I have a DC connected to most of my stationary tools and two ambient air filters, and a Festool dust extractor (shop vac) that I connecto sanders and the Domino and the like. Over the years my DC pipes (plastic S&D lines) have become covered in fine dust from static cling. I could wipe them down, but figure its fairly pointless and in fact it may be beneficial to allow it to continue. Any dust stuck to the pipes is not getting into my lungs. But If I wanted to clean up what should I do/use. Is there something like a dryer sheet or whatever I could wipe the pipes with that would resist the return of the dust? Is there some way to ground or treat the pipes to eliminate the phenomenon?
I've heard of running wires inside the pipe and grounding the wires. That might fix it, but as you say, those pipes are doing some filtering for you
I think the wire would need to be on the inside, where the static charge is generated.
On the whole, I think I would just knock the accumulation off now and then, or try to get it with the shop vac. Maybe just before going on vacation (as if any of us actually go on vacation as opposed to spending it in the shop).
PVC is an effective insulator. The wire will not "ground" the piping. BTDT. The wire will only effect the plastic surface about 1/4" on either side of its contact points. They will also foster build-up of chips and may cause a clog, especially if turning shavings are sucked up.
Only real option is to put a dust brush on a wand and vacuum off the exterior of the piping. I actually do this with a hose connected to a DC port as the accumulation on the pipes' exterior is a good indicator of how well the shop air is being cleaned by the DC and the air cleaners.
I will have to go look closely, but I have the low voltage wiring to the blast gates wound around the pipes and I think there is a stipe about and inch on either side of the wires that does not have dust. And, when I installed the system, I was reluctant to run a piece of wire inside for fear of clogging, but I ran aluminum tape in the earliest pipes in the system and grounded that. Having disassembled the system and changed it several times I can not remember if the tape is still continuous and grounded. I doubt it.
I think I am going with the outside of the pipes is collecting the deadliest of the fines. It also provides a visual history of the various species.
My shop pipe is metal but I have a flexible urethane pipe connecting the thickness planer to the chip blower. In dry weather I have gotten jolts off this pipe rivaling my electric fence charger.
Static is a problem in furniture factories. Collection pipe has spark arrestors to stop the propagation of a flame ignited by static.
The idea is to give the static a path to ground before building up in the plastic pipe. That is why I said it probably has to be inside the pipe rather than outside - outside wouldn't work at all, like you said.
However, this is all speculation on my part, the proof is in the testing.
They had an initiative going in wood processing plants to reduce surface dust accumulation on piping, structural beams, and really anywhere it could settle out from the air. Housekeeping Violations. If the facility being inspected under this NEP is not a grain handling facility, the surface dust accumulations (i.e., dust accumulations outside the dust collection system or other containers, such as mixers) are over 1/32- inch deep, and such depth covers an area of at least 5% of the total area of the room, with an upper limit of 1000 ft2, then citations for violations of 29 CFR 1910.22 (housekeeping) shall be issued. The standard provides in pertinent part: "(a) Housekeeping. (1) All places of employment, passageways ¿ and service rooms shall be kept clean¿ (2) The floor of every workroom shall be maintained in a clean¿condition."
On the outside of the pipes as well; poked a little stub of wire through the pipe to "bleed" off the static charge in the dust stream. Didn't work either, and got the same little clear area where the wire touched the outside of the pipe. Waste of copper wire.
A building I was in, in Richmond had dust on top of the beams about two inches deep. Clean up was astounding.
In my shop obscure places behind boxes and other junk will have amazing amounts of dust behind them. How much air flow does that require? Under the DC fitting that captures most of the dust off my RAS a little cone of dust builds up. I clean it up and it reappears. Very Interesting.
We had a customer that worked from his garage, building small kitchen jobs and the like. One day when we delivered lumber he didn't look too good. Turns out he was handling some cabinet part that hit something on the ceiling that accumulated dust. His wood stove ignited the displaced dust cloud and blew him out the garage door, that was fortunately open.
When I first installed my dust collection system using pvc pipe there was lots of static inside and outside of the pipe. After several years of running the static is gone. There is little if any accumulation of dust on the outside and the pipe won't even wiggle the hair on your arm if you get close to the outside of the pipe.
Downy Liquid, or any other brand of liquid clothes softener will work wonders! As an Engineer in a factory where we had Printed circuit manufacturing we often had to deal with static electricity.
We purchased softener in 55 gal drums! Our part handling trays / bins were plastic, these were dipped in a solution of distilled water and softener. We had Spray bottles in every electronics department with the same solution used to spray other surfaces. We even sprayed the office carpets with the solution. With the trays / part bins it required a re-dipping at intervals.
With your plastic pipes it should be a one time ever few years to eliminate the Static buildup. The reason the softener works is that it is hydroscopic (attracts and holds water molecules).
You can experiment with the quantity you want to use, something like a couple of caps full in a regular spray bottle may be adequate.
I was thinking I heard that. I don't have any such stuff at my house. I am allergic to it in my clothes. A friend recently brought some in one a nice fluffy dog blanket. I ended up at the doctor with patches of hide missing from itching.
I am also wondering if the dust on the pipe is not a benefit? Where would that dust end up if I prevent it from sticking to the pipe? In my lungs?
>>>I am also wondering if the dust on the pipe is not a benefit? Where would that dust end up if I prevent it from sticking to the pipe? In my lungs?
Ahh, a something new to sell to woodworkers - plates hanging from the ceiling energized with high voltage to attract fine dust.
Where is the dust coming from - insufficient dust collection? If currently ineffective I wonder if there is something you can do in your shop for now to remove the residual fine dust from the air such as a ceiling air cleaner with good filters. I saw an electrostatic filter available for the Jet air cleaner.
Seems to me that there would be a limit to the amount of dust your pipes would retain before they quit collecting it for you and it just floats around the air. And some disturbance might suddenly release a cloud of dust for your lungs to filter.
Grounded metal duct work might prevent buildup. BTW, I use 6" PVC ducts on my cyclone DC and never get dust sticking to the horizontal pipes - I put them in the trusses above the ceiling.
