In his email, he gave 3 separate
issues. #1-wood, #2- not wood, #3- metal. Each of these need separate
consideration. The easiest is wood. Both Delta, Jet and many others make wood
dust collectors. Most units are now the single-stage style- meaning the
incoming material travels right thru, and impacts, the wheel. Steel is more
resistant to the material’s impact and steel wheels are what is found in the
single-stage units.
With that in mind, let’s look at
each: wood would be fine with single-stage units and standard bags- no issues,
however, with ‘not wood’, you’d need to be concerned about the bags themselves.
At its most basic, wood is a porous material- meaning if the airflow was hard
enough, *some* air could pass thru it. Not so with ‘not wood’. If the inside of
the bag was coated with Gel-coat or resin, the airflow would stop and either it
just wouldn’t work, or the pressure would build up and cause a bag seam to
rupture. Your best bet here is to just collect it in a two-stage system like
Cincinnati Fan has. This was the company that Delta used to get their
50-180-series units from. You’d want your dust to just drop into the barrel and
not get to the bag to clog it up. Now for metal; metal is a whole different
ballgame. If you are collecting wood and metal at the same time and using a
single-stage, STEEL wheel, once the wood dust got to the critical ‘lower
explosion level’ of 40 grams per cubic meter of air, and a metal spark was
injected into the mix, a dust explosion is a real possibility. It would be
safer to use the Cincinnati Fan style, two-stage collector as they use cast
aluminum radial wheels so sparking is not as much of a concern; however, if you
have a pile of wood dust in the bottom of the barrel and a grinding spark of
metal made it thru to that pile, you could have a smoldering fire occur. Mixing
metal and combustible material is never a good thing. Metal dust collection is
best handled by a dedicated unit such as Delta’s old 49-826. (for those who’ve
read this far and might need a good ferrous metal dust collector, I happen to
have a brand new one- never used- $4000.00 value for only $1500.00) But it will
not do the multi-material collecting either. It’s not good for anything but ferrous
metals.
Send your questions or comments
to:
Toolsmartz@bellsouth.net and we’ll see what we can do to help you.