Dust collection grounding of duct tubing, is it necessary??

[Clay Crocker]

I have no experience with PVC duct systems since I have metal duct work, but I have had first hand experience with static shock even in my shop. My metal duct is run overhead with a 4" X 6' black, Jet, plastic, flex hose drop to my planer. In the winter, when humidity is low, working around the running planer/dust hose would lead to some painful static shocks (FWIW, I am a bit of a sissy when it comes to static shock). Wrapping a bare copper wire around the outside of the plastic dust hose and terminating one end on the planer frame and the other end on the metal duct work eliminated the static discharge problem. In regards to the OP, all of the evidence I have seen indicates that the chances of a fire or explosion caused by static discharge is very remote if not impossible.

[Kerry Wright]

Tweaked that a bit for you... once the skin is pierced and you get past the subdermis, resistance can drop to under 10 ohms, depending. A shock to a dry hand can be nasty... same shock to a sweaty hand or one that punctures the skin (sharp end of a cutoff wire, for example) can quickly turn deadly. We're definitely more of low-resistance path (comparatively speaking), though, not an insulator.

Ya I dropped a zero.......dang it was just here

[Ole Anderson]

 I am surprised that no one has chimed in wondering why you are planning to run 4" pipe, when most machines need 5" or 6" pipe to handle the airflow for adequate dust collection. I ran steel, and only one of the reasons was so that I didn't have to deal with a possible static shock while working around fast spinning blades.

[Paul Stoops]

As I recall, the OP didn't specify the size of his DC. Ducting larger than 4" requires a DC fan with enough HP and a large enough impeller to handle it. Neither did he specify the lengths of the runs in his shop. There is some interesting info about DC's and 6" ducting in this article: http://www.portercable.com/uploads/P...Collectors.pdf.

[Jim O'Dell]

With my 5hp cyclone and 6" PVC ducting, I can feel the hair raise on my arm when I get close to the piping, but I have never gotten a shock from it. I did hear a ticking noise one day using my lunchbox planer hooked up to the cyclone. It took a while, but I finally found that the wire in the flex hose from the PVC to the planer was arcing to the planer extension bed. I extended the wire and hooked it to the bed and no more arcing. Jim.

[Fred Belknap]

I get shocked when I buff bowls in the winter. My lathe is used to buff and it is bolted to the concrete floor. My wax and buffing compound is broken from picking it off the lathe and getting shocked after buffing. I think it is the shoes I wear, if I keep part of my body against the lathe when buffing I don't get shocked. Maybe bare feet would work or naked.

[shane lyall]

if I keep part of my body against the lathe when buffing I don't get shocked. Maybe bare feet would work or naked.

Now theres an image I DID NOT need this early in the morning Fred! LOL! I used the standard S&D pipe from Lowes and it isn't grounded. I do get a shock every now and again but it seems like after it built up a layer of fine dust inside it gets better. I had to much time and tested it out. I took a short piece and foged the inside with hair spray, let it dry, then conected to my system. I ran collecter for about 10 mins with 1 gate open then started sanding. I know it may cut down on flow but I don't get poped every time I touch it. May seem silly but it worked. I get shocked when I touch somewhere else but never that short tube. Once I've run it a few months to check long term I might do my entire system. Mainly want to make sure it don't keep building as to block off my flow. So far after about two weeks I have about a 1/16 thick layer. YMMV

[Jerome Stanek]

I get shocked when I buff bowls in the winter. My lathe is used to buff and it is bolted to the concrete floor. My wax and buffing compound is broken from picking it off the lathe and getting shocked after buffing. I think it is the shoes I wear, if I keep part of my body against the lathe when buffing I don't get shocked. Maybe bare feet would work or naked.

If you get an anti static wrist cord and put it on your ankle and ground it to your lathe then you wouldn't get shocked. and if you move away to far it will pop right off the lathe. They have a coiled cord so you won't trip over it.

[Jeff Hamilton Jr.]

There is some interesting info about DC's and 6" ducting in this article: http://www.portercable.com/uploads/P...Collectors.pdf.

Hi Paul, don't know if its just me, but this link give me a "404" link not found error.