I read Rod Cole’s article “PVC pipe dangers debunked” in FWW#153. He says useing 4 inch plastic pipe on a dust collection system of 3 hp or less does not pose any risk of explosion. I’m thinking of using 6 inch plastic sewer and drain pipe for the main along with an Onieda 2 hp Dust Gorilla. I would wrap copper wire around it and ground it.
My question is, does having a ground around the outside of the pipe eliminate or reduce the static charge inside the pipe to the point where it’s safe? Has anybody used grounded 6 inch plastic pipe? I wuold appreciate any advice. Thanks.
Replies
You can go to this page by Rod Cole, he has some suggestions:
http://mywebpages.comcast.net/rodec/woodworking/articles/DC_myths.html#inside
At one point it was suggested to use Aluminun ducting tape down the outside and through the inside to help control the static buildup on the PVC pipes.
This is mainly to avoid nuisance discharges, i.e., you don't get zapped whenever you touch the duct.
Myth busters tried to get a pipe to charge up with static and failed big time. But for the five minutes to wrap a wire along the pipe.............worth doing!
How do you like the Onieda 2 hp Dust Gorilla as I am considering getting one. Also, did it arrive in good shape after shipping?
Life is what happens to you when you're making other plans .
I have not used the dust gorilla yet. It did arrive in good shape.
JerryYou didn't ask me but I'll butt in. I've had my 2 HP Dust Gorilla for about 2 months. I love it. The quality of ALL components is over-the-top!. Even the nuts and bolts are top grade. Assembly is easy but the topmost unit - motor and cyclone - is heavy. You may want some help installing that. (I'm glad one of my sons was home for Christmas and had a friend visiting.)I needed some extra space and rotating the top head (I think it has standard 60 degree increments) was either too much or not enough. A friend made an adaptor for me at 27 degree offset that was perfect.I'm glad I don't have to change bags anymore.Frosty
I appreciate you comments and your post has sealed the deal, a 2HP Gorilla is in the future for me.
Life is what happens to you when you're making other plans .
"My question is, does having a ground around the outside of the pipe eliminate or reduce the static charge inside the pipe to the point where it's safe?" Another reference from Mr. Cole's site.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Hi,
I saw a cabinet shop one time that had used 6" pvc for it's dust collection. But instead or wrapping wired around it he used metal tape down the length of all the runs and connected them appropriately. It worked fine and was easy to install. Plus, it wouldn't foul or clog like running a wire system inside would.
Paul
ps never saw any static buildup ( dust clinging to the outside ) I worked ther for two years.
Edited 2/17/2007 12:31 pm ET by colebearanimals
4 years ago I ran dust collection through out my shop for a Jet1100. While pricing the difference between PVC and metal ductwork I realized that they were so close as to be negligable. And after reading the debates on static issue, I went with metal piping.
Give it a look, kill two birds with one stone so to speak.
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http://www.drawingwithlight.smugmug.com
Has anybody used grounded 6 inch plastic pipe?
That's an oxymoron. PVC is an excellent insulator; it thus cannot be grounded.
I've gotten shocks from metal components (e.g., blast gates) used in plastic pipe DC systems. The air and the inside of the pipe pick up static charges from rubbing against each other, and the air ends up depositing some of this charge on the blast gates and any other ungrounded metal it comes in contact with. These metal parts should be grounded.
What BarryO said: PVC can not be grounded. Wrap the whole pipe with a metal foil, ok, this will work, but no matter what anyone says, you can not ground PVC.
"Grounding PVC Pipe" is a poor choice of words and as you and others have said it's not possible to ground a non-conductor. It is possible to build up a static charge in a non-conductor (rubbing a baloon on a hairy arm, dragging your feet across carpets, etc). That charge will discharge into a grounded conductor or a person. Wire or tape would more accuratlely be described as a "drain wire" similar in function to shielded cable drain wire. If one was really worried about it, I would suspect that grounding the metallic blast gates would be just as effective and a whole lot easier/cheaper than any of the other methods mentioned.
To the guy that compared metal duct to Sch 40 PVC he's right on the approximate cost push. 4" and 6" Sch 40 PVC fittings are crazy expensise. However others would do well to look at thin-wall plastic drain line not Sch 40. Much, much cheaper.
Too bad we can't get the Myth Busters to test this subject. I'd expect the same results as the purported pantie-hose static or cell phone ignited fume disasters at the gas station - myth busted.
John O'Connell - JKO Handcrafted Woodworking
The more things change ...
We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized. I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.
Petronious Arbiter, 210 BC
John:I even meant loosely interpreted, you can't even get current flow from PVC with any type of wire. I tried when I had a PVC piping system. The immediate area close to the wire is clear of dust, but static still causes the rest of the pipe to attract dust, and if the pipe was against a wall, that wall area picked up a charge and attracted dust as well. It'll give me a good zap sometimes. Not worried about dust explosions, but I can get a 1" zap in the winter. You can get PVC to discharge static, but you can't get it to conduct current, which is what you need to ground the system.
So what your saying is the static along an entire length of duct won't discharge to ground via the grounded metal blast gates, so you need to provide a continuous path to ground along the length of the duct with a conductor?John O'Connell - JKO Handcrafted Woodworking
The more things change ...
We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized. I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.
Petronious Arbiter, 210 BC
Yes, you essentially have to turn the pipe into a conductor. One idea I was toying with before getting all metal ductwork was to use PVC pipes, then totally wrap them with the foil tape used in the HVAC industry, which is available at the BORG, and ground that. This wouldn't eliminate static in the pipe, just keeps me from getting zapped and the PVC coated with dust.I had to be resourceful, but in the end I was able to get a metal system for not much more than a PVC one. With my main trunk being 8", PVC pipes and fittings were really expensive.
Actually, the myth busters did test it. Some myth about a plastic pipe on a job site being sandblasted killing a worker when they touched it. Episode 20.It was busted.
Cool I'll have to watch for it.John O'Connell - JKO Handcrafted Woodworking
The more things change ...
We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized. I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.
Petronious Arbiter, 210 BC
Oneida is renowned for its tech support. Why don't you call them for an opinion -- both on the grounding issue and the size of the pipe for your runs?
6" seems big to me, and it's probably very expensive, since you will probably have to buy it thru a plumbing supply house.
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"It is what we learn after we think we know it all, that counts."
John Wooden 1910-
I work in the natural gas industry where plastic pipe is used extensively for underground distribution. We have procedures for grounding an excavated pipeline before doing maintainance or repairs, thus minimizing the risk of static discharge. But, to answer your question, grounding the outside of the pipe will not ground/discharge static buildup on the inner pipe wall.
I believe these issues have been put to bed many times. "Grounding" your plastic pipe is not a safety issue. If you are concerned about getting zapped from time to time, then ground the parts that are within normal operating reach. Otherwise, forget about it.
SRD pipe is a lot cheaper than smooth walled metal pipe for dust collection. HVAC metal pipe may be comparable in price, but it is crap.
Good luck,
Todd
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