🚀 go-pugleaf

-From: dietz@cs.rochester.edu (Paul Dietz)
-Subject: Re: Aluminum as rocket fuel?
-Date: 1 Jan 93 14:54:12 GMT
-Organization: University of Rochester

-In article <19077@mindlink.bc.ca> Nick_Janow@mindlink.bc.ca (Nick Janow) writes:
-> It could be mixed with oxygen,
-> since molten aluminum forms an oxide slag cover.

-Does it?  Aluminum oxide is more dense than aluminum metal (spec. gravity
-of 4 vs. 2.7 g/cc.)

I used to set up little blast furnaces in the back yard and melt aluminum.
I can assure you that molten aluminum very quickly forms an oxide skin -
it takes about a second or two, if I recall correctly. The surface layer
very gradually gets thicker over time after that. I don't recall any
indication that the oxide was sinking to the bottom to any appreciable
extent.

I was never able to come up with a satisfactory way of casting the aluminum -
it tended to react with whatever I was using as a mold. Anybody know of a
way to do it? 

(Come to think of it, I never tried making the mold out of fired clay. That's
one approach to the "lost wax" process.)

John Roberts
roberts@cmr.ncsl.nist.gov