Why are damp/wet welding electrodes impossible to weld with?

Uglydog

Uglydog

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Lately we've had a lot of rain in MN, humidity is up (please no comments about what the humidity does to my hair).
I've been doing a lot more arc/stick/SMAW than usual. Thus, have a lot of rod around (6010/6011/7018).
Yes, I've got a lot of spatter and porosity.
I bought a used rod oven, cheaper than I could put a light bulb in an old dorm refrigerator.

My Question is: why does a little bit of moisture cause such a huge problem?

A casual search of the internet produced many suggestions for drying and keeping rods dry. But, no explanation for the reason it is impossible to get a decent weld out of damp/wet rods.

Is this some sort of inorganic chemistry puzzle?
Should you choose to respond, please make any reference to the periodic table comprehensible.
 
I would guess the moisture interferes with the chemicals used in coating the rods, or makes them less functional. Also, the coating becomes loose (at least mine do if too moist) and flakes or chips easily. Again, I'm guess this would effect the ability to get a good weld.

Now we'll wait for a real welder to chime in - I may be all wet..........
 
The problem with damp rod is that it causes hydrogen embrittlement of the weld, causing cracking; the 7018 rod is especially important to keep dry. In shops doing sensitive welding jobs, only enough rod to "burn" is doled out to weldors so it can be used up before it can take up moisture. A light bulb in a refrigerator is not hot enough to dry out rod.
 
Not a "real welder" and I can't spell "comprehensible" but this has always been my understanding. First what does the coating do? It burns and creates a carbon dioxide (mostly used on steel stick electrodes) gas shield or bubble that excludes oxygen, nitrogen and water vapor to protect the arc and the molten metal at the electrode tip. If the rod is wet it produces water vapor in the shielding gas thus dispersing the arc and imediately coroding the molten metal.
 
benmychree said:
The problem with damp rod is that it causes hydrogen embrittlement of the weld, causing cracking; the 7018 rod is especially important to keep dry. In shops doing sensitive welding jobs, only enough rod to "burn" is doled out to weldors so it can be used up before it can take up moisture. A light bulb in a refrigerator is not hot enough to dry out rod.
Click to expand...

"hydrogen embrittlement"

I believe you with out question.
But, what does "hydrogen embrittlement" mean?
Why is 7018 more susceptible than 6010?
Sounds like something my Welding Instructor would have said.

Thank you for the prompt response.
But, why does this happen?
 
Hydrogen Embrittlement is more of an issue with higher alloy and strength steels like HY 80 and 120 and the like... It's also known as delay cracking, because it occurs well after the weld is completed and in service. Another name for it is under bead cracking because it tends to happen directly under the weld in the base metal, hidden from visual inspection. The underlying effects are still being debated by people well above our collective pay scales, but it has to do with the hydrogen moving around after the weld and causing general chaos on an atomic scale.
As to why damp electrodes cause problems like spatter it has to do with what was mentioned above, generation of more gases than the flux can handle.
the 70 series rods use a flux that is similar to cement, roughly speaking, and its not very tolerant. The slag does most of the shielding work with the 70 series.
60 series rods, especially 6010/11, use a cellulose coating almost like a type of paper or cardboard and actually need a moisture content to burn right, somewhere around 10% by weight(?). Shielding for the molten metal comes more from the gas generated than the slag, which is too thin and fluid to keep the atmosphere away. I've seen (and bought a pack for fun) of rods that were made for cutting and chamfering which turned out to be 6010 rods that had around 30-50% moisture in the flux, much more forceful arc that would tear through plates instead of welding them. Cutting torch did a much better job but if you were in a pinch it might work....
 
DON'T USE THIS METHOD FOR CERTIFIED WORK!!!!!!

you can bring back rods that are dampened by putting them into a 350*F oven for an hour or so- if the rods aren't soaking wet.
do not attempt with 7018, it is a low hydrogen rod you would be defeating the purpose, unless you are in a real pinch ...

a method i learned as a youngster was to fire up the welder and short circuit a damp rod for 20 seconds or so or until you see the moisture evaporate or smell burning.
i did some hack welding on trailer ramps with some dampened 6011 this way, the trailer ramps are still together 20 years later.
 
So, who welds with anything but MIG anyway? I have not used stick rod for years! (and), as there is no flux on mig wire to cause the problem by taking up moisture --- I realize that I am perhaps oversymplifing this, but, ------ I rest my case.
 
The only welder that I have, besides oxy/act, is a stick welder. Easy, cheap, no consumables besides rods. KISS. And it just works.

-Cody
 
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