I used lumiweld rods to fix a nigh on impossible to replace oil filler horn on my old motor. The horn was an aluminium alloy of un’known composition & the break had to cleaned with a stainless steel brush (supplied with the rods). The lumiweld made a superb job of rejoining the the broke pieces. The only down side is the lumiweld metal is very hard & cleaning up the joint was a bit of a chore.
The repair was made using a plumbing propane torch. The hotter you can get the workpiece the better the lumiweld flows. As mentioned the lumiweld material is hard as hell & it took a fair amount of filing & emery cloth to get the repair looking tidy.Note to self: I do NOT need another process to experiment with!!
Mind you, it doesn't cost the earth...... Did you just use it with propane, or does it need a hotter flame like oxy-turbo?