It is currently Sat Oct 21, 2017 6:07 am Advanced search

Question on high cleaning (95% positive) and torch

Tig welding tips, questions, equipment, applications, instructions, techniques, tig welding machines, troubleshooting tig welding process

Question on high cleaning (95% positive) and torch

Postby bossler » Tue Aug 08, 2017 11:03 am

Hi.

I already asked one the following questions in my introduction, but I assume introductions are not read by everybody. ;)
So I try it here again:

#1
On my machine I can adjust AC balance from 1-10:
1=95% negative
5=50% negative
10=5 % negative
So far, I was welding aluminum at around '3', meaning ~70% negative, 30% positive. Seems to be a kind of standard setting.
What about this '10' setting with only 5% negative and 95% positive? I did not try it yet and never saw any recommendation going that high with the cleaning action. Is there any practical use for this setting?

#2
I got a used 17 style torch set to replace my heavy 26 "bulky European style".
Before first trying it out, I wanted to check if there are any leaks. So clogged the ceramic with my thumb and turned on the Argon flow. For maybe 1s it seemed to hold the increasing pressure, then there was some leakage at the white insulation ring.
Actual welding went ok, I like the smaller torch a lot.
But still, I was wondering how tight the whole gas setup has to be. Is it ok for a torch to leak if the pressure rises considerably, or should it really hold the full outlet pressure of the regulator when I clog the ceramic?

BR,
Bossler
bossler
New Member
 
Posts: 5
Joined: Thu Jul 27, 2017 10:17 am
Location: Germany

Re: Question on high cleaning (95% positive) and torch

Postby noddybrian » Tue Aug 08, 2017 2:12 pm

Hi Bossler - welcome to the forum.

The 95% setting would have no use in welding that I know of - however some folks like to put a small ball on the tungsten after sharpening by turning the balance as positive as it goes then using just enough amps on the pedal to create an even ball on a piece of scrap copper prior to actual welding - returning to a more usual 65 / 70%.

In an ideal world the torch would hold pressure 100% but if you block off the ceramic - pressure will build up to the regulator / flow gauge static pressure - this is often 50 >80 psi which is excessive to expect a perfect seal so the tiniest of leaks is likely acceptable if your not having gas issues - as all the time you have flow there will be very little pressure & hence no leak - it maybe worth trying different combinations of insulator / ceramic in case one has a mark in causing the small leak.
noddybrian
Weldmonger
 
Posts: 1156
Joined: Thu Jan 24, 2013 12:13 pm

Re: Question on high cleaning (95% positive) and torch

Postby Arno » Wed Aug 09, 2017 1:24 am

bossler wrote:What about this '10' setting with only 5% negative and 95% positive? I did not try it yet and never saw any recommendation going that high with the cleaning action. Is there any practical use for this setting?


The question also is if these percentages on the adjuster are absolute on your machinr or if it only has a certain absolute range between cleaning/penetration balance where the knob only adjusts the balance on this partial scale.

Eg. the 'real' shift to cleaning or penetration from the middle 50/50 may well be only +/-20% but your adjuster allows 0% (eg. -20% cleaning) to 100% (+20% cleaning)

Not saying that this is the case on your machine, but the A/C balance adjustment is one of those areas where a lot of manufacturers give their own interpretation and implementation and it's not always very clear from the machine front panel or documentation what they actually do.. Don't you just love it when they do that.. :roll:

So the balance adjustment effect may not be as extreme as you expect. Unless you are expeciencing a serious amount of tungsten balling and possibly melting/dripping on the 'max cleaning' setting...

Bye, Arno.
User avatar
Arno
Guide
 
Posts: 194
Joined: Mon Nov 04, 2013 7:51 am
Location: The Netherlands

Re: Question on high cleaning (95% positive) and torch

Postby bossler » Wed Aug 09, 2017 1:47 am

Hi both.
Thanks for your response.

So for the torch everything should be just fine. I also think that the normal operation pressure is way below the pressure where the leaking started.

Regarding AC balance on my machine, the manual explicitly mentions a range from 5% positive up to 95% positive current.
If I have some time I will do some tests at 95% positive, just to see what it's doing and come back with some results.
The biggest tungsten I have is 1/8" (1,5% La), guess I will start around 5A to not ruin it on the first start. :D

Bossler
bossler
New Member
 
Posts: 5
Joined: Thu Jul 27, 2017 10:17 am
Location: Germany

Re: Question on high cleaning (95% positive) and torch

Postby Lightning » Wed Aug 09, 2017 8:13 pm

bossler wrote:If I have some time I will do some tests at 95% positive, just to see what it's doing and come back with some results.


Don't expect to have much tungsten left, afterwards. It will probably get vaporized.

I once accidentally left my machine set to DCEP (for stick welding) and then went to tig weld. Stomped on the pedal and got a loud POP! The tungsten was gone right back to the collet, and the heat of vaporizing the tungsten broke my alumina cup!

Never did that again...
Lightning
Active Member
 
Posts: 32
Joined: Wed Aug 24, 2016 9:55 pm

Re: Question on high cleaning (95% positive) and torch

Postby Simclardy » Wed Aug 09, 2017 10:52 pm

bossler wrote:Hi both.
Thanks for your response.

So for the torch everything should be just fine. I also think that the normal operation pressure is way below the pressure where the leaking started.

Regarding AC balance on my machine, the manual explicitly mentions a range from 5% positive up to 95% positive current.
If I have some time I will do some tests at 95% positive, just to see what it's doing and come back with some results.
The biggest tungsten I have is 1/8" (1,5% La), guess I will start around 5A to not ruin it on the first start. :D

Bossler
You won't need much testing.lol

Sent from my SCH-I535PP using Tapatalk
Simclardy
New Member
 
Posts: 19
Joined: Mon Jul 24, 2017 9:41 pm
Location: Cape cod mass

Re: Question on high cleaning (95% positive) and torch

Postby bossler » Mon Sep 25, 2017 6:57 am

Finally I found some time to do the "test" that I announced...

Using 5mm (~3/16) Aluminum plate, unknown alloy with a little cleaning.
Image


All the following shots were done using 1/8 1.5% Lanth electrode, #17 torch with standard set-up and #5 cup.
AC frequency around 80Hz. AC postive at 10, which is described as "95% pos. current" in the manual of my machine.
Nothing really scientific, just tried to puddle and if some shiny spot appeared traveled a little bit.

I noticed that the arc was not very stable, arcing off to the cup quite a lot.
With my non-experience, I assumed it's because of the high cleaning, but a test at the end with "normal" cleaning settings showed almost the same arcing to the cup, so maybe a #5 cup is just too small for a 1/8 electrode.

So here's a series of pictures, starting from 15A up to 95A in 10A increments.
It's nice to see the tip of the electrode balling more and more with increasing amps.
I stopped at 95A as I didn't want to smoke my #17 torch which got quite hot, and I was too lazy to change to the 26.

Image
Image
Image
Image
Image
Image
Image
Image
Image


And some overview
Image


Here's the tungsten after the test.
Image



Hope it's entertaining for some people. :-)


Bossler
bossler
New Member
 
Posts: 5
Joined: Thu Jul 27, 2017 10:17 am
Location: Germany

Re: Question on high cleaning (95% positive) and torch

Postby AndersK » Mon Sep 25, 2017 12:36 pm

At least you know, by looking at that nice shiny ball, you have no problems with neither gas quality nor leakage :mrgreen:
User avatar
AndersK
Weldmonger
 
Posts: 651
Joined: Sat Mar 30, 2013 11:49 am
Location: Sweden


Return to Tig Welding - Tig Welding Aluminum - Tig Welding Techniques - Aluminum Tig Welding