Man I hate when people mystify their holy grail product. Aluminum Soldering using zinc been around for long time. Making flux core soldering/brazing/welding wire just as well.
Oh the magic trade secret alloy is probably some variety of AL802 soldering alloy (high temp soldering or low temp brazing if you will) which is 98% pure zinc. Which explains tensile strength also.
For better details look up here http://www.handy-one.com/htmdocs/products/aluminum_filler_alloy_metals/al802.html
For more Al brazing options: http://www.handyharmancanada.com/TheBrazingBook/Section%203/Part%2015.htm
For field repairs you need darn good torch. Aluminum conducts heat very well so it tends to escape welding/soldering area.
For brazing/soldering to work you got to heat up base metal to solder melting temperature and keep it there. Aluminum is particularly nasty for this since it conducts heat so well. It's no coincidence they keep those aluminum peaces in a heavy metal wise. I bet if they pointed thermometer at those they would be conveniently pretty hot (preheated). I mean it's no gimmick or magic, that definitely stuff works but you need to use right technique in right conditions. Soldering Monty's cracked t-case in field, forget it. In the shop, with practice definitely possible.
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