On Jun 24, 9:20*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
cavedweller fired this volley in news:533a8fc7-
:

The traditional way to determine moisture content is to weigh the
item. ÿThen heat the item to about 250 degrees for an hour or so.
Then reweigh the item. ÿThe reduction in weight will be because the
water has been driven out of the item.

Dan

Is there any way he could build a scale accurate enough to weigh the?
Why?

First of all, the method recommended doesn't even come close to assaying
the percentage of moisture contained in the flux. *It measures the amount
of moisture lost from drying, yes. *But when you compare that against the
total weight of the rods, it's an almost meaninglessly small percentage. *
The wire doesn't absorb moisture, only the flux coating. *In addition,
some coatings (like iron particle or iron oxide-based fluxes) absorb
water and oxygen, and permanently bind them up in the form of corrosion
of the particles -- so the method won't work for them, at all.

Wet-weight/Dry-weight comparisons are only accurate for materials not
sullied by an extreme offset in weight of some more dense component.

You could weigh a wet then dry bag of (say) cornmeal and determine the
percentage of moisture. *But you couldn't weigh a semi with ten bags of
wet cornmeal of unknown weight, then dry them and weigh the whole rig
again and come up with anything meaningful.

So... with welding rods... the ONLY way to know how much moisture they
have in them is to KEEP them dry at all times in a rod oven, and not ever
allow them to absorb moisture -- or you may ruin them permanently.

LLoyd

I was not seriously recommending that he actually measure the moisture
content. If he did the next question would be how much moisture makes
them unusable. And that of course depends on whether he is welding
high strength steel where hydrogen is a problem. He never did say
what kind of electrode he was concerned about or what he was thinking
of welding.

But if you want the moisture content, weighing , heating, and
reweighing would be the first thing I would try.

Dan