Gas Welding aluminum

Welding Aluminum with Oxy/Acet DOES NOT work due to the impuritys from the enviornment entering the weld area. Tig or Mig are used specifically for the reason that it has a shield of inert gas such as Helium or Argon surronding the Stinger wich keeps impuritys out of the weld area.

Glenn Hendrix Hendrix Machine & Tool. Inc.

I gas weld aluminum. I use my Henrob torch for this but any gas torch will do. The trick is to keep your gas pressures set low. If you need more heat then change to a larger tip but keep the oxy and acetylene pressures no higher than 4 psi. The other thing that you will need is some flux for your aluminum rods and a good set of special goggles for viewing the weld properly. A few years back everyone was using these cobalt blue goggles but they weren't that good for your eyes. I use goggles that have a gold reflective surface on them. I picked them up at the welding shop and they work really good. Welding aluminum is a bit tricky because the color doesn't change when the metal heats up like steel does. Aluminum is a bit like plastic, one minute its there and then all of a sudden the floor drops out and you have a big hole. The trick is to look for when a skin appears to form on the surface and then push your filler rod in and a way you go. Without the special goggles, you won't be able to see the skin effect. Practice on lots of scrap stuff first before getting into some more serious work. You'll get the hang of it in no time.

---------------------------------- Brent Philion Jan 22, 12:08 am

With the lack of an AC tig machine and an AC inverter appearing to not be in the cards in the near future i"m looking at using Oxy/Acetylene to do the al Welding due to the availability of an OA rig. Mainly i used it for cuttingbut thats not to say its impractical for welding. If i remember right OA has been used for Al welding for a long time specifically in the aviation industry.

Compared to TIG how hard is OA welding of aluminum and are there any special types of requirements for doing it? The only OA welding i would be doing would be on Al and the rest of the time it would be used for heat/cutting

I already have an OA torch (Cheap Harris style kit) but stumbled across a real Victor 100 Handle Might i be better off getting a fresh welding tip for the victor 100? than the giant beast of this harris one?

I will likely never weld larger than 1/4" with most work being smaller than that (1/8" to 1/16")

I would have to disagree with this statement. I have been gas welding aluminum for years.

----------------------------------------- rghendrix Jan 22, 1:36 am

Welding Aluminum with Oxy/Acet DOES NOT work due to the impuritys from the enviornment entering the weld area. Tig or Mig are used specifically for the reason that it has a shield of inert gas such as Helium or Argon surronding the Stinger wich keeps impuritys out of the weld area.

Glenn Hendrix Hendrix Machine & Tool. Inc.

Go to

Allstate also sells aluminum brazing supplies. They call it Allstate #31

I use Western brand quick disconnects for all my torches. They work very well. I also use their disconnects for my shielding gasses.

I find it easier, but then I've got a fair bit of OA experience with steel and I'm a complete numpty with TIG.

One thing I did find is that the aluminium alloy affected things. Magnesium alloys (about 15% Mg) in vehicle or aircraft sheetmetal was no problem to work, purer aluminium didn't give me such good results. Welds seemed structurally OK, but never looked as neat.

Tool up with the right fluxes and go to it for some practice. These things are fairly easily available, but the English flux for 15% Mg is obviously the best stuff - if only for the name "Hari-Kiri No. 2" ! (read the Landrover service manual).

A word on fluxes though - these things are horribly toxic when heated, and their vapours. I'd been using them for years, but I blanched when I found out just what was in them afterwards. Now I'm a _lot_ more careful about ventilation than I used to be.

I was wondering when somebody was going to post this URL.

The "sharp flame point" is a carbonizing flame(?) And aluminum welds need the extra carbon.

One tip (I think from Bud Davisson?) was to place a wooden match stick on the weld line and just weld thru it... Haven't tried that one - but ?

The metals need to be absolutely clean. Tinman recommends a stainless steel brush that is not used for anything else - ever.

and all the rest...

My single biggest reason for OA welding aluminum is the "bird in the hand" theory. I have an OA setup basically used for heating and occasionally cutting and a DC tig setup. Putting 100-200 to touch up the OA kit is a lot more affordable than putting in 1-2 thousand for a replacement tig welder with the 2000 dollar tig welder MAYBE meeting my portability needs. I'm about 50/50 right now with me needing to get myself or the welder near the work or the work being able to come to me

Until I swap out my Miller XMT for a dedicated AC/DC TIG machine i'm sol for trying to tig Al on DC (I tried anyhow despite understanding why it doesnt work and it took me into the corner and beat me and made it crystal clear why and how AC tig works)

your Descriptions though dont really sound any different from What it does on TIG when i had access to an AC/DC machine.

Perhaps i should ask it this way how close is it to tig without the pedal control? I know i needed a Lot of practice to do Al in tig when i was learning but i saw the same conditions I think.

David Bill> Sounds about what I would have said. I found there is a subtle change in

I'm interested in how you do this, since most information on your method is highly lacking on the web. Please, tell me more!

You can weld Al with DC but use the reverse polarity to what you would use for steel. I have never tried it. It does result in much more heat at the torch so you would need to make sure the torch was up to it. I think this would be like running AC TIG with the cleaning setting maxed out.

Quite similar except you can control the heat with the torch distance and attitude, also you can add more rod to the pool briefly to cool it and help bring it under control. You also don't have to worry about dipping the tungsten or hitting it with the rod. I would say that welding Al is only slightly trickier than welding steel. I learned to weld steel with OA and had a few years practice then tried Al and was laying runs under control on Al after about 5 minutes practice. Due to the similar skill between TIG and OA if you are having trouble with TIG then it going to require practice with either process.

Tried it using both polarities and scrubbing like no tomorrow

DCEN It hold an arc but staunchly refuses to flow liberal application of filler can bind them but there is no strength (Logical reason being the aluminum is encased in aluminum oxide which is forming a solid shell

DCEP Black coating forms on the base metal arc wont strike

that COULD be me under scrubbing it (with the decicated AL only SS brush mentioend in other posts which i already DO have)

But if so then i'm buying a few ss brushes for the dremel and using it to prep my welds if i need to DC weld on AL again

I'm fine on Steel and stainless TIG AL tig i was in the process of learning then bought a DC welder and stopped

I dont thing i'm ready for an AWS test yet on steel or stainless (I grind way too much tungsten for now)

but i can produce decent welds when i'm patient (they might be good welds but i'm my stiffest critic and i dont think so

I seem to remember that DC welding of aluminium required the use of Helium as shielding gas; which do you use?

Peter, The Netherlands.

Argon

Gas welding AL is pretty tricky, and if you only need to weld AL infrequently it might be better to hire a TIG set.

You might want to try out the special lenses. They make a night and day difference if you are Al welding (I couldn't imagine doing .025-.035 well without them). I don't find it as necessary brazing Al.

Run a helium mix with a small amount of argon to ease arc starting. You can also try scratch starting it (with hf on though) Once you see the skin just pop the skin with the filler.

Sounds like your filler needs to be cleaned too based on the DCEN problems.

What the purpose of this?

I gas welded aluminium long before I got a Tig. Mind you, the Tig is easier to learn, but then again I learned it after I was gas welding.

For me the trick is very low gas pressures, as low as about 1 pound of Acetelyne and 2 pounds of oxygen. Then, heat control. Take the torch back if you start thinking you are too hot. I used flux cored rod, but some say separate flux is better as the rods have too much. Finally, don't try to get a puddle started in the work, start it with some filler rod. Melt a little blob and let it start to puddle and flow with the work, not the other way round (same with Tig, actually, and the "ah-ha" moment for my personal welding journey). then start to work your bead using filler rod to freeze the pool and move on to the next quarter inch of bead. Kind of a series of blob-melts until you get the hang of running a continuous bead. And always heat control - don't get too hot. Think tiny, actually - tiny flame, tiny bead, tiny movements, tiny heat. 1/16" filler rod, which is also kind of tiny. If you try for tiny at the start, you'll stand a better chance of getting normal, which with gas welding is a lot bigger than Tig beads can be.

It works. I found 1/8" thick sheet the best to learn on. .050" is doable, thinner than that takes real skill.

Brian