The
Value of Welding Rod Ovens
When
I first started welding school about a billion years
ago we had a rod oven in the shop. Not knowing what
the heck it was, I went up to it and opened the door.
Seeing a bunch of rods of various sized diameters, I
grabbed a handful and pulled them out. Then I promptly
threw them all on the floor when I realized they were
burning the heck oughta' my hand!
That's
how I learned what a rod oven was and I got a lot of
laughs watching other new guys learn the same way I
did. Funny that although I used it for quite a while,
I had no idea why the rods were placed in the rod oven.
I figured the rod oven kept them at a certain degree
that was better for starting or something.
Finally
one day in metallurgy class the instructor informed
us rod ovens were to keep moisture out of low hydrogen
rods like 7018. 7018 rods will leave porosity (worm
holes) in the completed weld bead if they have hydrogen
present. Just like the name states, low hydrogen, it
does not tolerate hydrogen and needs to be in a rod
oven after the can is opened.
The
rod oven keeps the rods dry, or dries the rods out.
Where there is moisture, there is hydrogen, so that
is why they need to be dry.
An
urban myth as popular as just about any of the crazy
urban myths out there is that an old refrigerator makes
a good rod oven. They DON'T!
A
good rod oven is built tough, sturdy, and seals tightly.
It has temperature settings that are precise and easy
to set. An old refrigerator may be built well and even
seal well, but most of them used in the field have a
light bulb of one form or another to produce heat. This
heat is uneven and is distributed unevenly so that some
rods are heating to one temperature while others aren't.
AWS and Electrode Manufacturers specifications call
for precise temperature settings, not approximate
ones.
With
a refrigerator and light bulb there is no way to regulate
the temperature and no way to make sure it is heating
evenly. Rod ovens are built to thermally reflect evenly
and uniformly throughout the oven making sure ALL rods
are heated to the same temperature.
Ovens
built by Keen are developed by engineers, then built
to exacting standards and specifications by craftsmen
who take pride in their work and product. Rod ovens
are very reasonably priced but even more, are priceless
when it comes to the service they provide. If you are
ever unfortunate enough to have a weld rejected, you
are NOT going to sound good explaining about how your
rod oven is a beat up old refrigerator with a dang ol'
light bulb in it!
