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Silver soldering forged steel


#1

Hi

I Build western jewelry, belt buckles bracelets and stuff. I use
steel (but just plate not forged) copper brass german silver and
sterling. Kind of self taught through books and videos.

I have a blacksmith friend that wants me to silver solder some
forged mild steel leaves onto forged steel conchos. Having a heck of
a time. It doesn’t seem like my flux is working right.Most of the
time the solder just balls up on the part. Maybe due to impurities
in the forged steel.

Any help woud be appreciated
Thanks Garth


#2

Go to your welding supply and get some Harris Stay-Silv Brazing Flux
(black). This will allow you to get better fluxing action than the
white paste flux. Also I would get some Harris Safety-Silv 56 silver
solder. It melts at a 1145-1205 F so it is equivalent of an extra
easy silver solder but it flows very well. It is a little too yellow
for most work on sterling (about like most other extra easy solders)
but on steel or copper it works great.

James Binnion
@James_Binnion
James Binnion Metal Arts


360-756-6550


#3
... It doesn't seem like my flux is working right.Most of the time
the solder just balls up on the part. Maybe due to impurities in
the forged steel. 

What flux are you using?

I’d use ‘Black Flux’ for that job, or another flux designed to
operate at 1000C (1800F) and to keep down the steel oxides, and use
hard silver solder.

Brian
Auckland NEW ZEALAND


#4

I would guess that you are not getting the metal hot enough. Use a
bigger tip or build a wall with fire brick around it to contain the
heat.

marilyn


#5

Brazing will fix your issues (brazing rods and oxygen+someting for
fuel).

David


#6

Hi all

Thanks for all the Ideas

I ended up drilling a hole in the center concho, then tig welding a
short piece of rod to back of the leaf.

I then put the rod through the hole and tigged it again from the
back side of the Cocho.

Garth


#7

There are other things to consider than the flux. The black flux is
better on ferrous materials than the white but that will work too.
Don’t ever rely on flux to clean the metal surface. It keeps the
surface oxide free when heated.

Always clean the surface mechanically before silver brazing. On a
forged steel item you may or probably want to retain the black oxide
surface from the forging. This is an iron oxide, magnetite that is
mill scale when thicker. then just spot polish the area that you want
to solder then flux.

The balling up of the solder on a clean surface indicates first that
you are melting the solder before the base material is hot enough. If
the surface is dirty that does it too.

The rules may call for a neutral flame, but a very slightly reducing
flame will work better.

This insures that the flame isn’t oxidizing. With silver brazing you
want to heat the part so it will be at soldering temperature before
you apply the filler metal. On very heat conductive materials-- brass
and copper, silver etc. this requires a big brushy flame depending on
the object mass.

On a very poor conductor like stainless steel and a little less for
steel, you don’t need to get the whole piece hot just the area you
want to join. In this case a much smaller tip is what you want as you
will get the joint zone hot quickly and then be able to run the
solder around the joint. Keep the heat toward the big side. If you
don’t stick and the material gets black – clean up and start over–
fooling with it won’t help. Practice.

see: http://www.handyharmancanada.com/TheBrazingBook/bbook.htm

jesse