I am making aluminum tanks for my truck's radiator. I am planning on
using 1/8" thick sheet because the reason that none of the plastic tanks
hold up is that they flex and distort.
The only welder I have is an oxy-acetylene torch. Can I weld the tanks
using 1/8" 6061?
(What I mean is,,,, I can WELD 1/8" aluminum, but I know that in thinner
sheets the 6061 tend to crack) The tanks are about 20 x 3 x 4 inches.
I will try to get 5052 or something softer if they have it, but may be
stuck with the usual.
'Can't help you with the welding itself, but 3003 is even easier to
work with than 5052. It's not quite as strong but it forms better and
it's probably the easiest aluminum *alloy* to weld. It's used for car
bodies, mailboxes, deep-drawn things, and so on.
I can't get my head around the part you're trying to make, so this may
be off topic.
How are you welding aluminum with an oxy-acetylene torch?
There's a rod called Welco 52. Also sold at much higher price as
"miracle rod" at RV shows and the like.
It's more like soldering than welding. I've had excellent luck
fixing motorcycle parts with it.
FWIW, Welco 52 technically is a solder (the conventional dividing line
is 800 deg. F; Welco 52 melts at around 750, IIRC). It's a zinc alloy
that wets aluminum very nicely and that can solve a lot of difficult
joining problems. Anybody can learn to use it in minutes.
You just have to watch out for strength and corrosion issues. It's not
as strong as brazing or welding.
Regarding O/A welding of alumnimum, it's tricky. I've tried it but not
enough to be any good at it. There's no red color of the metal to
guide you. It just goes "shlump" all of a sudden. But it's a neat
skill to learn. A lot of airplanes were built from O/A-welded
And if you do more than a little bit of it, watch out for the
radiation given off by aluminum O/A flux when you apply the torch. It
will play hell with your eyes. There are special goggles made just for
Construction of the Space Shuttle:
"The three-level crew compartment is constructed of 2219 aluminum alloy
plate with integral stiffening stringers and internal framing welded
together to create a pressure-tight vessel."
Much of the rest of the forward fuselage is riveted 2024 frames, stringers
Since the shuttle is technically an aircraft during re-entry- then I
guess you win, Jim.
But other than that? I'll stand by my statement.
I've seen the video of the new spacecraft being stir-welded.
But that thing is a ballistic object - not an aircraft.
The skin, brackets, and tanks, Richard. Not the frames. But those
pieces were still life-critical jobs.
When O/A was used in commercial production of aircraft, the frames
were not aluminum to begin with.
O/A was used until the 1940s for many aluminum aircraft-welding jobs:
I couldn't find any references but I remember from my _AM_ days that
Northrup pioneered all-welded aircraft. Frustrated with how slow O/A
was, they developed early versions of TIG.
But they made aircraft with O/A prior to that, with few rivets
I have never seen a welded aluminum airframe either. Some pieces, here
and there, but nothing approaching "A lot of airplanes were built from
O/A-welded aluminum." Northrop's N-1M and N-9M tailless flying wing
prototypes were wood.
- Cool Fact -
Northrop's XP-79 "Flying Ram" was a twin turbojet, flying wing fighter
built of welded magnesium plate, designed to slice through enemy bombers.
Oh, please. You guys are being real hard-noses here. If I had said
"built with" welded aluminum instead of "built from" welded aluminum,
would you have been happier? I'll have to be more careful with my
It was more than "a few bits and pieces." The entire business of gas
welding aluminum grew up with the aircraft instustry, including both
the use of O/A and oxy-hydrogen. The latter was almost exclusively
used for aircraft construction.
Hey, I never said they were. See above. But O/A and oxy-hyrdogen were
the only methods used to weld thin aluminum before 1942.
Welded fuel tanks in WWII planes; some srtuctural parts; complex
aluminum shapes in skin parts, as in the bomber photo on the Tinman's
site. And other "bits and pieces."
Northrop's flying wings were designed from the start to be made of
welded *magnesium*. But there was no practical way to weld it at the
beginning of the war, so the first prototypes were made of molded
John Northrup had conducted experiments with aluminum monocoque
construction in the 1930s. At the beginning of the war, he (and some
others) anticipated a shortage of aluminum and so designed his flying
wings to be constructed from magnesium. Mag can be welded with O/A but
it's very difficult and tricky to get good strength. So his company
developed an early version of TIG. After 1942, that's how he made his
A bad idea that was soon dropped, as it turned out. The Germans had
the same idea and also dropped it quickly.
Without making a big project out of it, Kent White says there is
"much" aluminum gas welding on the P-51, the B-24, the B-25, and the
Now, you're saying they weren't "held together" with welds. I think
you're morphing the discussion from built-with, or from, to
But suit yourself. The point was that gas welding of aluminum was an
effective way to fabricate a lot of aluminum pieces on aircraft before
TIG came along. That was in the context of O/A welding of aluminum.
From _Airplane Welding_, J.B. Johnson, 1929:
"The [gas] welding of aluminum in aircraft construction ranks second
in importance to steel. The principal application is the welding of
gasoline and oil tanks. It is the preferred method of construction in
the case of military aircraft and is being used successfully in
commercial airplanes where the maximum pay load is the goal."
He says exactly the same thing in another book, published in 1941.
Most of the aircraft-manufacturing training manuals of the period
talked about the importance of learning to gas-weld aluminum. Welded
aluminum parts were all over the place on early aircraft.
But be a hard case if you wish. d8-)
No expert here on use in aircraft, but we used the welded 5052 I
suggested for fuel tanks in lieu of wet wings. Although the welding
and choice of material worked, it was NOT the best thought. We should
have stuck with the design.
In my last airplane, I used a welded 5052-H32 tank.
I actually did all of it myself except for the final welding.
Sonny did that - then swore he'd never do another one.
It was a lot of fun. There are pictures of that going together
in the photo CD download.
And, to cut Ed a tiny amount of slack, there are a lot of welded
fittings used in aircraft construction; some of them may be aluminum. :)
Weldability of 6061 is very good with TIG. I've never had problems
with cracking with either 5356 or 4043 filler. I can't say whether
oxy-acetylene introduces any problems welding 6061 not present with
5052 is generally more corrosion resistant.
6061-T6 tends to crack because it is harder. If you anneal it first it
will bend without cracking. After annealing (and welding it will
anneal it in the HAZ) 6061 will age harden to about the T4 condition
in about a month. So maybe it will start to crack down the road. I
would try to get the 5000 series sheet. Of interest to you maybe is
the aluminum solder sold at hardware stores and the like. I tried some
of the stuff recently and was amazed at how strong it was and how well
it stuck. I don't know if coolant would affect the joint though.
Doug, the plastic tanks on radiators have always worried me, though they
seem to work for most applications. I admire/envy your intention to
make your own, but just before making your own tanks, you might ask an
independent radiator repairman if he can get one with metal tanks or
perhaps buy metal tanks for what you have.
I agree that looking around for a new replacement is a better option. The
last new radiator I bought to replace a Mopar plastic-tanked one, was all
brass, although it was made in Asia, maybe Indonesia.
The cost was surprisingly affordable, about $110 IIRC, bought from a local
independent autoparts/bodyshop supplier.
With the varied sheet stock, welding filler and/or using aluminum repair
rod, you may encounter unusual corrosion issues as previously suggested..
therefore, a waste of time.
Metals being corrosion resistant to hot coolant and the various other
elements in the solution may be an issue worth avoiding.
"DanG" < email@example.com> wrote in message
Vehicle = 1996 Ford Explorer 4.0
There are no metal ones for mine that I could find, I looked online for
a few days. At this point I'd pay $300 for an all-brass one that was a
The tanks I can weld with aluminum filler rod.
The (aluminum) cores are dip-brazed together already, so I doubt that
corrosion is an issue with that.
I've been through four of these in about eight years, all different
brands, and they all failed the same way. The broad sides of the bigger
tank bulge out a bit, and then the seal leaks where the bulges are, and
there's no way to fix it. And it always leaks worst in the extreme cold:
15F~10F. Vehicle overheats & shuts down,,, cylinder heads warp....
So this is why I say, no more plastic. I want metal only. THICK metal.
One article online describes them building aluminum radiator tanks using
.080" aluminum and bending the sheet to avoid having to weld the two
longer seams. Fuck that, I will use .125" and weld all the seams. It
ain't that hard.
I originally thought of cutting off the crimp tabs, and then making
screw-clamps that would go all the way around both sides of the core to
hold the plastic tanks on better. But after seeing how the leaks are
happening, I don't think this is worth trying. I would bet that the edge
of the plastic tanks would just break off if they were held harder to
the core seal. You'd have to keep those broad sides from bulging out
somehow, and the only ways I can see to maybe do that are more difficult
than just welding up some aluminum tanks.
I haven't decided if the aluminum tanks will clamp-on or if I will just
braze them on. I kinda like the idea of a replaceable core, but don't
know how standardized they are. Judging from the one I've cut apart and
the one still in the vehicle, the cores appear to be pretty close to
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