cellulosic "stick" & soaking rods in water

Hi everyone
Hope you don't mind going around a fairly familiar topic again. I am likely to drop out of the newgroup activity but may demonstrate
welding every now and again. So want to get my facts straight.
The topic:
Cellulosic electrodes (SMA/"stick" welding) and the effects of soaking them in water prior to use.
I believe that you get these effects from soaking your cellulosic "stick" electrodes in water prior to use:
(i) the electrode can take a higher current without charring the end portion of the rod -- for a 2.5mm (~0.100inch) rod, can go from 70A (rec'dd) to 80A
(ii) the arc becomes even more penetrative than the standard penetrative cellulosic arc -- due to high hydrogen-in-arc levels?
(iii) arc-blow is lessened -- not understood, but often the main reason weldors dip their cellulosic rods in water before welding with them
What you can achieve through dipping your cellulosic rods in water:
* deeper weld penetration. (ii) alone makes for an ability to make or demonstrate "keyholing" through thicnesses of weld-root exceding the wire diameter of the welding rod. (ii) and (iii) combined (say 80A DC with a 2.5mm rod) allows you to get full corner fusion / penetration on fillet welds even when the plates are scaled rather than ground silvery clean (for lap joints, can get corner-fusion on mill-scaled bulged-edge rolled flats)
* the arc-blow thing - keep harshly-crackling directional arc focussed to the intended position of the weld pool right to the end of weld, where otherwise arc-blow can be causing a soft undirected arc towards the end of the run.
Looking to the "on the other hand" aspect, there are no deleterious effects from having pre-soaked the rods in water prior to welding? Is this true? Are mechanical or any other properties affected? As a metallurgist, I would have thought that the water, dissociated in the arc, would deliver itself as oxygen to the weld pool and would chew into more of the deoxidisers and maybe reduce the weld carbon level, giving a slightly soften structure - but then, the shield of hydrogen is going to be even greater and all in all, you expect a sound welds averaging at some insignificantly slightly softer yield strength compared to "out of the can" rods???
For sure there will be more hydrogen in the weld, but it's a case of "in for a penny, in for a pound" with cellulosics -- if the steel is higher-strength and hydrogen-susceptible (to hydrogen cracking) you are going to need precautions like preheat whether or not you dipped your welding rods in water???
How I do it (soaking the cellulosics prior to use):
I have a "tube vase" of about 40mm dia (1~1/2inch) tube standing upright from a flat sheet base onto which it is brazed. The tube is cut to a height which just the exposes the metal top of the rod, which goes in the clamp, sticks out of the top. The tube is filled with water. I put a new rod in as I take one rod out, leaving one rod in the water for the duration of the run of one rod. The exact height allows me to keep my welding gauntlets dry (avoid getting them wet), as only have to touch the dry top of the rod. Only some cellulosic rods seem to be happy with this (Fleetwelds don't seem to like this, for instance).
Main cellulosics I have used are 6011's (because pipe-welders also use AC oil-cooled welding machines here) - "Arcos Nu5's" - which seem to be well-liked in these parts (UK).
Particular reason for asking:
I particularly want to check my facts for if I am ever demonstrating welding with cellulosics. If there is something wrong with doing these "techniques", I want to know now...
That I can get corner fusion in filler easily is one reason why one would show the "soaked cellulosic" trick. The inherent extra penetration plus the ability to use an extra 10A and still have a clean-running rod right to the stub allows a visible gouged-in corner penetration. I judge the extra 10A to be acceptable in this way -- one deduces no charring if on suddenly breaking the arc, whipping up ones visor and looking at the rod end, there is a little jet of flame (few mm) out of of rod for a second or more, plus a yellow flame like match flame rising vertically from the end of the rod for a few seconds (charring and the cellulose would already have been burned away so no flames and blackened burned end of rod is seen).
The other reason is that one would be tempted to show just how much root-face you can keyhole through with a cellulosic rod. It is some demonstration!
What I like to demonstate:
I really like the "keyholing-the-root full-thickness weld penetration" with cellulosics on a V-prep joint because it demonstrates spectacularly * effect of hydrogen on the arc characteristics * very clear use of liquid metal surface tension effects to control a weld
One would contrast these characteristics to the very limited penetrating power of other rods such as rutiles, though show their smooth top-beads.
The "welding" demonstrations are a more controlled and applied version of the demonstration where you soak a cellulosic in water and slowly push the rod through a 12mm / 1/2inch steel plate, keeping the rod burning unmoving in the same place, until the rod goes right through the plate, you slide it onwards until the arc goes out, release the clamp from the electrode then tell everyone they can lift their visors and have a look. The sight of a 1/2inch plate with a thin rod stuck right through it looking like some super-arrow is usually considered an "awesome" demonstration by class. Particular thoughts on this demonstration?
So any thoughts / knowledge / experience on this matter ?
Many thanks in advance.
Richard Smith
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Are you aware that at least some welding codes, i.e. AWS D1.1 Structural Welding Code, require that "electrodes shall be dry?"
Just what you want coming back at you. Welder from your program does this on a code job. CWI busts him for it. Boss calls you and asks what the hell are you teaching.
Your ideas on introducing hydrogen into the weld are remarkably naive. You teach welding?
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Footy - cellulosics contain cellulose in the flux. That's the woody stuff in wood. Literally, cellulosics contain things like sawdust. It breaks down in the arc and gives hydrogen. That is how cellulosics work. Sky high hydrogen. It gives them that ferocious penetrating arc. They have additional moisture in the flux. That is why Fleetwelds come in tins. Keeps the moisture IN. "use straight out of the tin". Say you are in Arizona in summer and it is a desert - you open the tin and use the elecrodes fast. Too dry and you risk porosity. That goes for rutiles (xx13's). They rely on some moisture.
The only ones you can dry - and you really can bake them dry - are basics - because they generate their own carbon dioxide sheild from the calcium carbonate (limestone) in the flux. CaCO3 -> CaO (flux) + CO2 (shield)
I know, I know - it sounds crazy - on the one hand you have drying ovens for "lo-hi" basics, while on the other you have sky-high hydrogen and that must not fall too low!
But on many welding processes you have to back-gouge the weld (never done that myself - more theory to me, 'fraid) because the root is not good without the penetrating power of the cellulosics. But use cellulosics and you may have to pay in needing preheat. "lo-hi" or cellulosic - take your pick.
Richard Smith
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Most welding engineers I have dealt with are extremely cautious and wouldn't take a chance on wet rods. A lot of steel welds will take hydrogen without catastophic failures but codes are written to be on the safe side I have often been told by so called "experts" to drive the moisture out of the plate when preheating. I have given up arguing. If someone says to use low hydrogen when it really doesn't need it I don't argue. Generally I go to 6010 if I want more digging action and if I want a milder version I select 6011. I could not see it being pracitcal to soak rods before use. It is just one more bother I don't need. I also am not big on penetration. Open roots, open roots with backing bars, or simply backgouging and welding are more idiot proof procedures. If a fillet requires more penetration at the corner then a bevel prep is the answer. Randy .

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<snip>

<snip>
Randy, probably my inability to comprehend what I read, but I am unsure if you are agreeing or disagreeing with "Open roots, open roots with backing bars, or simply backgouging and welding...". Can you elaborate a bit more? Thanks. John
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When you want your weld metal to reach completely through the joint you have several design options. For piping carrying fluids open roots are popular. Both edges of the mating pipes are bevelled and the welder has to run a weld at the bottom of the vee enough to melt both edges and allow a slight bulge of material on the inside of the pipe. This takes skill in that you can end up with grapes of solidified metal on the inside. This will disturb free flow and in the food industry be a site for bacteria to collect. For structural round piping and large structural tubing an easier joint is having the ends bevelled but one installs a ring of material on the inside. At the mating point of the two tubes a gap is left that is filled by the backing ring. The welder need only weld the edges and fuse into the ring. There are no worries about melting though. Butt joints with backing bars are common in structural steel. Often backing bars are left on if cosmetics is not a concern. Backgouging involves welding up your butt joint from one side without a concern with the quality of the root weld. The item is then turned over and the root is removed by arc air gouge, plasma gouging or grinding. After removal a good quality weld is done in the groove. Often the phrase " gouge to sound metal"is used on drawings. It infers that your first bead in the root is junk anyway and you will be removing it from the other side when you turn your weldment over. The idea of "penetration" bothers me because people think that turning up the heat or using a higher penetration electrode is the answer. The real answer is correct design of the weld joint and the weld procedure. In a pressure vessel shop welding to a nuclear code this can be volumes of worksheets and procedure sheets. At home in your garage it takes a moment to stop and scratch your head a bit before just starting to weld. If you need 100 percent penetration, bevel prep the joint then weld on the side that you cannot reach with a grinder. Grind out the other side of the joint to sound metal and weld it up. I don't disagree with people who like penetration but what is more important is proper fusion at the joint surfaces. I hope that clears it up a bit. Randy

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<snip>

real
<snip>
Randy, I think you have previously posted on this topic over the last couple of years. You were the one that helped me, as a newbie hobbiest, finally understand this point. Many thanks for your clear answers -- you are on my list of must-read posters, along with Ernie and a couple of others!
Andy
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Randy, That was a very clear and concise explanation.Do you work in the welding industry? Are you retired?

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Thanks Randy, "DDRUC612"
Continuing about stick welding technique...
As someone only a few months out in learning these skills at technical college, found that it was difficult to control the penetration side when root-running with rutiles, whereas had very wide "band of good control" when penetrating with cellulosics.
Am I missing something? Maybe I am a little over-enthusiastic having found the control of "keyholing the root" and have not been observant of ways to get a good penetration bead using other techniques? I know that running uphill with basic stick, can get controlled penetration by blowing something approaching a keyhole. Run so that can see the edges of the root face melting away in little "melt cusps" - little slightly semicircular "melts" into the plate prep-edge. Never managed to find the equivalent of this downhand.
So with rutiles (commonly used here in UK), found needed very thin root-face on V-prepped butt joint, then tended to get alternation between drop-through with "icicles" and lack-of-penetration grooves displaying the original root prep. on the under, penetration, side. Could find no tightly-controlling technique - was making a steady run at "the best conditions I could find" and accepting what I got.
So are there a range of techniques I am missing out on?
I did read the post - a good configuration where it is feasible is to have a backing ring in a tubular section and a wider "root gap", so can get in with good current at each and all edges, so the whole "penetration" business is put firmly out of the way.
But when there is no backing bar or ring? Maybe best really really avoid?
Thanks in advance - always appreciate the great answers and help that appears here on this group.
Richard Smith

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I think a cellulosic-coated electrode derives its highly penetrating forceful arc from the presence of hydrogen generated by the flux. If you pre-dry these electrodes you impair their performance and I suppose if you soaked them in water you would improve their performance.
I certainly don't like to see cellulosic rods used, particularly on pressure vessel welds, because of the risk of hydrogen cracking. However I did read somewhere that none of the defects found during the welding of the Alaskan oil pipeline were attributed to using cellulose electrodes.
From the experimentation work done by TWI, the risk of hydrogen cracking comes from damp fluxes not damp parent metal. The heat from the arc will rapidly dry the parent metal in the vicinity of the arc.
If you want to know more about pre-heat: - http://www.gowelding.com/weld/preheat/preheat.htm
Regards John

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That's what we all need on the job, co-workers soaking there rods and returning the unused rods at the end of the shift to be handed out again. Talk about a loss of controls.

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snipped-for-privacy@ntlworld.com (Richard Smith) wrote in message

I thank you all for your follow-ups.
Some of you seem deeply concerned and I have probably offended some folks' professional senses. My apologies.
If you were working on a commercial job you take cellulosic rods (xx10's) straight from a freshly-opened can and use them. No argument about that. Specifications would demand it. The customer would pay for it. There is no issue. That's what any weldor, supervisor or welding engineer insists upon.
I was thinking of "school workshop" type demonstrations. And, in general, I do get asked to demonstrate welding.
On basis of your comments, I have decided never to mention or be seen to dip cellulosic rods in water unless I am demonstrating the "pushing a 2.5mm cellulosic rod through a 13mm (1/2inch) plate of steel" demonstration. That is the power of the welding rod, but it isn't welding. Anyway, the rod will often do it "as received", without damping, anyway.
If I ever test a rod or two for actual welding, prior to a demonstration, and get the cellulosic's equivalent of "erectile dysfunction" - lazy undirectional non-crackling arc, arc-blow, weak pool formation, etc., due to rods which have been left in the open in a very dry centrally-heated atmosphere for months -- well, whether I do anything about that will remain between me and myself, and I won't mention anything I've done to restore the roaring directional arc.
And we are talking about test coupons here, not actual structures.
So thanks again.
Richard Smith
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Those responding in a negative manner evidently don't use these rods, and are confused to the point of thinking you're suggesting lohi be dipped in water before use. You see the same confusion when people post (quite often) on the internet that cellusosic rod should be stored in a oven. Those that do use these rods for a living know that a certain amount of moisture content is needed for them to function right.Thay also understand that these rods shouldn't be stored with lohi (or basic as they call them on many parts of the world). We do quite a bit of downhill pipe welding with 6010, 7010 and 8010 rods (in the U.S.) and understand the need for moisture in the rod. (We also do work that requires lohi stored according to whichever code we're working to, so we know and understand the large difference). I know several pipeliners that have been on jobs where they solved repaire rate problems by filling rod cans with water and immediatly turning the can upside down where it's left to drain overnight. But, your method of actually dipping the rod in water right before burning it strikes me as pretty radical, and like you said, not something you could do on a real job. At least in the U.S.. But, I do understand the valid reasoning behind your post and would maybe suggest you try the above mentioned method of puting some H20 back in the rods.
JTMcC.

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I have made thousands of pipe & tube pressure welds using 6010 & 7010 rods. I have never found the need to add water to the rods, even when there stored in a oven along with Lo-Hi rods. Correct joint prep, heat (amps), and even grounding will stop most rod performance related problems (finger-nailing). Cellulose rods (6010, 7010, 8010, etc.) are my rod of choice when repairing defects in workmanship (other welders bad x-rays). They provide excellent cleaning action and penetration to remove porosity, fuse non-union, and span (root) large gaps.
Welders that are proficient with these rods make awesome looking horizontal pipe & tube weld caps. These caps look like a herring bone chain, tight bead placement, just above flush, and flat.
With proper preparation & rod size joints welded with cellulose rods don't require additional moister be added to the rod flux. Experienced welders can see a changes in rod performance in rods of the same type pulled out of tool box rod pouch, oven, or new can. Fingernailing can be controlled by change rod heat (amps) or arc length.

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COLD CRACKING ANYONE??!!
Bert Newfoundland
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Want to minimise further contribution to this thread, as it is a bit wacky and has been divisive.
Cold cracking - the hydrogen level of a cellulosic is so high (about 20X that of a proper low-hydrogen welding system, such as well baked "basic" lo-hi SMA rod or solid-wire MIG), the extra percentage increase from my rather extreme treatment is not going to do that much. Only a few percent extra cracking tendency. Well, in a way I am checking whether that is for real. As hidden internal cracking is so unfortunate, you should never be this close to onset of cracking. If you could actually sail that close to cracking onset (hypothetically), you are going to be getting cracking where the plate metal is a bit colder, near flanges where the frozen-in strain is a bit higher, etc, etc.
So basically - I can see where you are coming from, but no, not really (?). If you are welding a higher-strength thicker steel in a cold (not raging desert) climate, you should be preheating the joint regardless (?) - a few extra percent hydrogen is going to make 2/10's of not a lot of difference.
I am something of a scientist who has studied this area, so what I was really trying to do is find out what the real welding folk out there do and what your experience is -- and I have learned a lot.
Believe some say dipping cellulosic rods in water limits arc-blow - and that does seem to work from my own experience and observations. That was perhaps what I was really angling at - does it cause any other harm? Is the practice forbidden?
Can I jump to a humourous note? I stylised this practice with a carefully made "tube vase" because the instructors were never quite managing to prioritise the stick-welding bay. Well, as you can imagine, when I started emerging with welds (fillet with drawn arc, V-prep butt with dragged keyholed pipe-root style welds) which looked good and passed all tests including (not!) break - when other folk started to try to copy, suddenly the instuctors very quickly found a bit of time to come by the stick-welding bay!
Sorry all; I can't help it! I am often perceived as someone who gets mischievous horns sprouting out of my head every now and again.
well...
Thanks to all and best wishes
Richard Smith
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