How to properly ground dust collection system?

mattbyington

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Hey team!

As some of you know I have a Hammer A3 31 on the way.

In preparation I purchased a Rockler dust collector to get more CFM than my Festool CT.

You can see the picture I posted towards the end of this thread:http://festoolownersgroup.com/other-tools-accessories/just-ordered-a-hammer-a331!/30/

So, I purchased this grounding kit from Rockler without really knowing if it was necessary or not.

The weird thing to me is that on the label, it says to run wire both inside AND around (outside) the DC pipe.

See picture below. I was planning on only running it inside the hose - would be cleaner, simpler, and look better.

Thoughts? Is it really necessary to do both?

Thanks!

Matt

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Dave Stanton made a video about installing such grounding.

What is the main purpose for YOU to have your DC system grounded?

Is is to protect the tools or to prevent static discharge on your body?
 
Thank you [member=68525]usernumber1[/member] (great username) and [member=66597]Mario Turcot[/member] .

Sheepishly, I will admit I'm not really sure what I am trying to accomplish.

I just read that it was important. I've never had a big DC system before. I've really only ever had the Festool one.

I know the Festool hoses are anti-static and stuff and figured "hey, if Festool did it, I should probably do it for my DC system for the planer".

Haha..anyways. I'm not using PVC pipe - using Rockler's stuff. Which just arrived today:https://www.rockler.com/clear-flexible-dust-collection-hose-optional-sizes

So I guess I'll read through instructions online and figure out what to do, if anything!

Matt
 
The external grounding doesn’t make much sense to me.  If you have a lot of dust in the air outside your DC system, something’s wrong!  And as the referenced article says, there’s no reason to expect a buildup of static on the outside.
When I installed a DC in my shop I ran bare wire through the plastic pipes, using Lee Valley’s grounding kit, which looks more-or-less the same as Rockler’s.
 
I've done a good bit of reading on this topic as I'm just about ready to install 100 feet of 6" diameter thin-wall PVC sewer and drain pipe (ASTM2729) and 20 or so fittings, all going back to my Clearvue CV1800 cyclone. I've also seen Dave's video, and his method doesn't work very well. I think there are two good solutions here:

1. Run adhesive-backed metal foil tape along the inside and outside of your ducting. Obviously, it's running the tape inside a long duct that is the real challenge. I'm going to weld a little puller rod to a pole to accomplish this for my 10-foot pipes, then follow it up by shoving a mop head down it to ensure good tape adhesion. Do the same for your fittings and make sure your tape aligns and comes in contact with all components in the system. Connect fittings with sheet metal screws and then tape around each connection to ensure an air-tight fit. This is a lot of work but it's much preferred to running a loose wire inside the duct, which will rattle around and also obstruct dust collection.

2. The alternative is do nothing. If you notice you're getting shocked when touching your tool or fittings, spray the touch points with StaticGuard. There is a lot of debate around the potential for fires caused by PVC ducting and sawdust. I have not heard of a single documented incident of a fire being caused by a hobby woodworking shop. Now, if you're working at a sawmill, yes, you want to have a proper system with spiral ducting but that's also 7x more expensive than PVC. Lots of good reading on this topic here and here.

I'll be foil taping my ducts as mentioned earlier. Not because I think it will be any safer really, but when the whole place burns down (due to some other unforeseen reason), I don't want my insurance company to have a reason to not pay out.
 
Disclaimer: I am in no way an expert in electrostatic. This is about my understanding and personal experience.

Matt, the main purpose of grounding a DC system is to avoid electrostatic discharge & effects. Body discharge is annoying but very minor. The effects might be even worst for some people, where your body hairs raise when too close.

Some people are more subject to electrostatic. If this has never been a problem for you then grounding your DC pipes is a waste.

Festool & electrostatic? Festool made their hoses anti-static to protect the electronic board residing in the CT. Electrostatic can kill some electronic components therefore you need to prevent any discharge to the unit.

As far as I know the Rockler DC do not contain any electronic board and if it was to have one it should be self protected and isolated properly.

Note: In a small shop, fire & electrostatic is a myth.  There is zero stats on this.
P.S. You may have a different take and it's fine  [big grin]
 
I have a basement shop with plastic sewer line ducting run through the ceiling around the shop and y-drops around the perimeter.  I ran interior grounding wire like the Rockler kit.  I soldered the joints at each 'y' branch for the drops and it's been fine for 18 years with no issues.  The hoses I use have spiral wire imbedded in them.  The wire is grounded to a Laguna dust collector with cyclone in a closet.

The only issue I have to be aware of is not to pick up tissue or paper towels that might get caught on the interior wire joints leading to reduced air flow or stoppage.  Other than that, zero problems.  And no apparent static on the hoses.
 
Mario Turcot said:
Disclaimer: I am in no way an expert in electrostatic. This is about my understanding and personal experience.

Matt, the main purpose of grounding a DC system is to avoid electrostatic discharge & effects. Body discharge is annoying but very minor. The effects might be even worst for some people, where your body hairs raise when too close.

Some people are more subject to electrostatic. If this has never been a problem for you then grounding your DC pipes is a waste.

Festool & electrostatic? Festool made their hoses anti-static to protect the electronic board residing in the CT. Electrostatic can kill some electronic components therefore you need to prevent any discharge to the unit.

As far as I know the Rockler DC do not contain any electronic board and if it was to have one it should be self protected and isolated properly.

Note: In a small shop, fire & electrostatic is a myth.  There is zero stats on this.
P.S. You may have a different take and it's fine  [big grin]

Listen to this right here.

Even grounding PVC is a waste of time, because the static is localized. You'd have to ground almost every square inch of the pipe to have any real effect. You aren't moving the volume of air nor dust in a home shop to have an explosion. Worry more about sucking up screws and such that might hit the impellers.
 
I was tired of getting zapped all of the time and also the static charge on the vinyl hose attracted any saw dust on the floor so the outside of the hose was always covered in saw dust.

So I formed a loop of 12 ga solid copper wire that would fit into the vinyl hose.

[attachimg=1]

It pokes out through the side of the vinyl hose and attaches to the vinyl spiral wire and a short piece of 14 ga stranded wire which has a Molex connector on it.

[attachimg=2]

Any sawdust or wood particles will charge up the copper wire and the spiral wire will carry the charge back to the dust collector. The Molex connector is used to connect 10 foot lengths of vinyl spiral hose. Each 10 foot piece of vinyl spiral hose is set up in the very same manner. Inside copper wire, connected to spiral wire & Molex connector. This allows any 10 foot section of hose that I add will continue the ground path back to the DC

[attachimg=3]

At the dust collector, another short piece of 14 ga stranded wire is connected to the spiral wire and then grounded to the DC chassis. I've been using this method for the last 15+ years with great success.  [cool]
 

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I used those wire kits to ground my 4in PVC system on the inside and outside of the pipes.  I never get static even though I only ran the wire on the straight stretches inside and none thru the Y's and elbows.  Just made it a lot easier.  You drill a little hole at each end of straight stretches and wrap the wire around the outside of the pipe taught and tie to sheathed wire from there in series to be grounded off at the machines.  It's not hard to do, and it's cheap insurance.
 

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I have an Hammer A3-26 Planar/Jointer which I purchased in April along with a Jet Dust Collector.  I use the clear dust hose with metal wire support and have experienced no static build up.  If I needed to ground the dust hose, I would just run a wire from the hose to the dust collector and let the normal machine grounding do the work.  Where I have seen static buildup is when PVC pipe is used for ducting.  In this situation I have used the same grounding technique as Dave Stanton in his video.  Nothing unique or too difficult.  In the later situation, it is important that an actual "ground" is achieved.  If you are ever unsure, just drive a metal stake into the ground and wire to that stake. 

On a separate note, I really enjoy my Hammer A3-26.  It is a definite step up from my old Delta benchtop planar which I had for 25 years. 
 
IndyWoodworker said:
On a separate note, I really enjoy my Hammer A3-26.  It is a definite step up from my old Delta benchtop planar which I had for 25 years.

Congratulation on your Hammer.  [thumbs up] That's one nice machine I'm looking to get in the future. Aiming for the A3-31  [smile]
 
I would suggest the spiral cutter versus the planar knives.  I have had very good luck in reducing or eliminating tear out when planning hard maple.  Similarly, no snipe on the boards.  I wrote a short evaluation in the FELDER site about the A3-26 and my early experience. 

I just want to mention that I chose the A3-26 and it fit my needs.  I could have gone to the A3-31 as well, but I looked at my 28 years of woodworking and could satisfy all my needs with the -26.  I really do like the product, I wasn’t too sure when I ordered it but I am sold.  Definitely a good investment.  All the best when you purchase your machine.
 
I know I am a couple of weeks late to this party.  I would not bother grounding your set up.  I used the same (original style) dust collector as you and moved the Rockler expandable hose from tool to tool.  I never had a static issue.  I still use the same Rockler expandable hose along with some PVC and a different dust collector.  As for tools, I use this setup on a SawStop PCS, Hammer A3-31, Supermax 19-38 drum sander, router table, and soon a Laguna 14BX that I picked up over the weekend.  I have not had a single static issue yet (I am somewhat surprised as our winter air is usually very dry, although today it is a balmy +10 degrees Fahrenheit).

Sent from my iPhone using Tapatalk
 
I remodeled my shop a couple of years back and part of the remodel was my dust collection piping (approximately 140' of 4" PVC). I previously had no grounding on the outside but for a brief time I had a single stranded wire inside. This was a a problem because of long planer and jointer chips hanging on the wire, disrupting flow. So, I removed it and it stayed that way for about 20 years.  When I did the remodel, I added a bare copper wire wrapped around the outside and attached to the pipes with ring lugs and screws. I followed the info found here on "the Down to Earth Woodworkers" post (https://www.youtube.com/watch?v=sCPiu0zQwyI). I didn't do this because of fear of a dust explosion though. I did it to keep the static electricity from drawing the light dust to the pipe and it collecting on it ruining the clean look that I was going for. I hope this helps
 
I think grounding is also necessary to prevent sparks that can trigger dust explosions.
Dust explosion is a rare phenomenon, but it does happen now and then.

wpz
 
Michael Kellough said:
[member=60107]Stanleywc[/member]  Does it (grounding) actually keep the surface of the pvc clean?
Yes, it works great. I have not vacuumed the piping off since it was installed and it has very little if any dust on them at all. I do run a JDS air cleaner during the winter, my hand power tools are Festool with dust extractors and all of my stationary equipment is attached to a central dust collector though.  But I used this same type of set up prior to the grounding too and I had significant dust stuck to the piping when I removed it for the remodel. I was actually surprised that it worked so well
 
wpz said:
I think grounding is also necessary to prevent sparks that can trigger dust explosions.
Dust explosion is a rare phenomenon, but it does happen now and then.

wpz

I read up quite a bit on that subject years ago, and it is non-existent in what is a home shop setting.  Systems of 5HP or more are where this is possible to happen.  Most home shops are 3HP or lower.
 
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