7018 and Moisture

[Haywire]

I'm a little confused about what I see on the shelf at the store. I have been reading how you have to keep 7018 sealed till you're ready to use them and then keep them in a rod oven after you break the seal.

I have repeatedly seen 7018 sold in unsealed cardboard boxes. I bought a pound tonight to try, and it was in an unsealed 1lb carton from the factory.

What's the story?

Ian

 

[gwdixon]

Unless you are doing code work or live in 90% humidity it is not really a problem. For farm work it will be just fine.

Wet 7018 will weld much harder and lose the "low-hydrogen" features but otherwise it will not be an issue.

Lincoln makes a 7018 Excalibur that is supposed to be moisture resistant (expensive). I've used it and can't tell the difference from the Hobart 7018 that comes in an unsealed cardboard box. But the humidity was 11% yesterday so that may be a factor.

 

[grsthegreat]

I'm a little confused about what I see on the shelf at the store. I have been reading how you have to keep 7018 sealed till you're ready to use them and then keep them in a rod oven after you break the seal.

I have repeatedly seen 7018 sold in unsealed cardboard boxes. I bought a pound tonight to try, and it was in an unsealed 1lb carton from the factory.

What's the story?

Ian

not sure. i have always purchased mine in a 5 pound box thats always plastic wrap sealed. I do have a small rod oven in my shop. The rods go directly into the oven after i open them.

Ive never seen them in a bulk bin here at the supply houses in north idaho.

whats really scary about the 7018 rod is when you read all the safety warnings on the package...yeiks.

 

[mrmikey]

Supposed to be stored at 250F and used within 6 hours I believe, if left opened for longer rebaked at 600F once only.
You'll more than likely find no visable defects in the weld other than an occasional pinhole in the bead. The problem is underbead cracking due to hydrogen embrittlement caused by the moisture absorbed into the rod, you won't see it. Unless you're doing code work I wouldn't worry about it.
One problem you might find tho is the flux flaking off and the rod starting to fingernail.
Saying all that, mine are stored in a plastic, screw top rod contained in the garage similar to this Safetube Welding Electrode Storage Container .....Mike

 

[Shield Arc]

If you're interested in the facts, this is right out of an AWS D1.1 code book.
Low Hydrogen Electrode Storage Conditions. All electrodes having low hydrogen coverings conforming to AWS A5.1 shall be purchased in hermetically sealed containers or shall be dried for at least two hours between 450 degrees and 500 degrees before they are used. Electrodes having low hydrogen coverings conforming to AWS A5.5 shall be purchased in hermetically sealed containers or shall be dried at least one hour at temperatures between 700 degrees and 800 degrees before being used.

And here are the exposure time limitations for low hydrogen rods.
7018's are changed out every 4 hours on code jobs, 8018's every 2 hours, 9018's every hour and 10018's every 1/2 hour.

But as stated, if your not doing code work.
You wouldn't believe the structures I've built out of beams using 7018 that I had to pour the water out of the can of rod because some carpenter type left the lid to the gang box opened on a rainy day.
Wet / damp 7018 can be a PITA to run at low amps. High amp welding, I just place the rod in the electrode holder, and stick it to the base metal and let it heat up. Sometimes you can see the water boil out of the rod. But they will run better!

 

[jake98]

some carpenter type left the lid to the gang box opened on a rainy day. ....

I just place the rod in the electrode holder, and stick it to the base metal and let it heat up. Sometimes you can see the water boil out of the rod. But they will run better!

part 1: sure, blame the carpenter..

part 2: gotta love it.. :thumbsup: