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I read that 7018 will absorb moisture readily and must be kept in a sealed container, exact requirements of a max time rod can be out of the container, etc. Must this be strictly adhered to, or is this mainly for AWS requirements?
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TomK -
Once the original sealed container is opened it gets exposed to humidity and the clock start ticking until it needs to be stored in a rod oven. Going back into a sealed container does not work because you've let humidity into the container.Originally posted by Tom Kroegel View Post
The maximum exposure limit if I recall correctly is 4 hours. This can vary based on the appropriate welding code.
7018 is a low hydrogen electrode which also makes it hygroscopic. When it absorbs humidity, and you weld with it, it is no longer a low hydrogen electrode, the water the flux absorbed breaks down, and you run the risk of getting hydrogen inclusions in your weldment.
Whether or not you need to strictly adhere to having a good oven and paying attention to exposure times really depends on what you are using the rods for. Most hobby welding would not be a super great issue. If you are a shop that does work that needs to adhere to welding codes, then it's extremely important.
There will be people who may tell you to get an old refrigerator and stick a light bulb in it. That is not a rod oven. Real rod ovens are built so that they maintain AT LEAST a 250 F temp throughout the entire oven guaranteed. Some welding codes will require higher temps. If you need a rod oven bite the bullet and spend the $.
Edit: I remember another member here, who said instead of using a rod oven, he just buys small package of 7018 and doesn't open till it till it's needed, if he has a code quality job he needs to do.Last edited by moya034; 12-11-2008, 10:53 AM.Lincoln Idealarc 250
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i just watched a video at school and they said to keep 7018 in an oven between 250 and 400 degrees and never take out for than two hours worth the rod at a time...Comment
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The exposure limit is usually4 hours, but it is a good practice to take out only what you will use in 2 hours of welding time to insure that you don't have to worry about returning rods back to the oven.Originally posted by blazin454 View PostLincoln Idealarc 250
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That's a good idea until you've crawled 500ft. in 30min. in between pipes and valves and all kinds of other mess to get to the joint you need to weld. Once you get there and only have 1lb. of rods with you and you have to go back and get more it is not feasible. Might be a good idea in the welding school world. Also in my experience you can't put rods back in the oven(not saying you "can't" do it, just that it's not allowed), they just get thrown away. And if you are just practicing learning how to weld at home in spare time, there is no need to worry about storing in an oven. I've welded with rods that stayed out for 2-3 years outside an oven and they welded just fine for the task. But like you said if it is code then yes you need to worry about it, for the reasons stated.Originally posted by moya034 View PostSA-250 Diesel
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Thats why I use a heated quiver...It can take about 2 1/2 packets of rods so gets you up to the next break easily....Originally posted by delwelds View PostComment
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That would be a great idea, but I work in nuclear plants. They are really, really strict about rod's and time out of the oven. Even GTAW wire has to be thrown out at the end of a shift. Coated rods are good for only 5hrs. out of the oven then they have to be tossed. If you get caught welding with rods beyond the issue time then you have trouble with the plant manager and the NRC.Originally posted by MIKIEweld View PostSA-250 Diesel
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I hope they let you take the waste rods and electrodes home.Originally posted by delwelds View PostComment
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LOL! Ha, yeah right! They throw all that stuff away. There is too much risk and liability with having a contaminated (radiation on the rod) rod leave the premises. I'm not sure where they take them to get rid of them. I think they go through de-con. and separate the contaminated ones from the "clean" ones. I hope they donate the "clean" rods to a community college or something, but who knows...Originally posted by Timinmb View PostSA-250 Diesel
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Most likely not. I do believe they would just send them along with the rest of the low-level waste to be diposed of. They may frisk them to check for high-level contamination, but still bury them (It would be hard to de-con the flux). I saw a lot of good things permanently disposed of at Big Rock Point when they tore it down.Originally posted by delwelds View PostLast edited by Tux_Rules; 12-16-2008, 05:14 AM.Hobart Stickmate® LX 235 AC / 160 DC
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I work in the same environment as you... And heated quivers are the only way we're allowed to store rods outside of the holding oven..... And if your quiver isn't calibrated your still in trouble...LOLOriginally posted by delwelds View PostComment
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I hear you man, Really all I try to do is stay out of trouble while I'm there working! Oddly enough they don't provide us with heated quivers, we're just stuck with the plain old hard or soft leather ones.Originally posted by MIKIEweld View PostSA-250 Diesel
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well we watched another video today and it did say rods kept out for a max of 4 hours... and they could be "re-baked" but only once and i believe it was for like 9 hours or something like that...Comment
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This is true, however many jobsites will not allow the practice of rebaking the electrodes.Originally posted by blazin454 View PostLincoln Idealarc 250
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Vacuum Rod Container?
Instead of constantly running a rod oven for maintaining low hydrogen rod how about making a rod holder out of a piece of 2" pipe with end caps on both ends and drill, tap, and place a fitting onto one of the end caps for hooking up an air conditioning vacuum pump. Open your rod up out of its fresh container and then place into this rod holder. Suck out all of the air and then equalize the air pressure with an inert gas such as nitrogen. It would seem to me that you would have rod that is portable without a rod oven and is no different from the freshly opened new rod other than the time difference between transferring containers and drawing a vacuum down. No expense of burning the electricity of a constantly running rod oven. Have several of these containers with a small amount of rod in each so you can proportion your rod to the task at hand.
Has anyone else thought of doing this? Seems like a simpler solution. I just read a thread about one guy that was trying to build his concept of a mobile rod oven using his vehicles exhaust. Exhaust gas has a lot of moisture in it. Water is a by product of the combustion of hydrogen. People putting light bulbs in old refrigerators for storing rod. Some people don't have any concern about storing the rod in the open air.
What are your thoughts on this? I have yet to implement this concept.Comment
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