Tips on welding/grinding aluminum

I am fabricating a project for my father for his (and my, same day) birthday in april. Its out of aluminum diamond plate. Its going to be a maltese cross with some other things im going to fabricate welded to it. In the center i will have the firefighters prayer painted with flames surrounding the center with the numbers of every station he has been assigned to.

the only problem is i have no clue how to work with aluminum. Ive done some research on how to grind it, but i dont know where to start mig welding it.

heres the cross cut out (plasma cut)


heres the design before i cut it.

 

You are using a Mig with and aluminum spool and gun right? They also have disc or flap disc for aluminum only

 

I would have done it in steel. Why? Cause I haven't the slightest clue when it comes to aluminum.

 

im not sure. Im going to pick up a few of those flap disks tomorrow. Im still looking around for a welder. im using my welding classes right now and im not sure if we have the spool gun. Would TIG be easier? Keep in mind the aluminum is only 1/16th

 

I wanted to but im short on funds and i was given a fat chunk of this diamond plate among other pieces of steel tubing and metal and such

 

Ah ha!

 

Wow, 1/16" aluminum will be just about impossible to weld, especially with Alum MIG. I find welding anything less than 1/8" to pretty much not be worth my time. TIG would be the way to go, better heat control that way but it still takes some skill with TIG on that thin of aluminum. Way easy to melt through it...

 

you can use a arc welder to weld aluminum with an aluminum welding rod but you have to switch the welder to reverse polarity, If you use a mig welder you have to get a special gun and different gas

 

Better off using tig. Also make sure you clean it REALLY good before you weld. Any contaminates will mess you up.

 

x2, Contaminates are a huge factor, makeing sure its clean will go a long way. If you have never welded aluminum with a tig you might want someone who has to give you a hand or you will have holes all in it (aluminum heats up extremely fast), and you will not be able to get the diamond plate look back in it after too many blow troughs.

There are grind wheels and flap disc's ment for aluminum, also remember aluminum grinds very very easy, unlike steel.