[TR] blasting media

[Randall]

> I had heard that black beauty was more health friendly to me 
> the operator. Is 
> that so?

Frank, I'm certainly no expert, but my understanding is that glass bead is
essentially equivalent to coal slag (Black Beauty) in terms of health risk.
The truly dangerous substance is sand ... the difference between glass and
sand is that glass is amorphous (meaning no crystals) and it's the fractured
crystals from the sand that can result in silicosis if they get into your
lungs.

> and is the grit grade going to give me the same 
> results as IM 
> getting now?

Again, my understanding is that the finest grade of BB is more aggressive
than glass bead and will leave a rougher surface on soft metals like
aluminum and zinc (pot metal) alloys.  What I've been told is to only use BB
on steel and iron.

> Also it seems from the McMaster Carr info that black beauty 
> requires a lot 
> more pressure to run than glass. True?

I don't believe it's so much a matter of "requiring" more pressure, only
that glass bead is typically used for more delicate work where lower
pressures are also appropriate.

Randall