Same stuff as 'lumiweld'.
Surprisingly easy to do, but if its a big bit of ally you need to get a lot of heat into it, My blowlamp could only cope on smaller pieces, a propane torch or oxy torch would be needed on medium to large jobs.
Its simple to do, really clean the area with the stainless brush provided, heat each part and 'tin' each bit with the filler rod as you would do with solder.
Join the bits together and heat, when the filler melts, add a little more along the joint, and a really smooth joint results. Its hard to get it wrong, as long as you can get enough heat into the metal.
The joint is bloody strong as well, stands up well to structural use.
