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Up Topic Welding Industry / General Welding Discussion / Fluxcore worm holes
- - By jsdwelder (***) Date 07-23-2008 16:27
I'm sure this has been asked on here before, so forgive me for being redundent but, what are your opinions as to why you sometimes get the worm holes or worm tracks with FCAW. I've heard many different reasons ranging from moisture in the wire ,to excessive voltage, to bad gas ,to bad wire and so on. We have run FCAW at work for a long time without it being any problem at all, and now this week we have all gotten it at different times. It has been very humid and rainy all week. So any suggestions??????????
Parent - By OBEWAN (***) Date 07-23-2008 16:51
I once ran some flux core wire that had problems with drawing lubricants.  If the stickout was too short, the lubricant on the wire went into the weld and caused wormtracks.  If the stickout was longer, the lubricant burned off the wire before it went into the weld puddle.  It could not be too long though or there were other problems like porosity or the weld shape etc...
Parent - - By hogan (****) Date 07-23-2008 18:22
Two main issues that I know of 1 slag solidifies too quickly: not allowing gasses to escape. 2 technique: follow manufactures recommendation for gun alngle, travel and clean off mill scale
Parent - - By swnorris (****) Date 07-23-2008 18:33
Moisture in the flux is one problem that causes worm tracks. The moisture can get into the flux due to a poor joint seal in the wire manufacturing process, the wire being stored in a damp or humid location, or the wire being unprotected when it's on the spool on the welding machine. Baking the wire before use sometimes helps, and using a slightly longer wire stick out preheats the wire and reduces the potential for hydrogen contamination and worm tracks. Using the high end range of the weld current, slowing down weld travel and increasing the weld size all may help.
Parent - - By Milton Gravitt (***) Date 07-23-2008 18:57
I have been told that worm tracks will pass a RT. Do you think this is true. Has anyone in the forum had trouble passing an RT with worm tracks.I've always try to get them out so I don't know if they will are not.
                                              MG
Parent - - By new tito (***) Date 07-23-2008 19:13
Funny this topic has come up again.  We've been gettin a few worm tracks here and there.

But to Milton, yes, my welder's last weld busted RT (ASME sec VIII spot RT) due to these tracks.  They were not visible on the surface, but the RT indications were a dead giveaway of what it was.  Anyhow, they were rejected as slag inclusions, but that's not what they are.  ASME criteria for spot RT mentions something about slag "or other cavities"...so yes, it was rejectable.

Also, it could have very been rejected for an elongated indication, had that terminology been mentioned by the criteria.  But again, it was not visible on the surface.  Seems to have not fully come to the surface!
Parent - By Milton Gravitt (***) Date 07-23-2008 23:09
The worm tracks that I'm thinking of are on top of the welds we always GTAW adding a little rod to blend in the track in with the weld and if there where a slag or a cavity in it the hold dang thing would blow out. That's when you bring the grinder and the arc gouge.
      MG 
Parent - By hogan (****) Date 07-23-2008 19:32
RT will show a difference in 2% of part thickness, typically
Parent - - By jwright650 (*****) Date 07-23-2008 18:59
I had one guy who kept having trouble with these in our shop, so I paid a little closer attention to what he was doing since he was the only one out of the 50 welders who was having this problem. Found that he was running his machine out of procedure with way too much voltage so that he could get his travel speed up. See he would talk the day away and then try to play catch up before he went home to keep his super off his back.
Parent - - By swnorris (****) Date 07-23-2008 19:09
John,

Around here we have a name for guys like that.... unemployed.  I see that you referred to him in the past tense.
Parent - By jwright650 (*****) Date 07-23-2008 19:36
You catch on quick ;-)
Parent - By Wrench Tech (**) Date 07-23-2008 22:11
I once had a problem with wormholes.  A welder I know and respect told me it was caused by the voltage being too high.  I was also using and argon/CO2 mix at the time.  I turned the voltage down just a little and swiched my shielding gas to straight CO2.  ( all at his reccomendation)  Never had a problem with it since.  Tom
Parent - - By DaveBoyer (*****) Date 07-24-2008 04:47
    If I remember corectly there was a thread dealing with this topic called "Worm holes & chicken tracks" It would be worth doing a search, as the thread was pretty comprehensive, even technically deep at times.
Parent - By turbolaser (**) Date 07-24-2008 22:16
Do you prep your base metal, if you do is your base metal prepped the same as it was before the worm track problem?  Maybe your purchaseing agent got a good deal on some wire from another vendor, some wire that has been sitting on the shelf forever.
Parent - - By bbwinc (**) Date 07-25-2008 02:00
Do a search on my poster name, bbwinc then click on running dual sheild ,lots of info. Also are u using sheilding gas or straight up core wire?
Parent - By jsdwelder (***) Date 07-25-2008 09:59
Thanks for all the replies guys. We use an ESAB 71T with 75/25 Ar/Co2. Our material is prepped the same way every time. It is SA-106 to welded to A108. Always new material and always clean. A friend of mine had mentioned excessive voltage as did some of you. The other day when I was getting it, I took the spool out and put in a new one right out of the box and the problem instantly went away with no machine adjustments at all. Leads me to think it is more of a moisture problem as the spool I replaced had sat out all weekend when it was humid and rainy.
Up Topic Welding Industry / General Welding Discussion / Fluxcore worm holes

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