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Soldering troubles


#1

Hello all,

I"m trying to solder a ring together, and I’m having the same
problem on pieces of test metal, hoping I can find some answers here.
My problem is simply that my flux burns up too quickly. I’ve tried
adding more flux, reducing the size of the piece of solder I’m trying
to melt, and a number of other things, but it just won’t work. I’m
using medium grade silver solder (70%), but I’m wondering if my flux
isn’t the issue. It’s paste flux that came with some electrical
solder, is this the problem?

Thanks in advance, Devan Moorman.


#2

That is certainly a problem. Fluxes made for soft solders (tin-lead,
etc.) will not work for hard solders, which are really brazing
compounds. You need to get a flux designed for hard soldering. The
most basic is a simple paste of borax; but not the washing powder,
that’s not pure borax. There are plenty of prepared hard soldering
fluxes for sale by your favorite tool supplier.

BTW, anybody still grind their own borax?

Elliot,j


#3

I cant say your using the wrong flux as Id need to see you use it.
However your certainly not using the right flux.

The simplest is ordinary borax.

However that wont take a lot of heating. so google for Johnson ever
all round brazing flux for all your silver work.

Its highly reactive, water soluable, and dissolves copper and silver
oxides very well. Use lots of it, all over your work it will also
leach out fire stain as well.

Ted
In
Dorset UK.


#4
I'm using medium grade silver solder (70%), but I'm wondering if
my flux isn't the issue. It's paste flux that came with some
electrical solder, is this the problem? 

Sounds to me that the flux is for soft solder, rather than silver
solder. If that’s the case then it’s useless for your requirement.
Get some Johnson Mathey EasyFlo flux (or equivalent), mix it to a
thin paste with water and a drop or two of washing-up liquid, and it
should do the job beautifully.

Regards, Gary Wooding


#5

There seems to be a bit missing from this post. so ill add it.

I suggested you google for Johnson Matthey stainless steel grade
Easyflo brazing flux.

It comes in a 500 gram plastic screw topped pot in powder form. Also
its hot water soluable.

Its a superb flux for just about very brazing job, and its the only
flux I knowof that leaches out fire stain from silver. It wont do
aluminium bronze brazing and proper brazing with brass. that needs a
much higher temp flux.


#6

Paste flux from electrical suppliers will be for soft solder such as
lead and tin. Electrical suppliers don’t do much hard soldering.

Move up to plumber suppliers for hard solder fluxes, and move up
again to jewellers suppliers for the same hard solder fluxes at
similar prices, but more tailored to what you need for jewellery.

If in doubt, use borax powder very cheap at the supermarket; also
cheap at jewellery suppliers.

Alastair


#7
I suggested you google for Johnson Matthey stainless steel grade
Easyflo brazing flux.

Superior #601 white brazing flux here in the U.S., I have used it
for over 30 years. I have used it on sterling, gold,copper, brass,
and ferrous metals.

Richard Hart G.G.
Denver, Co.


#8

Hi Elliot,j

My cousin who is many years older than I am was a jeweller & he gave
me a Borax cone & piece of slate he used for years, so I am now
grinding Borax.

Phil S


#9
I'm using medium grade silver solder (70%), but I'm wondering if my
flux isn't the issue. It's paste flux that came with some
electrical solder, is this the problem? 

Electrical solder flux is intended for soldering copper, not silver
or gold or suchlike. It’s likely to have something in it that would
cause problems (present or future) when used on silver.

Margaret