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Low melting temperature solder


#1

Does anyone have experience or know of any sources dealing with
solder alloys. I understand the range of melting temperature
available in high temperature silver solder, but I’m working with
materials that require the use of solder in the range of tin solder
(450 deg F). The trouble is, they all tend to melt in the same
range, making multiple solderings nearly impossible. So I’d like to
know if anyone knows about formulating other low temperature alloys
that melt at different temperatures. I’d experiment with alloys
myself if I could get tin-silver and silver-copper alloy eutectic
curves.


#2

Michael,

Stay Brite solder melts at a lower temp than 450F.
Stay Brite is also lead free.

If you don’t care about lead being in the solder, then any
electronic solder will work.

Veva Bailey


#3

I don’t have specific but it shouldn’t be hard to find
once you find manufacturers of the types of solder you already know
about. One thing I have done that you may or may not find useful is
make my own hybrid of a low temp solder mixed with something at the
low end of silver brazing solder’s temp. range.

This all started from a bad experience I had repairing a silver
bracelet, Native American Southwestern Indian style, eons ago. I was
happily torching away when the whole body of the thing started to
slump, which was so far out of normal reality that I didn’t snap right
away what had happened. The idiot who had first made the bracelet
had used low temp. solder to attach the bezel cups and decorations
to the bracelet, the biggest NO NO !!! of all in that sort of
silversmithing, in my book.

So, when I was wondering about solder somewhere inbetween the
melting range of low temp and what I always called silver solder
(silver brazing), I thought of this wierd alloying that had occured
between the soft solder on the bracelet and the silver that it was
in contact with. I’ve never done this even remotely scientifically,
but it’s always worked, in a fairly common application I have/had
where I need more strength than soft solder offers, and a lower melt
temp than brazing allows. I did a little research and found one
solder that is almost all Cadmium (decided not to use it) that melts
at about 700F, and that’s more or less the range I wanted.

What I ended up coming up with is simply cutting up small pieces of
the super-easy silver solder (“56”, I believe) and whatever
tin-based soft solder I have on hand, roughly half-and-half, or
leaning towards more of the soft (maybe 60-40 or 2/3-1/3, whatever).
I carve out a depression in soft firebrick and smelt the two
together with lots of the Stay Brite liquid flux.

These mixtures are a little on the brittle side when you’re pounding
out ingots into choppable thickness, but really have been perfect for
what I intend them for, which has mostly been attaching embossing
components onto the face of pancake blanking dies, to make my
feindishly clever One Step Blanking -and-Embossing Dies.

I’ve posted about it before, but basically, using regular silver
solder, the heat subjects the pancake die to temperatures high enough
to distort the die and cause misalignment, which can be fatal (to the
die), and with some designs, de-tempering of the steel will be an
issue. The problem with soft solder is that it gives out under the
high pressures used in the hydraulic press for embossing, so this
hybrid solder is a good compromise, and is my only practical
alternative, since the one that’s actually made for this temp. range
is so toxic. In your position I wouldn’t hesitate to experiment ; you
might easily come up with suitable variations using only a small
amount of braze mixed in with the soft, maybe around 10% or 20%
braze.

Dar
http://www.sheltech.net