OK, new opinion after using these (or trying to use them) for a while. They work great for repairing holes, but I can't get the hang of welding things together with them. It makes a big difference when trying to use different "grades" of aluminum-at least for me. The more common grade I can buy locally is 6061, and my welder buddies tell me that it is especially difficult to weld with gas rods. Softer grades are supposed to be better adapted to gas applications. So, if you are considering these just be advised of what I have experienced. TIG welding is still the best.