Model Forum / Radio Controlled / Water Models / September 2004

there are aluminium soldering kits and I have had a lot of sucsess soldering
a broken aroplane engine back together
try loooking at http://www.techno-weld.co.uk/home.html its so easy and if
you are a member of a club they do a great talk and demonstration (or at
least they did 4 years ago) and as for stainless I never have tried

Soldering Stainles Steel (SS) is relatively easy if...

1. Everything is CLEAN, no oxidation, no oil from your fingers, no
nothing.

2. You use a more aggresive flux. Rosin-core solder typically used for
electrical work will fasten SS to steel. But not if you are depending
on the rosin core flux. Get a small container of plumber's paste flux.
It is much more active and will do what you need.

3. Practice good heat control, the joint has to be hot enough to get
the solder to flow. Notice I said "the joint has to be "hot enough".
The soldering iron or torch is hot enough to melt the solder, but if
the joint is cold, the solder will not flow and the joint will fail.
But don't get the joint too hot because that promotes oxides which
prevent the solder from "wetting out".

4. EVERYTHING IS CLEAN. Trust me on this, if things are not clean, you
are just wasting your time. If your first attempt is not satisfactory
and you want to start over, you need to first clean evrything again.
This includes the flux residue from the first attempt.

Here is a page which discusses a resistance soldering unit and
soldering fundamentals:

http://www.cox-internet.com/drspiff/electronics/resistance.htm

Good Luck

First saw this at a BOC trade show some 7 or 8 years ago. As said VERY
easy as you only use the annealing temperature of Aluminium, found by
heating
until soap goes black, and the instructions are very comprehensive.

BOC still sell it here in Ipswich, so you should be able to get it most
places in UK.

As for stainless if its not too thin, and can take the heat Brazing woks
very well, as does silver solder.

Cleanliness is a must, as are the correct fluxes.

Neither of these techniques should hold too much bother once you have a go
and get the temps correct.

Let me know if you have trouble getting hold of the TchnoWeld. As I
remember
it was used for joining copper fuel pipes to aluminium fuel tanks, by the
MOD, so should be ok for most jobs.

Hope this is of some help.

Cheers Vaughn

find a local machine shop and ask them if they can do it.

sometimes if you word your request right, it'll cost you almost nothing.