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canman
06-22-2005, 03:55 AM
Any one know the secret to tig. aluminum?
Its been over 5 yrs since I picked up torch and was never good at it to start with.
Any help would be appreciated since my BOSS is trying to be an @#%^&%$#$% about something he could never do him self.
canman

Swarf&Sparks
06-22-2005, 06:45 AM
Yup, you need an AC HF machine for a start. Only way you're gonna weld ali with a TIG. Balance between cleaning the oxide off the metal and getting the heat into it.
Negative half cycle, you're same as other metals. Pos half cycle, you're blowing the crap off the top of the pool. (presume you know that standard TIG is DC, electrode negative) Zirconiated tungsten, not ground, just heat the electrode on scrap til the end balls. Wave balance (pos-neg) and practise! Plenty of ali scrap around http://bbs.homeshopmachinist.net//smile.gif
Rgds, Lin

x39
06-22-2005, 06:51 AM
Don't forget to clean the area to be welded first with a stainless wire brush.

Swarf&Sparks
06-22-2005, 07:10 AM
Thanks X, terue http://bbs.homeshopmachinist.net//smile.gif
And if critical, clean not only the metal but also the filler with acetone.

coles-webb
06-22-2005, 07:19 AM
Freshly cleaned of all corrosion is a must. All aluminum has corrosion on the surface, these oxides that form quickly take a higher temperature to melt. If you do not clean your aluminum properly and shortly before welding it will take more heat to melt the oxides formed. Once you have melted through them the temperature is too hot for the aluminum underneath causing it to burn through. Having the proper distance to keep a stable arc and the correct angle so you are preheating the metal ahead of the weld will help also. If the material is thin or you need more practice, back it up with a piece of clean copper to diffuse the heat and help prevent burn through. Ensure your joints are tight and you clean all sides of the area to be welded. If you want to be good at TIG welding of Aluminum, you have to practice allot and when you get good at it, keep doing it or you will loose it. Once you are good start to experiment with no copper backing and trying to close gaps. The harder tasks you will learn from. If you stick with the easy and known your skill will not grow. There is a link below to Lincoln Electric with different articles on welding.


http://www.lincolnelectric.com/knowledge/articles/list.asp

Mike

Swarf&Sparks
06-22-2005, 08:04 AM
Sorry CW, but no way you start with backing. Copper, ceramic or otherwise. Just sit a coupla bits of scrap on the bench. After you're happy with machine adjustments, torch angle, etc; just move on and weld more scrap coupons unsupported. If you start by relying on backing to hold the pool, you'll never learn to weld ali.

Forrest Addy
06-22-2005, 08:39 AM
I gotta add my 2 cents.

Clean, grease free aluminum within the influence of the weld zone is an absolute must. Not only must it be clean and grease fress but cleaned between passes with a rotary stainless steel wire brush that has been used for no other purpose.

coles-webb
06-22-2005, 09:27 AM
Swarf&Sparks:
Sorry for the confusion with the copper backing, I meant if you are welding thin material, that copper backing will help or if you want to weld a project and want less chance of burning through, copper will help dissapate the heat. The copper is not there to hold the pool of aluminum. I agree that it is good to learn with peices on a bench with no back up to start.

Mike

Wirecutter
06-22-2005, 09:45 AM
3Phase? tatoomike68? You gonna chime in?

3 Phase Lightbulb
06-22-2005, 11:05 AM
I've welded a lot of 1/16th alum sheet, but I don't have any experience with thicker materials yet. What works great for me:

1/16th Pure Tung electrode. balled over about 1.5 X the electrode diam. Using a #4 cup (~1/4" opening), electrode sticking out of cup about 1/8", Amps set to 50-55, Argon flow set to 20 CFM, A/C balanced, HF continuous.

I like to TIG alum with the electrode as close as possible to the alum. In fact, I can't even see the electrode, but I can see it's reflection off the pool. I like to adjust my heat until I get just the right sizzling sound. It took me about 6 months to key on the right sound. Once I have the right sound (Kinda sounds like bacon cooking). I heat up the pool, dab some filler into the pool, and raise my torch up just a tad at the same time because when I dab my filler, the pool rises and my electrode is just a 1/16" or so away from the pool so it might touch the rising pool if I don't add filler and lift a tad with my torch each time. Once I add filler, I wait just a 1/2 second more, then move over about 1/4" and lower my torch down ~1/16" and start making another pool.

I hold the torch in my hand like a pencil and the only thing touching the work to help me keep it steady is my pinky finger. I drag my pinky finger on the work with very light pressure when I'm moving the torch to setup for the next bead. If you try holding the torch and resting your arm, or your palm then you're not going to be able to smoothly adjust your position while you're welding. You'll tend to be jerky and also you'll have serious problems trying to weld on something that isn't smooth. I lightly drag my pinky finger so I can hold the torch and move it very precisely over any "terrain". This is a big help because before I learned to only drag my pinky, I used to rest my arm/hand on the welding table and every time I move my arm/hand, it was a jerky movement.

Most of my initial TIG welding was done too quickly with too much heat. My best welds take about a full minute for every 4" of alum sheet. I found you have to be patient, and really focus on your heat and the sound. I found once I could recgonize the sound and key off how much heat I have based off just the sound, I almost instantly became twice as good. One thing that helps a lot (for me anyway) was to run beads on alum sheet without even looking. Just close your eyes, and play with the torch heat and distance from the sheet while you try and weld beads without looking at anything. This helped me focus more on the sound than getting mesmerised by focusing on the arc, the filler, the sound, the pool, etc. Some of my nicest looking beads were done with my eyes closed. Some of my straightest beads were done with my eyes open http://bbs.homeshopmachinist.net//smile.gif

It takes a long time, and it takes a lot of dedication.. Progress was very slow when I was learning so it didn't seem like I was getting any better even after several hours, but I would notice a difference the following day so just keep in mind that TIG welding is more like an ART that takes time and a lot of patience with yourself to learn..

Also, TIG welding is like hand writing.. Everyone develops their own style and it's much easier for you to develop your own style than to try and copy someone else's natural style.

-Adrian

lathehand
06-22-2005, 11:34 AM
If the work piece will be anodized, shear a thin strip off the edge of the sheet to use as filler rod.

Tony
06-22-2005, 11:47 AM
a topic near and dear to my heart.
use zirc tungstens and never look back.
pure will spit alot at higher amperage.

got to get in there real tight with aluminum. start running a few beads on scrap, no butt joints yet. puddle won't flow like steel on butt joints, will give you a headache.

be warned that welding mystery 'scrap' could give mixed results. there are a few unweldable alum alloys out there. make sure its not magnesium.

i find diff alum alloys to respond differently to arc frequency. castings like lower frequency (25-100hz) ..

like the others said, make sure everything is clean. REALLY clean. don't leave it laying around too long as alum with develop an oxide in minutes (that you should clean off again).

-tony

tattoomike68
06-22-2005, 02:40 PM
((3Phase? tatoomike68? You gonna chime in?))

not much I can say about tig work on aluminum.

the last tig I ran was 14 years ago in college.(and spent more time on thin stainless)

I use a spool gun on a big miller deltaweld 452 for aluminum, mostly golf cart frames that the old boys got drunk and played demolishion derby on the golf course.

I farm tig work out to a shop up the road where it gets done right by someone who knows what he's doing. http://bbs.homeshopmachinist.net//smile.gif

Swarf&Sparks
06-22-2005, 11:22 PM
3 Phase, you make a good point. Since you can't walk the torch on ali, I developed a technique of holding the torch in thumb, pinky and ring finger, then use index and second fingers to slowly 'walk' down the weld. Needs a good glove tho! Or clip some sorta sacrificial insulating material onto the work. (not too close to the bead, don't want contamination)

3 Phase Lightbulb
06-23-2005, 10:43 AM
<font face="Verdana, Arial" size="2">Originally posted by Swarf&Sparks:
3 Phase, you make a good point. Since you can't walk the torch on ali, I developed a technique of holding the torch in thumb, pinky and ring finger, then use index and second fingers to slowly 'walk' down the weld. Needs a good glove tho! Or clip some sorta sacrificial insulating material onto the work. (not too close to the bead, don't want contamination)</font>

I'll try and remember to take a picture of how I hold my TIG torch.. I'm right handed by the way so I'll post both the normal, and flipped image http://bbs.homeshopmachinist.net//smile.gif If you can post a picture of your technique that would be cool too.

-Adrian

Swarf&Sparks
06-23-2005, 11:32 AM
I'll see if I can lay hands on a digicam Adrian. I'm also right-handed, but can weld left in a pinch.
Rgds, Lin.

Wirecutter
06-23-2005, 11:36 AM
<font face="Verdana, Arial" size="2">Originally posted by tattoomike68:
((3Phase? tatoomike68? You gonna chime in?))

not much I can say about tig work on aluminum.
</font>

's ok. I brought it up 'cause I remember you posting pics of some of your work. Very nice.

3 Phase Lightbulb
06-23-2005, 08:10 PM
Here is how I hold my TIG torch.. I hold it like a pencil, and use my pinky finger to just lightly touch the table. I'm not putting ANY pressure on my pinky, it's just there to give me feedback. I can basically hold the torch in any configuration/angle and it doesn't matter if I'm reaching far away, or if I'm holding it close.

http://www.bbssystem.com/projects/torch2.jpg

http://www.bbssystem.com/projects/torch1.jpg

-Adrian

precisionworks
06-23-2005, 08:57 PM
Adrian,

The only time my gloves look like yours are during the first five minutes of use. After that they are black, brown, grey, etc. New gloves are such a treat, sort of like new socks &lt;LOL&gt;!

Aluminum TIG is really easy (assuming that you can oxy-fuel weld with and without filler, and that you can stick weld in all positions). Sign up for a TIG course at your community college. This is a difficult skill to learn without hands-on instruction by a highly skilled teacher. Twenty to thirty hours of correct practice is the quickest road to correct GTAW welding.

Aluminum isn't difficult, but it is different. Don't expect to learn how to do it by reading or watching a video. You'll be glad that you spent the money and the time to learn it correctly.

------------------
Barry Milton

3 Phase Lightbulb
06-23-2005, 09:34 PM
I just started wearing that pair. They have about 15 seconds of use http://bbs.homeshopmachinist.net//smile.gif I stock pile them on my machine. I'm down to a few pairs left http://bbs.homeshopmachinist.net//smile.gif

http://www.bbssystem.com/projects/sync250dx.jpg

-Adrian

JRouche
06-23-2005, 09:58 PM
Gloves dont look like the only thing you stock pile, nice "pile".

Can I come browsin fer a cup? http://bbs.homeshopmachinist.net//biggrin.gif

Damm, now I feel like I gotta go change that chipped cup, thanks! JRouche

3 Phase Lightbulb
06-23-2005, 10:42 PM
<font face="Verdana, Arial" size="2">Originally posted by JRouche:
Gloves dont look like the only thing you stock pile, nice "pile".

Can I come browsin fer a cup? http://bbs.homeshopmachinist.net//biggrin.gif

Damm, now I feel like I gotta go change that
chipped cup, thanks! JRouche</font>

Cups are cheap.. The #4's up to #10 cups are $.61 cents each. I spent a whoping $6.10 for TEN cups in each size. Here is where I buy my TIG Consumables. If you know of a cheaper place, let me know:

http://store.weldingdepot.com

Here is my current pile. The top rows are regular cups #4 to #10. The bottom row has all of gas lenses, gas lense cups, and collets for .20", .40", 1/16", 3/32", and 1/8 " diag electrodes. (Warning, large detailed picture 2560 x 1920):
http://www.bbssystem.com/projects/cups.jpg

-Adrian


[This message has been edited by 3 Phase Lightbulb (edited 06-23-2005).]

Swarf&Sparks
06-24-2005, 12:21 AM
Thanks Adrian, pics make it clear. I have tried that way but don't find it comfortable. I hold the torch with hand over the top, and 'walk' index and second fingers down the work.
Also, thoroughly agree with Precisionworks. I did my course at a local TAFE (community college) in the shipyards just north of here. We actually started on ali. I guess scrap was cheap cos of the number of yards building high speed aluminium cat ferries (Austal, Oceanfast, etc) The teacher was superb. Usta build nuclear containment vessels. Anyone in the UK will probably know BNF Sellafield http://bbs.homeshopmachinist.net//frown.gif He taught us to *weld* not to pass exams http://bbs.homeshopmachinist.net//smile.gif
Rgds, Lin

3 Phase Lightbulb
06-24-2005, 12:35 AM
It was uncomfortable for me for several weeks, but I kept at it and now I don't even think about it, I just watch the torch move automaticaly. My TIG instructor taught me that. A lot of the joints I plan to make will require me to free hand the torch which is what I'm basically doing except I lightly drag my pinky to help provide feedback as I keep getting better with the free hand.

-Adrian

canman
06-24-2005, 06:21 AM
Thanks for all the advice on TIG al. I already see somethings I have been doing wrong. Thanks to all who contributed.
Canman