I have read several articles on the pros and cons of using metal instead of PVC piping for dust collection systems. There are also articles stating that grounding and bonding PVC does little good in the effort to prevent static discharge. Can someone put this issue to rest by providing a definitive answer to the metal vs. PVC question? Is PVC piping safe with proper grounding and bonding or should it be avoided altogether?
Michael Dresdner: The woodworking shop is inherently unsafe, but as safety levels go, plastic piping might be the least of your worries. That is not to say that metal is not a better choice – it is. Metal is also a more expensive choice.
We could get into a long discussion about the relatively low odds of plastic pipe being able to generate a sufficiently strong static discharge to ignite a column of dusty, fast-moving air inside dust collector piping. It would go nowhere, except to prove that scientists, like most of us, fail to agree on much of anything. In short, you will continue to see all sides weigh in.
You want my opinion? My own shop dust collection system is piped with 4″ plastic sewer pipe, which, by the way, is ABS, a plastic both tougher and more flexible than PVC. That’s the same plastic used in the old days for telephones, back when Western Electric made them to last fifty years no matter how often they were dropped. Ah, those were the days.
Rob Johnstone: The last time I answered a similar question my tendency to wisecrack got me in a good bit of trouble. So this time around I will play it straight. It is my opinion that the concern over the danger of static electric charges building up in PVC exhaust ducting is significantly overblown. With that as a groundwork, I would never tell a person to go against their concerns – if the possibility of a discharge of electricity causes you to worry, go with metal ductwork.