Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic Welding Industry / General Welding Discussion / Arc Blow on Vert T joint GMAW process?
- - By Jeffrey Grady (***) Date 06-09-2008 04:04
Hello folks. I have had problems in the past with Arc Blow with SMAW in DC and have corrected it by switching over to AC. My question is, How prevelant is ARC BLOW in GMAW? I have watched as my arc wants to favor one plate or the other when welding a T joint in vert down. My only correction for this has been to up the Voltage and wire speed. That has seemed to help correct the problem. Are there any other suggestions for this phenomenon. I ask because there are prequalified machine settings in place. There is no weaving or gun articulation that seems to be alowable per company policy as they state it affects the strength of the weld. I've used a slight cresent motion even though they don't allow it and they can't see any difference, I just can't get caught doing it.
any suggestions would be greatly appreciated.
Respectfully, Jeffrey Grady 
Parent - - By aevald (*****) Date 06-09-2008 04:55
Hello Jeffrey, they've got you kind of boxed in if they won't allow any manipulation of the gun. You CAN experience arc blow with the GMAW process similar to that experienced when using the SMAW process. When this happens you may need to check for the location of your ground and make some changes with it if possible. I would also speak to the "THEY" people and see just exactly how they would like you to take care of the arc wander issues that you're having. First try using the search function of the forum to see the various responses that are listed under "arc blow" or other similar headings, there is a host of information contained there to help with this issue. Real basic suggestions might go something like this; make sure that you have a good point of contact where your ground is connected, try to weld away from the ground whenever possible(this one can be rather tough in many cases), avoid having set-up magnets in the vicinity of the welding that you are doing, if you happen to be team welding (two operators welding fillets on opposite sides of same part) try to stagger your arcs one in front of the other one instead of directly across from one another. As far as not being allowed to work the gun while you are welding, I would possibly explore this point to determine where they came up with the restrictions on this. Just a little bit more to consider. Good to hear you're doing so well in your latest endeavor. Best regards, Allan
Parent - - By Superflux (****) Date 06-09-2008 05:44
Worn contact tips (or wrong size) and some times certain "cheap" brands of tips with loose tolerances, coupled with excessive feed roller tension (puts unnecessary curl to the wire) can cause wandering of the wire that resembles arc blow. It's quite common for operators to want to crank down on the feed roller tension to avoid the problems associated with not keeping the gun and cable assembly straight enough and creating a new set of problems...
Also if the material handlers use lifting magnets, the parts become magnetised and you just have to deal with it.
Arc blow does occur with GMAW, it has just been my experience it rarely is an inherent trait of the process and is the result of other factors.
Semi-auto is great when it all works and a major pain when it don't!
Hope you can get it all sorted can be really frustrating.

ps. good luck getting any kind of favorable/constructive response from "THEY"
Parent - By aevald (*****) Date 06-09-2008 06:36
Very good points, Superflux. Regards, Allan
Parent - By Jeffrey Grady (***) Date 06-09-2008 16:36
Thanks for the suggestions. I hadn't thought to check the roller tension. I never know who might have been on any particular machine on the morning shift, or what they may have done to the machine. I'll be more conscious of how the machine is operating and make what adjustments i can to over-come the wandering wire. I really get frustrated at times and wish I had a stinger in my hand instead of a gun!
I won't get anywhere asking questions of "DEERE"! They seem to want simple robotic repetition...not thinking people.
Respectfully, Jeffrey Grady
Parent - By Jeffrey Grady (***) Date 06-09-2008 16:17
Hello Allan,
  I must admit..."they" are hard to pin down as to WHO exactly "They" are. I haven't seen a WPS as yet, and this is all handed down "word of mouth" for the purposes of testing for Big Bad Deere and Co. I have no Authoritative contact person to submit RFI to. The EOR is off limits to us, as they don't really want people who have minds that Question the process. The CWI is an unseen person who examines test coupons in secret. Then writes up results that are handed over by another Deere employee. It's a big mess to try to figure out right now.
I thank you for Your response and advice.
Respectfully, Jeffrey Grady

PS. on a more up-beat note...things ARE really starting to look up for me! I have my self nomination and resume submitted to CPOL, for welding positions at the Arsenal. I hope all goes well with that.
Parent - By Steve (*) Date 06-25-2008 10:39
I would question; wire speed, speed of travel, pre heat tempature, interpass tempature, polarity required for the wire, electrode stick out, any binding in the gun conduit, material thickness and if all else fails read the specification sheet for the wire your using. Check both amperage and voltage as your welding using test meters not the machine gauges they may be wrong!
Parent - By Kix (****) Date 06-25-2008 14:20
You always want to weld away from your ground, not toward it.  So if your running a vertical down T-joint, put the ground on top of the t-joint and weld down.  Vice versa if your going up.  Same goes with horizantal, overhead and just about any situation.  Try it!!;-)
Up Topic Welding Industry / General Welding Discussion / Arc Blow on Vert T joint GMAW process?

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill