Setting Up A Tig Welder

I'm working on setting up a TIG welder for the shop. It is a Lincoln Square Wave 200. It is not a production welder, but it has more features than the average base model TIG welder. What gas, electrodes, and filler rods should I use? Mostly using it for aluminum, and stainless steel. May use it for some mild steel also.

I worked in a sheet metal factory were the produced aluminium and stainless vats for the dairy industry. Learnt a little bit there. Stainless rods have to match the grade of metal being welded in all grades and types. Aluminium I think is the same They only used straight Argon gas for these metals. Argosheild was used for black metals. Things may have changed since then though.

Yeah, straight Argon will work for over 95% of applications and likely all you'd ever need. Helium can be added for higher amp aluminum but you don't have enough amps for thicker aluminum. For steel usually E70S-2 rods. Stainless is usually 308 or 316. 316 has more corrosion resistance. 309 is used to join stainless to mild steel but is sometimes used for non stainless steels. 312 is like 309 but higher strength and can be used for any difficult to weld steels. Aluminum is usually 5356 or 4043 but a lot of welders like the newer 4943 over 4043. If I recall 4043 is good for cast aluminum and 5356 is more for structural aluminum but they can sometimes be exchanged. It helps to know the grade of aluminum you're welding. Your welder is transformer based. It uses differently prepared and sometimes types of tungstens compared to a newer inverter based Tig welders. If you can find them 2% thoriated tungsten was the go to for steel and stainless with the tip ground to a dull point. Always grind lengthwise or you'll get an erratic arc. They can be hard to find because the safety police discovered they give off very low levels of radiation. You'd have to welding in an enclosed space for years to get any radiation poisoning. Lanthanated or ceriated are another options or E3. For aluminum you can use pure tungsten and it will form a ball on the end. Higher amps you can use zirconium tungstens. They last longer and handle higher heat than pure tungsten but you're probably fine with pure. Aluminum runs on AC and requires continuous high frequency. Steel/stainless uses straight polarity/electrode negative. High frequency (start only) helps start the arc without touching the tungsten on steel/stainless.

And there you have it, nice rundown WD.

I wanted a tig welder and bought a used Miller 330/A. I was lucky and got to take some tig classes. I learned a lot very interesting. I went to look at this welder and thought i would just have the seller weld something and if it worked buy it . He was showing something else and told me to try it. I did and it worked ok so i bought it. The tank didnt go with it and it was awhile before i got a bottle but when i did wouldnt jump a arc the only way it would arc was to scratch start it by touching the electrode to the work. I need to get back to messing with it maybe some thing happened moving or hauling it ? There is a salvage store close by me that sells tig rod cheap so now i have plenty.

Old Doug said: I wanted a tig welder and bought a used Miller 330/A. I was lucky and got to take some tig classes. I learned a lot very interesting. I went to look at this welder and thought i would just have the seller weld something and if it worked buy it . He was showing something else and told me to try it. I did and it worked ok so i bought it. The tank didnt go with it and it was awhile before i got a bottle but when i did wouldnt jump a arc the only way it would arc was to scratch start it by touching the electrode to the work. I need to get back to messing with it maybe some thing happened moving or hauling it ? There is a salvage store close by me that sells tig rod cheap so now i have plenty. Click to expand... The blokes I worked with always had a peice of scrap they'd place beside were they were welding to strike the arc. It keeped the metal polishers happy.

High frequency start helps with starting the arc on steel without needing to touch the tungsten. A really good Tig welder I know said to rest the side of the nozzle on the work and slowly tilt the Tig torch up to start the arc without touching the work. Some newer Tig welders have touch start where you initially touch the tungsten but the arc doesn't start until you lift the tungsten off the work.

Putting the torch on reverse polarity and striking an arc for a couple seconds only on a piece of copper can clean a lightly contaminated tungsten. It works when doing aluminum with a balled tungsten. Pennies can work.

Tones said: The blokes I worked with always had a peice of scrap they'd place beside were they were welding to strike the arc. It keeped the metal polishers happy. Click to expand... Was this when Tig welding? Have seen it when stick welding but good Tig welders don't usually have stray arcs.

Welder Dave said: Was this when Tig welding? Have seen it when stick welding but good Tig welders don't usually have stray arcs. Click to expand... Yep, from a hazy memory it was to prevent tungsten inclusion in the weld particularly when making pressure vessels. Every weld layer had to be tested and the first 2 or 3 runs required tig weld. Me being the newbe usually got the job of argon backing when they did the first run on SS vessels. A barstard of a job, lots of sore eyes but 1 heck of a tan. Only stayed there 10mths, the lure of mud,dust and diesel dragged me back to dirt work. Also it was the first and only time I worked inside and punched a time card.

I think this machine has HF start. I'll post the specs when I have some time here. It has the foot peddle. Do you start with it part way down or with it on the floor?

It should have a start, off and continuous high frequency switch.

Tones said: Yep, from a hazy memory it was to prevent tungsten inclusion in the weld particularly when making pressure vessels. Every weld layer had to be tested and the first 2 or 3 runs required tig weld. Me being the newbe usually got the job of argon backing when they did the first run on SS vessels. A barstard of a job, lots of sore eyes but 1 heck of a tan. Only stayed there 10mths, the lure of mud,dust and diesel dragged me back to dirt work. Also it was the first and only time I worked inside and punched a time card. Click to expand... That makes sense especially if just using a DC welder with no high frequency start or remote amp control. I think experienced Tig welders could establish an arc without getting tungsten inclusion but a starting block was used as a precaution. Was the starting block tacked on the vessel or somehow clamped on?

Tacked on but this was 40 odd years ago,figure tig welders have changed a bit since then.

A lot of codes wouldn't allow anything tacked on especially if it was a critical vessel requiring a Tig root pass.

I need to try it agin there may be a problem or some thing that got switched when it was hauled .

Welder Dave said: It should have a start, off and continuous high frequency switch. Click to expand... I read in the manual that HF start come on when you push the peddle and is active for 1/2 second. There is no switch for it other than that.

Here are some specs on the welder: Amps 10-200A Pulse 0-20 pulses per second AC Balance 60-90% AC Frequency 60-150Hz AC or DC-Electrode negative TIG

Mr. Wrench said: I read in the manual that HF start come on when you push the peddle and is active for 1/2 second. There is no switch for it other than that. Click to expand... Ok, that will do the same to avoid tungsten contact with the work. Other Lincoln Tig welders have a 3 way switch. How does continuous high frequency work, is it automatic when you switch to AC for aluminum?

So the pulse you can turn on and off. Would you use that on AC or only on DC? AC balance comes on at 75% default when you switch to AC mode, and then you can adjust it from there. AC frequency I think is different than HF start. HF start would be a more powerful, higher frequency the would kick in just to start and it can not be adjusted or turned off I think on this machine. When you switch to AC mode it's default is 90Hz. It came with 1/16 and 3/32 electrodes and a #7 nozzle. The electrodes have red or purple on the end so they must be 2% Thoriated? With the amp rating of the machine I think 3/32 is the biggest you would go.