it will stay sharp for the most part, the flat will round just a bit but i have had it look like new after welding with no signs of use at all. after i stoped dipping the tung. in the weld i found they realy last a long time. i use 2% if i didnt mention it.
as long as you can turn the amps down the top end should not be an isue for blowing threw the aluminum. its just a tricky thing to get right.