THICK ALUMINUM WELDING

I need some help.
I am making a gigantic " weather vane type thing" (technical term?).
(some very thick material and I am slightly intimidated)
its made up of 4 arms coming out radially from a central bearing unit.
the arms are a mix of rectangular tubing (6" x 2" x 1/8" thick.) and
3/8" plate.
the central unit is machined from a round of 12" 6061. it rotates on a
hardened point with a delrin collar.
I need to stick the arms to the bearing. The two pieces mate on a
flat groove vertically along the bearing.
____the question______
is the extra penetration gained from using Ar/He worth the extra
dollars?, (we've been using straight Ar)
also, aside from oxy acetylene, what pre-heat methods have any of you
had luck with?
any help would be much appreciated.
Reply to
Ardilla Volante'
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Don't know if this will be of much help, but I had to fabricate a rectangular box out of 3/8 aluminum that had to be welded "in place" on the rear bumper of my wife's motor home. I have a Miller dial-arc 2000 tig welder and I couldn't get it hot enough to take a weld and no way to pre-heat. Finally had to drive the motor home over to a friend that had a mig set up for aluminum. That did the trick. Bill
Reply to
lathenut
It seems to me that penetration is only an issue if you're trying to weld clear thru something. I think if you can get a puddle going, you can make a weld. What difference does it make how deep the puddle goes into the metal, as long as the pieces are fused together?
So I would think that if you can get a puddle going on the 12" round with argon, you can weld it -- and if you can't then try a hotter gas mix or a bigger welder.
Reply to
Don Foreman
You didn't say how thick the piece is. If it is really thick then use a high Helium mix, like 75% Helium 24% Argon.
Propane weedburners work great and are fast.
Reply to
Ernie Leimkuhler
it is about 8 inches at the thickest spot.
Reply to
Ardilla Volante'
Say Ernie..I picked up a tank from Reliable Tools sometime back..they tend to sell me their tanks cheap cause they dont want to mess with them..
2.5% CO2 7.5% Argon 90% helium
There was a piece of masking tape that said "stainless steel"
Is that too much CO2 to use it for tigging? Will it burn up my electrodes too fast or can I use it for Aluminum or general welding?
If I had to guess..I figure it was for MIG..but its got 2000lbs of gas in it and Id hate to have to vent it cause I cant use it.
Thanks
Gunner
The aim of untold millions is to be free to do exactly as they choose and for someone else to pay when things go wrong.
In the past few decades, a peculiar and distinctive psychology has emerged in England. Gone are the civility, sturdy independence, and admirable stoicism that carried the English through the war years . It has been replaced by a constant whine of excuses, complaints, and special pleading. The collapse of the British character has been as swift and complete as the collapse of British power.
Theodore Dalrymple,
Reply to
Gunner
well, I stuffed the lug into my viking gas oven, baked it at 400 for an hour, wrapped it in a blanket and brought it out to the shop.
the welds look great, and seem to be tough enough to stop a truck.
nothing like a little south seattle engineering.
thanks for the info
zak
Reply to
Ardilla Volante'
That is a helium tri-mix and it is excellent for MIG on Stainless steel. It will also work great on regular MIG, with no spatter at all.
High penetration and smooth welds.
On TIG it will destroy your tungsten.
Reply to
Ernie Leimkuhler
Glad to hear it.
Reply to
Ernie Leimkuhler
Ok! many thanks! Ive been using it to blow up balloons for the grand daughter..makes em float pretty good..including a condom...(her mom nearly shit)
Ill hang on to this in case I run out of Mix gas, then use it up and then refll with Ar.
Gunner
The aim of untold millions is to be free to do exactly as they choose and for someone else to pay when things go wrong.
In the past few decades, a peculiar and distinctive psychology has emerged in England. Gone are the civility, sturdy independence, and admirable stoicism that carried the English through the war years . It has been replaced by a constant whine of excuses, complaints, and special pleading. The collapse of the British character has been as swift and complete as the collapse of British power.
Theodore Dalrymple,
Reply to
Gunner

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