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Posted by Alan Andrews on March 23, 2008, 2:39 pm
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Some time ago I purchased a 50# box of E7018 Hobart electrodes. I'm not a
professional welder, nor do I have occasion to do that much welding, which
means that I had an open box of low hydrogen exposed to atmospheric humidity
for quite some time, like a year.
I'm in the midst of building a custom steel fence on the front of my
residence property and some of the welding will be done with low hydrogen.
At the local welding supply I mentioned in passing the story about the
opened rods and asked if low hydrogen rods actually "got old," like I'd
heard for ever. They indicated that they did indeed degrade, such so that
they couldn't even be reconditioned in an oven.
When I got home I called Hobart and spoke with a technician who said that
once low hydrogen was exposed to the atmosphere, it immediately started
*irreversibly* degrading, and that, yes, re-drying them in an oven didn't
help. I said that that would seem to indicate that a chemical reaction had
taken place (with what I thought was rather inert inorganic material
(rutile, for instance)) and he, sorta handwavingly (if that's a word) said,
yeah.
To confuse and confound the question, I found a document on the Web from
Lincoln Electric that indicated that Lincoln E7018 could indeed be reclaimed
by drying in an oven (http://www.jflf.org/pdfs/papers/fabguide.pdf, p. 7).
So...what IS the story on storing an open quanity of 7018 for protracted
periods, in out of the weather (my garage, for instance), but nonetheless
exposed to Southern-style humidity.
Thanks,
Alan
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Posted by RoyJ on March 23, 2008, 4:03 pm
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The Lincoln "Stick Electrode Product Catalog"
http://content.lincolnelectric.com/pdfs/products/literature/c210.pdf
page 46
has this to say
<start quote>
Re-drying Low Hydrogen Electrodes
Re-drying, when done correctly, restores the electrodes’ ability to
deposit quality welds. Proper re-drying temperature depends upon the
electrode type and its condition.
One hour at the listed final temperature is satisfactory. DO NOT
dry electrodes at higher temperatures. Several hours at lower
temperatures is not equivalent to using the specified
requirements.
Electrodes of the E8018 and higher strength classifications
should be given no more than three 1-hour re-dries in the 700° -
800°F (370° - 430°C) range. This minimizes the possibility of
oxidation of alloys in the coating resulting in lower than normal
tensile or impact properties.
Any low hydrogen electrode should be discarded if excessive redrying
causes the coating to become fragile and flake or break
off while welding, or if there is a noticeable difference in handling
or arc characteristics, such as insufficient arc force.
Electrodes to be re-dried should be removed from the can and
spread out in the oven because each electrode must reach the
drying temperature.
Electrodes which have come in direct contact with water or which have
been exposed to high humidity 180° - 220°F for one hour, then 650° -
750°F for one hour.
<End quote>
That temp schedule is not achievable in a standard rod oven, hence the
comments you get from the various sources.
Should you use it? If this was a critical application, toss the rod. If
it is not a critical application, you can use your judgment about drying
the rod per the schedule, then deal with "if there is a noticeable
difference in handling or arc characteristics, such as insufficient arc
force". In most cases, the problems with lousy rod far outweigh the cost
of the rod, not to mention the cost of materials and the time to weld.
Alan Andrews wrote:
> Some time ago I purchased a 50# box of E7018 Hobart electrodes. I'm not a
> professional welder, nor do I have occasion to do that much welding, which
> means that I had an open box of low hydrogen exposed to atmospheric humidity
> for quite some time, like a year.
>
> I'm in the midst of building a custom steel fence on the front of my
> residence property and some of the welding will be done with low hydrogen.
> At the local welding supply I mentioned in passing the story about the
> opened rods and asked if low hydrogen rods actually "got old," like I'd
> heard for ever. They indicated that they did indeed degrade, such so that
> they couldn't even be reconditioned in an oven.
>
> When I got home I called Hobart and spoke with a technician who said that
> once low hydrogen was exposed to the atmosphere, it immediately started
> *irreversibly* degrading, and that, yes, re-drying them in an oven didn't
> help. I said that that would seem to indicate that a chemical reaction had
> taken place (with what I thought was rather inert inorganic material
> (rutile, for instance)) and he, sorta handwavingly (if that's a word) said,
> yeah.
>
> To confuse and confound the question, I found a document on the Web from
> Lincoln Electric that indicated that Lincoln E7018 could indeed be reclaimed
> by drying in an oven (http://www.jflf.org/pdfs/papers/fabguide.pdf, p. 7).
> So...what IS the story on storing an open quanity of 7018 for protracted
> periods, in out of the weather (my garage, for instance), but nonetheless
> exposed to Southern-style humidity.
>
> Thanks,
> Alan
>
>
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Posted by Ignoramus14119 on March 23, 2008, 8:58 pm
Please log in for more thread options Roy, would a gas fired barbeque oven work for this application, if it
could achieve 650-700F (as mine can, IIRC).
i
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Posted by RoyJ on March 23, 2008, 10:07 pm
Please log in for more thread options A decent double burner BBQ should get up to the proper temp. Regulating
it for an hour might be dicey. Lincoln was rather specific on the temps
and times. I have a type K thermocouple thermometer that reads
accurately at that temp, most folks would not have something suitable.
Another issue is that the air in the BBQ is likely to be fairly high in
moisture but no more so than any other gas fired oven.
Ignoramus14119 wrote:
> Roy, would a gas fired barbeque oven work for this application, if it
> could achieve 650-700F (as mine can, IIRC).
>
> i
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Posted by Martin H. Eastburn on March 23, 2008, 11:40 pm
Please log in for more thread options How about a timer controlled - counter oven - a convection oven or the like.
e.g. smaller than a microwave. Has temp control, nice trays, long enough,
and has a timer. Nicer than building one or buying one - pick one up
at a driveway sale!!!
I got moms after she passed and we had one so the older but nicer one went
to the shop. Nice convection oven.
Martin
Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/
Ignoramus14119 wrote:
> Roy, would a gas fired barbeque oven work for this application, if it
> could achieve 650-700F (as mine can, IIRC).
>
> i
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> professional welder, nor do I have occasion to do that much welding, which
> means that I had an open box of low hydrogen exposed to atmospheric humidity
> for quite some time, like a year.
>
> I'm in the midst of building a custom steel fence on the front of my
> residence property and some of the welding will be done with low hydrogen.
> At the local welding supply I mentioned in passing the story about the
> opened rods and asked if low hydrogen rods actually "got old," like I'd
> heard for ever. They indicated that they did indeed degrade, such so that
> they couldn't even be reconditioned in an oven.
>
> When I got home I called Hobart and spoke with a technician who said that
> once low hydrogen was exposed to the atmosphere, it immediately started
> *irreversibly* degrading, and that, yes, re-drying them in an oven didn't
> help. I said that that would seem to indicate that a chemical reaction had
> taken place (with what I thought was rather inert inorganic material
> (rutile, for instance)) and he, sorta handwavingly (if that's a word) said,
> yeah.
>
> To confuse and confound the question, I found a document on the Web from
> Lincoln Electric that indicated that Lincoln E7018 could indeed be reclaimed
> by drying in an oven (http://www.jflf.org/pdfs/papers/fabguide.pdf, p. 7).
> So...what IS the story on storing an open quanity of 7018 for protracted
> periods, in out of the weather (my garage, for instance), but nonetheless
> exposed to Southern-style humidity.
>
> Thanks,
> Alan
>
>