DC Tig Aluminum ?

[GiantTechGuy]

Any body ever tried it. Here's an interesting thread over at AWS.....http://www.aws.org/cgi-bin/mwf/topic_show.pl?tid=6980

[TEEJ]

I've never heard of DC tig on al.

[mondtster]

I know it can be done, but I've never tried it. I know there was someone on here that tried it (a few years ago maybe?) and posted their findings but I don't remember who it was.

[Toddy]

DC on big thick stuff. Our welder at work does it all the time. AC just wont penatrate on the big stuff. He doesnt change anything just switches the machine to DC.

Toddy

[StinkBug]

In my readings about the history of TIG I read that they first welded Aluminum with DC, but eventually discovered that AC was a far superior process. It definitely can be done, but it simply isn't the best way to do it.

[Nowhere]

So that cheap harbor freight DC tig will weld aluminium?

DC is not recommended for aluminium less than what thickness? 1/2"? 1/4"?

[silvrjeepr]

It sure makes sense to be able to DC TIG AL. Guys with DC only migs are welding AL all the time. Just one of those things that I never had the time to play with...

[Gusagus]

the way it was explained to me was, that the oxide coat on the aluminum melts at a higher temperture then the aluminum itself. when welding in ac part of the pulse is removeing the oxide layer then the next half of the pulse is doing the welding. going off that you should be able to weld aluminum with DC only, if your prep is good. the other reason for useing ac with aluminum is the way the aluminum transfers heat.

so that cheap harbor freight DC tig welder in therory should be able to to aluminum, but i don't the the skills to do it, or the patience to do the prep in order to get that little thing to weld aluminum.

note: i'm not a pro welder, and have only taken a couple of welding classes which is what i'm baseing my info from. anyone in the know feel free to correct me.:smokin:

[Wicked_S10]

I too have never tried it, but from what I have read, it takes an enormous amount of current to DC tig aluminum. So, if that holds true, then the POS chink-o-matic HF tig won't pull it off.

Later,
Jason

[ETO]

I have done this quite a bit in the past. We usually used it to weld 3/8" and thicker aluminum where it was hard to get deep enough penitration with A/C current we also ran Helium gas with the D/C current as it welds hotter than argon gas. Beware the welds will be slightly more brittle than with the A/C current so I would not recomend doing it on any structural parts unless you have a way to get them heat treated after words. You can use a A/C stick welder and get a high frequency box to help get and keep the arch going. This would be the cheapest way to weld aluminum at home.

[orange02ss]

It can be welded with DC, the problem is that DC cant clean the natural oxides in aluminum (poor weld quality). The AC sine-wave along with the high frequency cleans the oxides and keeps them from contaminating the weld.