Ok it's not worm tracking so what is it?

By Kix

Date 07-25-2007 13:41

I saw something yesterday i haven't seen or maybe i have, but never really found out what it was. We're running an ESAB E81T1-Ni1mH4 flux cored .045 wire on 3/8" armor plate. Yesterday i went to a subcontractors shop to see what they got going on and i had them weld a few coupons for me and this is what i saw. They were getting these dimples all in a row about an 1/8" in from the top toe and bottom toe of the weld. It looked like porosity, but there were no holes. In a few of the dimples there looked to be a some small BB's with flat tops just sittin in these tiny craters. It looked kinda like someone took a writing pen and just started peckin all these lil dents along one side of the weld or sometimes both sides, but never down the center.
Now the trouble shooting that has allready been done to fix the prob. Played with gas flow= nothing, Checked o-rings and for leakes=None, Tried to brand new rolls of wire=Nothing, made sure of no Contaminants=Nothing, went from 26v with proper amount of wire to 29v with proper wire setting=helped some, but still showed signs of the dents.
Here where i work we have had no problems with this wire running anywhere from 22v to 29v.
I would just like to know what these lil dents with BB's in them are and if you what might know how to fix the prob it would be greatly appreciated!!

Thanks, Kix

By makeithot (***)

Date 07-25-2007 15:44

Kix , I ran across the same proplem and also went through all the steps you have mentioned in the end it was just a matter of adjusting the amount of wire stick out. for the the wire I was useing minimum stick-out was 3/4". trying to run any thing short of that produced the same problem you have mentioned. the flux needs time to heat up etc in order to do it's job effectivly. Henry had some really good info on this topic and a link to a web site that explained it all among other things (very informative). It is a couple pages back on the forum now. ?????

By reddoggoose (**)

Date 07-26-2007 16:42 Edited 07-26-2007 16:46

Kix,

I'm with makeithot on this. Worm tracks can come from hydrogen in a wire that might have some excessive moisture that has been absorbed into the flux of the wire. Now granted I understand these are not worm tracks, but I wonder if they are similar in nature. A longer stick out will help preheat the wire and burn out any moisture that can cause the tracking. Let us know how it works out I'm curious.

Good luck

By Kix

Date 07-26-2007 16:50

I even went under the hood on this one and i welded it the same way we do it over here playing with the stickout and i still got the pin craters running the length of the weld. Keep in mind that in most of these craters there is a BB chillin in the crater with the top of the bb coming flush with the face of the weld. These bb's are staying pretty much the same size of the crater. So if you have a tiny crater there is just a tinie bb that fits inside and as the craters get bigger so do the bb's.

By reddoggoose (**)

Date 07-26-2007 17:15

You said that you ran the wire back at your shop with no problems. Were you welding on the same base material that the sub is using? You also mentioned that the problem lessens when you turned up the heat. Makes me think of gas that needs more time to escape. A larger puddle with more heat will give any gas more time to escape. However, you shouldn't have to weld at ungodly heats to get this wire to work. Another thing you might want to look at is if they are storing the wire according to manufacturers specs. You also mentioned that you tried a different spool of wire, was it from the same manufacturer? Maybe try another manufacturer using the same classification wire.

By reddoggoose (**)

Date 07-26-2007 17:26

Kix,

Is the wire tradename Dual Shield II 80-NiH4?

By Lawrence (*****)

Date 07-27-2007 00:58

Kix

Not familliar with your electrode, but, FCAW is a very finnicky process and every manufacturer has its own published parameter sheets. I would say to start off by finding out exactly the WFS, Voltage and Stickout they suggest and try that. If you still see those little squiggles (gas bubbles that have evolved but frozen at the top of the weld reinforcement) try turning down the voltage in 1/2 volt incriments.

If that doesn't work you have at least taken the first basic steps in troubleshooting before starting to worry about more exotic causes

By Kix

Date 07-31-2007 12:33

Reddogoose, Yes this is the ESAB dual shield II 80-NiH4. Even when this wire is working properly it doesn't run as smooth as your basic standard flux cored wires in my opinion so i think i'm going to scrap it and go with a E71T1 or E81T1 wire. I have to come up with a WPS for this armor personnel carrier now so i can go with whatever wire i want if i end up haveing to qualify by testing witch i think i will have too. Anyone know where i can get an ASTM# for this Hardox AR500 armor plate?

By Milton Gravitt (***)

Date 07-27-2007 01:27

Kix what type of shielding gas were you using. Do you think it be the gas contaminated or just bad.

By makeithot (***)

Date 07-27-2007 16:03

Kix, Be sure and keep us posted as I am interested as to the solution and cause of your proplem. A few years back when I worked in a less then clean shop we had a similiar proplem that was also solved by useing a felt wiper on the wire before it goes into the drive rolls.??????

By darren

Date 07-30-2007 05:46

hey makeithot. i have suggested these wipers to our welding supervisor and qc and was told that they were a waste of time. i personally believe they are indispensable. they said it would impart impurities to the final weld. i have used them for years and it only takes one use of them and to see the crud and schmootz that is caked on the pad after just one roll of wire to prove to me at least that they are very effective at keeping unknown contaminants out of the weld.
darren

By makeithot (***)

Date 07-30-2007 16:12

Darren, couldn't agree more. Not sure how they would be adding to the contamination of the weld.

By darren

Date 07-30-2007 22:50

the cleaning solution is what was cited as the possible contaminant. i really think it is the old "thats not the way we did it in my day" thing that is so pervasive in the industry and especially in our shop. our break is pre war (ww2)!! we are a high end pressure vessel shop and we just this year got plasma cutting machines for the floor. and they came with a helping of "see what i do for you guys to make your job easier". so i just do what im told and bear with the insanity.
darren

By Kix

Date 07-31-2007 12:37

I also totally agree with the scrubber on the back especially where i'm working? ;-) Those lil suckers pick up hella crap off that wire. I think it helps keeping the dam inside of the lineners cleaned out more then anything.

By makeithot (***)

Date 08-01-2007 19:22

Kix, Have you found the solution to your problam yet or pin-pointed it's cause??

By Kix

Date 08-01-2007 20:15

Big negative on the solution or cause. Some parts came in from the sub contractor the other day and a few welds on the part had the craters. How do you inspect this stuff when you don't know what it is. If i could go to this place and spend some time with there setup i might be able to come up with a cause and a solution. We are haveing no problems in house at all so i can't experiment with what we got.

By makeithot (***)

Date 08-01-2007 23:15

No worries, I am just curious as I am myself trying to increase my knowledge base on FCAW not that there isn't a wealth of information out there, it is nice to hear some first hand experiences - cause,effect,solution. I often feel that, that information is worth 10 fold what some book may over. Not that that information isn't of value it just takes awhile to apply it all and I don't have alot of time for experamintation even though, when I can I try to fit it in. Lately it has been "hair straight back" with no end in sight.