Well, the problems I was having were all thermodynamic in nature.? My little 500 BTU per hour water chiller simply could not take out the 6000 BTU's / hr that the diff pumps were putting into the water loop.? When I switched back to flowing 75 deg F tap water at about a gallon per minute once thru the diff pump water jackets and dump to the ground the problems went away.? I am now dedicating the little chiller to the vapor traps so they are running at like 55 deg F.? I can now run the diff pumps for the 3 hrs it takes to get the chamber down to aluminizing vacuum levels. ? ??
I am noticing that if I heat the tungsten coils slowly that the aluminum candy canes fall off the coils much more often.? When I heat the coils fast the aluminum canes melt in about 5 seconds and wick onto the tungsten as they should.? Not sure how to fix this.? For now, I will heat the coils fast and pay the price of some tungsten oxide getting driven off the coils before the aluminum.?
Drew in sunny Florida
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On Mon, Sep 26, 2011 at 11:11 PM, SVC
<donmattox@...> wrote:
?
When heating tungsten filaments to
evaporate aluminum the first thing that is vaporized is the tungsten
oxide. This is why you either need to strip the oxide off
(electropolising or by chemical cleaning using an oxidizing agent)
before heating or you should use a shutter (closed while premelting
the aluminum on the tungsten).? The aluminum will melt and wet
the tungsten at temperatures way below what is needed to evaporate the
aluminum. When the temperature is increased the aluminum will
evaporate Then open the shutter).? Don
