GLASS BEADING of actions = INCOMPETENCE

[Stan Kroeker]

>WHY  would you not use some non-harmful abrasive,  like pecan shells, the dust
>of which is less hard than the centerpins, so that any dust residue in the
>centers would not wear away at the pin and the felt?
>
>Additionally, one doesn't have to go to great lengths to avoid the dust (
>cellulose) generated when blasting with shells, whereas glass beading produces
>silica dust, with a real threat to health with silicosis.
>
>Just for the sake of the customer's property (the action does belong to them )
>you might at least try shell blasting. It will not work on metal as well as
>glass beads, because they "explode" when they hit metal and blast off the
>surface with extremely sharp edges. Then of course, the particular glass bead
>is sharp dust, and no longer a bead. Just ask your abrasive supplier about
>this, or try a small sample against metal and see how the character of the
>material changes,  or use a microscope and actually look at the residue.
>
>If you disagree with this statement PLEASE DEFEND YOUR POSITION.
>
>Bill Simon
>Phoenix

Bill,

Since you have put us 'bead-blasters' on the defensive, perhaps you could
start by sharing some more scholarly evidence of the dangers of the glass
bead 'dust'?

Personally, I don't care to breath any kind of dust, toxic or otherwise, so
I take the precaution of using a well sealed booth with a vacuum attachment
to exhaust the floating debris soon after it is blasted.  I also wear a
dust mask as added protection.  I don't have the benefit of microscopic
analysis to back up my understanding of how glass beads abrade the surfaces
we blast but I am picturing them as microscopic bowling balls as opposed to
jagged microscopic rocks (sand).

I believe that most of the floating crud that is generated is the dirt we
are blasting from the parts.  The beads themselves fall immediately into
the hopper where they are recycled, seemingly forever.  As to your concern
over damaging action centers...well, there is simply no direct line of
spray against any of the centers so it is hard to imagine how these
microscopic spheres are going to take a 90 degree turn and enter the
bushing to cause such imaginary havoc.

>I say " IF YOU USE GLASS BEADS  TO BLAST PIANO ACTIONS,  YOU ARE BEING
>INCOMPETENT."

Well, I'll wait for the Gallup poll to come in on that one.

Best regards,

Stan Kroeker
Registered Piano Technician