Re: ATM Aluminum solder

["Clive Milne" <milnecd@wantree.com.au>]

>I want to solder some aluminum tubing together.  Does anyone know how 
>those low temperature solders do on ATM stuff.  

...Hi Lui....
Yes, in theory it is stronger than the base metal, ......however in my 
experience I have found the stuff to be tempremental....  the strength
of the joint is greatly effected  by any oxides or impurities....even a
trace and the joint is toast.... I also found on heavy (5mm) gauge stuff
that an oxy / acetelyne torch is required to supply enough heat, 
unfortunately the impurities in the acetelyne flame seem to make it
damn near impossible to get the stuff to work.....
....I perservered for a week or so, going through different types of 
sand paper and several stainless steel brushes before giving up
on the stuff, I use a MIG welder now, and I am so impressed with the
integrity of the joins and relative ease of use that I find it difficult to
imagine going back to the Alu~solder.

....The fact that none of the hardware chains around here will 
entertain the idea of stocking the stuff is a bit of a clue that I am not
isolated in my experience..... 

..Ohhh, and after I had consigned the Alu~Solder to the deepest
corner of my tool box, a model engineer friend of mine suggested 
preparing the work with nitric acid .....   Never tried it, but he assures
me that it solves the problems.....   

......I think I will stick to the MIG welder, just quietly......    ;-)