I tried it on some leaking rivets which were just too deformed to rebuck anymore, and at least in my case, the temperature you had to get the aluminum for the brazing rod to liquefy was so hot that it warped and deformed. Granted, this was with an older 12' sea nymph, but it caused more problems than it solved by deforming the hull.
I had mixed results attaching strips of a heavier gauge material (1/16" thick 1/2" flat bar) to little cuts of angle to make a tackle rack. The brazes turned out to be brittle, and in a year of use roughly half the brazes have failed. Again, the melting point on the braze is so close to that of the aluminum that on several pieces I actually melted the aluminum with the torch before the brazing rod would flow. Some of the brazes have held, but they were the ones where the aluminum was close to its melting point and very soft at the point when I was working. I can tell after the fact because the aluminum was deformed and needed to be touched up with a file so it didn't have protrusions interfering with the tackle trays.
I'm certainly not an experienced welder, I can definitely do a better job than Weld-Bilt with my mig working aluminum now (not that that's saying too much either) but I've had no luck with this product. Before anyone comments on the cleanliness of the aluminum I cleaned it thoroughly each time with both a degreaser and rinsed with alcohol then wire wheeled each spot to be worked with a stainless wheel I have only for working on aluminum.