Joining Small Aluminium Tube

I'm trying to make a set of scale retracts out of aluminium tube (7/32",
3/16" and 5/32" but wondering how best to join the parts. I know that if I want to WELD aluminium then I need to TIG weld it, but is it possible to braze/silver solder this?

I should know the answers, coming form an engineering background, but it's been a while...

Silver soldering or brazing alloys don't work on aluminum.

See the product selection chart at http://www.jwharris.com/jwref/chart/

The fillers of choice for soldering aluminum to aluminum are Alsolder
500 and Al-braze 1070.

Then see the product descriptions at http://www.jwharris.com/jwprod/solderalloys/

Neither Alsolder 500 nor Al-braze 1070 contain silver.

What I've actually got is a sort of T-piece, with one length of tube passing at right angles through a hole drilled in the other. After looking a bit deeper on the web, it would appear that I can use silver solder on aluminium, so maybe I'll give that a go.

Thanks for the tips,

Just looked at the JB Weld info on the web and may well give this a go.
Sounds like a simple alternative.

Not mine. I simply needed to solderalumium tabs on some LIPO cells I had bought. A google search got me to a model train shop who sold me some
Carrs Grey Flux. That was the killer breakthrough. With a hotttest irin setting and an open window (fumes are VERY unpleasant), I gobbed this blue jelly onto some baking foil, fed in multicore, and by golly it wetted it!

Once tinned of course the problem was solved.

I note you are in Oz. Try a google search on 'alumiium solder paste' and 'Carrs flux'

Carrs are, I think UK bvased, but have European and commonwealth reach, whereas US suppliers seem to have the paste more.

The paste is, I think, mixture of solder and flux.

Try it, but remember aluminium aircraft are bonded together with epoxy.
Given the arrangement you have, that might be the easiest solution, and if you are painting the result, just as acceptable as brazing.

Its p[ossible to soft solder it useing aluminium specificflux and a special solder, although for electrical ork, standard multicire seems to work OK,.

However I would regard epoxy as a stringer solution.

I have welded aluminium years ago as an apprentice, usng oxy acetylne.
Bloody mess. Very hard to stop it melitts p[ossible to soft solder it useing aluminium specificflux and a special solder, although for electrical ork, standard multicire seems to work OK,.

However I would regard epoxy as a stringer solution.

I have welded aluminium years ago as an apprentice, usng oxy acetylne.
Bloody mess. Very hard to stop it meliting.

How come no-one has mentioned argon arc welding ?
When I was a young sprog (back in the mists of time) aluminium was welded by means of argon arc and (I think - it was a while ago)
aluminium rods of different gauge.

The chap who normally did the argon welding was playing about one day and actually welded 2 pieces of aluminium foil together.

Has argon arc gone out with the ark ??