TIG welding aluminum

[HoleshotHolset]

I don't know what I'm doing wrong... . but whatever it is I hope to correct it.



I have tried pre-heating, stainless steel wire brushing the ever living heck out of it, etc.



I'm using my machine on AC output, pure tunsten (balled) in the torch, and a boatload of amperage.



I can't get it to form a nice weld pool like regular old steel... . and when I do get a weld pool to form I'm usually at the point of turning my workpiece into a puddle of molten metal.



Any suggestions or tips?



Matt

 

[83 crew cab]

your dong it right thats whats fun about alum try and get some 1/4 in 6061 to start with its about the easiest George

 

[willyslover]

hey Matt. . most of the good welding shops have how to video's [some for rent also]. . some are well worth viewing a picture is worth a 1000 words. .



watching puddle control and once you start seeing it and hearing it you'll progress rapidly. . the sound will tell you quick if your heat is to low as well as to high. . then your eyes will see what your ears tell you [after practice, pratice,pratice]... trust me LOL



heck. . most adult education programs have night school for welding, that's how I started and got the basics for each type of welding [well worth the time IMHO]

 

[esommer2500]

Hehe... .



We did some aluminum in class the other day, and it is WAYYYY different than doing mild steel. Sounds like you have the torch setup right. My instructor showed us how to 'ball' the end of the electrode using a copper pedestal. (You are using pure tungsten, right?) The biggest difference I saw, besides the sound while running on AC, was how much farther away the electrode is than when welding mild steel with 2% thoriated electrodes. Instead of 1/16" to 1/8", it was more like 1/2". Besides that, I don't have anything else I can tell you, besides practice, practice...



Eric

 

[d90boy]

How thick of aluminum are you trying to weld holeshot? If memory serves you have that 180 amp Miller. You won't be able to go very thick on aluminum with that machine. I have a 250X that will go to 310 amps and it's too small for aluminum really.

 

[Boomer II]

Are you using a foot pedal?

 

[83 crew cab]

d90boy all we have at work is the 250 and 90 % of or welding is alum i have used it up to 3/8 inch the 180 should be plunty big enough fr at lest 1/4 inch George

 

[jmadden]

It's been quite a while, but here's what I remember or think I remember...



Turn the amperage WAY UP... push the pedal way down... and when the alum. starts to pool you need to back way off the pedal just keeping enough current to maintain the pool. This is not like welding mild steel. Preheating should not be necessary. You shouldn't really need much wire brush unless the material surface is really bad/filthy... I use a Miller 180SD and/or a Lincoln 175... both have handled 1/4" alum. without a problem.



Use what seems like very large diameter alum. filler rod.



Personally I have found pure tungsten to be over-rated... I use 2% for everything.



What type of gas are you using... and do you have the cfm set high enough? Gas is very important. I run pure Argon... have yet to experience a problem. We run blends at work that result in a little more heat w/ the same amperage.



Someone already hit on the most critical thing... PRACTICE!



Good luck.





jm

 

[Jim Fulmer]

Matt, I have a 175 lincoln and have no problem with welding except the user, never tried the 1/2" method... now I have to try that, lay the touch over and point it to the direction your traveling at say a 45 degree angle, seems like everytime I have problems I'm almost verticle on the torch. I just did a small aluminum job and learned allot on it, if you have bad aluminum you might have to weld it bad then V grind it and re-weld it with then now good filler. I would like opinions on this as I'm learning too.



Jim

 

[HoleshotHolset]

Holy crap! (doesn't that remind you of the 'old man' on 'Everybody Loves Raymond' ??! ) I didn't expect such a response!



You know, I was thinking of using the 2% thoriated tungsten... having that ball on the end of the pure tungsten electrode made the arc go all over the place.



I'm using 100% Ar, Miller Syncrowave 180SD Digital set to A/C (I even tried moving the 'Dig' control all over the place... more cleaning or penetration didn't do much... . ) - pedal almost the whole way down at 180A with about 20cu. ft/hr of flow on the gas.



I think the bulk of my problem is the filler rod - it's rather small in diameter. When welding on thicker mild steel - I quickly realized I needed a larger diameter filler rod. DER!



The first time I used A/C - I spooked myself with the sound of it. The neighbors look at me funny everytime I use A/C - it makes a lot of racket.



Question: When welding aluminum - do you absolutely have to use the exact same grade rod as the base metal? If so - how in the heck do you know what the base metal is if it's not printed on it?



You guys rock!



Matt

 

[jmadden]

I'm not the expert, but I don't think you could match the grade of the filler to that of the material if you wanted to... I just haven't seen more than 2 or 3 filler choices (Aluminum/Silicon and Aluminum/Magnesium are the only 2 I can actually think of)... and there have got to be more types of aluminum material than that. Would you use the EXACT same grade rod for mild steel or stainless or... think compatible, not identical.



Try some nice 1/8" filler rod... and provide some feedback on whether it makes a difference for you.



jm

 

[Amianthus]

Finally!!! Something I know a little about.

Okay. We weld a TON of Aluminum here at work. All kinds and all thicknesses. SO I think I can speak with some expertese on this.



If you're welding thinner stuff, try this. Set the machine for about 80 amps and use a 3/32", 2%, Ar setup. Start your arc and hold it. First the metal will crust over a little, then you'll get your puddle. Then weld normally. Be sure to watch your puddle size. If it starts to get too big, you're gonna blow through pretty soon.



For thicker stuff, use a 1/4", 2%, Ar or Ar/He mix. Set your machine as high as you can. With anything over 3/8" you're gonna be looking at around 200-300 amps to get it to weld. The stuff can be pretty forgiving, I think. Puddle starts fast and once started, you can really motor along. You should be running about 35 CFM gas flow. That will probably help alot.



With the Ar/He mix, it will make a ton of noise but you won't need as much current. You can also weld it with DC and He. But it's gonna take a long time to fill up your groove.



If you want more specific help, I will need to know the thickness of the metals you want to weld, alloy (if you know), rod size, electrode size, rod alloy, and application. 5356 rod will weld most Al pretty well. but there are some times where 4043 would be better.



If you feel confident in my advice, I can maybe get you started with MIG. Heh, heh.



Just let me know. On the forum, if you please.

 

[esommer2500]

How are you getting the ball on the end of the electrode? Our instructor used a copper 'pedestal' because he said it reflects the heat the best.

If you're welding thinner stuff, try this. Set the machine for about 80 amps and use a 3/32", 2%, Ar setup. Start your arc and hold it. First the metal will crust over a little, then you'll get your puddle. Then weld normally. Be sure to watch your puddle size. If it starts to get too big, you're gonna blow through pretty soon.

This is pretty much what we did in class. We were welding on 3/32 pieces that were laying around. HH, what size metal are you working on? If it's not more than 1/4" you might try turning your amperage down a bit?



Eric

 

[willyslover]

Matt. . watch out... soon you'll be asking about chill bars and such LOL

 

[HoleshotHolset]

I'm really hooked on welding - to the point that I try to spend as much time as possible in the garage and folks here at work are finding stuff for me to do for them!



Amianthus / everyone: It seems to me that my filler rod is my biggest issue. I just need some bigger filler rod.



I'm still having a hard time 'seeing' the weld pool form with Al. I'm so used to mild steel moving around nicely and making a cool little molten puddle... Al is VERY different.



I was just informed today that my 'contact' at the place I buy all my welding supplies at has left the company. That figures... .



Great thread, don't you think?!



Chill bar? Isn't that where you'd buy a margarita or ten? :-laf



Matt



On edit: If I'm welding thicker than 1/4" I need to turn my amperage DOWN?!

 

[jmadden]

I believe the direction was...



if the material is not more than 1/4" thick (i. e. , if it less than 1/4" thick) turn the amperage down.



jm

 

[HoleshotHolset]

I did it again... I'm reading code on one screen and the TDR on another. My bad.



Thanks for the correction.



Matt

 

[RDusch]

Matt,

what shield gas are you using Argon?? if so try a Unimix Argon and helium and use a larger than normal cup, i also use 3/32 and 1/8 " tungsten makes working with alluminium alot nicer... . Rick

 

[Agades]

helium will transfer more heat to your weld than argon



dont use helium for anything thinner than say 3/16" thick

it takes too many amps to establish a good arc and you'll burn through



rule of thumb

you should get a good clean puddle within about 3 seconds or your not going hot enough



aluminum disipates heat very fast so if you go really slow the piece will load up with heat and the whole thing will just melt into a blob before you even get a weld



hot and fast is important



as far as matching the base metal



you can get close but probably wont match it perfectly



if you are having a cracking problem use a high silicon content rod like 4043



if you need high strength use a 5000 series rod

5356 is popular



4000 series is not as strong as 5000 but flows better and has less tendancy to crack



I like the appearance of a 5000 series weld better

the puddle freezes quicker and makes nice ripples

(if you know what yer doing)



if the piece is to be anodized do not use a 4000 series

the color wont match



WHAT ELSE DO U WANT TO KNOW

IF I DONT KNOW THE ANSWER I MAT BE ABLE TO FIND IT



(I teach welding for a living and run a welding and fab business)

 

[83 crew cab]

Agades I got question for you I got some rod form the company store lost freight and cant find a chart that shows me what it is here you go nippon welding rod co WEL TIG KP12Cr hat number RB1756 MS8998 thanks George