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TIG Arc Problem

Posted: Sun Aug 24, 2014 9:28 pm
by HitMissTom
:?:

I am an old guy, but a newer welder who is trying to learn. I have practiced T joints like the YouTube videos suggest and sometimes it comes out ok. I just change the TIG tungsten electrode from 3/32" thoriated to 1/16" ceriated, which had a gray color painted on the end. What I was trying to weld was a 3/8" square tube to a 2" square flat plate. I sanded and cleaned with lacquer thinner both parts and used E70S-6, 1/16" filler rod. The welder was set for 85amps, DCEN, Argon at 15fpm, good ground, no pulse, #7 cup, gas lens and with the 1/16" ceriated electrode. For the life of me I could not get the arc to go the the center area of the T. It seemed to always want to arc over to either the 3/8" square or the flat, also it seemed to arc from the sides of the electrode as well. I changed the stick out to shorter and longer, no help. I then tried to weld on a flat 1/8" scrap plate and that worked. I changed back to the 3/32" thoriated electrode, got some more 1/8" scrap and made a T which welded the way it was supposed to!
Any thoughts as to what was going on?
Thanks, Tom

Re: TIG Arc Problem

Posted: Sun Aug 24, 2014 10:05 pm
by MinnesotaDave
Only thing that jumps out at me is 85 amps is quite low for 1/8" - more in the 125 amps range would be better.

Try this miller online calculator to help out settings - could help :)

http://www.millerwelds.com/resources/ca ... ulator.php

Re: TIG Arc Problem

Posted: Mon Aug 25, 2014 7:53 am
by Fat Bob
Hi Tom. I agree with Dave, your not running enough amps for that joint and material thickness. Are you getting your electrodes nice and sharp?

I'm going to move this over to the Tig forum where you'll get more views.

Re: TIG Arc Problem

Posted: Mon Aug 25, 2014 8:45 am
by TRACKRANGER
Hi Tom

Another thing to try is to make sure you have an earth connection on both parts of the tee junction. If only one part is getting a ground, then the arc will want to head to that part.

As mentioned above a good sharp electrode will also help.

Does the problem only occur until you first get some filler into the joint, or is it continuous?

Re: TIG Arc Problem

Posted: Mon Aug 25, 2014 3:07 pm
by Adam's Got Skills
i might be stating the obvious but are u sharpening ur tip of ur tungsten the length of the electrode? if u grind em perpendicular they tend to wander more. As far as everything else u seem ok...except the heat on 3/8" steel.

Re: TIG Arc Problem

Posted: Mon Aug 25, 2014 3:27 pm
by Braehill
Tom,
Some electrodes split lengthwise and are not easy to see, especially 1/16. Cut it back a 1/2" at a time and retry it until you get past the split. I'm not saying this is your problem, but I have had this happen and the arc would wonder up the electrode instead of coming off the tip.

Sometimes you just get plain old bad electrode too. I've noticed this more since I started getting the cheaper imported ones. They seem to have bad spots throughout the length of the same piece like it is not mixed well when they are making them. Try a different piece completely and see if the problem continues.

Those are a few things that I've found but I still use a transformer based welder and they don't seem to be as prone to tungsten problems as the inverters with all the bells and whistles do.

Len

Re: TIG Arc Problem

Posted: Mon Aug 25, 2014 6:23 pm
by HitMissTom
I guess this is how I reply to the folks who answered my question.
First - Thanks!

The tungsten has been sharpened to a fairly good point (like a pencil) using a drill turning it against a diamond wheel in a parallel direction (like the videos show). All the suggestions, amps, split tungsten, good ground to both pieces, etc., make sense to me. I will check all things mentioned and repost results mid/later this week.
Thanks, Tom

Re: TIG Arc Problem

Posted: Mon Aug 25, 2014 7:26 pm
by Bill Beauregard
You leave out a lot of information. Low amp density is a common cause of arc wander. In this case turn up the heat. 3/8 to 3/8, essentially a t joint, wants a lot more heat than that. A blunt grind like a golf pencil works well to deliver the arc to the end of the tungsten. Your goal is to have the arc length equal to the diameter of the tungsten. A little more gap is in order for a beginner. I never leave myself with nothing to prop on. TIG welding free hand is impossible for me. A TIG Finger helps immensely.

Re: TIG Arc Problem

Posted: Tue Aug 26, 2014 7:40 am
by Oscar
You need to set the machine/pedal to minimum ~300 A. Ain't no way you're properly welding 3/8" to 3/8" with only 85 measly amps. Rule of thumb is ~1A per 0.001" of mild steel thickness. 3/8" = 0.375, so you're ~295 A short.

Re: TIG Arc Problem

Posted: Tue Aug 26, 2014 8:46 am
by Braehill
I think that we might look back to the OP and see that he said he is welding 3/8" square tubing to a 2" square plate, and doesn't mention the thickness of either one. They could be .020 wall and 16 guage for all we know, so the amperage would depend on the thickness of the two peices. Let's wait for him to reply back with his findings before we get too carried away.

Len

Re: TIG Arc Problem

Posted: Tue Aug 26, 2014 12:38 pm
by Oscar
I thought he meant 3/8" thickness. Yup, most definitely have to wait to actually know what in the world he is doing.

Re: TIG Arc Problem

Posted: Tue Aug 26, 2014 5:35 pm
by Bill Beauregard
Agreed, not clear what his mission might be. Could be very thin and too big a tungsten, or too thick for the amperage.

Re: TIG Arc Problem

Posted: Tue Aug 26, 2014 6:36 pm
by HitMissTom
Found the problem; and the square was 3/32" and the 2" plate 1/8" thick, should have mentioned that important fact as well. Anyway, I turned up the amperage to 120 and did a better grounding arrangement to the vertical square tube and it welded as expected, or as best as I could for now.
Thanks for all the input. :D

Re: TIG Arc Problem

Posted: Tue Aug 26, 2014 6:45 pm
by HitMissTom
You all are right about the information missing. The 3/8" square tube is hollow and only about 3/32" thick, and the 2" plate is 1/8" thick. Anyway, by increasing the amps to 120 max and getting a better ground to the square tube it did weld up like I expected, at least the arc went where it was supposed to.
I need to learn complete communication as well as welding!
Thanks to all! :D

Re: TIG Arc Problem

Posted: Wed Aug 27, 2014 7:28 am
by TwentyFourSeven
Edit.... Sorry, thought you meant aluminum.

Re: TIG Arc Problem

Posted: Wed Aug 27, 2014 9:49 am
by HitMissTom
It's steel, 3/8" od square, material thickness about 3/32" hollow. Miller suggest 100~120 amps, and less for inverter.

Re: TIG Arc Problem

Posted: Wed Aug 27, 2014 12:04 pm
by Bill Beauregard
1/16" or at most 3/32" tungsten.

Re: TIG Arc Problem

Posted: Wed Aug 27, 2014 6:34 pm
by HitMissTom
Thanks, Tom

Re: TIG Arc Problem

Posted: Wed Aug 27, 2014 7:50 pm
by Braehill
This post has run off the rails more times than not, wow. Tom, just so you know, it's not usually like this, but now you can see why it's important to get as much info out there in your post as you can right from the start.

Your post will get highjacked and turn into something from left field on occasion but not where it keeps getting the variables all twisted. It ussually happens when someone'd ADD kicks in and we have a lot of that.

Len

Re: TIG Arc Problem

Posted: Wed Aug 27, 2014 8:32 pm
by Otto Nobedder
Here's a fresh hijack, HitMissTom,

Is your screen name from a hobby involving hit-and-miss engines?

Steve S

Re: TIG Arc Problem

Posted: Thu Aug 28, 2014 6:27 am
by Drifta-X
Hey Len, don't mention add or ADHD unless u have it.
I have adh --- oh look there is a squirrel

Re: TIG Arc Problem

Posted: Thu Aug 28, 2014 7:14 am
by Bill Beauregard
Q: How many ADD kids does it take to screw in a light bulb?
A: Do you want to ride bikes?

Of course they'd be arrested. The government has outlawed light bulbs!

Re: TIG Arc Problem

Posted: Thu Aug 28, 2014 7:25 am
by MinnesotaDave
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image.jpg (64.5 KiB) Viewed 991 times

Re: TIG Arc Problem

Posted: Thu Aug 28, 2014 9:57 am
by Superiorwelding
True story; we were in the back hard the other day and my son came up to my wife and I to ask a question. Half way through his question he goes "look a squirrel". It was so perfect and we just died laughing. He stood there looking at us like we had lost out minds. :lol: (There was really a squirrel behind us)
-Jonathan

Re: TIG Arc Problem

Posted: Sat Sep 06, 2014 10:16 am
by HitMissTom
I say I am new to welding and ask a question. So I get some honest constructive responses, and for those I say thanks. Then I get a lot of critism and smart replays from others! For those replies, Let's work on a laser printer repair where I can respond by providing smart replies to their questions. I think I better will find other forums in the future!