Hi Steps,
No idea exactly. What i CAN tell you is that is is definitely NOT a new idea. I saw the EXACT same thing maybe 30 years ago. The trouble with aluminium, is the oxide layer, this is how it protects itself. The bare metal corrodes until it has formed this oxide layer which acts as a barrier to further corrosion, and unfortunately to welding and most other things too.
This layer forms instantly. Did you know you can soft solder aluminium too?? This stuff is most likely. more or less the same thing. The idea of soft soldering it is VERY old..
Anyway, it goes like this. You heat the metal to the melting point of the solder [or this stuff] You melt some of the solder onto the surface of the aluminium and it will sit there in blobs. You then scrub the surface with a stainless steel brush. This abrades away the oxide, and the solder [or this stuff] will then "tin" the surface. Once this is done you can then solder it is the usual way like you would if you were soldering copper plates together.
Cannot see it working quite as they say..... The bit about the threads. They state further on that this stuff has "very high surface tension" so they can bridge the hole in the coke can. This high surface tension would stop it filling the threads of the bolt unless you manage to tin that first. Also, how you going to wire brush down the hole?? you would need a rifle cleaning "bore brush" of the right size and the bristles on these stop half inch short or the end.. Not saying you could not do it, just it would be VERY tricky. Much rather a helicoil myself..
Just an old idea recycled....
The only other thing you can do, is to Oxy/Acetylene weld it. This is tricky to start with, and, you need very corrosive flux, that you must scrub off afterwards or it will eat its way through the aluminium, so no lap joints or "Tee" joints either, as the flux would be trapped in the joint. Pure aluminium is not too bad, but the alloys..... terrible to do.. I only had to do it once, not nice at all, and trust me, i am a VERY good gas welder.... I know a chap that used to do BSA motorbike cases with O/A though, and he thought it was easy!!!
This leaves tig. Tig removes the oxide by an electrical process. You have [with one VERY rare exception] to use AC and what happens is that on the positive half cycle, after positive ions in the arc have blasted the surface of the metal the electrons coming up from the plate lift up and remove the oxide. The shielding gas stops it reforming, but you still have to make sure every thing was spotless to begin with, wire brushed with a stainless brush and preferably wiped off with acetone first. You can actually see the oxide being removed as you weld!! It sort of looks like sandblasting going on alongside and around the weld...
john....
