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

On structural steel jobs which run a combination of flux-core and stick primarily Low Hydrogen 7018, but 8018, 9018, and 11018 as well i have seen inspectors go though the job site and break the flux off electrodes left out so they won't be put into service. You can flip out and go off on the inspector but it will ruin the job going forward.

The issue as i understand it and is as stated before is hydrogen embrittlement,under bead cracking.

So its complicated but instead of turning into steam the water in the coating of the rod releases the lone hydrogen demons not being able to get out because they are now trapped under the weld and they hate being alone they go around breaking stuff.

This problem is in the root of the weld which is the foundation and special care must always be taken with the root pass. Best advise is learn how to weld hot and only use dry rod.

We often use 7018 mr (moisture resistant) which just means it can be out of the oven a little longer before being used. From a back yard sense as you weld most of the moister is cooked off and moist rod can weld a bit rough but still make serviceable welds.

"The mechanism starts with lone hydrogen atoms diffusing through the metal. At high temperatures, the elevated solubility of hydrogen allows hydrogen to diffuse into the metal (or the hydrogen can diffuse in at a low temperature, assisted by a concentration gradient). When these hydrogen atoms re-combine in minuscule voids of the metal matrix to form hydrogen molecules, they create pressure from inside the cavity they are in. This pressure can increase to levels where the metal has reduced ductility and tensile strength up to the point where it cracks open (hydrogen induced cracking, or HIC). High-strength and low-alloy steels

Hydrogen embrittlement can occur during various manufacturing operations or operational use - anywhere that the metal comes into contact with atomic or molecular hydrogen. Processes that can lead to this include cathodic protection, phosphating, pickling, and electroplating. A special case is arc welding, in which the hydrogen is released from moisture (for example in the coating of the welding electrodes; to minimize this, special low-hydrogen electrodes are used for welding high-strength steels)." wickapedia
 
Franz© said:
"but the real problem comes from the water changing state to steam just above the surface of the puddle and blowing the deposit everyplace but where you want it.
Click to expand...

That makes sense!

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sniggler said:
On structural steel jobs which run a combination of flux-core and stick primarily Low Hydrogen 7018, but 8018, 9018, and 11018 as well i have seen inspectors go though the job site and break the flux off electrodes left out so they won't be put into service. You can flip out and go off on the inspector but it will ruin the job going forward.

The issue as i understand it and is as stated before is hydrogen embrittlement,under bead cracking.

So its complicated but instead of turning into steam the water in the coating of the rod releases the lone hydrogen demons not being able to get out because they are now trapped under the weld and they hate being alone they go around breaking stuff.

This problem is in the root of the weld which is the foundation and special care must always be taken with the root pass. Best advise is learn how to weld hot and only use dry rod.

We often use 7018 mr (moisture resistant) which just means it can be out of the oven a little longer before being used. From a back yard sense as you weld most of the moister is cooked off and moist rod can weld a bit rough but still make serviceable welds.

"The mechanism starts with lone hydrogen atoms diffusing through the metal. At high temperatures, the elevated solubility of hydrogen allows hydrogen to diffuse into the metal (or the hydrogen can diffuse in at a low temperature, assisted by a concentration gradient). When these hydrogen atoms re-combine in minuscule voids of the metal matrix to form hydrogen molecules, they create pressure from inside the cavity they are in. This pressure can increase to levels where the metal has reduced ductility and tensile strength up to the point where it cracks open (hydrogen induced cracking, or HIC). High-strength and low-alloy steels

Hydrogen embrittlement can occur during various manufacturing operations or operational use - anywhere that the metal comes into contact with atomic or molecular hydrogen. Processes that can lead to this include cathodic protection, phosphating, pickling, and electroplating. A special case is arc welding, in which the hydrogen is released from moisture (for example in the coating of the welding electrodes; to minimize this, special low-hydrogen electrodes are used for welding high-strength steels)." wickapedia
Click to expand...

This is all beginning to make sense!
 
Sponge sponge sponge.. Hope this is all going in my head
 
I have seen some weldor's drying rods with a torch. Certainly not very professional, but I guess it will get you through a backyard welding job. I assume you are welding with AC/DC, since 6010 is a DC only rod. 7016 is also a low hydrogen rod, but I don't think it is used as much as 7018. I'm not sure but 7016 may be a DC only rod. I also tend to use the 7014 series rod for general purpose work and 7018 on jobs that require some impact resistance.

I don't do a lot of welding these days and do not have a drier. I keep my rods in 2 inch pvc pipe that I have cut to size and capped each end. I only take the amount I need ( a few rods at a time). My stick welder is an old Lincoln Idealarc 300 amps in AC and 250 in DC, also have a mig for the smaller jobs.
 
The 7016 is a Lo-Hydrogen rod we have used it here for welding hot dipped galvanized plates which are embedded in precast concrete for parking structures. The embeds are stainless on the decks and hot dipped galvanized on the walls you put a slug in between the embeds and make the vertical weld on either side.

7016 is the only rod I know of for code welding through galvanized coating without grinding first. It acts like 7018 with more bite, more sparks and less of a hard shell coating.

Keeping wire dry in or fresh out of a new sealed can is the way to go, for the small shop buying the ten pound cans is probably better. Inspectors are worried about what they can't see that is micro cracks in the base metal at the root of the weld (hydrogen embrittlement) from wet or damp rod welding wet steel ect...

You don't have to be on a structural welding job to institute simple best practices for welding these include, using dry rod, cleaning the joint to bright metal before welding, and preheating before welding basically 150 deg f for steel under 1 inch.

The preheat is to heat up around the weld zone so you will have more uniform cooling of a wider area after welding this reduces the stress on the weld itself as the area cools. As you get into welding thicker steels preheat and post heat become critical. Even if its just some 1/2 inch thick material you can notice that it just welds better when you warm it up with a torch.

Bob
 
OK, the Hydrogen enbrittlement is right but the cause I think got missed. An electric arc is hot... 10K degree hot. Steam is not an issue at this temperature. What actually happens is the moisture gets into the arc and the heat actually breaks the molecular bond of the hydrogen and oxygen. Now there is only a very small amount of vapor so it's not going to turn into a big roaring flame but it burns. It gives off other chemicals when mixed with the gasses created by the flux and part of the hydrogen enters the molten steel. All the while the free oxygen begins to burn the steel. Think cutting torch. And you can always tell a good cutting torch operator, he's the one that maintains the cut when the heating gas is removed. Yes, you CAN continue to oxidize the steel and continue a cut with no heating gas. Best I have ever done is about 4 inches. So since torch cutting is high speed oxidation, any oxygen (what the shielding gasses are trying to displace) are being created below the gas dome, it tends to screw up the weld a lot. 7018 rod is the one that is the MOST prone of all standard rods to draw moisture. I have heard that a welder on inspected welds will only remove a few rods from the rod oven at a time to keep them from cooling and drawing moisture from the atmosphere. I can't say it's a fact but I have heard it multiple places from multiple weldor's. (a welder is a machine, a weldor runs it and creates welds old school term). Of course with any sort of gas or other non desirable contaminate in the weld creates porosity, popping, inclusions and other issues with the weld.

Go find a largish military ammo canister... not a 50 BMG can, something for RPG's or bazooka rounds. They are about 15X15X30 and open on the end. Install a 100 watt (if you can find if not 2 60's) in the bottom and affix a plate that is well supported. Store your rods in the can in metal tubes and loosen the top and power up the lights a few hours before welding. Another thing that works well is a microwave oven that don't heat. Rip out the crap, put in a ceramic light socket and a 100 watt bulb and keep them dry and hot that way. I have saved some rods that were in bad shape doing that.
 
OH, and for the sake of knowledge. In addition to 7018's there are 8018 9018 10018 and 11018 rods.
I won a bet using 11018's once. A company I worked for had these big steam tables that had a rubber bladder pad in them.
The bladder was held down with 96 2 inch 1/4-20 bolts and nutted on the bottom. To save time they would simply chisel the heads off the bolts as opposed to unscrewing them but someone bought grade 8 bolts. About 10K of them so they were used. New chisels were made up with a 2 foot length of drill steel welded on to extend them. They broke at the weld constantly due to the forces needed to cut the heads off the fasteners and the poor welds being done. I told them I could get it done, and have the weld hold and was laughed at. After all I was the computer guy what could I know about welding. So I bet the shop guys lunch for a week that I could get it done. I beveled them, welded them with 11018 and then tempered the welds with a torch and open air cool down. The shop supervisor was ****** when he found me in his shop welding. But it was nothing compared the how mad the other guys were when the chisel held for a week. Before they would go through 3 to do one press pad. The one shop guy got so mad he put the chisel in a big press and bent it in two trying to get the weld to fail.... if finally broke 4 inches from my weld. So I welded up 4 more sets and ate cheap for a week. And the last time I talked to anyone up there, they still were using those chisels I welded up 5 years later.
 
We scrounged an old fridge and took the door light switch out so it would stay on and stashed all our welding rod in that. Here in Florida the humidity is always high so this has helped a lot.
*********Just Saying************Gator**************************************************
 
Keith Foor said:
OH, and for the sake of knowledge. In addition to 7018's there are 8018 9018 10018 and 11018 rods.
I won a bet using 11018's once. A company I worked for had these big steam tables that had a rubber bladder pad in them.
The bladder was held down with 96 2 inch 1/4-20 bolts and nutted on the bottom. To save time they would simply chisel the heads off the bolts as opposed to unscrewing them but someone bought grade 8 bolts. About 10K of them so they were used. New chisels were made up with a 2 foot length of drill steel welded on to extend them. They broke at the weld constantly due to the forces needed to cut the heads off the fasteners and the poor welds being done. I told them I could get it done, and have the weld hold and was laughed at. After all I was the computer guy what could I know about welding. So I bet the shop guys lunch for a week that I could get it done. I beveled them, welded them with 11018 and then tempered the welds with a torch and open air cool down. The shop supervisor was ****** when he found me in his shop welding. But it was nothing compared the how mad the other guys were when the chisel held for a week. Before they would go through 3 to do one press pad. The one shop guy got so mad he put the chisel in a big press and bent it in two trying to get the weld to fail.... if finally broke 4 inches from my weld. So I welded up 4 more sets and ate cheap for a week. And the last time I talked to anyone up there, they still were using those chisels I welded up 5 years later.
Click to expand...
I think if one looked up these procedures per the AmericanWelding Society , one would find that an old fridge and a light bulb do not cut it, at least for the high strength, low hydrogen rods; it takes a holding oven to keep rod dry for use, where the rod is literally too hot to handle, and after sitting out for a relatively short amount of time, requires baking out at an even higher temperature and back to the holding oven to avoid brittle welds.
 
Well not being a professional welding shop I don't recall that we ever had any of those high strength , low hdrogen rods.
Our low tech low cost method worked fine for what we did.
The poor folk got to do it the poor way.
**************Just Saying********************G********************************
 
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