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Epoxy and embossing with a hydraulic press


#1

I’m working on a series of pieces which need detailing, and was
planning on doing it in the hydraulic press (20 ton). Unfortunately
my first pass at making the die didn’t give the amount of detail I
wanted, so I need to change my approach.

My question is whether epoxy would hold up reasonably well if I
added extra material using it instead of soldering. It would sure be
a lot faster and more straightforward!

My current master is 16 ga brass, to which I’m adding 16 ga nickel
silver wires in strategic places. It might also be reasonable to put
the whole thing on a different base, maybe using the brass master
(somewhat adapted) as a positive plate, instead of adding the wire
to it.

I need to emboss 18 ga. sterling, the pieces about 5 inches (12.6
cm.) across. The silver is dead soft.

I’d appreciate any feedback on this- many thanks!

-Amanda Fisher


#2

Amanda,

I have had success with an Aluminum filled epoxy product from Anchor
Seal Corp. I have cast molds from wax models using this product and
then used these molds in hydraulic dye forming with a 20 ton press.
The product # is SY6018. The web link is:

http://www.anchorseal.com

If you call them they are helpfull with tech advice.

Joel

@Joel_Schwalb
www.schwalbstudio.com


#3

Dear Amanda,

The problem you may have getting detail in embossing could be from
the thickness of the silver. “With embossing on the hydraulic press
greater detail can be achieved when using a thinner gauge.” (from my
notes taken at a Cynthia Eid workshop on hydraulic press use) Switch
from 18-gauge to 24-gauge and I bet you’ll get better detail. Don’t
worry about structural strength as the embossing will add strength
to a thinner gauge metal.

P.S. I would definitely solder any detail wires to the master from
the get go - otherwise you’ll find yourself re-gluing the wires to
it multiple times later on.

That lesson was learned the hard way!

Good luck,
Nanz Aalund


#4

I didn’t catch the original post, just one of the responses, and I
have a few comments about the general process. Most of my experience
here is with adding wire designs and 3-D forms right onto RT/Pancake
blanking dies, but the forming and embossing aspects are basically
the same as with emboss-only setups.

The response I read suggested using solder instead of epoxy for a
better join, and since I’ve rarely used epoxy I’ll mostly refer to
soldering. The times I have used epoxy were in conjunction with
screws, and both were used to attach a cast-aluminum 3-D form to a
large blanking die.

To keep this at a resonable length I won’t go too much into
blanking-die-specific issues, but will try to relate things to
emboss/form-only setups. One frequent issue is the choice of solder
to use. The two common types are brazing (silver soldering
temperature range ) and soft soldering (tin or lead based solders,
operating much much cooler). Brazing solder (I usually go with a “56”,
that melts at the low end of that range) is permanent, and I can’t
recall any failed joints, even on tiny items at high pressures in
high volume runs. One nasty problem occurred with a 4" ring of 16 ga.
nickel wire that wasn’t soldered all the way around to it’s flat
base. The unsoldered sections of wire shifted, and of course had to
be relocated and fully soldered. Actually, I recall parts of that
joint DID tear off, but that’s the only one I remember coming undone
with brazing solder.

Another problem I had with that one was warping of the flat bases (
4.5" squares of 14 ga. steel). The ways I counteracted that were 1)
use thicker steel, and 2) heat from the front and back, alternately.
This helps keep one side from expanding more than the other, which if
it happens, will bow, or saddle the whole plate.

Or, behind door #3… you could use a low temp. solder. The
advantage being that the lower heat isn’t usually enough to warp the
plate (or blanking die). I use tin or something like Staybrite. The
disadvantage with soft solders is that under high pressures they
become weak, and will either break or allow parts to migrate with
repeated cycles. One way to help is to really pile on the solder ; so
that there’s enough mass on the sides of the wires that it doesn’t
give the wire a place to migrate to. Not as easily, that is.

My real innovation (to this exact situation) is to make a hybrid
solder that melts somewhere in the middle between brazing and soft
soldering. There is very little made that operates in this range, and
it’s pricey because it doesn’t come in small amounts, and the one I
liked (700 degrees F.) was almost all Cadmium. So what I do is melt
together (approximately by volume) 2/3 soft solder and 1/3 "56"
brazing solder (56 does have about 20% Cd, so no breathing, etc.),
using the Stayclean flux. It takes a lot of extra heat to get the 56
alloyed in, but once it’s done it melts at a reasonable temp, and the
same flux works. The strength gained with this solder is enough to
hold wires down much better than with pure soft solder, and the lower
heat required becomes much less of a problem with warping plates (and
blanking dies).

Dar Shelton
http://www.sheltech.net