Welding Tips and Tricks

We are working out of the Hobart Institute of Welding Tech GTAW book. They specify 3/32 tungsten electrode at 45-55 amps for open root butt joints on .060/16 gauge mild steel.

It seems like every technical manual, or welding calculator I've seen online, recommends 1/16 tungsten at higher amperages.

Is this a common occurrence in industry? I'm trying to understand the discrepancy between what I see recommended by most resources and what I'm being told to do. I'd like to know how to make an informed decision on when/why to choose 1/16" or 3/32". It seems like 1/16 tungsten is often indicated, even for 1/8"/11 gauge steel, but we've never even had access to these electrodes.

I can certainly do it with 3/32, and pass the weld criteria, but it seems like there is more heat distortion and less room for error that I would have thought. The .060 stainless material in particular wants to warp and discolor more than I'd like.

Is using the smaller tungsten easier/better for welding .060 in the various joint configurations you'd see in welding school? Or should I just forget about it and chalk it up to my limited skills? I'd purchase 1/16" myself if it that would maximize my ability to learn properly.

That's OK. You can weld razor blades with 3/32 electrodes.

If you're getting a lot of warping and heat distortion, try upping the heat and moving faster. Your overall heat input will be less.

And let it cool down in between passes.

Normally, I will use a 1/16" tungsten up to about 125A but you can use 3/32" if you have a good grind on it.
I suspect they're using 3/32" rather than 1/16" to cut down on tungsten consumption due to dipping, regrinding, etc.
They may also be trying to teach you the principle of "weld hotter, weld faster" to reduce distortion, warping.

3/32" is sort of the "all purpose" tungsten size that stays in my torch about 95% of the time. I'll usually only switch sizes if I want to weld heavy aluminum (go up) or if I have something thin and delicate that I want to get right the first time (go down a size or two). But for practice/learning, 3/32" should be fine.

Company I work for supplies 1/8” tungsten and we work with like 10-14 Gauge stainless typically.

I have 1/16 tungsten "cause it is cheap. I can buy NOS from the internet cheap. It'll work fine if you don't go big. On the other hand, steel works very nice with a sharp 3/32. Due to the melt back, I still like 1/16 for very thin aluminum sheet.

Thanks guys! I'll make an effort to up my speed/heat and see if that produces optimal results.

I may buy some 1/16 tungsten just to get a feel for what the differences are, though. And now I want to try welding razor blades.

FrozenTundra wrote:I may buy some 1/16 tungsten just to get a feel for what the differences are, though.

If you sharpen your 3/32 tungstens to a needle point, there will be no difference. That's kind of the point.

Read this thread and watch some of the videos: http://forum.weldingtipsandtricks.com/v ... =5&t=12761
I learned a lot!

Louie1961 wrote:If you sharpen your 3/32 tungstens to a needle point, there will be no difference. That's kind of the point.

That has not been my experience when welding at real low amperages for the tungsten size in question ... though all I'm using are transformer-based welders (don't know if that makes a difference).

If I try to use a 3/32" tungsten to weld at, say, 30A, even if it's sharpened to a sharp point, I find the arc is erratic and jumps around. I'm also using cheapo Chicom tungstens (2% Lanth) from ebay ... again, don't know whether this makes a difference. YMMV.

Seems to me the logical thing to do would be ask the school why they supply the tungstens they do.

That has not been my experience when welding at real low amperages for the tungsten size in question

There's a lot of variables in play...how you prepare the tungsten/grind the tip, etc. I have never had a problem with my transformer TIG at any amperage on DC. I don't do any thin aluminum so can't say I have first hand experience on AC at low amps. But Jody has done at least one video on this topic, and his conclusion agreed with mine.

Franz© wrote:Seems to me the logical thing to do would be ask the school why they supply the tungstens they do.

I will certainly do this.

I have been on spring break for 10 days, and during that time I've been watching videos, reading forums, listening to podcasts, and going over technical manuals. I've got so many new questions....I guess I just got a little impatient.

Also, I've come to find out that even welding school instructors disagree about some pretty fundamental things. I like getting the different opinions, and trying to understand in which context they most significantly apply. Knowledgeable people can often have disparate opinions, while still both being 'correct' from within their own frames of reference.

That is what makes life so interesting.

FrozenTundra wrote:
Also, I've come to find out that even welding school instructors disagree about some pretty fundamental things. I like getting the different opinions, and trying to understand in which context they most significantly apply. Knowledgeable people can often have disparate opinions, while still both being 'correct' from within their own frames of reference.

That is what makes life so interesting.

You're learning well grasshopper.

You only think you're seeing disagreement in the school setting. When you get on jobs keep both eyes open and watch machines getting reset at shift changes and lunch. Not only does current change as cables heat up, different men run at different speeds, and some still remember the old cheats.

FrozenTundra wrote: Also, I've come to find out that even welding school instructors disagree about some pretty fundamental things. I like getting the different opinions, and trying to understand in which context they most significantly apply. Knowledgeable people can often have disparate opinions, while still both being 'correct' from within their own frames of reference.

That is what makes life so interesting.

My welding program was mostly staffed by people with no technical knowledge. They all had good techniques and were able to give good guidance on tig mechanics but ask them a question about metallurgy and it was all blank looks. Get from them what they have to offer that they are good at and then go home and play with things outside of their little box. Learning this is going to be up to you and deciding how far down the rabbit hole of understanding theory you want to go.

Try blunted and needle sharp electrodes. Try welding rusty crap metal. Grab some 2000 or 7000 series aluminum and try welding it. Weld cast iron with whatever you have on hand... The crap that everyone says not to do is worth trying as most of it will show you plain as day why it doesn't work.

To answer your first question though, distortion makes me think your arc length is too long and it is ramping up your heat input. Try holding a tight arc and just doing autogenous welds with that 3/32. Bet it turns out nice and flat.

-Sandow

https://www.youtube.com/watch?v=-L1UgdtpCpw