Welding Tips and Tricks

Hi All
I have just brought an old (old) Cigweld TransTig DC140 , Real Basic stuff no pedal no HF and no AC ......
I understand that you can weld Aluminium with one of these machines and if anyone here has any Tips I would really be greatful.
I have a lot of respect for Jody and Thank him very very much for all the info he provides us.
Iam keen to have a go at the Tig practice Jody recommends in his Video (The one where he lays beads on an ali sheet).
Other than its good seat time and will help develope my skills I have no other reason for welding Ali .
Thanks in advance for your help
George
Wanganui
New Zealand

Hello Shed dweller, Well ..... got a kinda ok news, and a not so ok news for ya. The not so good news is that if you really want to tig Aluminum, and are new to the skill, ( art form ) if I may, you will be somewhat dissapointed if not discouraged all together with this machine. The reason being the lack of A/C ( with HF ). Remember with anything other than an Advanced square wave capable Inverter based unit, the arc goes out basically as the AC wave form crosses thru the zero point, especially on an older transformer based, A/C sine wave. That is why HF is continous on AC and start only for DC. So at the very least to really do " nice clean " aluminum welds you want at minimum an AC capable machine, even if you have to buy an external HF generator module, ( not particularly expensive actually ) to then do aluminum.

Now the kinda ok news, ....... yes you can weld Aluminum with DC. I am somewhere around a 30 year Tig guy, and started out on chromoly bike frames in the late 70's ( worked for a company that had the entire Red Line account ), to racing motorcycle frames, on to eventually aerospace components etc. And just about anything in between. Everyone talks about large diameter tungsten with very low amperage DC reverse. Ooops, I'm showing my age, lol. (We used to call it DC straight or DC reverse). So let me update my terminology, .... DCEP or DC Electrode positive. The current is flowing from the metal TO the tungsten, which then is bearing the brunt of the heat. Many guy's ball their tungsten by doing this prior to switching the machine to AC to weld AL or Mag. With anything more than low low amperage AND a 1/8th in tungsten, you will just burn the tungsten right up. It can be used tho to weld VERY thin sheet, and you will of course have maximum cleaning action, ( same as if you had an AC machine with adjustable balance and cranked it to max cleaning or electrode positive.) NOW what a lot of folks don't realize is that you CAN successfully weld AL set to DCEN! Sharpen your 3/32 2% thoriated to a point as you would for steel much like if you had an Inverter Tig unit. I used to weld some structural boom towers 20+ feet long, for concert stage lighting back in the day, for Fleetwood Mac, or Supertramp, can't remeber, .... anyway the bases at each end were 1 inch + thick Aluminum plate. We beveled where necessary, and did multiple passes with weave bead caps, using old Linde Ucc 305 units, socking some 360 amps into it. (Btw, those big ole Lindes are the finest welder i have ever used i believe to date! SUPER stable arc down to an Amp or two!) Anyway we certainly could have used AC, but with a fixed balance of oh 50/50 or maybe 60/40, we could not get the penetration on that thick of material that the process called for. DCEN puts all of the heat to the work piece, maximizing penetration.

Ok, ... so now the caveats. We also were running High ratio Helium/Argon mix. Helium results in a hotter weld but also helps with cleaning in this situation. Remember in DCEN you basically have NO cleaning to speak of. I do not recomend this for beginning Tig welders learning on Aluminum! The weld pool will appear scummy and dark, with a deceptive wet in. IE you will not easily recognize when and how to add filler rod. It is very unforgiving to a stray tunsten dip. It is a advanced or specialized technique that is out of the norm, used in situations where it is called for only. So in my long winded fashion, .... yes you can Tig in DC, but it is going to suck, and be a real pain in the A**! I am sorry my friend, just my humble opinion, but your efforts may be well spent on trying to get even a cheapo AC + HF unit, just as a starter for trying aluminum. Or of course as everyone likes to say, save up for a miller, lincoln etc etc. A lot of the old machines now can be had for a song, .... but they are big and heavy to ship and haul!! Best of luck to you, ......

Thanks for the info Trackmaster , I am good with Mig and love stick heaps .Understand what you are saying as I have 24 years in automotive engineering.........Where did the time go ?
I will learn some skills on sheet metal with the Tig as that is why I got it.Hopefully I dont have any problems there ?
Any info from a Pro like you would be great , I have only ever used a Tig once in my life mid 80's I think.
Well Take care buddie and thanks for the reply
Regards
George

Ah George, thank you for the compliment, whether or not it's accurate or deserved is another thing altogether, ha! Seriously, just my take. Many other skilled folks around. Good to know that I'm talking to another "young" man like myself! lol! Yeah man tig the heck outta some steel with that unit! Prolly scratch start on a piece of copper and then move to the weld yes? You can do a lot with a simple machine like that. Some folks describe Tig as a difficult process, ..... I think once ya get the idea down it's pretty easy. Just like anything tho it just takes practice and real world experience to be consistant, and get it right on the first try at a part. Take care my friend, - Lou

Thanks a million Lou , You are a very humble and honest man in my book , Still reackon your a Pro........Cant beat time on a job .
Take care and look forward to chewing the fat again
George
P.s
Thanks for replying

Aluminum can can be welded in dcsp . using the highest grade of helium, do not used party balloon grade, this process is for deep penetration so thin metal is out for this process. Feed the rod and watch your heat, I've welded it with HF and no HF. Preheat to 200 and let cool down between every weld, keep weld and material clean, good luck!

Thanks OD1

I'm gonna give the ali a miss , enjoy the Tig welding too much to go on a bad buzz with the ali.
I'm Hooked and now the Mig and Stick are fast becoming dust collectors!
Thanks for all your guys help
Regards
George