email@example.com (Vernon Tuck) wrote in news: firstname.lastname@example.org:
Hello Vernon, Store your 7018 electrodes in the oven, since you have one, you might as will make use of it. Heat tomb em' Cut yourself some lengths of PVC pipe to the electrode lengths you use in the other electrode types you like to make use of. I have several 2",
1", and 3/4" PVC pipes that I have put the PVC end caps on the ends to make storage containers. I can carry these around with me in my back pocket, lay them where I'm working, etc. The key is to keep electrodes sealed from the air. Do not leave the containers open for longer than it takes to remove what you need to use in the moment. You can make larger sized ones for storing larger volumes. "Hone" the ends of the pipe with a light grit sandpaper, this allows for a better seal and easier removal of the PVC pipe caps. 6011/6010 electrodes like a little moister, I think it's something like 3-5%. Bottom line, just seal them in a container of this type when removing them from the factory container. If you do so, all will be good. You can do the same with the other SMAW electrodes as will. Just remember you do not want to leave electrodes exposed, as they will pick up moister from the "air". If they are sealed off from it, your ok. Your not going to be welding on any nuclear vessels soon, right? This will certainly suffice then. Take care.
You can buy big, like 5lb boxes of silica sand at a pet store. It's the same stuff that comes in electronics boxes in those little packets that say "Silica Gel DO NOT EAT" It absorbs a heck of a lot more moisture than rice and when it gets old, you toss it in the microwave for a couple minutes and it's good to use again.
It's sold as "Silica cat litter" and looks like road salt....not the grey clay stuff. It usually comes in a clear plastic jug...bout $10 cdn for 5 lbs.
probably wouldn't want it loose with your rods, but you could fill a couple film canisters or something and poke holes in the lids. Drop them in you rod tubes, and seal them up.
"Paul Keating" wrote in news: email@example.com:
Paul & Easton,
I guess you guys are addressing the moister content that would be captured in the container itself, upon opening and closing the container. I think your thoughts in these regards are a thoughtful one. The only place I see upon using this idea, that may create a problem, is the cellulose fluxed rods (6011/6010, etc.), where it may "take away" the moister that is needed in these rods for optimum "performance", as it may draw off the needed moister in these type rods.(don't know myself, haven't tried it, just making an observation) If these type of rods are either of poor quality, or the moister content is not right, you can tell fairly easily by striking up an arc with the rod. There should be a slight convex to the electrode end, and the flux should be tight right up to the edge of the balled end. If there is any chipping, or the electrode is bared up past the edge of the convex ball much, or the flux is fraying/swelled out on the end, something is wrong in these regards. Also if the flux is very brittle at the end. Some peoples aggravation, in striking an arc with these rods can many times be related to this problem.(improper moister content) If the flux is missing or frayed away at the electrode end, your essentially trying to strike an arc with a "bare" piece of wire. The proper moister content has a large play in these regards in the cellulose type elecrodes. These electrodes if the moister content is right, can be bent/bowed/radiused to weld in confined areas etc. If the moister content is not right, the flux will break away when trying to do this.
I beg to differ on the Silica Sand is equal to Silica Gel. Sand is pure SiO2 and doesn't have other complex rocks like Granite crushed up.... The gel is a dry and hydroscopic 'jelly'. The Gel is typically round but can be crushed.
I have bags of both kind. The sand is heavy stuff. The gel is like Jell-O!
Desiccare, Inc of Richland Mississippi is one maker - MIL-D-3464 Type I & II Once moist, reactivate 16 hours at 245 F
Nomenclature: Desiccant, activated gagged, packaging use and static dehumidification.
Then excuse my misuse of the term "sand". The stuff I was referring to then I suppose, is silica gel, specifically sold as a dessicant/hydroscopic media....it's sole intent, as marketed, is to absorb cat urine. I, and several aquaintances use jugs of the (clean) stuff in chest freezers to prevent condensation when the freezer is run above freezing (as a kegerator.) It does the job VERY well.
FYI The "official" listing of the electrode storage and drying requirements, as taken from the AWS specification A5.1 ("Specification for Carbon Steel Electrodes for Shielded Metal Arc Welding", Table A2 in the appendix). This information is extracted from this reference but is not an exact copy since I did not want to take the extra time to reproduce the table. I also left out some electrode types that are not commonly used.
E6010 and E6011 (i.e. cellulosic types): Store at ambient temperature, holding ovens are not recommended, drying is not recommended
E6012, E6013, E7014, E7024: Store at 60-100 deg F with maximum 50% relative humidity, holding oven to be 20-40 deg F above ambient temperature, drying can be done at 1 hour at 275 deg F
E7016, E7018 (i.e. low hydrogen types): Storage in ambient conditions is NOT recommended, holding oven should be 50-250 deg F above ambient, drying can be done at 1-2 hours at
500-800 deg F.
My additional comments are as follows: Ernie and others are correct about the E6010 (cellulosic) electrodes. They are designed to have some moisture in the flux coating, typically about 5%. The moisture (i.e. water) is what gives these electrodes their deep penetration characteristic. The water molecules disassociate in the arc producing hydrogen. The hydrogen alters the arc physics so that the arc column constricts, thus, increasing the energy density which produces the increased penetration. You can't see the arc physics effects going on but you can see the increased penetration by the arc digging into the base metal.
The E7018 low hydrogen electrodes are designed to have extremely low moisture content (it can vary but it is typically 0.2% or less out of the manufacturers can or out of the drying oven). The low hydrogen characteristic is desired because of weld cracking considerations. (Yes, this type of hydrogen delayed cracking does actually happen, but normally on thicker material and higher strength material.) However, for "hobby shop" welding, this type of cracking is not normally a problem. Without proper storage (i.e. holding oven), the E7018 electrodes will still run OK, they just won't be "low hydrogen" anymore. Eventually, the flux coating can absorb so much moisture that it begins to degrade, but this can be a long time (months rather than days or weeks).
Let me know if anyone has questions on other electrode types (low alloy or stainless steel).
Your info sounds spot-on, as best as I can say given my lack of real in-depth experience.
I have worked on welding and welding consumables in scientific development.
This is what I believe to be the case:
Of "stick" welding, only basics can be low hydrogen, as cellulosics and rutiles as stick-welding rods need moisture.
The same doesn't apply to flux-cored-wire MIG, because the shielding gas shields and the flux fluxes. The flux does its electric stuff, alloying / microstructural refinement and weld-pool control. Basic and rutile FCW can be / are both low hydrogen. There's no "cellulosic FCW" that I have ever heard of. It would be a bit irrational. You can switch to uphill welding techniques using rutile FCW where flux weld-pool control and good properties allows you to lay very full beads of beautiful shape and smoothness with easy slag detachment, so you save time on not having to dress the welds - and not having to preheat anything like as much (if at all?) due to low hydrogen.
They need some moisture content. I gather cellulosics (xx10's) come in a metal tin *to keep the moisture in*. On a welding site such as pipeline welding you would use-up the rods quickly so retention of the water after opening the tin is not usually an issue in commercial practice. Hydrogen is provided by the cellulose, but more is better if you have decided to go down this route of having a very penetrative welding rod giving a fast-freezing weld, at the cost of having to deal with avoidance-of-hydrogen-cracking issues in serious applications like 1inch/25mm thick pipes a metre in diameter, or the like. Cellulosics are only encountered as "stick"/SMA/MMA welding rods.
BTW - you can *hear* the "arc physics" at work. Compared to the gentle cracking of basics and the moderate hiss of rutiles, cellulosics sound like they should generate enough jet thrust to blast you backwards (they don't do anything of the kind, of course - it's just the sound). Plus the arc voltage goes higher, so you get more heat for the same current. 70A on a 2.5mm cellulosic would be quite penetrative indeed, where 70A on a 2.5mm rutile would make for quite gentle welding.
They don't generate (much of?) a shielding gas, so need moisture in the flux. Some hydrogen is much much much preferable to nitrogen from the atmosphere getting into the weld and producing very brittle welds.
They shield by the dissociation of calcium carbonate in the flux into calcium oxide and carbon dioxide - so they do develop a shield of CO2 gas and don't need moisture in the slag. The ingredients of the flux are very thermally stable so you go right ahead and bake the moisture / hydrogen level down to a very low level indeed. You can weld thick sections of strong steel with manageable to zero preheat. Mechanical properties are good
additional point - mech. properties*
rutile stick gives inclusions which look the size of dinner plates when you look down a microscope. They'd act as dangerous stress-raisers if the weld metal were strong, so you deliberately leave it with a very low strength and consequently easy ductility.
The same doesn't apply to rutile FCW, and I can't remember why, hard as I try. It gives very fine inclusions which are actually microstructurally useful for pinning grain-size to a fine (tough) size plus triggers nucleation of tough very fine intragranular microstructures. So you can have a high strength weld metal. Strong and adequately tough at Arctic temperatures.
So rutile stick and rutile FCW-MIG are very different creatures.
Diffusable Hydrogen in the weld metal of a multiple pass weld on heavy wall pipe, typically done with 70+, an 8010 rod, is really pretty low. Because of diffusion during the multiple pass procedure. Similar to the hydrogen level of a single bead of a LoHi rod. Still more than if the weld was made with LoHi, but quite low nonetheless.