From: jstevens@aaron.carleton.ca (Jonathan Stevenson)
Subject: Re: Zinc Powder
Organization: Carleton University
Date: Fri, 10 Apr 1992 14:53:09 GMT

In <1992Apr10.032155.10728@deeptht.santa-cruz.ca.us> spcecdt@deeptht.santa-cruz.ca.us (John DuBois) writes:


>     My 1960 edition of _The SCIENTIFIC AMERICAN Book of Projects for
>the Amateur Scientist_ (C. L. Stong) describes making zinc/sulfur rocket
>engines.  My wacky Jr. High science instructor made an enormous batch of
>such fuel intending to pack it into a rocket, but decided it would be too
>much trouble so just poured it out in the quad and lit it (after several
>attempts).  Quite spectacular, but I wish he'd put it in a rocket.  Oh
>well.

>	John
>-- 
>John DuBois	spcecdt@deeptht.santa-cruz.ca.us	KC6QKZ


My father built a rocket using 40% Zinc/60% Sulfer around this time.
I wonder if he got the idea from this article (He did read SCI
AMERICAN at that time)?  Incidently, he was able to obtain powdered
sulfer from a drug store, and you can still get the stuff in some
stores today (sulfer is a laxative).  The powdered zinc was obtained
from a local paint manufacturer at that time.  I don't think that
modern paints use zinc or powdered metals anymore (most are just
plastics) but rust-paint may.  Whether modern companies would simply
hand over the stuff to your average citizen is another question!

As to how good this fuel is:  The stuff actually has a name (AMMOTAL?)
and was quite popular in small military rockets (in fact, I think it
was used in the first U.S. bazookas in WWII) as the stuff is quite
stable.  It is also the only fuel that I know of that is not oxidized
using oxygen (sulfur, same family on the periodic table) appears to
serve as "oxidizer".  The zinc is the fuel/catalyst as in one.  My
father's rocket (circa. 1960) was simply a long length of copper pipe
with the stuff dry mixed and packed into it (no core, cigarette
burning).  The thing used wooden dowel/plugs bolted in place for the
endwall cap and nozzle (drilled to 1/2" obviously !).  According to
the local newspaper which photographed the launch (and had the article
where I got most of my info on the event), the rocket, which weighed
over 10 pounds and was 4 ft long (and 1-1/2" dia) with metal sheet
fins, went up to an altitude of over 2500 ft.  Not bad for a very
heavy and crude rocket!  

I have tried to duplicate the results using modern materials (lighter
rocket, cardboard tube motor casings) but with no success as I could
not find a large enough supply of zinc powder.  Regulations (esp.
concerning dangerous chemicals) appear to have been alot less stict
back in the early 1960's.  

The Chemist/Druggist:        "May I help you, Lad?"

Boy:      "I'll have 5 pounds of powdered zinc and a some potassium
           chlorate please.... And some sulfur with that, too!"

The Chemist:        "Hmmm....Bad stomach aches, eh?  That'll be $2.15,
                     son." 



------------------------------------------------------------------------------
                                        
    JJ DDDD   SSSS     Jonathan D Stevenson                     
    JJ D  DD SS  SS    Dept. of Aero & Mech. Engineering     
    JJ D  DD  SS       Carleton University (Ottawa, Canada) 
    JJ D  DD    SS 
JJ  JJ D  DD SS  SS    E-Mail: jstevens@ccs.carleton.ca        
 JJJJ  DDDD   SSSS          

"My hovercraft is full of eels"

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