[AT] Classic Blast

[ROBBRUT at aol.com]

Walnut shell blast media has indeed been in use for some time (In my own  
experience, more than 29 years), works very well for many applications, and is  
commercially available.
It does have one documented shortcoming however, and  that is the  media 
breaks down into fibers and walnut oil when it impacts the surface and  begins to 
fracture.
Now, that in itself is not much of a problem, but if those  components have 
the opportunity to get back together again they will.
If the reunion happens to be in an oil passage, the result can be  
disastrous, even fatal.
Many years back a helicopter crashed at an air show in Germany.
There was great loss of life as a skydiving team (I believe) was  aboard.
The crash was due to a rotor shaft bearing failure which was  traced to a 
clogged oil passage.
The debris causing the clog was analyzed and found to be made up of  
recombined components of the walnut shell media which had been used to  blast the 
inside of the transmission housing during a recent overhaul.
Since then, the Army has prohibited walnut shell blasting on any items  which 
have pressurized oil passages.
Tractors should be no problem, but as for carbs, etc.... well, forewarned  
is.........
-Bruce