TIG Welding 6061 aluminum

I have two long aluminum bars 1/4 by 1 1/4, connected together in a parallel configuration:
[==============] [==============]
(they form a knife handle that holds the tang of a knife, sandwiched between them).
I need to weld them together with TIG and my question is how. Again, 6061, they are 1/4" thick. What filler is best to use and what amperage. Should I use lanthanated?
i
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On 8/30/2010 4:53 PM, Ignoramus24925 wrote:

If the material is butted together, you should just be able to fuse them together. A bit of polishing when done and probably wont even be able to tell they were welded.. If you need filler, then I would suggest the same type of material.
http://www.millerwelds.com/resources/calculators/tig_amperage_calculator.php
that says to use 190-220 amps
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What's that Lassie? You say that tnik fell down the old rec.crafts.metalworking mine and will die if we don't mount a rescue by Mon, 30 Aug 2010 17:08:28 -0400:

You can't get 6061 filler rods. Use 4043 or 5356.

Shouldn't need that much, just to hold 'em together.
--

Dan H.
northshore MA.
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On Tue, 31 Aug 2010 00:36:10 GMT, snipped-for-privacy@privacy.net (dan) wrote:

6061 CANNOT be welded without adding filler rod. I have the magizine article at home. That's why there is no such thing as 6061 filler rod.
Thank You, Randy
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Generally true because of its susceptability to cracking. The filler mitigates that to some extent. However, in this case use of considerably less heat than usual would suffice, since all the weld has to do is keep the sides together and hide the joint. It's more cosmetic than structural. Less heat --> less susceptability to cracking.
I've done autogenous cosmetic welds with TIG in 6061 with no problems. http://citeseerx.ist.psu.edu/viewdoc/download?doi .1.1.34.176&rep=rep1&type=pdf
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What's that Lassie? You say that Randy fell down the old rec.crafts.metalworking mine and will die if we don't mount a rescue by Tue, 31 Aug 2010 09:19:23 -0500:

Yah. I know. That's why I said above to use 4043 or 5356.
--

Dan H.
northshore MA.
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6061 CAN be welded without filler, but it does not make a real good job, and using strips of 6061 sheet DOES work in a pinch - when you want the weld to totally dissappear when ground down and polished.
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On Tue, 31 Aug 2010 20:46:04 -0400, snipped-for-privacy@snyder.on.ca wrote:

Just so, which I'd think would be the objective with an ally handle encasing a blade.
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This not some kind of an art piece. This is a very big kitchen knife with a very thick handle. My FIL uses is to, like, split frozen meat and such etc. So I want a handle that would survive pretty extreme abuse and would be relatively pleasant to hold.
This is rapidly becomes a big dollar project due to the time spent, materials wasted etc, broken drill bits but I treat this as a if it was a fee for getting education.
i
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He also likes to pound its back with a hammer.

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Make a froe club (beetle) for him. It's less dangerous, more suited to the task, and easier to use. It also won't damage the knife.
LLoyd
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Ignoramus24925 wrote:

You need a very close fit between the parts, clean carefully and clamp to hold in place. 1/4" thickness is out of the narrow range of my knowledge. I got some filler wire from the welding store that worked well, I'll look up what it is. I also got some MIG wire, and was not able to make that work right at all. lanthanated electrodes should be good. You'll need a pretty thick electrode and a lot of current. You will need to play the arc over the parts for a minute or so to preheat before welding, and once preheated, begin welding and keep the arc moving quickly to prevent the dreaded "blop" on the floor.
You will have much better results with a gas lens, it can cut your Argon consumption by half, and that stuff is getting EXPENSIVE!
Jon
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Jon Elson wrote:

OK, the MIG wire that I couldn't get to work was 5356. The filler rod from the welding store was ER4043, and worked much better.
My welding book recommends Zirconated electrodes, but I think newer practice is to use Lantanated for aluminum, and I think that is what I used when I did a bunch of frames out of rectangular tube. For 1/4" aluminum, the book recommends a 5/32" electrode ground to a very wide point, 200-300 Amps, 1/8" filler wire, 10 IPM weld speed, a 1/2" cup and 25 cu.Ft./hour gas flow. You can reduce gas consumption with a gas lens.
I have a Lincoln Square Wave TIG 300, but I've never done 1/4" thick parts. That rectangular tube was about 1/8" wall thickness. I preheated the work by playing the arc over an area for about 30 seconds and watched closely for the very subtle signs that the metal was heating up. One trick was to melt a little bead of filler metal on the surface of the workpiece, and when it begins to sag from heat conducted through the workpiece, you are nearly ready. Cleaning the work and filler wire with acetone before starting seemed to help, as well as wire brushing the weld area.
Jon
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On Aug 30, 4:53pm, Ignoramus24925 <ignoramus24...@NOSPAM. 24925.invalid> wrote:

Ask over in Sci.engr.joining,welding. Pay attention to what Ernie says. Do not join without adding filler.
From a post on s.e.j.w by Ernie on butt welding.
You have to make sure your edges are clean and oxide free for them to flow. Also, the specific alloy makes a big difference. 6061 and 6063 should never be flow welded together. You need a filler rod, 4043 or 5356.
5052 can be flow welded together, as can 3003, and 1100. 5086 should have a filler rod, either 5356 or 5556.
As long as the edges are touching you should get a good flow on a seam with no keyholing.
From another of Ernies posts.
1 amp per 0.001" of thickness. So 1/16" wall tubing is about 0.063" = 63 amps. Got it? Set your amperage dial to a hair over this, say 65 amps. Keep your arc short and your tungsten clean. Be agressive with the filler rod. If the aluminum appears to be melting away into a hole, get some filler in there.
A good test to see if your amperage is set correctly on the machine is to disable the foot pedal's ability to control the amperage. Just use it as a contactor control.
This will allow you to really see how much amperage to need to weld your pieces.
For thinwall aluminum go for a 1/16" Lanthanated, Ceriated or Zirconiated Tungsten.
Stay away from Pures or Thoriated. Thoriated tungstens tend to shed bits of tungsten into the weld on AC, and Pures can't take any heat.
Dan
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On Mon, 30 Aug 2010 15:53:04 -0500, Ignoramus24925

I'd say somewhere between 150 and 200 amps, but watching the puddle will quickly tell you when you have it right.
Thoroughly scour the work with a stainless brush thoroughly before welding. If it was done 15 minutes ago, do it again.
I would prefer a zirconiated tungsten to lanthanated, but La will probably work OK too. I would avoid pure tungsten and definitely avoid thoriated. I haven't tried ceriated.
For filler, I'd probably cut a strip of 6061 sheetmetal, or use 4043 or 5356. On thin material I'd use 4043 because it melts more readily, but on your job 5356 would not be a problem and it would probably provide a better color match with 6061.
Since it's a knife handle, I would anodize it when it's finished to avoid the problem of black hands from aluminum oxide in the kitchen. 5356 will give a better color match when anodizing.
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On Mon, 30 Aug 2010 21:28:29 -0500, Don Foreman

Could you anodize that o.k. with the steel blade in there? I assume you'd need to guarantee the solution didn't get trapped in there.
Pete Keillor
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On Tue, 31 Aug 2010 08:07:03 -0500, Pete Keillor

Yes, you need to keep the solution out of the cavity and also need to protect the external steel from the solution -- wax, tape, asphaltum, nail polish, or what have you.
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Don, and others, thanks. I was too tired yesterday to do anything, but maybe today I will do it. I will mill a V-groove along the weld line, for better weld appearance and deeper penetration.
i
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On 8/30/2010 6:28 PM, Don Foreman wrote:

If he's trapping the blade during the welding process, then it can't be anodized...
Jon
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wrote:

Ernie recommends one amp per .001 inch of thickness and then some variation depending on configuration. So if you think of this as kind of a butt weld that has been oriented strangely.........well that would be about 250 amps.
Dan
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