Replies

1. 
   ownersrep | Jan 24, 2004 12:43am | #1

   Talk to Oneida.  For a shop that size, you can certainly justify a cyclone dc and they will do all the design for you.  Have heard both positive and negative about putting the duct in the floor - you certainly want to have some cleanouts designed in for when (not if) it plugs.

   Jim

2. 
   WayneL5 | Jan 24, 2004 02:29am | #2

   Did just that.  Went through Oneida and they were a big help.  Nice system.

   I limited my under slab ductwork to the minimum needed -- one duct that took the system from a position along one long wall across the room to the other wall, picking up the table saw along the way.  Everthing else I ran above the floor along both walls.  That gave me the most flexibility to alter my layout with the minimum amount "set in concrete" as the expression aptly goes.  I used metal duct work to be certain that static electricity would never be a problem.

   My slab was about 1' above grade, and was on several feet of stone and sand, with good slope away from the shop outside, so I was comfortable that the duct would not collect any water.  And, it has not.  When assembling the duct, I ran a bead of caulk in each joint before pushing them together.  I used a non silicone caulk, because silicone is corrosive to metal.  I ran a strip of 2" wide vinyl tape around each joint, and along each longitudinal seam.  I oriented all the longitudinal seams on the top side.  To keep the pipe from being jarred loose from the concrete pour, I ran one small self drilling sheet metal screw into each joint, but oriented it to the top to reduce the chance of it catching a bit of wood.  And of course, the stubs need to be capped so the crew doesn't get concrete in them.

   I had no cleanouts, because there was only one straight run with the table saw in the middle.

   Make sure your downstream stub is far enough from the wall so it lines up with the inlet of the dust collector.

   I used the system a lot and never had a problem with it.  I inspected it once and had no buildup or moisture.

   The $40 bucks or so extra for the muffler is worth it.  It reduces the noise a lot, though the system is not quiet.  But you always have hearing protection on when using power tools anyway.

   Don't forget for your tablesaw to put your electrical power in the slab, too.  The conduit can be PVC (which works well underground), but the stub through the slab should be metal because PVC is too easy to break off if you trip over it.