Grounding Dust Collection Hose

How do you ground flex pipe for a dust collection system? (And is it even worth doing?) February 19, 2013

Question
I’m finally getting around to grounding my 20' length of dust collector 4" flex hose. I’ve read to use a bare stranded copper wire, 16AWG, and that antenna wire will work too. The only problem is I can't find any bare stranded wire in San Diego! Where can I purchase this, and if I can’t find it can I use another type of copper wire?

Forum Responses
(Dust Collection and Safety Equipment Forum)
From contributor J:
I haven't done what you're planning to do, but you might have better luck searching for braided ground strap/cable. The braid keeps it from coming apart since there's no insulation jacket to fill that role.

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From contributor F:
First off you should lose the 20' of flex hose. There's not much you could use that would be worse than that. As far as bare copper wire, any home center, box store, electrical supply house, basically anyone who sells wire will sell what you need. Lastly I don't know what you'll gain from grounding the flex hose anyway? Your machines should be grounded as well as your dust collector. I don't see what you'll accomplish by grounding the flex hose?

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From contributor G:
You are worried about static buildup I presume. If you look elsewhere in the archives there is a site to a study that indicates that there is nothing to worry about in small diameter tubes. (The static discharges, if any, are insufficient to ignite even the worst dust/air mixes.) The wire is of no value.

The reason that the static builds up in the first place is that the plastic is an insulator. Running a wire through a plastic (insulator) tube only grounds the part of the tube it touches. The entire inside surface of the tube which is not intimately in contact with the wire is still carrying the static charge. (Because the tube is an insulator the static charge does not flow to the wire). The tube is an insulator so the static charge does not travel around the tube to be grounded by the wire. All you have provided is a nice grounded place for a really big discharge to arc to (although the article mentioned above suggests that such levels are never reached by a small diameter tube.)

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From contributor R:
I grounded my 6' of 6" flex hose for my planer which built up a lot of static electricity. I just grounded one end of the wire helix to the metal on the planer and then the other end to the metal duct and then I did not get shocked.

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From the original questioner:
The reason I wanted to finally ground my black flex hose was because of the chip dent I've been getting when planing old growth western red cedar. When I'd walk under the hose my hair would stand up, and I heard that grounding might help the flow.

Here's what I did. I found that ground wire at my local Rockler store. I also picked up some new clear flex hose that has a spiral wire all around the outside. The rep said to just ground each end of that wire and not even run a new wire inside. That's what I did, and now I have no static when I walk around the hose. It’s kind of neat seeing all the chips getting sucked away. It cleared up my chip dent about 50% too.