removing aluminum anodizing

A word on those welding rods, muggyweld or whatever. It works best on thin stuff like trim and radiators. I tried to repair a crack in a cast al 6 intake Choke stove and could never get the al base hot enough To melt the rod. I only succeded in melting the rod into the crack and the. It promptly fell out after i ran my finger over the cooled weld. So like the demonstrator does, heat the base and wipe the rod onto it until it flows and cthen build up your repair. I was on that intzke for 10 minutes with a mapp gas torch and could not get it hot enough. Oxy would have done it but i didnt have a rig. it probably would have not worked there anyway as it was over the exhaust riser and it gets pretty hot there. Tig welder did it up in aboou 10 seconds.