Bob,
I usually blast via a commercial blasting cabinet, with vacuum attached. The
vacuum I place outdoors. There is still a bit of leakage, so I wear a dustmask
whenever I'm blasting.
I've blasted several motorcycle engines, inside and out and one has several
thousand miles on it. So far, no indication of trouble. But, then I'm very
careful about cleaning up the pieces after beading. Running them through the
dishwasher (when wifey is not home) with cascade detergent. I wonder now if I've
been careful enough, lucky, or due for a $$$ engine problem.
An interesting side note: The people who rebuild the Amal carbs for english
bikes machine the gasket surfaces and refuse to accept bead-blasted carb bodies.
The reason? They claim the embedded glass dulls the bits too quickly.
Peter S.
B9471799
Bob Palmer wrote:
> Larry, Pete, et Listers,
>
> When I was working at Firestone a few years ago on the Wilderness tires for
> the Ford Explorer, I learned about the care and feeding of aluminum tire
> molds. Every hundred tires or so, the mold has to be cleaned, which they do
> by bead blasting with glass beads. The beads they use come, as advertised,
> as round beads. They don't remove any aluminum as long as they stay in one
> piece. That means the air pressure used has to be kept below 45 psig. At
> higher pressures, the beads break up exposing sharp edges that cut away the
> aluminum - and cause great injury if they get in your eye. Another word of
> caution that hits particularly close to home with me: Never, never, bead
> blast any surface that goes inside your engine! The media is almost
> impossible to remove completely before assembly, but with constant flushing
> of hot oil, it goes through your engine causing very premature failure.
> (Don't ask me how I know this.)
>
> Bob
>
> P.S. Gee Larry, and I thought you were winking at me 'cause you thought I
> was cute!
|