Got me a Lincoln TIG 200

So, after looking at tubular reviews I decided the TIG 200 was a good buy. Tried it out last night for the first time. Just on 120 volts. I was able to weld .125 thick 6061 using 3/32 filler rod with no problems. I fidled with the AC balance and the default 75% setting works great. I did try the 90% setting and even though it welded well the weld appearance was not so good, not shiny. Played with the frequency setting and it was really interesting to watch the arc width change. I didn't weld much with the DC but did try out the pulse feature. It is obvious that I will need too learn how to use the pulse feature but I can see how it will be great for thin stuff. The high frequency start function works well, it will throw an arc about 5/8 inch. I have a few small gripes. It uses an air cooled torch and comes with regular, not gas lens, cups and so on. The torch is a pretty good one for an air cooled torch, a model PTA-17F. It has the flexible head. I bought gas lens stuff for the torch when I bought the welder. My first welds were made on steel with the standard cup setup and the gas flow I usually use with gas lenses. I noticed porosity right away. Changing to a gas lens and the porosity went away and the weld appearance improved greatly. The post flow is about 5 seconds and cannot be adjusted. This must be to cool the torch. The pedal doesn't have the same feel as the old heavy one for the Miller welder so I am not sure when I have stepped on it enough to start the welder. This wouldn't be a problem except there is a slight delay between stepping on the gas and the arc initiation. A couple times I didn't think I pressed far enough and the arc started really hot. After welding stops if the pedal is pressed right away there is that damned delay. Another small gripe but I will get used to it. I am going to make up a water cooling adapter for when the welder is used in the shop as well as adding a post flow time external to the machine. I already have the right adjustable time delay relay so it will be pretty easy (I think) to use the pedal switch to trigger the time delay relay. Eric

Reply to
etpm
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I'm guessing the gas pre-flow time may be causing your delay.

There are quite a few good youtube videos for this welder. Also videos on the other settings that are new to you, cleaning, frequency...

I would like to have one but can't justify the cost verses how much I would really use it...

Reply to
Leon Fisk

That's very impressive! It took me a while to get the feel of doing Aluminum. First problem is nobody told me the work NEVER got hot enough to glow. Once I realized that bit of info from steel welding would not be available, things went a bit better. I have a square wave TIG 300, which is a fantastic machine, but large and heavy.

Gas lenses help reduce gas consumption, and Argon is getting pretty pricey.

Jon

Reply to
Jon Elson

Are you referring to ewe-tubular reviews, Eric?

Were you using less or more gas with the standard cup?

Yes, interesting review.

Newb here. Aren't the delay, and the resultant flow of gas while the weld cools, necessary to keep the weld from getting brittle? Even my little $200 Harbor Freight TIG has that post-arc time delay before the gas shuts off. Wish it had DC and high-freq start.

Do machines with water cooled torches not have that delay?

Reply to
Larry Jaques

You're right about the gas pre-flow delaying the arc . The pre is to give the arc some ionized (by the HF) gas to help start as well as shield . The after is to prevent oxidation as the weld cools . I think the gas lens setup gives better shielding with less gas than standard cups , at least it seems that way for me . Also , Jody has some excellent videos on all those controls and what they do . The Everlast EX250 I got a couple of years ago has all those bells and whistles , and his videos have been a really big help to me on how to use them . It also came with both a new water cooled and a used air cooled torch that they tossed in for free . I still haven't used the water cooled one ... but I'm pretty sure the pre flow delay is set by the machine and not the torch .

Reply to
Terry Coombs

If I'm not mistaken, it's not that the work won't get hot enough to glow, it's that aluminum is never emissive enough in the visible wavelengths for it to glow. If you watch aluminum casting, you'll see that the crucible is glowing a dull red, even though the aluminum inside is shiny. If the aluminum were "black" (meaning, if it were emissive), it'd be glowing that same dull red.

Reply to
Tim Wescott

Actually -- if your Harbor Freight TIG is like mine it *does* have DC. What it does not have is polarity reversal and pulsing to allow it to work well with aluminum.

Enjoy, DoN.

Reply to
DoN. Nichols

Yup.

Reply to
Larry Jaques

My old TIG welder is a Miller Gold Star. It has a post flow timer but no pre flow timer. Typically I just mash the pedal when first starting a weld in order to push all the air out of the torch gas line. The post flow is set long enough to keep the tungsten from turning blue. When I am welding a lot of passes I usuallyhave things set up so I can stop one pass and start the next pass during the post flow time. Whenever I need a longer post flow I just tap the pedal. The gas lenses really save on gas use, about half actually. When I get the water cooled torch adapter made I will also be installing a post flow timer. Eric

Reply to
etpm

Hmmm! Very interesting! Well, aluminum has a high specific heat, so it takes a lot of energy to raise the temp. So, it is possible that the crucible gets hotter than the melt. I've watched some guys do aluminum pours, and if you get the aluminum too hot, you get a lot of dross, so that is to be avoided. Also, when welding, you want the work JUST hot enough to fuse. Get it too hot, and it ends up on the floor. Due to the high thermal conductivity of aluminum, the range between welding and melting the whole piece is REALLY small. Much harder than with steel, for instance.

Jon

Reply to
Jon Elson

The standard cupo produces turbulent mixing with the surrounding air. The gas lens produces minimum turbulence, so that air is not introduced near the electrode. If you hold the torch so a stong light makes a shadow on a wall, you can easily see the flow of argon, and see the difference in how smoothly a gas lens flows out of the cup.

My Lincoln Square Wave TIG has adjustable pre-flow and post-flow timer settings. The gas valve is in the WELDER, not the cooler, so it is a welder function. So, it wouldn't care about the torch cooling. I have only used a water-cooled torch. I can't imagine air-cooled can be used at high current, the electrode gets WAYY hotter than the work.

Jon

Reply to
Jon Elson

Air cooled (actually GAS cooled) torches are available for use up to

300 amps. I used to have one. My new welder came with a gas cooled torch good for 200 amps. I exceeded the duty cycle for a 200 amp gas cooled that I used to own. I had been welding aluminum at the time. On several occasions I had done this, gotten the torch so hot I could only hold on to the very end of the torch handle. The last straw was when, as I was welding, the weld quality started to suffer and I noticed a strange burning smell. Flipping up the hood I saw that the torch was smoking. Smoke was pouring out of the cup as well as off of the outside. That's when I switched to water cooling. Eric
Reply to
etpm

I love my water cooled torch compared to the previous air cooled as it is far more flexible in use due to the nature of the lead construction. I have once seen a water cooled torch where the water cooled leads failed, the torch was fine and the leads replaced, but the kiddy using it found himself in a smoke cloud when the leads overheated and melted letting out the smoke and water. The water cooler was fine but for some reason the leads failed, maybe the welding unit, an old Miller Synchrowave IIRC, was rated for more than the torch, I don't know, but the leads were replaced and the welding station put back into service after a day or 2 when new leads arrived.

Reply to
David Billington

The Tinman's lens is for cutting the yellow sodium flare from flux when gas-welding aluminum. That flare completely obscures vision of the weld zone. The TM2000 lens completely blocks that yellow flare, greatly facilitating gas welding of aluminum.

Years ago weldors used cobalt blue lenses to block that sodium flare. They didn't work as well at blocking the sodium flare. I can attest to that; they were better than nothing, but not nearly as effective as the green TM2000 lenses. More importantly, they did not adequately protect the weldor from UV and IR rays. They are no longer used or available.

Reply to
Don Foreman

I've seen this sodium flare issue mentioned many times but have never actually experienced it when gas welding aluminium and using a standard gas welding filter as used for OA welding of steel. Maybe the flux formulation i have used in the UK differs from that in the US and it doesn't produce the flare or maybe it's a problem when gas welding aluminum but not aluminium as we have in the UK ;).

Reply to
David Billington

Right you are, David. Proper spelling and pronunciation _seriously_ affect the intensity of the sodium flare in our two countries.

I've only seen aluminum tigged once, and I wasn't knowledgeable enough to look for said flare. "I'd only seen Heliarc before that." he flatly stated, in a high-pitched voice. ;)

Interesting! Thanks for that, Don.

Reply to
Larry Jaques

We were not talking about TIG welding but gas welding aluminium where apparently some experience sodium flare from the chemicals in the flux used during the welding process to deal with the oxide on the aluminium surface. TIG doesn't require a flux and so the flare isn't an issue although the filter is darker and possibly stronger in UV and IR filtering due to the electric arc being used to perform the weld.

Reply to
David Billington

You're right. I wasn't paying enough attention.

Let's hope they're darker, for their eyes' sake.

Reply to
Larry Jaques

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