moisture in cellulose rods

Date 09-17-2014 03:13

True, Cellulose is carbon, hydrogen and oxygen (C6H10O5) {sorry, I'm not sure how to subscript numbers for chemical formulae}. And yes, the hydrogen and oxygen are in fact a 2 to 1 ratio. If I remember Chem 132 class, there seems to be a confusion in the definitions of a mixture versus a chemical compound. What I am understanding in this argument is the assumption that cellulose has "free water" in it. If that were the case, then we could go in the lab and grind up some charcoal or graphite, add a bit of water and voila! Poof, it would magically turn into fibrous cellulose. Even if it were to be written as C6(H2O)5 this still indicates a chemical/molecular binding of some fashion.
Simply put, NaCl is table salt. Add water and you have salty water... NOT NaClH2O.

By Superflux (****)

Date 09-17-2014 06:02 Edited 09-17-2014 06:04

OK, I will admit that I have been guilty of rehydrating 6010.
Back in '77 when I was with the Boilermakers 101 (I was a "Tankie") my Steward on the job showed us the dunk and dry method to cure the flux cracking problem. At the end of the day, we would quench the rods in a 5 gallon pail of water and ten spread them out on the sunny side of the tank floor to rehydrate overnight. We had it down to a science, we'd dry them off with rags and spread them out. I'm guessing we must have hit that magical 3-5% that Al spoke of because next morning, the cracks were gone and the rods burned quite well.

"There's a right way, a wrong way, and the way we is-a-gonna git'er dun!"...

Now the BIG question!!!
As a QC professional, would any of you CWIs or QA/QC reject the work if witness to this "rehydration" technique?

By jarsanb (***)

Date 09-17-2014 13:15

Absolutely I would reject and cut out all the welds. To start, where was the procedure you followed for this process and the verification data would be my question. Here is a study on rehydration and drying of XX10 electrodes by D.o.T.

http://ntl.bts.gov/lib/44000/44200/44214/44214.pdf

By jarsanb (***)

Date 09-17-2014 13:52

If you combine that information with studies posted here previously concerning hydrogen cracking studies then you can see that rehydrating XX10 electrodes is a huge concern that results in zero possitive results.

By lo-hi

Date 09-17-2014 16:10

That article was an interesting read, and once again I have a clearer understanding of fable and fact. Wondering if the addition of iron powder to 5p plus calls for any different storage conditions than regular 5p?

By ssbn727 (*****)

Date 09-17-2014 19:13

What you can do with those so-called rehydrated electrodes is to use them for farm code work, or you could scrape the flux coating off of it, and if you know a little about how to convert cellulose into gasoline? You can make enough gas to run a nano sized internal combustion engine so the gnats can pretend they're driving around you in circles in their nano sized hot rods...

You could also donate them to the local welding school so the students can learn about this. :twisted:

Now, has anyone ever read about how our colleague, Len Anderson invented a way to produce Low Hydrogen electrodes that are totally impervious to absorbing any moisture at all?

Therefore eliminating the need for a rod oven... He held a patent for this method of coating low-hydrogen electrodes until it expired... let's see if he wants to add to this change of direction in this conversation. :eek:

Respectfully,
Henry

By Plasma56 (**)

Date 09-17-2014 20:13

I was going to say I was in agreement with your statement about rejection and cut outs.
But I'm not and don't with a smile.

This discussion "may" be above my pay grade but after further review of the studies attached in review of this issue, it seems to confirm my thinking on the matter.
What I find unsettling is what seemingly is a failure to recognition the point of this discussion, seemingly proven, that moisture levels are critical to maximum arc performance when using a cellulose coated electrode. And that the useage of these electrodes require the same care and concern for condition as a low hydrogen electrode.

What I find disturbing, is educational facilities, Industry professionals, failing to recognize this as being an issue? Or seemingly understanding it is an issue? Finger nailing rods, piles of stubs at the end of the day...a passing grade but not much for thinking or depth of education.

"While adding surface moisture to the electrode may improve the operation somewhat, it will not
restore the deposit chemistry or properties to those for the as-manufactured condition, and will
likely increase the likelihood of hydrogen damage or cracking."

The word "Likely" makes me smile...Sound like someone doesn't know for sure? That's amusing. A sound best guess?
But I'm a welder, the quest for me is does it improve weldability and the answer is yes, somewhat. Old guys weren't all wrong it seems.

"Drying the electrodes results in a
lower voltage for a given arc length. All of these factors contribute to higher alloy recovery when
dried electrodes are used. The higher alloy recovery can lead to increased weld-metal strength
and increased cracking tendencies."

I'm trying to wrap my head around that statement? The arc voltage part. But I got it. Dry wood burns easier and hotter.
The flux coating burns up higher with less crucible cup forming.The magnetic field looses the strength to pull smaller droplet with greater arc force due to the dininishing field strength and focus to the core wire tip and the diminished field strengh results in a larger droplet transfer forming befor dispersing across the arc gap.
See, not just a pretty face.

I'm assuming the cracking comes now from deposit hardness and loss of ductility?

-It appears that the welds made using the inverter and certain manufacturer’s electrodes may be
somewhat more sensitive to hydrogen damage than those made using the motor-generator,
additional testing would be required to say this conclusively.

There's the rub. Inconclusive. Sounds like a good guess?

What I do know it I have done numerous cjp welds in an attempt to discover a truth. My truth is, dipping/ rehydrating attempts failed to cause an increase or incident of cracking/breaking out in "my" welded sample F3/F4 coupons during bend testing.
I do however weld slightly cooler in amperage, slightly wider gap, and of course, slower. With that logic, the weld remains hotter longer, the weld cools slower, and followed by F4 fills, dilluted to next to nothing.
Did I miss reading where they compared results to rehydrating a new electrode? But why would they?

When I was instructing welding for a living, my response to that question was always the same. In this day and age of liability, the onus falls on the welder to use his best judgement when he grabs a rod to remember that striking an arc places him in a position of being responsible for his actions and at risk for liability if a weld fails. I would add that just because someone says you can't doesn't mean you can't, just that you should think about the resulting actions if you do.

I will say however, we are all products of our upbringing, education, training, experiences and beliefs. I'm not convinced I would reject just because of that incident. However knowing what I know, some situations would call for it.

By ssbn727 (*****)

Date 09-17-2014 22:00 Edited 09-17-2014 22:53

If the standard or code one is working to states clearly that re-hydrating and/or drying Cellulose type electrodes are not allowed in any of the clauses then I reject - period! Unless the EOR overrules and states in writing that it can be done on that particular job...
How would I know this happening? Well, quite frankly one has to investigate as to whether or not this is happening by stepping back in order to observe and report, ask questions...

And the only way to verify that there is one or the other, or both is going on - in order to prove this is indeed the case, one needs to take samples of welds deposited with the electrodes being used, and then have them analyzed for increased amounts of alloying elements as well as any unusual amount of hydrogen that may have been trapped in the weld metal as a result of using re-hydrated electrodes, and/or drying the electrodes...

Remember that the EWI report is concentrated on very specific low alloy pipeline steel that will usually have a different chemical composition than the grade of steel used in erecting storage tanks so, remember what type of meat we're chewing on here in this discussion...

Plasma, did you write that you bend tested samples from 3 and 4F joints using cellulosic electrodes? What about groove joints?

"I'm not convinced I would reject just because of that incident" The problem doesn't stem from one incident... The conclusions and recommendations written in the EWI report are not based on only one incident, or just from studying the various field incidents where HAC was indeed found to be from... EWI also validated via testing the findings found @ all of field cases where the various factors that could have caused these failures listed in the report occurred... So they're presenting proven causes for these types of failures...

Now as far as the Lincoln electric report is concerned, it's pretty clear about what they warn pertaining to re-hydrating electrodes in an uncontrolled manner such as dipping the electrodes in a bucket of water... This is from the introduction of the Lincoln Electric report:

"Cellulosic-covered Electrode Storage Conditions – Influence on Welding Performance and Weld Properties R. Weaver and J. Ogborn The Lincoln Electric Company Cleveland, OH

ABSTRACT
Cellulosic-covered electrodes have been used for shielded metal arc welding (SMAW) circumferential welding of line pipe over many decades. They are characterized by electrode coverings containing organic matter. Unlike low hydrogen SMAW electrodes that achieve optimum results at low covering moisture levels, cellulosic-covered electrodes require much higher covering moisture levels for proper operation.

For example, pipe welders have been known to deliberately expose electrodes to the weather, or even dip them in water prior to use. Further, Johnson and Bruce [1] recently suggested that high incidents of hydrogen assisted cracking (HAC) might be associated with low moisture levels in the cellulosic-covered electrodes used.

This suggests further that storage and handling practices based on conventional wisdom in the field may not be sufficient as the industry transitions to more demanding applications and higher strength materials. Consequently, this work was undertaken to develop more definitive information on the performance of cellulosic-covered electrodes for three purposes:

• determine the influence of various storage and handling practices on electrode covering moisture,

• determine the influence of covering moisture on electrode operability, weld metal chemical composition and weld hardness, and -

• develop more definitive guidelines for cellulosic-covered electrode storage and handling practice.

Three different E8010 type electrodes (one E8018-G and two E8018-P1) were subjected to various storage conditions - temperatures from –40°C (-40°F) to 66°C (150°F), and time periods up to 196 hours. As temperature increased there was a tendency for lower electrode covering moisture levels with corresponding increases in weld metal alloy content (particularly Mn, Si, and Ti), increased weld hardness, increased weld strength and higher tendency to HAC. Variations in electrode operation were also noted.
KEYWORDS: SMAW, Cellulosic-covered Electrodes, Covering Moisture, Storage Condition, Weld Strength, Weld Hardness, Chemical Composition, Hydrogen Assisted Cracking

BACKGROUND
A recent paper by M.Q. Johnson and W. A. Bruce [1] dealt with incidents of hydrogen-assisted cracking (HAC) in the welds of line pipe welded with cellulosic-covered electrodes.
A number of topics related to the possible causes for the HAC in the girth welds were discussed. One of these topics was the effect of covering moisture on electrode operation and the resulting weld metal chemical composition and hardness This led to questions about storage conditions and the effect on covering moisture for temperatures between room temperature (24°C (75°F)) and 86°C (186°F) as well as for different lengths of storage time.

Consequently, this work was undertaken to take a closer look at the effects of reduced moisture levels on cellulosic-covered electrode operation and weld performance. Some of these effects are known through practical experience. The changes in operating characteristics are a more globular metal transfer across the arc and a less forceful arc. These changes in welding characteristics were consistent for electrodes that have lower covering moisture content. A possible mechanism explaining the relationship between covering moisture content and arc force could be the very rapid, extreme change in volume as water changes from a liquid to a vapor.

This rapid expansion might be causing metal droplets to travel faster creating more arc force. This rapid expansion could also be causing the molten metal to transfer across the arc as soon as it becomes molten which would result in a fine, spray droplet transfer. Conversely, lower moisture levels would have a lesser amount of vapor expanding which would lead to a lower arc force. It would also allow the molten droplets grow to a larger size before transferring across the arc, yielding a more globular droplet transfer. Field practice supports this idea. It is common practice (although not recommended) for welders to improve the operability of dry electrodes by re-hydrating them in some manner. A few examples of re-hydrating techniques are:

a) leaving containers open to the atmosphere in a humid location,
b) wiping them with a damp rag,
c) dipping the electrodes in water.

The potential problem with re-hydrating dry electrodes in this manner is the lack of control over the amount of re-hydration that actually takes place." Duh!

Then it goes on and on with theories and hypotheses which supposedly explain what, how and why these issues occur... And then we read the conclusions followed by the recommendations (API 1004ish!) which goes like this:

"RECOMMENDATIONS

1. Explore whether covering moisture loss occurs in unopened cans when stored at higher than room temperature conditions or whether it is just an “open product” phenomenon.

2. Explore an increased number of storage temperatures between room temperature and 49°C/120°F to determine at what storage temperature there are no adverse effects on welding operability and mechanical properties.

3. Explore design changes that will retain covering moisture levels more effectively, even when exposed to higher than room temperature conditions.

4. Explore whether electrodes can be designed and manufactured at the “equilibrium” moisture level, so that they are not subject to the variation."

I know just the person to figure this out... He Len Anderson!!! Here's a problem for you to solve and then sell your solution to the highest bidder... Are you interested?

I read both reports and I came to the conclusion that the EWI was much more thorough, and made far more tests than the Lincoln report, and was more in depth, covered all of the angles based on the various methods of testing used and overall, covered a wider amount of all of the various categories listed as well as the different conditions used to come up with their conclusions... The Lincoln report wasn't anywhere near as thorough and was very limited in it's scope...

I mean, how much more empirical does it need to be? The EWI report does include way more variables than the Lincoln report.. I suggest that you re-read this report thoroughly as opposed to just skimming through it like most people do these days

Respectfully,
Henry.

By Plasma56 (**)

Date 09-18-2014 06:53

Henry,

I didn't skim. I glanced over the report. Hey, I read the important parts. Some of what you quoted in length. Twice now I've read what I wanted to read.
Don't quote chapter and verse friend. Other then the important part we are no further ahead. You know it, I know it. Both reports as much say as you replied, the same thing.
It's how and what we learned from what we read.

The important part to me the welder was, store them properly or they don't weld as good. I think the noticeable effects might have read more colorfully?
From a CWI's view, sure fail it all and let Good sort it out. Code is Good. Written by man. He can change it but only when he gets agreement or can prove other wise.
The metallurgist says, somethings up, the results say so... we can say this and that, but we got to look at it further to know for sure. Don't change good.

The point worthy of mention again however is how failure to control the exposure times could very quickly have adverse effects to useability and metallurgical content quality. And rehydrating attempts to cellulose coated electrodes does hold similar effects.
And yes...in both instances with a degree of uncertainty still left as to why, we can say with a degree of certainty both practices, excessive exposure and rehydrating attempts should be avoided.
Code is good. Testing is good. Why is good.

The material specific nature of the question however was a distractor. Regardless of materials the effects are the same. Magic happens. I'm surprised you failed to tie that to this? Two disappointments today.
But code work is code work and enough typing monkeys in a room you get Shakespear maybe? No...just better enforcement on electrode exposure times. A more watchful eye maybe? Debate maybe. All good, and I didn't have to do much typing to get sparks flying.

Your a welder, and you read the paper. When the coating starts to dry, the common feature is diminishing arc voltages. No arc force.
The welder is trained to over come this by turning up the current. Or tighten an arc. The testing mentioned inverter. The smart welder will go through more rods because as they heat quicker with an increase in current and the length diminishes he looses control. Monkey see monkey do training. The result is a weld done hotter, faster travel speed,smaller deposit and quicker cooling rates typically and with greater contraction forces resulting. Your going to get more cracking concerns from a build up of internal stresses than you can contribute by some welder quickly dipping a rod IMO and experiences.

And yes, I made my discovery of awakening by doing.
With a hand held consistency I can only lie about honestly, 1G groove welds. F3/1/8" E6010 Root, F4/3/32" E7018 low hydrogen hotpass fill and cap. Bar stock 3/8" x 6" saw cut 37.5 bevel angle,Vee groove, 1/8" root land and 1/8" root opening after tacking. Miller XMT 350 10% arc control. Endless coupon supply. After a while, a very dangerous monkey group typing let me tell you. Myself and thirty student doing coupons. Even spent some sample time depositing coupons in glycerin watching bubbles rise and comparing results.
Not very much organized science but a simple basis for discovery.

I suggested to those that listened or were forced to listen, that the relationship existed between exposure and weld quality. Thank you Lincoln for your support. EWI report, wonderful stuff. It's still not being shouted out loudly, but it will eventually trickle into main stream delivery.

That consumable useage was directly related to this occurance is hard not to gather. Welder weld quality? Who listens when our education system is failing in it's training delivery to grasp this need for control or instruction of it?
Yup...check out what every CWI will be on watch for tomorrow? The odd instructor might think about. The student who wondered why he wasn't getting it now checks.

Henry, at the end of the day, somebody thinks about why or why not. Not everyone asks the questions however. Or shares the knowledge to the degree debate brings about. I think we made progress to increase understanding here. Didn't hurt my ego any or my pride. But it goes to show, this stuff never get old.

By jarsanb (***)

Date 09-18-2014 13:09

I was answering the question of - from a CWI perspective would you reject the welds if re-hydrated (paraphrasing)? I work in a very regulated environment. You are not allowed to scratch your ass without a procedure telling you how. So I'll go back to my response of "where is your procedure for dipping your electrodes in a bucket of water". I don't need any other supporting documentation or science to reject those welds if they don't whip one out.

By Plasma56 (**)

Date 09-18-2014 16:08

Yes. From a CWI point of perspective I would reject.

But you keep ringing the bell. It's about qualifying a procedure. While "we" wouldn't go through that effort, it's about all it would take to make it a legal practice according to code. So I did qualify a procedure. In my mind anyways.

The simple approach would be to accept that cellulose electrodes require proper handling, prompt useage from an open box or container. So I stand up and make a statement that starts a conversation. I wouldn't change a thing.
When you fail to have your own ideas, your left with the thoughts of others rolling in your head.

I'm not suggesting for a moment the system should be tossed, but when the system looks at increasing allowable inclusion limits because the repair rework is causing more damage to mechanical properties than the defect ever will, something is wrong. Or improving?
We need to know more.And our understanding of it.
What will they come up with next as we advance in our knowledge?
But it is what we have to guide us through the maze. And it is that, a guide.

And when I ask the question, why would it, the dip practice take place today in industry? I have to answer, someone doesn't know something, isn't doing something about it, or failed to put the controls in place to prevent it from happening. Who's job is that?

I stand by my comment however that other considerations will effect the mechanical properties of a weld deposit to a greater degree IMO than the dip. Seemingly, dried out cellulose coated electrodes will have that effect?

So yea. Reject it. And when you do, ask yourself why you had to?

By Plasma56 (**)

Date 09-17-2014 04:09 Edited 09-17-2014 04:14

Kent, I'm not those guys, but in a pinch I did talk to Lincoln about this when I was in an asking questions mode. Interesting topic and if one thinks about it, worthy of discussion to help welders weld smarter.
I'm hoping to attach a pdf for comment on this subject. I'm sure it will generate a degree of debate.

My quest to answer the question was because the college where I instructed failed to control the piles of E6010 stuffed into the open air rod storage for student use. I was of the opinion it should be limited to a box by box basis for student comsumption. Well, being right doesn't mean you get your way. And the subject matter dealing with the forbidden is discussed.

But I was right. Twice.

Corrected for spelling in my excitement.

Attachment: Cellulosicstorageweldproperties-WeaverOg.pdf - Thanks Lincoln Electric (153k)

By welderbrent (*****)

Date 09-17-2014 18:24

Didn't have a chance this morning to read the article in it's entirety but found it informative thus far. And definitely appreciate some of the comments about not being able to control the moisture levels using the methods mentioned and affirmed by Superflux (and myself) as having been used by 'tankies' back... a couple of years ago :roll:

.

Based upon my experience, manufacturer's specifications, and current research in the area, I would have to agree with others already posting that as an inspector I would not accept welding performed with re-hydrated electrodes. Lo-hy has prescribed methods of storage and when necessary re-baking (ONCE). This issue needs further work but I would stand on lack of proper acceptable procedures.

He Is In Control, Have a Great Day, Brent

By ssbn727 (*****)

Date 09-19-2014 00:01 Edited 09-19-2014 00:03

No! You give us your idea's if you know so much son! :grin:

So you "set the net and got the fish" eh? Really? Like I said before, give us your ideas since you claim to know so much...

Another exercise in futility IMHO... I hope you're still taking the anti - encephalopathy medicine Ken... I mean what is it that you really want to know Ken?

Respectfully for the most part,
Henry

By Plasma56 (**)

Date 09-19-2014 08:19

Hi Kent,

Have I got answers and ideas. Manufactures actually make them for this purpose. Few welding supply firms carry them? What's up with that? Nobody knew? No body cared?

But I have seen them go cheap on Ebay. While they are pricey by some standards, depending on the package, box or can size you purchase, decantering into small air tight containers will perserve them and that is the key. I bought Tupper ware from the local value store. I'm a cheap old prick. I also lable with product, supplier, batch, lot and date. Takes but a minute and for my needs it saves opening to see what I got.
Before you fill the containers however, check them for leaks by immersion in the sink. Fit for purpose eh? And old Tupper Ware will leak.
I don't do enough with basic coated electrodes to justify a rod oven plugged in, but for insurance I threw in a couple packs of desicant from my last box or three of crackers. Celery, lettuse or pasta containers. Got to love Tupper Ware. Next best thing in my books.

Hope it helps.

By 803056

Date 09-19-2014 13:25

A lot of people have those vacuum seal-a-meal in the kitchen cabinet collecting cob-webs. They work nicely for such an application.

I bought a seal-a-meal to package my welder performance test plates. The sealed package contains two test plates, a backing bar, and a copy of the material certs. The samples are clean, dry, identified, and no rust or contamination. I see no reason they would work for welding electrode as well. It is true the plastic can be punctured, but how often are the packages going to be handled?

As for drying rods, not a good idea for any of the rods if they have gotten wet or rusty. Low hydrogen rods; they have to be rebaked at a very high temperature once the exposure limits have been exceeded. Most people don't have the ovens for rebaking the electrodes at the proper temperature.

Best regards - Al

By Lawrence (*****)

Date 09-19-2014 14:10

Seal-a-meal !

Great thinking Al

Thank you sir.

By Milton Gravitt (***)

Date 09-19-2014 14:32

Great ideal Al, I think you may have started something. Thanks AL.

M.G.

By ssbn727 (*****)

Date 09-19-2014 15:25

I bet someone is going to show off something similar by using one of the doo-hickeys and paint it or change the cover so that anyone who take a quick look won't immediately recognize that it's actually a "Seal a Meal" machine and instead give it a ridiculous name like: "The Preserverator" or any other whacky name @ the Fab Tech convention this year... So look out for it Al. :surprised:

Respectfully,
Henry

By Plasma56 (**)

Date 09-19-2014 17:14

That is such a simplistic and practical approach to thinking out a problem that I'm left to ask the question, why isn't it in tips and tricks of the trade?
Al, It's a winner.
If a box of drinking straws comes individually wrapped, how far behind are we? Push a rock,push a rock. Eventually it moves along.
Good day to all.

By jarsanb (***)

Date 09-19-2014 17:45

We actually wrote that into standard in 2012. Great minds think alike!.......Yeah I wish

By Plasma56 (**)

Date 09-20-2014 16:14 Edited 09-21-2014 00:59

Edited- lots of me not offering my complete attention.

By ssbn727 (*****)

Date 09-21-2014 00:28

Please continue what you started describing in your last post.

By Plasma56 (**)

Date 09-21-2014 00:58

jarsanb. Gentlemen of the group. Lurkers and random readers.
Boom.Blam.Pisst.
Sounds of an explosion, rupture or leak. We want to know why. I'll tell you why. Someone is not doing something to prevent it. Respectfully.

Further to the EWI report. I'm back.

- Two of these cases required removal of many welds at an expense of over 4 million dollars, in spite of
the fact that established welding procedures were used.

I open myself up to further ridicule of course with a follow up to my previous posting which I must confess, I stand behind.

-Subsequent investigation into factors influencing the composition of weld metal from cellulosic-coated
electrodes revealed that arc length has a pronounced effect on carbon, manganese, and silicon
recovery.

I would describe the functioning operational characteristics of a SMAW cellulosic coated electrode like a thruster on a jet engine. Voltage is force present. Available voltage is dependent on the numerous variables.
   input power, power source and design, current, resistance.
-The understanding of the cruicble cup effects this application of force. (O/o)
-The moisture content is designed to aid in keep this restriction, or cruicble effect, assisting it to remain constant as the electrode is consumed.
-And the consistancy in restriction creating the cruicble cup effect does change as a result of other variables.
   - Amount of current used.
   - Ambient air temperture and humidity
   - Powersource and current used.
   - Storage conditions and exposure times.

Take the moisture away, or missplace the moisture, you got trouble. That electrode is a glorfied log, Yup...log. Dry wood burns quicker and hotter. Wet wood burns slower. Practical science.

-Subsequent investigation demonstrated that it was possible to effectively double the manganese
concentration and triple the silicon concentration when using cellulosic-coated electrodes that
have a low coating moisture content.

When I think about hydrogen being developed chemically in cellulose, that's deep man.
When I recall how the Hindenburg burn't up, how the H- bomb explodes, the rocket launches, I see a very agitatable molecule. So yes, too much agitation and you have anger and agression.

There's the voltage. The push. How do you diffuse a force, by opposition of equal or greater. In this case they use moisture in the coating from the out side inward. Bark.

-Subsequent investigation into factors influencing the composition of weld metal from cellulosic-coated
electrodes revealed that arc length has a pronounced effect on carbon, manganese, and silicon
recovery.

The rub. If you've never welded enough to "feel" the force, voltage, at the end of this electrode, you've missed out. Truly. And I'm sorry for you. It is rocket science as to why powersources have a different feel. Voltage effects dillution, heat input (expansion), cooling rates (contraction). Not failing in mentioning that these points allow the greatest effects to the molecule bonding and alignment during formations of weld deposit and HAZ changes.

Arc length effects voltage through a relationship to amperage in attempts to over come resistance during welding.
Powersource design seemingly accounts for differences in test results. No question. Reading a book or knowing the process?

With a by product of this electrodes arc combustion being hydrogen gas, a poor conductor, the allowable limits of moisture in the electrode coating creates a cruicble cupping that more completely covers the core wire core burning off from the core wire out allowing for a hotter focusing of arc energy to transfer droplets across the arc and use the hydrogen gas to heat electrode surface super hot quickly and burning up in the arc rather than mix with it and deposit acroos and into the weld pool.

The cellulosic coated electrode burns with the hydrogen gas created increasing the electrodes core wires face temperature. This higher increase in core wire face surface temperture follows with the surface shimmering rapid with an erupting movement of small droplets transfering across the arc from the electrode surface directed by the crucible cup effect of the electrode.
If the coating burns away too quickly due to a lack of moisture in the coating, or exposure allowing this to occur, then the electrons disperse more readily from the core wire surface and arc voltage is reduced. Droplet size gets bigger and larger droplet size effects composition.

- Subsequent investigation into factors influencing the composition of weld metal from cellulosic
electrodes revealed that arc length has a pronounced effect on carbon, manganese, and silicon
recovery. The increase in composition observed with variation in arc length could not explain
the extremely rich compositions observed in the cracked girth welds, however. Subsequent
investigation demonstrated that it was possible to effectively double the manganese
concentration and triple the silicon concentration when using cellulosic electrodes that have low
coating moisture contents.

What did I just say?

I like the codes. They serve to remind me to keep thinking.
AWS 5.1, A8.2.2 my copy says, Moisture itself does not cause cracking, but indifussible hydrogen that forms from the moisture in the arc can cause cracking.

- the drying process was carried out by placing the electrodes in an electrode oven for
a period of 7 days at 86°C (187°F).

That was seasoned wood.

-the re-hydration process consisted of placing the
oven-dried electrodes into a humidity cabinet for a period of 7 days at 27°C (80°F) and 80%
humidity.

Bend it around a canoe and call it a gunnel.

On the further matter of the testing procedures. Draw you own conclusions as to what the value is here? Or the results of what was done?
Some very smart young men in a room trying to come up with an idea to pass at the head of the class in my mind. A proff who's bored to tears witrying to get them to come up with origional ideas let alone a through understanding by putting forth an effort to learn,understand, apply and grow.
Shame on the system. Shame on us. What a waste of valuable resources and only mildly helpful in understanding or finding a solution to the lack of certanity on the matter.

It does allude to someone not being fully connected in the circle of understanding however.

-The voltage was held constant for the bead-on-plate welds; as a result the arc length was
automatically adjusted to maintain the set voltage. It was noted that in all cases, the arc length
was notably longer when the electrodes were in the dried condition.

I rest my case. If the arc length is notably longer is that a measured effect or a comment based on more electrode core wire showing with the loss of crucible cupping to the electrode end?

-The result is either a longer arc length when voltage is held constant, or a lower voltage
when arc-length is held constant, which is perceived as a “softer” arc by most welders.

Thats messed up. I'm really not sure what they are trying to get me the reader to grasp here. Or point they are trying to make?
The inverter power supply has a described steep volt amp curve. The result is manufactured limits to arc voltage when arc length changes? If this is understood, the difference in arc from softer to crisper would be minimal unless further amperage (arc control) is introduced.

-The changes in percentage elongation were not consistent with electrode condition. It was
expected that the dried electrodes would have lower elongation than those used in the asreceived
condition. In fact, five of the fourteen electrode/arc length combinations had better
elongation when the electrodes were dried than when they were in the as-received condition.
Similarly, rehydrating the electrodes only led to an improvement in elongation in five of the
fourteen cases. The latter is probably due, in part, to the fact that in some cases, rehydrating
the electrodes caused excessive moisture pick-up, porosity and/or hydrogen damage.

-Rehydrating led to an improvement in bend properties in many cases.
However in a significant number of cases, the bend properties were considerably worse for
those welds produced with rehydrated electrodes.

And the resulting testing for mechanical properties. Sizeable defects. Well, in perspective I'd say Boom.Blam.Pisst.

- Also, because SMAW is a manual process, it is more difficult for the
welder to maintain a 1-2 mm difference in arc length. As a consequence, it was decided that
tests should be done using a “short” (1-2 mm) arc length and a “long” (4-5 mm) arc length so
that the differences could be determined more precisely.

-The electrodes selected are listed in Table 1. The
electrodes selected were all 3.2-mm (⅛-in.) diameter.

Jefferson Encyclopedia says: ARC LENGTH
The distance from the tip of the welding electrode to
the adjacent surface of the weld pool.

I would suggest that anyone who has every reached a level of skill in welding, or chose to discover more than a superficial grasp in understanding the process, knows that arc length and maintaining it is the task.
If you see some guy pulling a medium arc by this test standards you have bigger things to concern yourself with then moisture or dryness in your rods.

I've learned or confirmed three things.
1) Cellulosic coated electrodes do require special handling conciderations to retain optimum operating characteristics, metallurgical deposts and resulting sound for purpose mechanical properties.
2) Arc voltage has again shown itself a great effect on weld quality, mechanical property developments, and metallurgical composition.
3) While a revision to the code will help this problem, education and practice goes a long way to curing it.

I'm done... almost.

jarsanb.
On the matter of great minds thinking alike, don't. Have your own ideas. Similar minds think alike.
Getting published is a release of energy. I'm about spent.
I don't share well but I like to share openly, similars mind get upset over disagreement. Part of the process. We all hope for agreement.
But I think better as a result.

Great minds probably produced this EWI effort for what ever practical use it offers the reader?
I am not selling this short on substance or effort. While alot of work went into this report, the people who's efforts to complete it could have with guidance, found themselves closer to the answers they purposed to seek? And they did demonstrate the ability to play with some neat stuff in commission of the report. Good stuff.
Understand clearly, who didn't do a good job? I don't think it was those guys.

How serious do you monitor exposure times? I Ask the question. It's shown to have an effect. The point in all of this was most don't monitor that condition. Where it evolved from a dip shake wipe and weld, too becoming a humidity cabinet 7 day sauna treatment is beyond me in scope?
Thats why education is the key, mixed with some thinking, followed by guidence for direction to explore further discoveries.
But I could be greatly mistaken I'll give you that.

If you made it this far...pat on the back.
Really...that was a long haul. For me anyways.
If your still here reading and haven't ignored my dribble, regardless of what they told you, if your in charge, and thats the last cellulosic electrode on earth and it's needed to seal the pipe line for things to flow. Don't say no because it doesn't meet code, I'll be really pissed off. Cold and pissed off.
But if it's not the last one, why take the risk in having to do the job twice? Use a fresh one.

I'm investing in packaging.

By Plasma56 (**)

Date 09-21-2014 01:10

And spell check.But I'm done.

By ssbn727 (*****)

Date 09-21-2014 06:43

No disrespect but, the posts on any of the threads in the forum are only connected because of their chronological order... However, that doesn't mean that the post before yours was meant specifically for you as I found out also many moons ago also...It's easy to get confused about who is actually responding to whom because of the order used for the posts, and how they are organized within their respective threads in here which isn't associated with the sort of model which some - if not most other forums do have written into their software...

When I read these reports, papers articles, thesis, studies, or whatever else one chooses to call them I try to focus only on the information that is relevant to the subect(s) and topic(s) being covered although I am in the habit of thoroughly reading each page from 1st letter to the last... I practice this because when I was younger, I was less patient than I currently am... I would pay dearly for my impatience by skimming through the information seeking only to find whatever it was that interested me and caught my curiosity at the time... But to read the entire paper? Oh No! I don't have the time for that! I would use that same excuse until all of the "leather on those shoes" wore out and I realized just how much I was ignoring everything else that was relevant to the entire paper... Causing me to improperly understand or rather, misunderstand the purpose of the paper, the message that the paper was attempting to express to everyone who thoroughly read it in it's entirety... To thoroughly comprehend the entire article, book, paper, study, or whatever else it was that was relevant to the subject at hand...

After this sudden realization of how I was going about it all wrong, I decided right there and then to read the entire contents of a paper, the entire chapter or two in a book - in fact, the entire book one page after the other as opposed to just skimming on the surface of the subject matter... I also decided to seek alternative publications of the same subject matter, and if there were any movies available that covered the subjects and topics I was either curious or especially interested about I would find a way to absorb & record whatever knowledge I could find inside...

The older folks in here remember when there wasn't an internet, and the only repositories available then to seek the knowledge desired was at either a local public library, or a secondary, post secondary school library or @ a community college and enrolling in night courses that covered the subject so, there was some sort of weak justification to skim through a book, or pass by what we thought was irrelevant data/information on the microfiche film, and seek only what we thought we needed at the time without realizing then just how much knowledge we were letting go by our curiosities through this sort of practice...

When the internet was first being used as an alternative for seeking knowledge and information, I was mildly interested until a colleague showed me a peek of the enormous potential it had as a vehicle that could eventually become the media of choice to seek information... And then the marketing & advertisement outfits discovered the potential for this new vehicle if you will to use in achieving both their short and long term goals of diversifying & expanding the potential to attract potentially new customer/clients attention via saturating and exploiting the world wide web... All of a sudden I got a bad feeling about the huge potential for committing cyber crimes of various forms like identity theft...

That caught my attention immediately after I recognized it and I'm glad I pursued it further... Because I took advantage of the opportunities available at the time to learn as much as I could about the internet, the software, hardware, malware, spyware, and viruses by a twist of fate in my life during that period of learning... I owe much to the friends back then who selflessly took the time and patience to teach me thoroughly about computers and the topics related to them...

Most of you already know that I had a liver transplant almost 17 years ago... Well, during the time I was on the waiting list which was about 4 years and a couple of months I had all this free time available because I couldn't work since I was disabled, immobile and generally speaking, I was slowly deteriorating inside, and around the rest of my body and in very poor health... Sort of like how things are currently although my transplanted liver is still going strong thank you Lord! This time it's totally different sort of health issues with different circumstances also...

Anywho, when I moved to Pittsburgh,PA where I was already familiar with the city because I was an NTL Boilermaker, and I worked through Local 154 at a variety of locations throughout South West Pennsylvania before I became disabled... I moved into an apartment building that was populated with mostly college students from the University of Pittsburgh's Oakland campus as well as Carnegie Mellon University...I made friends with one of them who currently is married and expecting his 1st child and lives in Brooklyn, New York... Jeff and his friends were also musicians and I just happened to be a Conga and Timbales player, a Percussionist if you will... So we jammed quite a few times, and even played @ a few gigs all over the region and had all sorts of fun doing so... As destiny or divine intervention would have it, these students were all Computer Geniuses!!! Computer wizards if you will... I knew practically nothing about computers except how to turn them on, and how to go online and only knew of a few DOS language commands which I learned from my little sister...

Jeff and my other friends make Buku money today as system administrators and troubleshooters for some of the largest computer equipment manufactures in the world and I'm not talking about PC's or Laptops oh no! I'm talking about the huge mainframe super computer manufacturers who cater to fortune 500 corporations.. Back then they were learning all they could about how these immensely complicated systems worked... Some which are much more sophisticated to learn about than what they taught me about at first which was fine by me! Still, they inevitably caught my attention and seduced my curiosity enough to learn more about them and as I type, everyday I learn a little bit more until I reach my goals to become qualified to certain certifications that would show to employers my proficiency, and thorough comprehension of the subject matter and how well I can navigate around a mainframe server... With the long term goal of becoming a computer system administrator...

In exchange, I taught them how to play the percussion instruments I previously mentioned, and how to go about getting a girls attention which was something they really were lacking in and needed to learn about in order to become successful at it.. This was the first time any of these kids were living independently, and away from their parents so I kind of acted like their long lost uncle... And wouldn't you know that the students I taught all graduated by finding the girl of their dreams, and then made the dumb mistake of marrying them also! Nah, I'm kidding! I'm really glad that they're happy building their own families and are doing well...

Although lately they don't keep in touch with me as often as they did when they first moved to NYC... Nonetheless, every month or so they call to see how I'm doing,and tell me about their latest discovery about living in the city... And they remind me about how I would describe to them how life was in the city when I grew up and then suddenly get excited, because of something I said about the city and how it turned out to be true once they discovered whatever it was I talked about when they were in school prior to relocating to NYC... These kids taught me well and I'm grateful for that entire experience... An old dog like myself can be taught new tricks as long as I'm willing to learn.

Respectfully,
Henry

By ssbn727 (*****)

Date 09-22-2014 04:47

I was going to continue adding to my last post, but I glanced at the time as I do on occasion, and realized that it was almost three in the morning! Plain and simple, it's the drugs I'm on that's keeping me awake late at night these days even though most people pass out on these drugs - go figure? Rambling? Why of course I was Brent and I'm glad you noticed because I feel more human in knowing that I can end up distracting myself as well if I don't pay enough attention to what I post, and validate my capability to write about stuff beside welding related topics also... However this is an active discussion still so I'm going to steer back into the topics pertaining with this thread...

Anywho, this is important to note about the phase two testing that was done in the EWI report with respect to the selection of welding consumables on page 14 of 66 of the .pdf...

"3.2.1 Selection of Welding Consumables
Because a higher strength level is a greater concern for hydrogen cracking, and because the majority of cracking problems which had been encountered previously had been with electrodes of the E8010-X classification, it was decided that electrodes of this classification would be used for the Phase 2 testing. The two electrodes selected were the Lincoln Shield Arc 70+ and the Hobart Pipemaster 80."

So E 6010 wasn't used in the tests that are described in the report from EWI and I'm surprised nobody noticed this unimportant, small little detail... Including myself I must admit.

Respectfully,
Henry

By kcd616

Date 09-21-2014 06:27

agreed
sincerely,
Kent

By electrode (***)

Date 09-21-2014 12:31

Plasma56,

quote:

"With a by product of this electrodes arc combustion being hydrogen gas, a poor conductor, the allowable limits of moisture in the electrode coating creates a cruicble cupping that more completely covers the core wire core burning off from the core wire out allowing for a hotter focusing of arc energy to transfer droplets across the arc and use the hydrogen gas to heat electrode surface super hot quickly and burning up in the arc rather than mix with it and deposit acroos and into the weld pool. ". Unquote.

Awesome!

By welderbrent (*****)

Date 09-21-2014 13:51

Ramble anytime. Good run of info. And I think it goes both ways but we definitely need divergence to get the whole picture. Being able to even slightly see things from another person's perspective only helps us to improve more ourselves.

He Is In Control, Have a Great Day, Brent

By jarsanb (***)

Date 09-22-2014 18:22

You've really missed the entire concept of my response (it appears to me at least), though you've grazed it a couple of times.

As a welding inspector (as far as job descriptions of companies I am familiar with go) your duties would be to make sure the quality standard has been followed and applicable procedures are followed as well. To let welders just willy nilly dunk electrodes in water is ridiculous. If this was written into a company standard then my responsibilities would be to make sure the electrodes have been dipped for the duration specified. That's all there is to it. If a company standard says to 'follow manufacturers reccomendations' on electrode storage, and Lincioln or Hobart or whoever have no mention of rehydrating in their recommendations then no rehydrating will be allowed. Yes, even if it's the last electrode on earth. My employer seems to like this approach, so it works for me. The "great minds think alike" quote was actually made in jest towards Mr. Al Moore, and more over - the respect that he brings to a conversation, even though we probably don't have similar thoughts on everything welding.

By Plasma56 (**)

Date 09-23-2014 01:16

No disrespect intended.

CWI's... Instructors, welders, can you tell me the handling chain of any cellulosic electrode useage on your job site? Duration of exposure times for cellulosic electrodes in that chain? Defect and cut out site rates? Is there a relationship? I say yes. Solution is prevention. Starts with education.

A good dish starts with fresh ingredients. Thats it. Who's ensuring freshness?

I have a great deal of respect for the tasks of a CWI in service. As well the vast knowledge they are required to learn and apply.
Sadly, there are alot more who need watching, even more who fail to see any concern and that is why we need codes to guide us. They however are not all incompassing and allow for sound judgement to be used with knowledge to guide us when required.

It's not personal. Nor ment to be disrespectful in statement. It's part of the process for change.

-If a company standard says to 'follow manufacturers reccomendations' on electrode storage, and Lincioln or Hobart or whoever have no mention of rehydrating in their recommendations then no rehydrating will be allowed.

I like the way your thinking. They also "don't" clearly say... Use in 15 to 20 minutes, 1 to two hours... or in some climates the coating will diminish in quality to cause concerns.

I mention in passing having made a statement about the last rod getting wet... it still applies.

We have expressed our thoughts. All good in my book. But all this typing made my fingers dry, I need a drink.

By kcd616

Date 09-21-2014 06:25

thank you Al
now esab has it on the banner ad :eek:

got you again, :cool:

but you got me first this time :cry:

sincerely,
Kent