Replies

1. 
   dgreen | Mar 04, 2007 06:08am | #1

   26" double drum sander and a 3hp Penn cyclone with external filters, no problems. My guess is the inside of the cyclone is a poor place for the filter.

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   "The West won the world not by the superiority of its ideas or values or religion but rather by its superiority in applying organized violence. Westerners often forget this fact, non-Westerners never do."
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   Samuel P. Huntington
2. 
   Lataxe | Mar 04, 2007 02:26pm | #2

   Mr B,

   I use a small Trend dust collector of the low volume, high pressure type - the sort usually recommended for portable power tools such as routers and RO sanders. I have seen it also badged as a Fein, with an orange rather than grey body. This collector works very well because:

   * The collector is dedicated to, and sits right next to, the drum sander with a short hose between the two. 

   * The collector switches on and (with a short delay) off when the sander is switched, via its integral current-sensing circuit.

   * The collector has 3 stage filtration: into a removable paper bag; through a fine nylon mesh bucket then out through a concertina paper filter. 

   1) The 1st stage paper bag gets 99.9 % of the dust and, when full, is thrown away and replaced.  As I recall, the bags hold around 15 litres - enough for quite a bit of drum sanding, in practice.

   2) The nylon bag gets most of the rest of the dust.  It can be easily removed and shaken clean, typically when the paper bag is replaced.  It collects only a very fine film of dust.

   3) The cartridge concertina filter gets the very finest and invisible stuff, down to 0.3 microns.  It too can be shaken free of accumulated dust - but it takes many cycles of paper bag changing before the accumulated dust begins to show on the concertina filter - which can also be washed, dried and used again.

   All this filtration keeps the air pretty clean. The suction doesn't seem to drop off, as the bag gets full, to any degree that allows visible dust to get out of the drum sander.

   But, just in case, there is also an air-exchanger filter hanging from the roof and runnng just above the drum sander.  This too has 0.3 micron filters, for that invisible stuff that is the real danger to one's lungs.  In summer, a small extractor also runs, at floor level, to exhaust the shed air to the outside.  (Too expensive to throw out the shed's heat in winter).

   The only disadvantage is the cost of the machine (£180 here) and the cost of the paper bags (£20 for 10).  personally I think the virtual elimination of the dangerous dust that drum sanders make is worth it.

   Lataxe

3. 
   BigK | Mar 04, 2007 02:50pm | #3

   Onieda now offers an external filter conversion kit for their older cyclones. They claim that this will improve the performance of that cyclone by 15%. The external set-up is much easier to clean. 45 minutes of drum sanding equals a lot of dust to be collected and filtered though. Your frequency for cleaning the filter does not surprise me, in fact in a left-handed way it is showing you how well your 2 stage collector is working. I would be rather reluctant to change to some other method for dust collection that is less effective.