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<DIV><FONT face=Arial>Joby, As an electrician, I would not want dust and sand in
the brushes, (commutators). These items have a tough life anyway, sand will just
eat them up. </FONT></DIV>
<DIV><FONT face=Arial> I suggest you make a filter box with some basic
pleated paper filters and maybe a fan or two to help with motor cooling. It is
normal for the brushes to spark in operation, but as sand and dust erodes them,
the sparking will be a lot worst. </FONT></DIV>
<DIV><FONT face=Arial> As an experiment, try running a skill saw while
blowing sand and dust into the motor vents. I'd bet it fails quickly. Let me
know what you do and how it works. Thanks, Dan</FONT></DIV></BODY></HTML>