Welding Tips and Tricks

Almost too embarrassed to ask but<<<< There's something either screwed up or something I've forgotten. Here's the poop. I'm running a Lincoln SP200 since it was new 10,000 years ago. Besides blowing a board a long time ago the machine is as consistent as anything else I've ever run. It started dirty welds quite a while ago . Lots of splatter and brown black smoke trails on the weld metal. I figured it was funky wire as I burn 50# spools and change/run out maybe once a year. I changed out a 1/2 roll of Lincoln L56 .035 for a NIB 50# L-50 .035. It was better but not perfect but then again good enough for the job at hand. It didn't have to be beautiful. Now I have a little job that has to be cosmetically presentable. I've upped the 75/25 mixture to 25cfm no difference. I ran the voltage up and down still no difference as well as the wire speeds up and down. I've changed contact tips, nozzles and insulators. I've checked flow into and out of the gas solenoid. I've checked flow at the Tweeko gun. I've plugged the ports at the gun looking for hose leaks. Everything checks out. Next I'm going to swap out the gas bottle. It's a 300cfm bottle with about 1500 pounds left in it. Bad gas? Maybe I'm standing on the wrong side of the table. Wrong foot? I'm looking for something. I've been welding for over 50 years so I'm pretty sure I may have forgotten or overlooked something but what?

Might be a bad or corroded connection inside the machine.

Poland308 wrote:Might be a bad or corroded connection inside the machine.

Nope.

I have changed and purged gas bottles and changed stingers. Still the same result. I keep going back and forth with a SP 175 on the gas and regulators and testing on the same piece of steel. It has got to be the wire. I'll swap that out tomorrow.

Sounds like you are troubleshooting as I would, eliminate the obvious one at a time. If that doesn't cure it I would start looking at the "hidden" areas....

First make sure wire drive system is working as it should, no slipping, sticking etc.

Next I would make sure your constant voltage welders voltage is constant. Use a decent meter like a Fluke 83 that has a min-max capture function. (If you have an old analog Simpson even better, less sluggish)

If you have access and want to get crazy use an oscilloscope. DO NOT use a PT on DC.

DLewis0289 wrote:Sounds like you are troubleshooting as I would, eliminate the obvious one at a time. If that doesn't cure it I would start looking at the "hidden" areas....

First make sure wire drive system is working as it should, no slipping, sticking etc.

Next I would make sure your constant voltage welders voltage is constant. Use a decent meter like a Fluke 83 that has a min-max capture function. (If you have an old analog Simpson even better, less sluggish)

If you have access and want to get crazy use an oscilloscope. DO NOT use a PT on DC.

Everything checks solid. Voltage stays rock solid. It welds smoothly but VERY dirty. Brown and black smoke residue and major dingle balls. It's almost like the current has been reversed.

Maybe someone was using it for flux core and switched it, DCEP for hard wire. Real interested in what you find out.

DLewis0289 wrote:Maybe someone was using it for flux core and switched it, DCEP for hard wire. Real interested in what you find out.

I'm the only one who runs the machine.
I'm going to change out the wire then if necessary change out the feeder with a LN7 GMA that I have.

Pull the whip out of the machine and check the condition of the O-rings. I'm guessing one or both have deteriorated over time and have either shrunk or split, limiting gas coverage and admitting air. Barring this, check the length of the whip for cuts or other damage that may cost you coverage at the nozzle.

Steve S

Otto Nobedder wrote:Pull the whip out of the machine and check the condition of the O-rings. I'm guessing one or both have deteriorated over time and have either shrunk or split, limiting gas coverage and admitting air. Barring this, check the length of the whip for cuts or other damage that may cost you coverage at the nozzle.

Steve S

Checked that too. I already changed to a different stinger (whip) and made no difference. The only thing I haven't done was an actual flow test right at the nozzle. I'm thinking that would be tough. I'm getting plenty flow by ear though with either stinger.
The funny, not funny, thing is I just got done welding in a trailer deck with 30' plus of bead with the same setup that is now giving me fits. No changes in wire, settings, gas, nozzle, nothing. Basically shut the machine and bottle off one day and come back a couple weeks later and everything is FUBAR. I just don't get it. I'm maybe starting to wonder if the regulator is starting to fail? I'm going to try a flow meter on it and have somebody watch the ball as I weld.

Sat for a couple weeks with carbon steel? i.e. E70s-6?

How damp/humid has your climate been?

Steve S

Re-reading, it looks like you've covered that.

Do you have a wiper on the wire, inside the feeder? Could it have collected moisture/WD-40, schmutz, anything? Sure, that's grasping at straws, but I'm hard put to think of something you may have missed.

Steve S

BTW, flow test at the nozzle is easy. They make a flowmeter especially for that (and it's cheap).

Noddybrian posted the following:
Read down the topic, and you'll see the "at the torch" flowmeter.

http://forum.weldingtipsandtricks.com/v ... f=5&t=4183

Steve S

Otto Nobedder wrote:Sat for a couple weeks with carbon steel? i.e. E70s-6?

How damp/humid has your climate been?

Steve S

We have a super dry climate. I'm welding in a very good weld environment. I have large pouches of the moisture sucking stuff that I keep in the enclosed wire feed cabinet that's built into the machine. The little SP 175 that lives right next to it is doing fine. Both are running Lincoln .035 L50 and 56 wire only difference is one has 50# and the other 12# spools.

No. No wiper on the wire. I've never needed it and the 175 doesn't even have the moisture sucking stuff. plus the spool in it has been there for at least a year and the 50# is only a couple months old. I'm going to swap wire and then regulator/flow meters in the morning. If I don't find something soon, I will start threatening the machine with severe harm and destruction. That seems to work with my computer.

Otto Nobedder wrote:BTW, flow test at the nozzle is easy. They make a flowmeter especially for that (and it's cheap).

Noddybrian has a topic on it. Let me dig.

Steve S

I could put a balloon over it until it suffocates to death. I'm starting to like that idea,,,,,

Speaking of flow meters, I have an extra Harris that is NFG. Should I send it for rebuild or buy another one?

John Chamorro wrote:

Otto Nobedder wrote:BTW, flow test at the nozzle is easy. They make a flowmeter especially for that (and it's cheap).

Noddybrian has a topic on it. Let me dig.

Steve S

I could put a balloon over it until it suffocates to death. I'm starting to like that idea,,,,,

My post died before it was born.

Here's the topic with the "at the torch" flowmeter:

http://forum.weldingtipsandtricks.com/v ... f=5&t=4183

3rd or fourth post down...

Steve S

Otto Nobedder wrote:

John Chamorro wrote:

Otto Nobedder wrote:BTW, flow test at the nozzle is easy. They make a flowmeter especially for that (and it's cheap).

Noddybrian has a topic on it. Let me dig.

Steve S

I could put a balloon over it until it suffocates to death. I'm starting to like that idea,,,,,

My post died before it was born.

Here's the topic with the "at the torch" flowmeter:

http://forum.weldingtipsandtricks.com/v ... f=5&t=4183

3rd or fourth post down...

Steve S

OK, I scanned through the thread and saw the flow meter but didn't see where or what it actually was. I started to get excited about the part bottle theory except I swapped bottles yesterday and purged everything out with no changes.

OK,,,,, I got a new whip/stinger/gun setup. I got a new regulator. I know that swapping out a bunch of new parts all at once doesn't diagnose the problem but I'm tired of f'ing with it. I need to get some stuff hot glued together.

You're killing me, fix that SOB, dying to hear what it was. I file stuff like this away in my head for the future in the seen it, heard it all category.

I think it was a little bit of everything. It has been getting away for a while now. I started noticing problems last year so figured it was wire and swapped it out. It got a bit better and so compensated with setting to get it "good enough" . My welding is truly what you call down and dirty. It's usually fixing something just to get it fixed as quickly as possible. In other words, blow and go welding. This time,,,,,,, I actually had to weld something that needed to be 100% correct and look !00% beautiful.
When I can't get it to adjust out then I start looking for mechanical issues. What I find is a couple of 30 year old whip/stingers that are getting funky. Connections aren't perfect and the liners a bit nasty and gas connections inside the whip that don't quite seal as good as they should. I also have a regulator with a weak diaphram. As the pressure to it drops so does the flow going out but only in one setting. That was tough to find. Next the SP 200 has volt settings and meter but no amperage settings or meter. It's sort of guess and go. I took all the settings back to the middle of the road and had the better half adjust on the fly to get back to the 'best weld settings. My tried and true dial settings were way off.
My end findings are
1.Bad whips. Just because you ave a spare don't assume it better than the other.
2.Bad regulator. Static cfm at 25 running flow fell to less than 18,,, occasionally. Set at 30 it holds flow, on or off trigger.
3.Settings outside reasonable parameters once the mechanical stuff was fixed.

Moral of the story is when you think you know it all, you probably don't.

Glad you got it going my friend. I was following this thread like a mystery movie. Every suggestion was on point and you were troubleshooting step by step.

How old is the liner? Could be very dirty.you could try spraying some clp cleaner down it an blowing it out with air gun.just because wire don't bind up doesn't mean liner is good.

How did you test the regulator?