aluminum welding

[boilerdave]

I have a chance of landing a job in my backyard.The county is installing solar panels.I am assuming that the frames for the panels will be aluminum.I have a miller thunderbolt AC/DC 230 shop welder and a miller big 40 dc constant current gas driven machine.Would either of these be of use or should I consider an alternative? If so can someone recomend a machine with portable capability which I will have to rent.TIG or MIG?

[Mainely,Bob]

To get you started you can go down to your welding supply shop and see if they have a trade in machine that`ll run a spool gun.After you make some cash you can go to a TIG with a water cooled torch.You`ll need the cooler to weld aluminum for any amount of time.
Don`t let them talk you into a mig or a suitcase wire feeder,you`ll spend more time playing with the torch and liner than you will welding.The only mig for aluminum that I ever used successfully was a push-pull unit(big bucks)or a severely cut down suitcase,like about a 4 foot whip with the suitcase hung overhead.
Trust me,you want a spool gun to start out.

You do know you can torch weld aluminum don`t you?

[BIGGUNDOCTOR]

I used to do frames for highway signs that were made from 1/4" web aluminum box channel. I did them with my large Miller MP65E Mig. I was running .0625" wire ,and a teflon liner. Just a pusher feeder, so I had to keep the cable straight to run best. A spool gun will be better, although if you are running a lot of bead you will be changing quite a few of those 2# spools. A push pull unit like a Cobramatic will take the larger bulk spools, and usually a better price per pound that way. Tig was just too slow for the frames. It took less than half the time to weld with the Mig compared to the Tig.

Aluminum requires some power to run since it sucks the heat up so well. If ya got the juice, spray arc is nice since it really cuts the splatter down.

The joints will have to be really clean before welding. I used a SS wire brush to scuff the naturally occurring anodize that forms on aluminum. Scuff till you feel the bristles biting into the aluminum, or put a weld prep on the edges.

Good luck with getting the job.

[arftist]

The Big 40 would run a spool on gun, with a pretty expensive adapter box from miller. Probably not worth it. The buzz box will not work since it doesn't have high frequency. You could get a high freq adapter but it doesn't really have enough power anyway. A good portable tig would be an inverter like http://www.thermadyne.com/thermalarc/products/prodList.html?brand=TAI&W2Code=TAI210000&W3Code=TAI312000&W4Code=TAI412400&W5Code=&W6Code=

[HWHII]

I have done miles of aluminum welding in my career. I have welded aluminum items in everything from skylite frames, structural, ASME IX xray quality high pressure piping, tanks, missile shipping containers and I could keep on naming.

I think you really need to look at upgrading your gear. Most items I have worked on required both MIG and TIG to get the job done. I have run MIG spool guns, Cobra Matic's short circut transfer and spray transfer and TIG on Miller, Lincoln, Esab and Linde equipment. I think the hot ticket for aluminum welding now is pulsed mig welding. I have trained and certified lot of men to use this process and it is easy to learn and works well out of postion.

If you are interested in more info PM me and I will try and help you out.

[Larry H]

I've done my share of alum., stick mostly,...mig secondly. If you are a good weldor, you can do a pretty good job with practice if you use thin rods 3/32 " for example,...with short welds or tacks, on 1/8 alum. I bought a hobart 110 volt machine after the supply guy welded a pass that looked like a tig weld. He used a pull-push technique. If you have time and materials, practice will pay off. ( it doesn't hurt if you get a quick lesson from someone who knows ). The heat was all the way up and the wire was all the way up.If you use a stick you have to push the wire into the weld and feel the resistance popping against the rod,... hope this helps

[Bryce Masuk]

I always thought all aluminum mig welding was spray arc?

at least that is what I have always done, maybe short circuit works with large diameter wire?


I would get the job first and get a used miller 251 or lincoln 255 with a spool gun.

your going to want a 250 class machine its the way to go for general shop stuff

[Mainely,Bob]

I always thought all aluminum mig welding was spray arc?

at least that is what I have always done, maybe short circuit works with large diameter wire?

I have always used spray arc for Mig with aluminum either conventional spray transfer or pulsed.Pulsed makes vertical and overhead easier.
Saw quite a few fellows trying short circuit like they used on steel,never saw one get the penetration you get with spray arc.
Cut a lot of SC work apart in order to clean,prep,preheat and properly spray transfer weld it back.SC`d aluminum may look sweet on the surface ,when they break you find out looks aren`t everything.

[Scott Hightower]

TIG will produce a more aesthetic weld.
MIG is OK but you should use a spool gun and you must use 100% argon as the shielding gas.

Both will take some practice.

Scott
Welders360