Ask your WELDING questions here. - Page 209

mr2autoxr · 09-18-2012, 04:46 AM

Hi,
I am fairly new to welding (2 years) and I have a MIG Lincoln 140c 120V unit I use in my garage on occasion. This past weekend I went to use it after it's been sitting for most of the summer and I ran into some problems. Keep in mind the welder is only about 2-3 years old.

What is happening is that I can't get the wire to feed out while I'm making my weld. I'm using .025 wire size and the appropriate sized wire rollers but it almost seems as though my gun liner is restricting the wire feeding through it.

Do the liners ever go bad? If I'm just pulling the trigger to advance the wire, the wire comes out fine. It's just when I go to weld where the wire stops feeding properly. I only get about 1 tach sized weld in and then the wire stops feeding.

I'm stumped and don't know if I can take the welder into my local supply store and see if they can fix it, or if I might just need to try a new liner?

Any thoughts?
Thanks,
Mike

bobivey · 09-18-2012, 04:51 AM

I would suspect that the wire got rusty and then plugged the liner. Change the liner and contact tip for sure, you may be able to peel off enough wire to get down to layers that are not rusty if not also change the wire.

David R · 09-18-2012, 05:24 AM

First replace the contact tip. Try again. Find the manual and read how to adjust the roll tension. Too loose, no feed. Too tight and it puts waves in the wire that will not pass throu the tip and it will weld about an inch. With stops feeding,. You clear at the tip but the tight drive rolls put a new wave in the wire.

Sent from my C771 using Tapatalk 2

kirkster70 · 09-18-2012, 05:27 AM

You may also need to increase the tension on your rollers a bit. There should be an adjustment knob.

Make your welding lead as straight as possible to reduce friction in the liner.

Quote:

Originally Posted by mr2autoxr

Hi,
I am fairly new to welding (2 years) and I have a MIG Lincoln 140c 120V unit I use in my garage on occasion. This past weekend I went to use it after it's been sitting for most of the summer and I ran into some problems. Keep in mind the welder is only about 2-3 years old.

What is happening is that I can't get the wire to feed out while I'm making my weld. I'm using .025 wire size and the appropriate sized wire rollers but it almost seems as though my gun liner is restricting the wire feeding through it.

Do the liners ever go bad? If I'm just pulling the trigger to advance the wire, the wire comes out fine. It's just when I go to weld where the wire stops feeding properly. I only get about 1 tach sized weld in and then the wire stops feeding.

I'm stumped and don't know if I can take the welder into my local supply store and see if they can fix it, or if I might just need to try a new liner?

Any thoughts?
Thanks,
Mike

kirkster70 · 09-18-2012, 08:42 AM

What should GTAW post flow be set at for 3/16" 5052 aluminum? Thanks in advance.

I think the rule of thumb is one second per every .01", but 19 seconds seems excessive to me.

David R · 09-18-2012, 10:10 AM

One second for every 10 amps. That can be excessive too. Post flow till the tungsten is cool enough to NOT oxidize. Any more is a waste.

kirkster70 · 09-18-2012, 06:06 PM

Quote:

Originally Posted by David R

One second for every 10 amps. That can be excessive too. Post flow till the tungsten is cool enough to NOT oxidize. Any more is a waste.

Thanks. Yeah, I'm @ 200a, so that would be 20.

I have it set at 14sec, with good results, and I may even try 12 tomorrow.

Thanks again.

mr2autoxr · 09-21-2012, 04:40 AM

Thanks for the tips about getting my welder to feed the wire properly. I have replaced the tip with a new one with no luck. I've also played with the wire tension as well and that didn't seem to help. I could tell when it was too loose or tight, and in the proper range still no luck.

You guys might be right about a slight coating on the wire or something as it sits in my unheated/air conditioned garaged. Humidity could have affected it. Doesn't look rusty, but you never know. I'll try to take some wire off and try to see if that works.

Is there anything you can spray into the liner to help clean it? That won't affect the welds?

David R · 09-21-2012, 04:47 AM

Replace the liner. The machine is no good if it will not feed.

Sent from my C771 using Tapatalk 2

KTM640Dakar · 09-22-2012, 05:13 PM

Quote:

Originally Posted by David R

One second for every 10 amps. That can be excessive too. Post flow till the tungsten is cool enough to NOT oxidize. Any more is a waste.

Yes. And you should flow gas as long as there is liquid weld metal. But mostly too keep air O2 off of the tungsten electrode while it is hot. Like Dave said you want to keep the electrode from oxidizing. Usually the bigger the diameter and higher the current, the longer the postflow.

djborden · 09-22-2012, 10:02 PM

Quote:

Originally Posted by KTM640Dakar

Yes. And you should flow gas as long as there is liquid weld metal. But mostly too keep air O2 off of the tungsten electrode while it is hot. Like Dave said you want to keep the electrode from oxidizing. Usually the bigger the diameter and higher the current, the longer the postflow.

What's the symptom of an oxidized tungsten ?

David

ER70S-2 · 09-22-2012, 10:42 PM

My turns black, instead of the normal silver.

Twin-shocker · 09-23-2012, 02:01 AM

Quote:

Originally Posted by kirkster70

Thanks. Yeah, I'm @ 200a, so that would be 20.

I have it set at 14sec, with good results, and I may even try 12 tomorrow.

Thanks again.

Those settings mean you are wasting a fair amount of gas...........if you have a watercooled torch, then cut time by half. Also a very good idea to use gas saver front end torch parts, as this will help to save even more gas.

David R · 09-23-2012, 02:32 AM

Quote:

Originally Posted by djborden

What's the symptom of an oxidized tungsten ?

David

The electrode turns black. Ya can't miss it. No big loss, just clean it up, re sharpen and resume welding. I use a belt sander and cordless drill. I then put a fine finish on the point with a tungsten sharpener.

MODNROD · 09-23-2012, 03:47 AM

OK welding guru's, here's my dumb-arse question for the week.

I currently have a 200A MIG (I use it gasless mostly, outside for 90% of the time), I can weld OK with the thing, but I'm not a welder (if that makes sense!). Used mostly for making exhaust systems, and light 3mm or 4mm chassis stuff.

I'm gettting close to having a shed (woo!hoo!), so can soon do all this stuff indoors, but I also would like something that will weld up aluminium (for bike brackets) and thin plate (for my VW Bug project), so I thought I'd get a TIG and practise, same as before with the MIG, and my 10 yr old MIG is getting long in the tooth.

Also, the actual TIG welding itself. I can use a MIG fairly well (without having a ticket and 20 yrs on the job of course), I can use stick too, and I'm not sure if it's relevant, but but my trade is in electronics, and I have held the highest soldering standard available for nearly 30 years (are the processes involved as similar as they look?). Will adapting be all that difficult?

I've seen 200A Inverter TIG/MMA (whatever that is......)/cutters for about $500 Oz and they look attractive. Will this size machine do the job I ask of it?

And yes, I realise a $2000 machine would do it better, but it's hard to justify the expense for what is really a hobby. A basic machine that will do the job is all I'm after, no frills. Is 200A the size I would need? 250A? 180A?

Thanks for any answers.

09-18-2012, 05:24 AM	#3123
David R I been called a Nut Job.. Joined: Oct 2009 Location: In Da Swamps of WNY Oddometer: 1,809	First replace the contact tip. Try again. Find the manual and read how to adjust the roll tension. Too loose, no feed. Too tight and it puts waves in the wire that will not pass throu the tip and it will weld about an inch. With stops feeding,. You clear at the tip but the tight drive rolls put a new wave in the wire. Sent from my C771 using Tapatalk 2 __________________ 2012 R1200R ! 2000 R1100RT (retired), 1976 R75/6, 11 Versys There is a seat for everyone.

09-18-2012, 10:10 AM	#3126
David R I been called a Nut Job.. Joined: Oct 2009 Location: In Da Swamps of WNY Oddometer: 1,809	One second for every 10 amps. That can be excessive too. Post flow till the tungsten is cool enough to NOT oxidize. Any more is a waste. __________________ 2012 R1200R ! 2000 R1100RT (retired), 1976 R75/6, 11 Versys There is a seat for everyone.

09-21-2012, 04:47 AM	#3129
David R I been called a Nut Job.. Joined: Oct 2009 Location: In Da Swamps of WNY Oddometer: 1,809	Replace the liner. The machine is no good if it will not feed. Sent from my C771 using Tapatalk 2 __________________ 2012 R1200R ! 2000 R1100RT (retired), 1976 R75/6, 11 Versys There is a seat for everyone.

09-23-2012, 03:47 AM	#3135
MODNROD Perpetual ponderer Joined: Feb 2009 Location: Midwest, West Oz Oddometer: 1,661	OK welding guru's, here's my dumb-arse question for the week. I currently have a 200A MIG (I use it gasless mostly, outside for 90% of the time), I can weld OK with the thing, but I'm not a welder (if that makes sense!). Used mostly for making exhaust systems, and light 3mm or 4mm chassis stuff. I'm gettting close to having a shed (woo!hoo!), so can soon do all this stuff indoors, but I also would like something that will weld up aluminium (for bike brackets) and thin plate (for my VW Bug project), so I thought I'd get a TIG and practise, same as before with the MIG, and my 10 yr old MIG is getting long in the tooth. Also, the actual TIG welding itself. I can use a MIG fairly well (without having a ticket and 20 yrs on the job of course), I can use stick too, and I'm not sure if it's relevant, but but my trade is in electronics, and I have held the highest soldering standard available for nearly 30 years (are the processes involved as similar as they look?). Will adapting be all that difficult? I've seen 200A Inverter TIG/MMA (whatever that is......)/cutters for about $500 Oz and they look attractive. Will this size machine do the job I ask of it? And yes, I realise a $2000 machine would do it better, but it's hard to justify the expense for what is really a hobby. A basic machine that will do the job is all I'm after, no frills. Is 200A the size I would need? 250A? 180A? Thanks for any answers. __________________ Every ride's an adventure if you can't ride for crap http://www.dragtimes.com/Ducati-Mons...lip-10329.html

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09-18-2012, 04:46 AM	#3121
mr2autoxr Adventurer Joined: Feb 2011 Oddometer: 17	Hi, I am fairly new to welding (2 years) and I have a MIG Lincoln 140c 120V unit I use in my garage on occasion. This past weekend I went to use it after it's been sitting for most of the summer and I ran into some problems. Keep in mind the welder is only about 2-3 years old. What is happening is that I can't get the wire to feed out while I'm making my weld. I'm using .025 wire size and the appropriate sized wire rollers but it almost seems as though my gun liner is restricting the wire feeding through it. Do the liners ever go bad? If I'm just pulling the trigger to advance the wire, the wire comes out fine. It's just when I go to weld where the wire stops feeding properly. I only get about 1 tach sized weld in and then the wire stops feeding. I'm stumped and don't know if I can take the welder into my local supply store and see if they can fix it, or if I might just need to try a new liner? Any thoughts? Thanks, Mike

09-18-2012, 04:51 AM	#3122
bobivey Adventurer Joined: Jan 2007 Oddometer: 28	I would suspect that the wire got rusty and then plugged the liner. Change the liner and contact tip for sure, you may be able to peel off enough wire to get down to layers that are not rusty if not also change the wire.

09-18-2012, 08:42 AM	#3125
kirkster70 moto junkie Joined: Aug 2008 Location: Virginia Oddometer: 1,632	What should GTAW post flow be set at for 3/16" 5052 aluminum? Thanks in advance. I think the rule of thumb is one second per every .01", but 19 seconds seems excessive to me.

09-21-2012, 04:40 AM	#3128
mr2autoxr Adventurer Joined: Feb 2011 Oddometer: 17	Thanks for the tips about getting my welder to feed the wire properly. I have replaced the tip with a new one with no luck. I've also played with the wire tension as well and that didn't seem to help. I could tell when it was too loose or tight, and in the proper range still no luck. You guys might be right about a slight coating on the wire or something as it sits in my unheated/air conditioned garaged. Humidity could have affected it. Doesn't look rusty, but you never know. I'll try to take some wire off and try to see if that works. Is there anything you can spray into the liner to help clean it? That won't affect the welds?