Degassing & Minimalist Plaster...
Part 1...
These 3 (three) pictures are the latest in my various attempts at developing some consistency in the LFMC process.
The plaster has been cut back to the absolute minimum, filling just the areas that have been machined out on the mill and skimmed flat.
The high density of the NOW compacted sand has virtually eliminated any surface finish issues, but excessive venting of steam from damp plaster hopefully will be also aided with this approach.
This White blob is a slightly used Chlorine pool puck that I found out in our garden shed.
After much advice, via the RCM group, the basic idea is to try and reduce some of the pitting that I've experienced by introducing a "Degassing" agent in the form of Chlorine into the melted pot before the pour.
This is the business end of a 32" length of Stainless Steel rod (1/16" walled) 9/16th inner diameter.
The flat was hammered down to help contain the chlorine gas within the molten metal, while a series of small holes are drilled around the end to allow the gases to bubble up through the melt.
The idea is that the Chlorine gas will bond to any hydrogen in the melt forming Hydrogen Chloride (??? correct me as always ...) as it bubbles up through the pot.
"Honest Officer, I'm going to a pool party, it's just chlorine, Man..."
These are the depth charges for the 6 pots of metal I'll be melting...
Each little twister is inserted into the tube, and the tube is inserted into the melt and gently swirled about at the bottom of the pot...
I've been STRONGLY advised to stay upwind of the HCL gas as it's corrosive.
I intend to wear a respirator along with the Face shield, just in case. I know some would say, "come-on, don't be such a baby, take your Hydrogen Chloride like a man!!!" But I fear I've already damaged my lungs enough.
It's Dec 20th 2004, 5:30A.M the dawn is slowly brightening the sky... Man is it ever cold out. The botched photo of the Thermometer is reading -29C, with the wind chill a face searing -44C.
Here is the burner, thawing out in the pattern shop after several hours of non-ignition.
It is so cold that the diesel is noticeably thickened to the viscosity of motor oil, and any water has crystallized and is getting impacted in the nozzle.
If I could just have gotten it lit for a few minutes I'm sure it would have become self sustaining as the water crystals would have melted once the burner was hot...
But not today...
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