<DIV>Hi David,</DIV> <DIV> </DIV> <DIV>I use a 100-140 (medium) glass bead.  The beads do not contain free silica. However, the MSDS sheet states that "dust in excess or recommended exposure limits MAY result in irritation to the respiratory tract"   I connected my blasting box (made from the plans in the Journal) to my dust collector.  All of the air is filtered before it reaches the dust collector so the beads do not disappear.  Another consideration is the junk that you are blasting off the wood and metal parts will then be in the air.  I suggest that you either exhaust the dust or wear breathing protection or both!  </DIV> <DIV> </DIV> <DIV>Regards,</DIV> <DIV> </DIV> <DIV>Steve Grattan</DIV> <DIV>Lost Chord Clinic<BR><BR><B><I>David Skolnik <davidskolnik@optonline.net></I></B> wrote:</DIV> <BLOCKQUOTE class=replbq style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #1010ff 2px solid">Help -<BR>There was what I <I>think </I>was a recent discussion (or at least mention) of bead blasting cabinets, where someone mentioned Harbor Freight Salvage as a possible source of an inexpensive unit.  I have been unable to find that discussion.  My question though is for anyone who uses this process.  The manual seems to strongly emphasize respiratory precautions.  Is this, in fact, a real concern, even with these smaller units? Also, what's the best material for cleaning action parts and screws?<BR><BR>Many thanks -<BR><BR>David Skolnik </BLOCKQUOTE> <DIV><BR></DIV>