I,m not sure how many here are good welders or what not but i found a product for us not so great welders called aluma weld. it is a welding rod that you need no flux for and can be used with just simple propaine torch and they show them abuseing the remade and welded areas and the weld not breaking but everything else is.

http://www.aluminumrepair.com/?src=google

take a look and tell me what you all think.

Rustbucket- I still have rods of that in my toolbox somewhere- I bought it a few years back to fix a pontoon on my boat. The complaint I had was it seems to melt quickly all at once, hard to control, hard to flow it into anywhere-probably would work with a lot of practice- I ended up using an aliminum flake mixture of epoxy to fix the boat-I even used the same thing to repair an alumimun transmission case.-Good Luck_AL