I've tried it with conventional solder and with silver solder, using a gas flame. The solder just forms small spheres and doesn't stick. Do I need a special solder or flux? what and where can I get it?
Aluminium won't take regular solder - the metal forms a very tough oxide before the solder can make an alloy.
There are 2 main alternatives:
1. Welding - a major skill, and too hard to describe here!
2. There is a special soldering system called Lumiweld - you can buy a sample kit that comes with some special solder, a stainless steel brush and
some instructions. I've used it, and the results aren't bad. Wouldn't use it for something structural, but good enough for most jobs
(I think it uses a zinc alloy as the solder). If you have a BOC shop in your town then they sell it, or you could try
Frosts
is this for a radiator?
I've used lumiweld satisfactorily on these before to make bleed nipple bosses etc.
got a tig now so no probs but used it in the past
Lumiweld and Techoweld - comes in sticks, you heat up the work piece, rub the stick on so it melts then poke away with the stainless steel rod to
break through the oxide.
It alloys with the alumimuim and if done properly is meant to be stronger than the original material 
Aluminium is extremely good conductor of heat so if your workpieces are large, your teeny plumbers torch won't be able to supply enough heat -
place a tray on top of a kitchen hob or camping stove.
I saw a demo of this at one of the shows last year - quite impressive. As said, you need a very powerful blowtorch to make a good 'weld' but the results are often stronger than the actual metal used
Used technoweld years ago. works well but needs abit of skill . quite dear.
B&Q used to stock technoweld or similar uner there own brand usually near the compressors and tools.
I have seen Technoweld used. Its pretty good.
Steve.
You can get special solder for aluminium, it's often used for soldering wires onto the backs of solar panels. It's still not as easy as
normal tin/lead solder to work with.
http://www.maplin.co.uk/Module.aspx?ModuleNo=3952&QV=Y
quote:
Originally posted by MikeRJ
You can get special solder for aluminium, it's often used for soldering wires onto the backs of solar panels.
http://www.maplin.co.uk/Module.aspx?ModuleNo=3952&QV=Y
quote:
Originally posted by 02GF74
***** NOTE - it has been discontinued hence maybe why the search failed?
I bought some aluminium rods from B&Q today. They didn't have the "kit" and only sold the rods in twos. I had a quick go just now and soldered about 50mm of pipe to a 0.5mm sheet. Its quite easy really and the joint is stronger than the [admittedly thin] sheet. It didn't seem to joint to copper too well but I can live with that. I need to get some more rods as they use up quite quickly then I'm away. Thanks everyone.
If you need anything welding up I am not too far away (near hinckey) and can always TIG it up for you (obviously copper included, but not to ally! )
Clean the surface with a stainless steel wire brush (if you have one) first.
Be careful with the heat, as its easy to melt the workpiece... Been there with my excellent blowlamp 
Both lumi and Techno weld are good products but require a little skill as ally melts easilt with too much geat.
A little practice is needed first, and pay attention to the heat you are applying as much as the solder and stainless abrading roc (stirring
stick!)
HTS 2000 is one of the latest to appear on the market, doesn't require the stainless brush etc. Not cheap though!
Have a look on google, there are some good videos of it being used.
I intend buying some direct from the US, much cheaper, even with the postage.
Cheers John
Can you build fuel tanks using sheet ally and lumiweld or would it not be strong enough or leak proof enough?
Ta,
Mark
There is some interesting info on the HTS range here.
http://www.aluminumrepair.com/
For a fuel tank, you need a professional tig welder. It should also be pressure tested when complete. The actual welding wouldn't cost much,
it's the time taken to fabricate the tank.
Don't skimp on safety!!!!
Cheers John
quote:
Originally posted by dern
Can you build fuel tanks using sheet ally and lumiweld or would it not be strong enough or leak proof enough?
would be a pain and a mess
Personally I wouldn't risk my life for a few extra quid getting it TIG'd
Fair points. I'll keep saving for the tig kit.
Regards,
Mark
how's the locost coming along dern? haven't been on the westie forum for a bit now, you still on there a bit?
re. ally welding, I need to sit down and get to grips with it, got the kit to do it now but just not had the time and don't make the mistake of
thinking that once you have an AC tig the ally welds itself, I have found it pretty tricky and I can weld stainless steel perfectly!!!
quote:Thanks for asking - slowly
Originally posted by NS Dev
how's the locost coming along dern? haven't been on the westie forum for a bit now, you still on there a bit?
