.
I remember using this method to take impressions of linotype plates
(commercial zinc or magnesium etched printing plates) The results
would be wax sheets with very precise "stamped" images of the letters
in the wax. Because the "precision" surfaces of the plates are the
high flat printing surfaces of the zinc plates, when cast, the
bottoms of the "stamped" letters are crisp and clean, and don't get
messed up when you clean up the castings, as the somewhat distorted
upper surfaces of the "stamped" images aren't what you look at (this
is the same idea as what you see with physically stamped letters
using hammer driven stamps directly on metal). This method was a
great way to make cast plates with crisp lettering on them, such as
for medallions or other needs. Now, generally done by cad cam direct
carving of the wax, which is simpler. But the older method still
works as well as ever.
Peter
