Originally Posted by
Singlespd
I guess we should ask the OP if the guy who welded it knew how to fix bike frames and did he drill the crack on both ends to keep the material from cracking more. Did he then grind a valley along the crack for the filler rod to pool and penetrate and did the welder use the correct filler rod for the type of aluminum used in the frame? Was it heat treated? We dont know. If everything was done correctly then I dont see any reason why it cant be ground down. Its up to the OP to decide if he want to take a chance
Just face it, you are wrong. I mostly deal with steel but it is never advised to grind down the weld when it's a structural component. I'd leave the weld as is and on top of that, it doesn't even look all that bad, after the paint gets some dirt on it, I doubt anyone would even notice the weld.