I had to dump the trans-hydraulic oil out of a tractor today. Its
contaminated with water. I've always just replaced it before, but the
price of oil has went nuts. And I'm a bit short right now.
I'm wondering about putting it in a metal bucket on a hot plate out in
the field. If you heat it to say 200, will it drive the water off?
Ah, a challenge. <g> Ok, the single-burner Coleman is going now, under a
3-lb. steel coffee can with 1/4" of water and a half-quart of cheap motor
oil...it's sounding like popcorn. POP! There it goes. 'Just sprayed oil all
over the plywood scrap I use for mixing small batches of concrete.
It better not be ruined, or I'll be annoyed -- at both of us. d8-)
Try it, Iggy. Now, if you're going to say that Karl can control the temp to
200 F, my response is, good luck. But stand back.
Well, I'm not putting a meat thermometer in there, but it went off pretty
damned quick. There are two sides to this but I'm not going to do the
physics. One is that the oil is putting a modest pressure on the free water,
and probably is raising its boiling temperature. The other is that the vapor
pressure of the heated water (vapor) may not have to be that high to form a
pretty violent bubble -- possibly below boiling temp at atmospheric
pressure. I'll leave that question to the physics people.
But the oil apparently does put some pressure on the vapor, which is why,
I'm guessing, it pops up violently when it reaches the oil's surface.
(That was my can for cleaning bicycle chains in kerosene. It better not be
About the hydraulic oil: We may have better living through chemistry today,
but when I had to deal with it, maybe 40 years ago, you had two choices. You
could have anti-foaming, or you could have water-emulsifying. But you
couldn't have both. The chemistries for those two features were not
So I didn't automatically assume that Karl had an emulsifying oil.
On Mon, 30 May 2011 20:57:26 -0500, Ignoramus17069
At 215F at sea level water is vapour. At 210 it's just hot water.
Somewhere in between there the water trapped under the oil approaches
it's "local" boiling point and starts rizing to the surface - and the
localized pressure reduces, causing the water to "flash" to steam.
When this happens it expands exponentially - something like 1700:1 -
blowing hot oil all over the place.
This is bad enough on an enclosed element - it is EXTREMELY DANGEROUS
when working with an open flame, as the splashing oil can easily
ignite, and the possibility of igniting the whole pot of oil, although
not terribly high, IS REAL.
Well, yes, I used to do that. This was a lot more violent -- a big POP! and
oil sprayed a fair distance.
As I said, I've done that before. I think the last time was when I was
around 20 and got the bright idea that I could dry the water out of an oil
can I'd left open outdoors. I put it on my dad's new gas grill to heat it;
'wound up running off to buy some more of those lava rocks before he got
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