7028 Problems

Date 01-13-2003 16:18

It appears the rods melts off too far back up into the flux. I noticed it when the rod cooled off while fitting other peices and when I went to tack it in place the rod was hard to start. You would have to beat the flux off until some rod would show and get it started again. Problem there is you never know how much flux may chip off and you might be left with too much rods sticking out of the flux.(not good) I had never had trouble with 7028's, just drag em along and very easy to weld with. Now, I see the welder's complaints are legit. They are fussier than the 7018's to get restarted. Aggrevating to tack with! The welders tell me that the rods don't have to cool off to have problems, they burned one and broke the arc, then tried to restart it while I stood their and he tapped and beat until the flux fell off the rod too far up to use and had to throw the rod away. He used a fresh rod right out of the oven. He tells me the rods right out of the sealed container do the same way. I've not been able to give these guys a reasonable answer about these rods, so I'm turning to someone else to help. Have the rods changed somehow in the last five years?
John Wright

By TimGary (****)

Date 01-13-2003 16:53

Hi John,
I've always solved the problem by simply tapping the end of the rod against the cement floor or other non-grounded material to break off enough flux to expose the rod tip. If too much flux breaks off then strike an arc on a handy piece of scrap set close by for that purpose. It's not enough to slow the Welder down unless they want to be stubborn about it.
This story reminds me of the WAWA Welders dolls I've seen for sale in New Orleans. The doll is dressed like a Welder, and when you pull the string it says "WAAAHH....WAAAHH!"
Will your WPS allow you to tack with 60XX rod instead? It's easier to restart...
Tim :)

By DGXL

Date 01-13-2003 17:01

Tim: Are these dolls available in bulk?

By bmaas1

Date 01-13-2003 17:34

Exactly, just break the flux off the end of the electrode or tap it on the cement.

Brian Maas

By DGXL

Date 01-13-2003 17:00

John:
This is common with these types of electrodes. The electrode is designed to do just that. I don't think it is melting too far back nor is there a problem with the electrodes. It is "built in" to the electrode to maintain a specific arc length as these electrodes are "dragged" across the workpiece. These electrodes are not whipped or oscillated like cellulosic electrodes.

When I was stick welding for $, I just got used to restarting almost any lo-hi or mud rod by scratching the pavement before a restart, it simply became a habit. Lot's of seasoned guys do this without ever lifting their hood and it was a perfect restart, barely noticable in the weld.

Other brands with the same classification may restart more easily, try another brand.

By jwright650 (*****)

Date 01-13-2003 17:27

We used to use a 6013 years and years ago, and we got away from them for some reason before I got into the Quality Control picture, I'll have to ask around to some of the older welders and see if they remember a reason why we switched. 6011 and 6013 are easy rods to tack with, but I didn't remember the 7028 being hard to restart when I was welding in the shop, so I figured the rods may have been changed in composition somehow over the last few years, making them tougher to restart.
John Wright

By CHGuilford (****)

Date 01-13-2003 17:51

I believe DXGL is right in that the rods are designed to burn back leaving the flux past the electrode. Thats why it's called "drag rod" because the arc length is maintained fairly consistently by dragging the rod on the joint. I used to burn 7028 by the 50 lb. boxful. I did my restarts by using a "stab and scratch" method so the flux would break back a bit and initiate the arc; similar to restarting 7018.
Sometimes the flux would break back too far and then we knew the rods were probably stored at too high a temperature. And sometimes, that's just the way that batch of rods was, we just had to live with it.
I didn't like tacking with 7028 much, mainly because the rods we used were large diameter and long (3/16" x 18") and you needed to run a short weld rather than a small tack by the time you got the puddle straightened out.
I don't know your application but if you are using 7028 because they start easily (excepting your restarts) for tacking, you might want to look at a 7018AC electrode and use the 7028 for welding the joints. 7018AC rods strike easily and run on almost any AC or DC machine. The little buzz boxes don't run them so well but I figure you probably are running bigger machines in your shop. Naturally, if you don't need low-hydrogen rods, you could use 7014, 6013, or other rods.

Have fun,
CHGuilford

By Dave

Date 01-13-2003 17:26

Yep, it's a common problem, but as already shown, easily resolved. Some welders simply pinch off the end of the rod. However, I think other respondents will agree that that method is best suited for finding holes in your glove.

By jwright650 (*****)

Date 01-13-2003 17:42

Thanks guys for your input,
I just never remember these rods acting this fussy when I used them years ago.
Anyway, I'll look into the 60k series rods as you know the flux is thinner and will start easier. If that don't work I'll have to make a trip to New Orleans to find some of those dolls I read about.
John Wright

By Dave

Date 01-13-2003 19:31

If you remember easy starts years ago perhaps your memory isn't serving you well when it comes to the particular rod. Could it have been Lincoln Jetweld 1 or Jetweld 3, both E7024 instead of the LH-3800?

By jwright650 (*****)

Date 01-13-2003 19:53

Dave,
The memory isn't what it used to be, no disputing that. The 7024 was and still is in the inventory around here. I'm definitely speaking of the same old rod that I learned to weld on and like others have said, 50 lb. boxes after 50lb. boxes of them. We used the 5/32" for tacking and the 3/16" and the 7/32" for welding Flat and Horz fillets. I never remember having to beat the rod, only scratch it and off it would go, similiar to the 7024 you mentioned. Maybe the flux properties have changed and the flux is harder or maybe we keep them to hot in the ovens. We keep them around 250F - 300F, depending on how long the door of the oven stays open when someone is loading or unloading pouches. I think there is one oven out of four that gets up to about 325F, but I hear the same thing from all the guys about the 7028.
John Wright

By DGXL

Date 01-13-2003 21:18

John:
The E7024 iron powder electrodes are easier to start in my opinion. The flux at the tip knocks off relatively easy. I use my fingers (without the holes-in-glove as noted. Good observation though...)

The E7028 are low-hydogen/iron powder electrodes, they (in my opinion also) are more difficult to restart. This is typical with many brands of lo-hi electrodes.

Out here in Zone 4 we are not allowed to use these (E7024) due to the lack of a requirement for impact properties for this electrode.

As I think about what CHG has mentioned (and a similar thought by him in another post), how much rod and wire we have all burned to learn these things. We should all have have a 401K with Lincoln or Hobart.

By MBlaha

Date 01-14-2003 21:11

I have used the pinching off for years!!!! Yes, it tells you when your gloves need to be replaced :). But after so many times, the calous gets tough. I used E7028 only on one tank job. We all had lots of trouble restarting, enough to the point that the Superintendent had us throw the rods after triking any arc with them regardless if we welded an inch or a foot.

By Michael Sherman (***)

Date 01-13-2003 22:19

John, just for your entertainment I am going to quote to you from Lincoln Electric literature: "E7028: The electrode has fast-fill characteristics applicable to high-production welds where low-hydrogen quality is required. It performs best on flat fillets and deep-groove joints, but is also suitable for horizontal fillet and lap welds. Excellent restriking qualities permit efficient skip and tack welding."
Now that we have said that, low-hydrogen has always had this problem as far as I remember. Lincoln has a new brand of low-hydrogen electrodes out called "EXCALIBUR" it is purported to have superior restriking capabilities. I have used it in demonstrations and have not really noticed much difference but my sales rep is always trying to push it on me. Good luck.

Mike Sherman

By DGXL

Date 01-13-2003 23:31

Hey Mike:
Maybe we've heard the same sales pitch on the Excalibur electrodes. Had the same sales jargon thrown at me just recently. I asked the rep. to demonstrate and he just smiled. I have not found restarting any different than with the old Jetweld electrodes.

(See my previous post on those who burn and get burned for a living.)

By mcavana (**)

Date 01-14-2003 00:30

I just want to know where I can order one of those dolls!!!!

mike

By DGXL

Date 01-14-2003 00:56

I would like to order a semi-full of them things!

By TimGary (****)

Date 01-14-2003 12:25

Actually, it was just a joke, but if someone patents it, I'll take my cut in the form of product!
Tim :)

By jwright650 (*****)

Date 01-14-2003 12:36

Mike,
I read that yesterday on the Lincoln web page in the pdf. files. I got a chuckle from it so I printed it out and handed it to the guys that were complaining yesterday. I asked them to read the second "advantage" listed by Lincoln...."Excellent restriking charectaristics makes the LH-3800 ideal for skip and tack welding".

DGXL,
I think the impact requirements may have been why we went to the 7028 instead of the 7024,6011 and 6013 we ran years ago to tack with. Anyone just starting out in the shop welding was handed a box of those easy strike rods(drag rods) to get the hand of welding before moving on to the 7018(magnet in the end rods). I had started a couple of guys out on the 7018 and they got frustrated and quit on me before I realized I should not have done that to them, since they had never tried welding before. And yes, my 401k would have benifited from investment in Lincoln and ESAB when I look back at the tractor-trailer loads of electrodes that come through this place in a months time. When you have sixty-five or more guys burning those things they go away in a hurry.
John Wright

By jwright650 (*****)

Date 01-14-2003 17:37

Lincoln is going to be in our shop 1/16/03, and I'll have him demonstrate any easy strike rod that he proposes. I really want him to try one of our 7028 rods and tell us it's an easy strike rod just like the Lincoln 7028 literature states! We'll see!!!!!!!!!!!!!!!! He's also trying to get us away from the ESAB wire and go with Lincoln wire.
John Wright

By welder_guy2001 (***)

Date 01-15-2003 03:19

maybe what they mean by "easy strike" is, it's easy to strike the first time, but nothing is mentioned of how "easy" it is to strike each time after that!

By jwright650 (*****)

Date 01-15-2003 12:11

Welder_guy,
The first time strike is great, it's the re-striking that's the problem.

I still say they have changed something from what it was a few years back, flux is my guess. Lincoln will never fess up to it, I bet. Probably their QC dept.'s fault, since I'm in QC myself I can say that, we are always the problem.
(Lincoln QC, I'm just kidding!)

But I've been wrong before and I'm sure it won't be the last.
Keeps me humble...
John Wright

By CHGuilford (****)

Date 01-15-2003 14:21

jwright650,
Just some speculation for you...... A couple of years ago a self-described middle level management person from Lincoln had told me that the formulas vary according to the commodities market. They report ranges on percentages for the chemical analyses for many reasons. Two of them being that manufacturing tolerances make it difficult to be more precise in their recipes and when the price of a chemical goes up, they can compensate somewhat with a "little of this and a little of that" using cheaper chemicals.
I can only assume this guy knew what he was talking about but have never verified it. I know the electrodes are supposed to meet the specification. However, I have to wonder if all that may have something to do with the differences you have noticed?
CHGuilford

By jwright650 (*****)

Date 01-15-2003 14:34

Thanks CHG,
I'm not just making this up or thinking I was using another rod. 7028's have been in this shop along time, at least the eighteen years I've been here anyway. The older welders all agree that it is not the same rod it was a few years back. So, I feel I wasn't alone in thinking something had changed.
John Wright

By welder_guy2001 (***)

Date 01-16-2003 01:52

well, in that case, you could probably just get some 7028 from a bunch of different companies and see what they're all like. CHG brought up a point i've never thought about...interesting! I know my last boss hated the batch of ESAB 7018 he got 'cause it would restrike and would just stick to the work rather badly...he always claimed, "See that? A Lincoln rod would just keep on goin." hehehe...it seems everybody has their favorites!