Need help diagnosing my welding set up for aluminum tig

[Miker57]

Here is my tale of woe. First my equipment, Trailblazer 280 NT connected to a 251D-1 High frequency box and a PC300 pulser. Right now only the Trailblazer and the 251D are connected in the set up. Oh, I'm also using a foot pedal and pure tungsten rod. All has been fine with this set up until the other day. For some reason when I try to weld aluminum all I get is black, burnt craters. I do have gas flowing and I'm using argon. I've managed to destroy one cup. I've noticed that I have what appears to be little pieces of tungsten flying off the torch when trying to get the puddle going. Frequency on the 251D is on continuous, all switches are on the square with the 14 and intensity I've varied from 0-100 with no change.
I did have the PC300 hooked up to this set up to see if it worked and how well it worked with some trials. Not sure if if works or not. Run on AC and did not notice any pulse when set at 1 p/sec. To be honest this part is all new to me. You ask why the pulser, looking for pulse capability without spending money on new machine. I'm not a full time welder although I have taken courses on it and have welded on and off over the years for various projects I've done. So I'm not a novice and not an expert.
As a side note when set up on DC everything is fine even with the torch still connected to the box with the high freq turned off. I have tried it with continuous and with start and that seems to be working fine base on how much easier the arc starts using high freq.
Thoughts, suggestions or something.
Thanks in advance.
Mike

[H80N]

You might have a bad or mismarked gas bottle....

it i not uncommon for the LWS workers to assume that ARGON means C25....

[Miker57]

Thanks for the response. I should have added that. I've been using this gas bottle and there were no issues before. I have MIG set up that uses 75/25 and tried that just to see if there might be a gas problem. Oh, my argon is at about 600 lbs at this time. The change of gas was to see if the pressure in the bottle had anything to do with it. The 75/25 was up around 1500 or so.

[H80N]

Thanks for the response. I should have added that. I've been using this gas bottle and there were no issues before. I have MIG set up that uses 75/25 and tried that just to see if there might be a gas problem. Oh, my argon is at about 600 lbs at this time. The change of gas was to see if the pressure in the bottle had anything to do with it. The 75/25 was up around 1500 or so.

Does it TIG OK on steel... DCEN...??

any tungsten discoloration??

gas flow rate..?? 13-18 Cubic feet per hour ?? measured at the cup/nozzle... with a nozzle flowmeter

A bad collet can change the flow even though the meter or ball flowmeter indicates proper flow...

this has become a real problem with poorly made imported parts...

https://www.arc-zone.com/index.php?m...84p33pmfcu1l0k

[ryanjones2150]

Start over. Disconnect everything and start over. See what happens.

[griff01]

Here is my tale of woe. First my equipment, Trailblazer 280 NT connected to a 251D-1 High frequency box and a PC300 pulser. Right now only the Trailblazer and the 251D are connected in the set up. Oh, I'm also using a foot pedal and pure tungsten rod. All has been fine with this set up until the other day. For some reason when I try to weld aluminum all I get is black, burnt craters. I do have gas flowing and I'm using argon. I've managed to destroy one cup. I've noticed that I have what appears to be little pieces of tungsten flying off the torch when trying to get the puddle going. Frequency on the 251D is on continuous, all switches are on the square with the 14 and intensity I've varied from 0-100 with no change.
I did have the PC300 hooked up to this set up to see if it worked and how well it worked with some trials. Not sure if if works or not. Run on AC and did not notice any pulse when set at 1 p/sec. To be honest this part is all new to me. You ask why the pulser, looking for pulse capability without spending money on new machine. I'm not a full time welder although I have taken courses on it and have welded on and off over the years for various projects I've done. So I'm not a novice and not an expert.
As a side note when set up on DC everything is fine even with the torch still connected to the box with the high freq turned off. I have tried it with continuous and with start and that seems to be working fine base on how much easier the arc starts using high freq.
Thoughts, suggestions or something.
Thanks in advance.
Mike

The "black" is the key along with the destroyed cup. It is a gas problem. Likely contaminated as you stated you were at 600 psi left in the bottle.

Griff

[Miker57]

First thanks to those who responded. Prior to the response suggesting pull everything apart and connect everything up I had done that. Kind of a default option when I'm stuck, for me.
Ok, for the answer, which I'm a bit embarrassed about. Somehow I ended having two bottles of 72/25 instead of one of Argon (Tig) and one of 75/25 (Mig). So when switching bottles I got the same result, no surprise there knowing what I know now. I'm not sure how this happened except the last time I got gas I was given the wrong bottle and I didn't check it. My fault there, lesson learned. Now that I have the right gas everything is working well. Again thank you for your help.

[griff01]

It happens! The good side is that it won't take you as long to recognize the problem next time.

Griff

[cruizer]

First of a ll I'd be setting the welder up for proper RPM, so if you happen to have a meter that reads frequency, the engine (kohler governor rod), must be set at 62.5Hz high idle 38hz low idle (at throttle solinoid). This is done with the engine wrm. Then we can try to figure everything else out.