I have read numerous times that grinding/cutting/sanding aluminum that needs to be welded with an abrasive disc is something that you should not do because the particles get inside the aluminum and contaminate it. I have some plate that I need to shape and have no way to make it circular without taking the grinder to it. If I grinded it down and then took a file to all the edges that I ground would it be ok to weld? I'd love to just test it out myself but it is 6061 and it cost me quite a bit and I only bought what I needed anyways. Any advice or comments would be appreciated.

 

it should be ok. just take a stainless wire brush to it before you weld it. i haven't had any issues doing it that way.

 

yeah youll be fine, wash it down with a alu cleaner (acetone or something along those lines) if you concerned about it, but you should have zero problems, i hardly wire my stuff down and it welds nice a pretty

 

grind it and then clean it up with a file called a "super shear" it's a super aggresive flexible file that's used for something else that I can't remember. It works awesome.

It really matters what kind of grinding wheel you use on AL too. Hard discs dig in too agressively and leave a lot of crap behind. I like the blue flap discs.

 

Yea you will be fine with a flap disc just make sure you havent been using it for steel. We also have an attatchment for a 4 1/2" grinder that lets you use velcro backed scotch pads. They work really well especially on very thin Alu where you cant afford to lose any thickness

 

yup all of the above work great. I really like a carbide burr for non ferous metal too. leave a very smooth clean finish. I dont even use any solvents if I prep an edge with a burr.

 

I use an Al specific grinding disk and cut off wheels to cut a good portion of the Al I fab and weld, and my welds are minty clean. I'll post up some pics soon.

 

Thanks for all the replies guys.