I just got a dust collector for my home shop for Christmas. My shop isn’t very elaborate (my wife calls it a “garage” – I call it my drive-in wood shop). While researching how to build up my system of tubes, I noticed most of the name-brand woodworking shops sell plastic dust collection tubing. Especially during the winter, the static electricity that builds up in this plastic is incredible and — growing up near coalmines — I learned that flammable dust and sparks don’t mix. To avoid the possibility of blowing up, is it worth the time and money to set up a metal-based dust collection system, or just go with the fancy plastic stuff and ground it?
For that matter, should all the woodworkers out there with PVC systems put more effort into grounding them? A recent article showed a shop-built downdraft table hooked up to a plastic dust hose & is this a time-saver or time bomb? Then again, is metal tubing connected to a dust collector sitting on rubber casters really grounded or just a suspended capacitor looking for a ground?
Michael Dresdner: This issue is one of the most hotly debated on Internet message boards. The best information from the most reliable sources I have seen is that, in most cases, you are perfectly safe running plastic pipe. Admittedly, if you can afford it, metal pipe is better. Plastic pipe may give you a shock, just like a shag rug paired with a wooly sweater, but it is not likely to generate a spark capable of starting an explosion.
Rob Johnstone: Let me start out by saying that, in over 25 years of woodworking, I have never heard of an actual explosion or fire resulting from the ‘static electricity on the plastic dust collection tubes’ danger. Tons of ink (both real and virtual) have been spilled discussing and debating this ‘issue.’ With that said, if you are concerned about it…ground the tubes with a wire running through the system. You’ll feel better, the electrical supply company will thank you, and you can then be considered an expert during the next online ‘discussion.’ Did I mention that I have never heard of a problem with static electricity exploding dust in a plastic tubed system?