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New to tig welding

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New to tig welding

Postby ChrisM » Fri Feb 09, 2018 7:02 pm

Good morning all,

Just started to learn tig welding and was wondering if some folks would be able to take a look at some practice welds and suggest what I could be doing wrong and how to improve.

Material: 1.6mm galvanized rectangular tube
Electrode: 2.4mm E3 tungsten
Filler: 2.4mm ER70S-2
Current: 70A, no foot pedal, 3 seconds down slope
Gas: Argon, 9 litres/min, #8 cup, gas lens

Weld 3 is the most consistent, but they have sucken rather than the filler building up.

Thanks,
Chris
Attachments
Weld4b.jpg
Weld4b
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Weld4a
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Weld3b.jpg
Weld3b
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Weld3a.jpg
Weld3a
Weld3a.jpg (67.42 KiB) Viewed 347 times
Weld2b.jpg
Weld2b
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Weld2a
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Weld1b.jpg
Weld1b
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Weld1a.jpg
Weld1a
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ChrisM
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Re: New to tig welding

Postby tweake » Fri Feb 09, 2018 9:00 pm

my $0.02 from another beginner,
it looks to hot and slow. i think probably way to slow.
check the backside it should tell you what happened.
tube can be funny in that it tends to overheat quicker for the given size.
also i would not use galv tube. your going to burn galv off the inside and make nasty fumes.
not the best stuff to learn on.
tweak it until it breaks
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Re: New to tig welding

Postby Poland308 » Fri Feb 09, 2018 9:34 pm

Try 90-120 amps. Your low heat is causing you to travel slow allowing the heat to saturate and cook the steel. Not ideal. But not bad for your first attempts.
I have more questions than answers

Josh
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Re: New to tig welding

Postby Bill Beauregard » Fri Feb 09, 2018 10:29 pm

Do not weld galvanized if you can avoid it. When you do TIG galv. you must figure out how to avoid fumes. A fan blowing on your face if it doesn't blow away shielding gas might work. An expensive fume extractor is desired.

Start with clean bare mild steel.
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Re: New to tig welding

Postby cj737 » Fri Feb 09, 2018 11:12 pm

Poland308 wrote:Try 90-120 amps. Your low heat is causing you to travel slow allowing the heat to saturate and cook the steel. Not ideal. But not bad for your first attempts.

90 amps for 1.6mm thick material? I think you misread something... probably closer to 55 amps would be better than 70.

Definitely do NOT practice on galvanized material. And, clean your tungsten now that you have welded galvanized with it.
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Re: New to tig welding

Postby ChrisM » Wed Feb 14, 2018 4:21 am

Hi all,

Thanks for your replies and apologies for the delay. Wanted to wait until I could get some more mild steel that was not galvanised to try again.

First photo is from stick welding at 50A. Guess I'm using that as my benchmark, not sure if that weld is decent or not. The finish isn't the greatest but for the most part is it okay?

Second photo I welded from right to left, started at 50A but had trouble getting the tube and filler to melt. Stopped 1/3 of the way and bumped up to 60A. Moved too slow and same problem, flat?

Third photo I bumped up to 70A, not the best looking but the filler is starting to build up.

Fourth photo I bumped up to 90A. This felt the best for melting the tube and filler. Looks like I moved too slow or didn't dip the filler often enough?

Has the welding improved, declined or indifferent?

tweake wrote:my $0.02 from another beginner,
it looks to hot and slow. i think probably way to slow.
check the backside it should tell you what happened.
tube can be funny in that it tends to overheat quicker for the given size.
also i would not use galv tube. your going to burn galv off the inside and make nasty fumes.
not the best stuff to learn on.

tweake, yes it did feel like I was going slow. Had trouble getting the base metal and filler to melt at low amps. The backside actually has the typical concave "meaty" look too it that I was expecting.

Poland308 wrote:Try 90-120 amps. Your low heat is causing you to travel slow allowing the heat to saturate and cook the steel. Not ideal. But not bad for your first attempts.

Thanks Poland308, 90-120A is inline with one of Jody's square tube welding videos: https://youtu.be/chUOzYmxOH4?t=4m09s
I think in my 90A attempt I was still moving too slow??

cj737 wrote:
Poland308 wrote:Try 90-120 amps. Your low heat is causing you to travel slow allowing the heat to saturate and cook the steel. Not ideal. But not bad for your first attempts.

90 amps for 1.6mm thick material? I think you misread something... probably closer to 55 amps would be better than 70.

Definitely do NOT practice on galvanized material. And, clean your tungsten now that you have welded galvanized with it.

cj737: 90+ amps seems high doesn't it, but I had quite a bit of trouble trying to get the tube to melt at 50A.

These welds look really dull and flat. Is it possible my welder is not working correctly? It's second hand and given I haven't welded with another tig welder I don't have much to compare with. It doesn't seem to melt the metal as cleanly as I've seen in Jody's tig videos. And the welds certainly don't have the same silvery shiny appearance.

Cheers,
Chris
Attachments
Stick.jpg
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Tig50A_60A.jpg
Tig50A_60A.jpg (68.82 KiB) Viewed 249 times
Tig70A.jpg
Tig70A.jpg (67.47 KiB) Viewed 249 times
Tig90A.jpg
Tig90A.jpg (66.14 KiB) Viewed 249 times
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Re: New to tig welding

Postby cj737 » Wed Feb 14, 2018 9:20 am

In this latest set of pictures, all of them show a lack of preparation. Your metal needs to be VERY CLEAN. Hot rolled, cold rolled, it doesn't matter. You need it to be bright and shiny. If the material is thin, you also need to clean the backside else the grime will pull through to the weld.

The 70 amp welds look plenty hot to me. Even the section of 60 amps looks about right since you had some heat in the material from the 50 amp portion of welding. I'd like to see a snapshot of your tungsten and cup setup. I suspect your tungsten is not properly tapered or is even slightly contaminated. And your stick out could be an issue. I don't see a defined gas coverage area either. This leads me to suspect improper arc length and torch angle issues (associated with being a new, less than immortal welder :D ;) ).

Learning to TIG weld by video and across the internet is a hard, hard, hard thing. Be patient, you're making progress every time to lay a bead. It will be many months, if not a few years before you develop real consistency and beautiful welds. Don't get hung up on that aspect. They must be strong, beauty is secondary. Even professional welders don't leave perfect welds every time. Instagram welding is NOT something to judge yourself by.
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Re: New to tig welding

Postby cj737 » Wed Feb 14, 2018 9:30 am

Let me give you a few practice ideas, if I may.

Clean your metal well first. Then set your machine to 80 amps. Tack two pieces together at both ends. Reset your amps to 50, and butt weld a section 1" long. Stop and let it cool. Bump your machine to 60 amps. Weld another 1" length. Stop and let it cool. Repeat this process, bumping every section by 5 amps.

After its cooled off, cut out the welds by making a parallel cut 2" to the side of each weld.This will give you a 4" wide section of flat metal, with welds down the middle. Inspect the backside. Then cut straight through the middle of each weld. Polish them up and inspect the fusion.

This type of test will help you to really understand heat and weld fusion. Plus, as a new welder, shorter repetitive welds is better practice than long beads. Once you get dialed in your amps, then, prepare some flat stock and weld longer beads (3-6"). If you pursue welding long straight beads with a TIG, you'll quickly get out of position and produce poor results. The best part of TIG is that you can start, weld, stop, and restart without any issues whatsoever. So there's no need to try and run a 2' long bead at one time.
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Re: New to tig welding

Postby Poland308 » Wed Feb 14, 2018 10:31 am

Does the tube have that standard oil coating that’s on most square tube? If so it’s on the inside as well and will pull through the puddle as you weld. It’s also partially from the fact that it’s galv tube. Even after you grind it there’s still some zinc in the pores of the metal especially if it was hot dipped. What size filler are you using? Can you cut out a cross section of one of the welds to see your penetration? This can reveal a lot even if you don’t etch.
I have more questions than answers

Josh
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Re: New to tig welding

Postby ChrisM » Thu Feb 15, 2018 4:26 am

Thanks for the feedback guys.

Sounds like I did not clean the tube as much as I need too. Here is how I prepared the joint. Ignore the top half, that's where I cut out the beads from.
RawTube.jpg
RawTube.jpg (46.24 KiB) Viewed 180 times


It's a mild steel tube from the scrap yard, so had to wire brush the surface rust with a grinder and then cleaned the area to be welded with a flap disc. The bottom half is how I prepped the joints. As you can see, I didn't make it overly clean which I can see now that I should.

Here is what the tungsten looks like after finishing the 4 beads. It was needle sharp when I started:
Tungsten.jpg
Tungsten.jpg (53.51 KiB) Viewed 180 times

Does the amount of stickout and cup size (#8) seem okay? Reasonable taper?

I've sliced up the tube similar to how you both have described. Here is how they look in the same order as my previous post. Stick50A, Tig50A, Tig60A, Tig70A and Tig90A:
BacksideRaw.jpg
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BacksideWireBrushed.jpg
BacksideWireBrushed.jpg (79.25 KiB) Viewed 180 times

Quite surprised there is so much filler on the back. Is that an indication of too much heat and penetration?

Here are the 4 beads sliced in half for a cross section view:
BacksideStick50A.jpg
BacksideStick50A.jpg (51.87 KiB) Viewed 180 times

BacksideTig50A.jpg
BacksideTig50A.jpg (31.09 KiB) Viewed 180 times

BacksideTig60A.jpg
BacksideTig60A.jpg (47.04 KiB) Viewed 180 times

BacksideTig70A.jpg
BacksideTig70A.jpg (43.65 KiB) Viewed 180 times

BacksideTig90A.jpg
BacksideTig90A.jpg (43.36 KiB) Viewed 180 times


What do you make of the beads. Most of the filler (ER70S-2) has ended up on the backside. Would you say the fusion is good and would have been a strong weld?

Cheers,
Chris
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