gmaw spray-arc jumping into gun

By Lawrence (*****)

Date 11-21-2007 19:32

Sounds like a feed problem.

Could be clogged/worn liner

Could be worn tips

Could be improper roller tension.

Could be wire feeder old age problems... I have some old D54 duals that did what you describe until they were overhauled.

If something grabs the wire and pinches it... The arc will run right up to the tip.

If the feed slows for any reason, loose rollers, inconsistant speed etc. The arc will run to the tip

Also a poor work lead connection can cause irregular voltage.

By hogan

Date 11-21-2007 21:06

i've looked into all mentioned items with no success. tried new rollers, tried an assortment of tensions, tried new liners(correct size),tip, no marks or distortion of the wire, good ground. feed is consistant and strong

By aevald

Date 11-21-2007 19:48

Hello Hogan, I believe Lawrence hit on many of the issues that are related to what you are experiencing, just a few others: are you using consumables other than the brand of your guns? A lot of the tips that are out there that are of an aftermarket variety really aren't a bargain as they are made from different alloys or there are other issues with their manufacture that will cause issues such as you are seeing. Are the parameters of this particular welding any different than you have usually used in the past, I ask this based on the duty rating of the guns, if you are operating on the upper end of the amp capacity of a particular gun model you may be overheating the tips and associated parts. Are the feed rolls of the proper type? if the feed rollers are marking the wire in any manner they may be wearing out the contact tip prematurely and causing erratic feeding and an excessive arcing inside of the contact tip and causing the burnback issues. Do you have any alignment issues of the drive rolls or do the bearings and other associated parts of the feeders have any excessive wear issues that would cause alignment issues for the feed rolls? This can cause wire marking as well and lead to erratic feeding. If you are using liners that aren't correctly sized for the .045 wire this can lead to feeding problems, using a 1/16" liner to feed .045 wire isn't necessarily the best choice because of this. Also if you have previously fed a lot of dualshield wire through these liners they can cake up with the dry lubricant that is on the outside of the dualshield wire and cause problems. Possibly consider changing to a new correctly sized liner. Using wire wipers with the hardwire to aid in keeping the liners free of foreign materials that might impede the wire feeding can possibly take care of some of this, you may already be aware, but don't use the wipers on the flux-cored wires. Just a few more thoughts for consideration. Best regards, Allan

By hogan

Date 11-21-2007 21:13

consumables are not the same as gun, but this set up has worked for this application for many years. using wiper. i've been at a loss as to what is going on. i think that i've tried all of the typical variables. this happens with different welders, different welding machines, same machine hooked up at a different location.

By aevald

Date 11-21-2007 21:42

Hello hogan, I just reread your post. Have you changed gas suppliers recently? There could be the slim possibility that there could be moisture in the gas, not highly likely, but nevertheless something to consider. You may have seen how a carbon arc torch works when you get moisture in the compressed air or possibly noticed the change in a plasma cutting system that uses compressed air when they are subjected to moisture. One other thing, are you using bottled gases or is your shielding gas piped in or coming out of a mixing system? There is the slim possibility here that you could have picked up some condensation in the system that might be contributing to this. Best regards, Allan

By hogan

Date 11-21-2007 21:49

just had my gas certified for a caltrans audit. moisture is at an acceptable level. we perform a leak test on all of our lines (soapy water)

By DaveBoyer (*****)

Date 11-22-2007 04:51

Have You tried a new nozzle & insulator and made sure there is no debris or anything that might energize the nozle?

By 803056

Date 11-22-2007 15:17

I think you are on the right track Dave. I was going to suggest replacing the gas nozzles.

Best regards - Al

By darren

Date 11-23-2007 11:05

you say that it has worked for years and then it came on all of a sudden, how old is the gun? try a whole brand new gun and see if it does it. for the price of a new gun you can save a lot of problems, and when you consider down time its probably cheaper.
my 2 bits
darren