brazing / gas welding

Happy new year ! We're getting to grips with our arc welding but we have a few threads to repair in small section tube on aftershock that we cant really arc weld / repair easy. We have been looking at some of the gas brazing kits (Mapp gas etc) eg.
http://www.screwfix.com/prods/67191/Han ... -Torch-Kit
and fluxless rods you can get these days for steel / aluminium eg.
http://www.aluminiumrepair.com/more_info.php

Anybody got any experince of gas brazing using disposable bottles and the torch adapters ? Also we'd like to try the odd repair repair on some of Maelstroms minor aluminium damage ourselves rather than rely on the welding company we use to keep us running.

Any advice appreciated. We dont really want to fork out hundreds on a tig/mig if we can help it !
Thanks, Will (and Ian !)