Electrodes

By Lawrence (*****)

Date 04-10-2014 12:37

You did not say which code/specification you are working to so I'll just assume it's D1.1

5.3.2.1 Low-Hydrogen Electrode Storage Conditions.
All electrodes having low-hydrogen coverings conforming
to AWS A5.1 and AWS A5.5 shall be purchased
in hermetically sealed containers or shall be baked by the
user in conformance with 5.3.2.4 prior to use. Immediately
after opening the hermetically sealed container,
electrodes shall be stored in ovens held at a temperature
of at least 250°F [120°C]. Electrodes shall be rebaked no
more than once. Electrodes that have been wet shall not
be used

By WTIS Date 04-10-2014 12:54

Yes D 1.1 I read that and 5.3.22 What I'm not clear about is how long they must stay in the oven immediately after opening the container. Table 5.1 shows that they can be exposed for 4 hours max, but is that after they have been initially put in the oven or after the can is open?

By SCOTTN

Date 04-10-2014 13:58

7018 low hydrogen electrodes in hermetically sealed containers may be initially used without any preconditioning. That is, they need not be heated before use. Electrodes in unopened, hermetically sealed containers should remain dry for extended periods of time under good storage conditions. Once the hermetically sealed container is opened, the electrodes are exposed to the atmosphere and begin to pick up moisture. Once opened, they should be placed in a holding oven to minimize or preclude the pickup of moisture from the atmosphere. I would just take out up to four hours worth of rods when you open the container and immediately store the remainder in a rod oven with a temperature of at least 250°F.

By WTIS Date 04-10-2014 14:24

Thanks, that's how I interrupted it. What's confusing is the wording in 5.3.2.2 It says Electrodes exposed to the atmosphere for periods "less" than those allowed by Column A, Table 5.1 "may be returned" to the holding oven... That implies that they were originally placed in the oven.

By 357max

Date 04-10-2014 13:58

7018 may be purchased in card board boxes (nit hermetically sealed) and per their manufacturer they are not Low Hydrogen until they are BAKED. Note Low Hydrogen ~ D1.1:2010 Commentary C-5.3.2.1. Also note Annex I ~ I6.2 Hydrogen Control Method. H1 Extra-Low Hydrogen, H2 Low Hydrogen & H3 Hydrogen Not Controlled

By SCOTTN

Date 04-10-2014 17:38

WTIS,

My interpretation of 5.3.2.3 is that your referenced "may be returned" to the holding oven, applies to electrodes that are originally placed in the oven immediately after the container is opened, as well as electrodes that were already in the oven prior to the purchase of more electrodes, i.e., a specific number of those electrodes are removed from the oven. If, at close to the 4 hour mark, not all of them are used, the remainder are placed back into the oven, on a different, designated shelf, or an entirely separate oven. Years ago part of my job was to sign out and collect electrodes. We had two ovens. One day, I would issue rods from oven 1 and put any unused/returned rods in oven 2. The next day I would issue rods from oven 2 and put any unused/returned rods in oven 1. If a welder was issued say, 24 rods, at the 4 hour mark, he'd better turn in 24 stubs or a combination of unused rods and stubs that totaled 24.

never put them in the same oven I removed them from that day.