Sandblasting Revisited

[John Dewey]

My statement was ". The only expense is the blast media and ordinary sand
box sand will let you experiment on an old junk action if you keep the
preassure low-10 to 20 psi."
Note the words _junk action_ and _experiment_. I much perfer 40-60 grit corn
cobs but feel low pressure is the important factor. As far as being abrasive
some of the stuff I blast off the parts is as bad or worse than sand.

John Dewey

-----Original Message-----
From: BSimon1234@AOL.COM <BSimon1234@AOL.COM>
To: pianotech@ptg.org <pianotech@ptg.org>
Date: Thursday, May 13, 1999 12:02 PM
Subject: Re: Sandblasting Revisited


>Different people have written;
>
><<an ordinary sand box sand will let you experiment...  The bead-suction
>tube... Learn to sense the feel of the beads flowing through the gun>>
>
>These statements appear to indicate that sand or glass beads are acceptable
>media for blasting actions. They are not!
>
>On old chairs and wrought iron fences, well - why not?  But no decent
>mechanic would suggest that one bead blast around even sealed bearings that
>will remain in place, and it amazes me that anyone would suggest using
blast
>materials  that produce highly abrasive dust on actions with all their
>delicate centers.
>
>I thought I would see lots of suggestions for harmless blasting material,
>ranging from almond shells and walnut shells to cracked rice and ground
corn
>cobs.  (all of these will clean up an action)
>
>For clarity. I suggest action blasting be done with ground and graded
almond
>shells, available from sandblast suppliers.  Called "Shellblast", this
>material can be re-used for years and will not harm the action as sand or
>glass beads will.
>
>Seems like a little knowledge is a dangerous thing.
>
>Bill Simon
>Phoenix
>
>P.S. - In medieval England there was a period in which diamonds were
becoming
>known. They knew a little bit about them, but not enough. In ignorance,
they
>commonly confused hardness with toughness, and the test for diamonds was to
>put one on a rock and bash it with another rock.  If it shattered, it
wasn't
>a diamond! One can only imagine how many diamonds were erroneously
destroyed.
>Then as now,  a little knowledge was a dangerous thing.
>
>P.P.S. - Diamond dust would also be a lousy medium to blast actions.
>
>
>