An interesting idea for soldering

Hi folks,

This may be old news for some of you but I tried an experiment the
other day that I thought I’d share for general
Recently someone asked about a copper colored solder alternative
for keeping colors uniform. I thought that, since gold of one carat
(karat?) can be soldered with a lower karat gold alloy, similar
things might work with other metals. I had read that cartridge
brass was substantially different in alloy than red brass and that
their respective melting temps were also different with the
cartridge brass melting at a cooler temp. Since I wasn’t sure if
this was ammunition-style cartridge brass or not, I pulled out an
old dented and spent cartridge case ( I also reload ammunition as a
hobby) and cut it down somewhat into little paillons. The brass at
the case neck is considerably thinner. I cleaned the brass up very
well before cutting it. I used handi-flux and tried to solder two
scraps of copper together. It worked very well. If one controls the
amount of this brass used it makes a very clean join. After I
pickled it I absolutely could not tell a color difference between
the two. I hit it with a stainless-steel toothbrush ( hard-core
hygeine) to really clean it up. I was then able to detect a slight
color difference but it wasn’t nearly as obvious as using silver
solder on copper. I haven’t tried red brass for copper but, with
careful torch control, it seems it could be used as well. The
melting temp of cartridge brass was considerably less than copper so
it worked well.

On a similar note I tried brazing steel with plain brass craft wire
sized at 20 ga. It requires the judicious use of brass and has a
distinct color difference on steel. Nevertheless it brazed quite
nicely. Cartridge brass would no doubt be useful here as well. They
may actually be the same type of brass, I don’t know.

On a completely different topic, I built a small toy steam engine
out of brass and copper. It functions properly when cranked by
hand. I’m in the process of building a small boiler for it (2 1/2’'
long and 1 1/2" diameter) to see if it’ll work in the real world.
My main difficulty at this point is in building a pressure relief
valve for it. I’ve got a prototype valve built but, without a way
to verify pressure, I have no way to calibrate the valve to safe
levels. Improper calibration here could lead to the thing exploding
somewhat like a small hand-grenade. Not something I’d want sitting
on my desk. I’m hoping to eventually fire it with a votive candle
or a small container of gelled alcohol like Sterno. This may not
be jewelry but, most of it being built on a miniature scale, I’m
getting plenty of practice cutting, filing, fitting and soldering.
It’s all metalsmithing in the long run. My engine plans came from a
book originally published in 1913 and consist primarily of 3 drawn
pictures and 60 sentences or so. Not a measurement to be had
anywhere, just basic descriptions of the component pieces. It’s been
a real adventure so far. If the prototype engine and boiler work,
I’m planning to shrink the whole thing down to about 4 inches in
any dimension. I may make it out of sterling but most probably
copper and brass because they look so good on tiny machines, all
polished up and shiny. I’ll keep the forum posted with my progress.
I don’t know who’s happier here, my beret-wearing artistic side or
my mad scientist with uncombed hair. Either way I’m having great
fun learning all of this. There’s enough science and creative
impulse in this project to keep both sides of me giggling like a
silly schoolgirl. I’m a guy so it isn’t pretty.


My main difficulty at  this point is in building a pressure relief
valve for it. I've got a  prototype valve built but, without a way
to verify pressure, I have no  way to calibrate the valve to safe

How about using nitrogen or CO2 with a regulator to deliver pressure
and test the operation of the relief valve. Every restaurant with a
fountain dispenser uses a co2 regulator to control the pressure and
should be easy to find a regulator inexpensively.

Dan Wellman