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Up Topic Welding Industry / General Welding Discussion / coating on mild steel tig wire
- - By wolfram (*) Date 06-08-2008 14:32
What is the coating on this wire and is it important to remove it before welding?
Parent - - By RonG (****) Date 06-08-2008 15:14
Most of the GTAW wire we purchase is Copper coated to prevent rust and no you don't need to remove it.
Parent - - By OBEWAN (***) Date 06-11-2008 16:59
I suppose the small amount of copper would not be a problem with most welds, but the fear may be that it might promote cracking in some stainless alloys.  Copper and stainless do not mix well and cracking is the result.
Parent - By RonG (****) Date 06-11-2008 19:06
Hi Steve, What you say is very true but I failed to mention I was thinking in terms of C.S. like E70S-2 etc.

In the Header of the original post the author alluded to mild steel and I just blurted out my reply with out mentioning what alloy I meant...
Parent - - By aevald (*****) Date 06-08-2008 18:22
Hello woalfram, the only time that I have seen this removed was on filler rods for welds that were being made on CS pipe in the nuclear industry. They would also make sure to remove any signs of silica along the edges of beads or in the crater anytime a termination was made, this procedure was carried out from root to cap. As Ron said, mostly this coating will not be an issue. Best regards, aevald
Parent - - By Stringer (***) Date 06-08-2008 23:03
aevald, are you meaning that someone would physically remove the copper from an ER70s-2 (for example)?!?
Parent - - By aevald (*****) Date 06-09-2008 00:53
Yes, they would use a piece of scotchbrite pad and draw the rod through it to remove the copper-colored coating down to brite metal. Regards, Allan
Parent - - By fbrieden (***) Date 06-09-2008 12:47
Followed with a wipe of acetone.
Parent - By js55 (*****) Date 06-09-2008 13:18
Fricken nukes. :)
Parent - - By RonG (****) Date 06-09-2008 13:28
Hi Alan, while I have heard of doing that in a Nuke I've never seen it done (removing the coating). I have only qualified a couple times in a Nuke (Cooper Nuclear in Neb) that wasn't a requirement how ever 8 hours of training (welding rules) followed by a written exam was and that was on top of the 40 hours of training followed by a written exam just to get unescorted privileges.

Been there done that and never want to do it again. It was a real lesson on why Nukes are not as efficient as they could be. It would seem as though there is little chance of  Chernoble incident at one.
Parent - - By tighand430 (***) Date 06-09-2008 13:53
Nukes are the safest places you could work. I've done x-ray joints in the nukes with copper still on the rod and haven't had any problems with it. 
Parent - By js55 (*****) Date 06-09-2008 14:05
There are thousands and thousands of nuke welds out there done with GTAW rod with the coating still on it.
Procedure qual after procedure qual done with the coating still on. And for nukes you have impact testing. In all the tests I've run I've never seen the coating cause a problem. We never took the coating off and easily achieved hammer stopping impacts at minimum design temp (in fact even had to drop temps to get em to break). Of all the things to worry about when welding or qualifying for nukes that one would be way way down the list. And not on my list at all.
Parent - - By aevald (*****) Date 06-09-2008 15:03
Hello Ron, and everyone else, please don't misunderstand my post, I didn't say that it was a requirement or would actually make any difference in the quality of the welds, it was a procedure that was being used by certain contractors at the Hanford site in Pasco, Wa. at the time. This was roughly in the late 70's early 80's. Best regards, Allan 
Parent - By RonG (****) Date 06-09-2008 15:47
I hear you Alan, I really did not think you were promoting it, I guess I should have alluded to that fact. I guess I was just bragging about having qualified in a Nuke, sweated blood I did and it was freezing out.

The whole experience was bad from my point of view due to the fact we were driving 180 miles (round trip) every day and working 12 hour shifts on top of it. At the on set I was really curious about working in a Nuke, not any more.

I needed a bottle of Oxygen in the area I was working, there was just a door separating me from the Welding shop where it was stored but the door could not be opened during an outage (rules). That meant going back through the RCA (Radiation containment Area?) doing the stripping down dance to my skivvies, getting a full body scan, put my street clothes back on go up stairs and out the front of the building, walk all the way around to the back of the building (and it's a big building) to the Weld shop, locate and push a bottle of Oxygen through the door (that could not be opened it turns out from the other side and no human could pass through it).

Then back around the building and down, suit up to enter the RCA. That was best part of the whole job because there was only one unisex locker room. 
Parent - - By js55 (*****) Date 06-09-2008 16:06
allan,
I understood what you meant. There are lots of things we see on specs, or practices, that our experience has told us probably doesn't make any difference. Sometimes even more so with nukes. By the way, my father-in-law worked for years at the Pasco plant.
Parent - - By RonG (****) Date 06-09-2008 16:42
Having said all that, I have to retract some of it.

I also went to Main Yankee (Bar Harbor) to do a little welding and that was a very pleasant experience. Different kind of unit but its closed now I am told. But the people were really fantastic and helpful.

I don't fault the Cooper people, I have seen for my self what a nightmare an outage can be in a nuke and all the seemingly dumb rules have very sound reasoning behind them.

I worked a couple years in Wa. (Olympia) but never got near the Pasco plant. I like that country real well wish I had stayed there.
Parent - By aevald (*****) Date 06-09-2008 18:37
Hello Ron, were you at Satsop? or possibly Beaver? They have both been decommissioned by now and most recently Satsop was made into a home siding plant which also has closed. As far as our state goes, I think it's a pretty nice place to live, a little less rain would be good but there aren't too many things that can bite or sting you, blow your house away or uproot and relocate it for you, the fishing and hunting are superb and for the most part the people are pretty good folks. Be talking with you more in the future. Best regards, Allan
Parent - By aevald (*****) Date 06-09-2008 18:20
Hello js55, your father-in-law may very well have known some of the instructors from the college in that area then. Buzz Colbert, Gary Colbert, Ed Hue were possibly instructors there at the time or they might also have worked with him out on the site. As for the nukes, I haven't personally worked on any, yet I have had many friends and acquaintances who have and they tell a tail of a different world than anything else that goes on anywhere. Best regards, Allan
Parent - By DaveBoyer (*****) Date 06-10-2008 02:17
Allan, I recall quite a bit of talk about copper inclusions causing cracks at grain boundries [in stainless steel] in the late '70s. Perhaps some folks over reacted to cover their butts.
Parent - - By Kix (****) Date 06-11-2008 16:29
Ya know Al, I bet it was more of a who was doing the procedure qual welding then anything.  You pick a guy to weld the test coupons for a PQR and if he prefers the coating to be removed then that is what the WPS will have to say.  The reason why guys prefer to remove the coating is because it makes the puddle not so soapy, but I never found it to be that much more helpful.  I personally think it's a waste of time to remove the coating, but that's my opinion against a million others.;-)
Parent - - By aevald (*****) Date 06-11-2008 16:49
Hello Kix, back when I was observing this process being done I was definitely a greenhorn and didn't have any sort of understanding of the why's or why for's. Which is probably why so many of us take things for granted and don't necessarily question the reasoning or logic behind a particular procedure. In some cases it isn't our place to make those sorts of calls. Just my $.02 Best regards, Allan
Parent - - By Kix (****) Date 06-11-2008 20:32
I guess what I meant about my statement is if you have a really good welder to do your PQR test coupon and he has a pet peave about removing the coating and asks if he can, only then would it have to go on the WPS.  That is if he gets the ok to do it by whoever is in charge of the testing.  I'd have to make the call of, if they are making their welds shoot without removing the coating then let it be.  What is your .02 on why nukes want the coating removed?  I'm interested as to what their reasoning was behind having guys do this.  Do you think it more for consistency purposes with the welders?
Parent - By aevald (*****) Date 06-11-2008 21:44
Hello again Kix, since I don't know the exact make-up of the "copper colored coating" that is applied to the various ER70S2,3,6 designations and whether this "coating" will float out, vaporize in the arc, combine in the form of some sort of metallurgical dilution of the base materials or possibly result in an inclusion of some sort I really can't say why these folks were removing it before proceeding with their welds. I do seem to recall additionally that in some cases they were using copper scratch blocks to fire the arc off on and then dragging it into the groove to make the welds so as to avoid tungsten contamination. This was before the days of lift-arc power sources and small portable inverters. Just a little more to ponder. Regards, Allan
Parent - - By weldgault (**) Date 06-09-2008 19:54
In come cases the Mfg. will use a petroleum lubercant as a drawing compound and should be removed, because it will cause problems
Parent - - By hogan (****) Date 06-09-2008 20:20
i know it should be some, but that's funny
Parent - - By jrw159 (*****) Date 06-09-2008 20:59
Thats one "fat finger" right there. LOL :-)

weldgault, were just giving you a hard time partner, no worries. :-)
Parent - - By weldgault (**) Date 06-09-2008 21:20
John West, A good friend of mine, but a little older.  W.E. Bethleham Steel.  But Initial C.  John Gault
Parent - By jrw159 (*****) Date 06-09-2008 21:26
Cool!
Parent - By spgtti (**) Date 06-10-2008 02:29
I've been on jobs where the tool/rod shack issues 80grit emery cloth to remove the copper coating off the wire before you use it. I've also come across some bare, uncoated wire, vacuum packaged in about 10 rod bundles in some plants. I don't ever remove this coating unless its part of a procedure because it just takes too long and doesn't seem to weld any different.
Up Topic Welding Industry / General Welding Discussion / coating on mild steel tig wire

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