how do you store your welding rods (7018)

[BeezFun]

When I've finished welding, can I simply return unused rods to the air tight container until next time, or will that "spoil" the others, so should I be putting them in an oven first ?

I can give you a data point for RG45 rod. I tried keeping it in an airtight container and after one year it was covered with so much corrosion I couldn't use it. Our weather here is very hot and humid in summer and really cold in winter. So I think think the problem is that when I open the container, moist air gets in. And then when the temperature changes the moist air can't get out of the container, so it condenses on the rods and they corrode. I've solved my problem by putting desiccant in the airtight container, and trying to be careful when and where I open it. In the hot humid summer, I go into the air conditioning where the air is relatively dry to open the container, take out a rod, then close it up. In the winter, I make sure I don't open the container unless the air is colder than the rods.

I think you have an added complication with electrodes because the flux absorbs water when it's out in the air and acts like a sponge, and if you put it back in an airtight container, it releases that moisture to the drier air and raises the humidity in the container. So I think you're on the right track about drying them out before putting them back in the container.

 

[MinnesotaDaveChalmers]

7018 flux does not actually absorb moisture like a sponge, is chemically bonds with it.

Here is what an ESAB manual says:
Lesson 4 - Covered Electrodes for Welding Low Alloy Steels
"4.2.0.1 When hydrogen bearing compounds such as water, minerals, or chemicals are present in the electrode coating, as is common with mild steel electrodes, the chemically combined hydrogen is dissociated into atomic hydrogen by the heat of the welding arc."

As a result, 7018 rods begin picking up moisture as soon as they are opened. Placing them in a plastic container will not protect them from this.
Only storing them in a heated container will eliminate the water pick-up since their won't be any in the air.
The only way to re-condition them is with very high heat. 500-800 degrees depending where you read it.

Some are able to be out for up to 8hrs, others only 4hrs. It says in their product literature.
(seems like some were a little longer than 8hrs)

For the vast majority of home use, none of this will matter

...and I am no expert on the subject...

 

[bigdeano]

7018AC<<<The AC is half the problem, I've had the same the trouble with those, I wont use them no more. It's not really a low hydrogen rod, 7018 DC rod is a better/stronger rod, you wont get no porosity with those but you need a DC welder.

Wish I'd known this before I bought them. I started burning the first inch off on a piece of scrap and they seem to work pretty good, but not perfect. Actually I use 7014 most of the time, no worries about moisture with them here in the soggy NW.

 

[Shield Arc]

I am no expert on the subject...

Your knowledge of welding, always amazes me! :thumbsup::thumbsup:

 

[bigtiller]

Will a frost free refrigerator be a good place to store welding rods ?

 

[jack707]

AC has a unstable arc that's why I bought a dc welder

 

[BeezFun]

7018 flux does not actually absorb moisture like a sponge, is chemically bonds with it.

Here is what an ESAB manual says:
Lesson 4 - Covered Electrodes for Welding Low Alloy Steels
"4.2.0.1 When hydrogen bearing compounds such as water, minerals, or chemicals are present in the electrode coating, as is common with mild steel electrodes, the chemically combined hydrogen is dissociated into atomic hydrogen by the heat of the welding arc."

I believe what that statement is saying is that the heat of the arc separates hydrogen that is chemically bonded to other materials, like the oxygen in water. It's not saying that the water chemically bonds with the flux. So in the case of water, it takes about 3600F to separate the hydrogen from oxygen in water molecules, well within the conditions in an arc. It's the release of the atomic hydrogen that causes the problems in the weld.

For the vast majority of home use, none of this will matter

Totally agree

 

[MinnesotaDaveChalmers]

I believe what that statement is saying is that the heat of the arc separates hydrogen that is chemically bonded to other materials, like the oxygen in water. It's not saying that the water chemically bonds with the flux. So in the case of water, it takes about 3600F to separate the hydrogen from oxygen in water molecules, well within the conditions in an arc. It's the release of the atomic hydrogen that causes the problems in the weld.

I believe I've combined 2 concepts inappropriately and should have kept the 2 ideas separate.

This is the link I should have posted in reference to flux and moisture.

From the AWS Welding journal:
"[snip]Hydrogen.The source of hydrogen is the moisture retained within the electrode coating. Baking of electrodes to ensure the moisture is removed prior to welding is essential. Other potential sources of hydrogen involve paint and grease and failure to remove moisture from the weld area prior to welding.[snip]"

My take on the concept is that if the coating only absorbed moisture like a sponge, it would not take such high temperatures to get it out of the flux. Only boiling temps would be needed.

Since they are using 500-800 degrees to release the moisture (prior to welding), that would seem to indicate something else is occurring - other than simple absorption.

The chemical bonds breaking so that atomic hydrogen can get into the weld is another separate concept though right?

 

[MinnesotaDaveChalmers]

Your knowledge of welding, always amazes me! :thumbsup::thumbsup:

Right back at you naturally :thumbsup:

But as you know, I'm a part-timer and there are so many people with more knowledge and experience than me. Bunch of the weldingweb crew come to mind.

 

[BeezFun]

But my take on the concept is that if the coating only absorbed moisture like a sponge, it would not take such high temperatures to get it out of the flux. Only boiling temps would be needed. Since they are using 500-800 degrees to release the moisture (prior to welding), that would seem to indicate something else is occurring - other than simple absorption.

There are two reasons I can think of that ovens are maintained at higher temps. One is to vaporize light oils, like WD40, kerosene and diesel, which usually boil at about 400-500F. The other is to heat up the large masses of welding rods that get put in there as quickly as possible. If the oven were at 250F, it might take 8 hours to get 50# of rods to 250F. If the oven is at 500F, it only takes a few hours to get the rods to 250F. If water were the only contaminant in the rods, and no one was in a hurry, the oven could be kept at the boiling point of water.

The chemical bonds breaking so that atomic hydrogen can get into the weld is another separate concept though right?

Yes, and chemical bonds take a large amount of energy to break, like the temperatures in a welding arc, or the UV radiation it emits. Chemical bonds are also interesting for welders because UV radiation has enough energy to break the chemical bonds in DNA molecules, and the mutations from that broken DNA is what leads to cancer. Lower energy radiation, like microwaves, TV, cell phones etc don't have enough energy to break the chemical bonds in DNA, and that's why they can't cause cancer.