| Sounds about what I would have said. I found there is a subtle change in
| the surface of the aluminium before it drops on the floor, I learned to
| recognise this and all went fine. I have never used anything other than
| standard OA welding googles for Al and never had an issue with being
| able to see what I was doing clearly. People mention using special
| lenses to cut the flare from the glowing flux but I have never
| experienced this. I have never welded Al with OA extensively and these
| days would typically use TIG unless I had a benefit from using OA,
| typically it leaves a more ductile weld which may be beneficial if you
| are doing panel work.
I'm interested in how you do this, since most information on your method
is highly lacking on the web. Please, tell me more!
Have you read all the responses to Brent Philion's original post. There
has been alot of good information given. My initial response was mainly
to agree with the reply by Buy_Sell but ad that against what most have
said about the need for special goggles I have never found this a
carl mciver wrote:
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.
O/A can definitely be used to weld aluminum. It is the first choice
of many for sheetmetal on aircraft and various automotive work. I
do it routinely with 1/16" and less, prefer TIG for thicker
materials. It would take a big tip and a lot of gas to weld 1/4"
aluminum, but it certainly can be done. 1/16" to 1/8" is easily
done with O/A. Some say that gas welds in thinner metal are more
ductile than TIG or MIG and hold up better to subsequent metalworking
operations like planishing or further forming.
I don't think welding aluminum is any harder with gas than it is with
TIG. With metal 1/16" and less I think it's easier -- but read on.
You can order a videotape on O/A welding of aluminum from
I've not seen it but it's probably a good start. You can also
download a short video showing aluminum being gas-welded from
www.cut-like-plasma.com It's objective is to sell the Henrob torch.
Don't worry about that. Your torch will work fine. The Henrob's
performance as a cutting torch is impressive, but others have
indicated preference for other torches for welding and the Henrob
is a rather pricey torch. Your torch, with appropriately-sized tips,
should work fine.
Special requirements: yes! Aluminum welding requires flux. The
reverse polarity part of the AC cycle cleans oxides with TIG,
flux does it with gas. Some welding stores will have it. The tin
man and cut-like-plasma offer it too.
Aluminum flux produces a bright incandescant "flare" that must be
blocked in order to see the puddle and to see when a puddle is
imminent. Eyewear that blocks that flare is absolutely essential
to successful gas welding of aluminum. Regular goggles don't do it,
not even close. It's not a matter of "dark" but one of blocking the
flare without obscuring the puddle.
Cobalt blue glass was used for many years, but is no longer used
because it doesn't block some harmful rays. There's probably some
OSHA overkill there for the occasional user, but I've used them and
can tell you that there is now a far better choice available.
The TM2000 green dydimium lens, available from the tin man,
cut-like-plasma and some other places, is a bit pricey but I'd regard
it as the single most important tool to have for gas welding aluminum.
It works extremely well. I know of no cheaper alternative that works
remotely as well.
Cut-like-plasma does offer an alternative lower cost lens.
I've not tried it. HIs video is obviously shot thru the TM2000. If
you're serious about learning to weld aluminum with gas, I would
strongly encourage you to get a TM2000 filter.
The other indispensible tool is a stainless steel "toothbrush" for
scrubbing the metal clean just before welding. They're available at
any welding store for well under $2.00 each. If you're familar with
TIG welding aluminum you know about those already.
I don't know anything about gas quick-connects. I sure wouldn't use
compressed-air quickconnects, don't even think about it! Those
either leak or are about to.
Go to http://www.tinmantech.com
They have all the info, and supplies, for gas welding aluminum.
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 love deadlines, especially the wooshing sound they make as
they fly by" - Douglas Adams
On Sun, 22 Jan 2006 10:34:22 GMT, Ernie Leimkuhler
Good stuff for thin metal, be sure to get the #31 flux as well. It
doe not work well (for me) on metal over .062" for some reason.
Allstate #31 was developed for HVAC work, joining aluminum tubing in
refrigeration systems. It works really well for that. I first
saw it demonstrated at an ASHRAE show when it was first introduced. I
Tinmantech also offers a similar brazing material, Aerobraze, with
I've had varying reports from others on these two materials: some say
one works for them while the other doesn't, and conversely. I don't
know why. I like them both on thin metal. The Allstate #31 is way
lots cheaper, available from Grainger.
The difference in temperature between either of them and welding is
less than 100 degrees F. That's a big difference on thin metal,
but I find it as easy or easier to weld as to braze on material .050"
and thicker. Neither of these materials work well for butt joints;
they're better for fillet or lap joints as one might design for
brazing. Butt joints and outside corner joints are best done by
I guess they're really different processes. I can cut a preform out
of either Allstate #31 or Aerobraze, set it in place with appropriate
flux, heat until it wets and flows resulting in a joint that looks
just like a silverbrazed joint in brass or steel. Welding aluminum
is, well, more like welding, melt and dab while controlling a puddle.
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 -
and all the rest...
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.
So from what i Gather from what everyone has said the only differences
and things needed to OA weld Aluminum on top of what i currently have are
1. ALuminum welding flux
2. Upgraded Eye protection to protect against Sodium Metal flares.
3. Possibly a better means of cleaning the AL before welding (acetone?)
4. Better ventilation/fume extraction because some of the stuff coming
off the weld will be really toxic stuff (or at least stuff best left
outside of my lungs) And stuff more Caustic than say a plain old Cigarette
For question 2 will an autodarkening Welding helmet in the OFF position
(Shade 5) cut it for getting rid of sodium flare? (I have a Miller Xli
helmet already and if it will work i'll be happy)
Otherwise my eyes and ears have served my great for my 26 years so far
and i'd like to at least have them in decent shape for 3 times the 26
theyve done. I'll accept slowly starting to fall apart at age 78 but i'd
just as soon be nice to my eyes and ears and such before then
Safety equipment to me is not a cost its an investment in the quality of
my work and in the preservation of my keester to weld again another day.
As for doing it its not that much harder than TIG and the added
difficulty does not seem to be enough to justify my running out and
buying an AC tig Capable machine to replace my XMT. the technique IS
different but its close enough that I should have minimal adjustment
pains compared to say the jump form Stick to TIG
Am i basically on the right path with the Synopsis i've came up with here?
By the way Thanks to everybody for all the info
Not nearly as well. A shade 5 pretty much darkens everything. The
idea here is to block the flare without otherwise reducing visibility
Sodium flare has a very narrow spectrum or band of colors around
yellow-orange, a small percentage of the total visible spectrum.
If a filter blocks those colors much more strongly than others, then
your visibility of the work and puddle is greatly improved. The
TM2000 is about a shade 5, but it completely blocks the sodium
flare. Totally, as in gone. Your first clue that you are near
welding temp is when the flux melts -- and you can clearly see it melt
and turn clear. The TM2000 can also be (and is) used for gas
welding steel including 4130, and cast iron.
I don't sell these things or get a kickback, I'm just thoroughly
impressed with how well they work. Professionals like Ron Fournier
and Kent White (the tin man) use them routinely.
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