You'd be surprised how much static is built up on the system. If you're
moving it around the shop at all you'll want to ground it so you don't get
shocked every time you touch it... and continuously while your touching it.
As the other reply points out people worry about dust explosions and such, I
agree with him I don't think it's a real danger.
"Astriapo" <[email protected]> wrote in message
news:[email protected]...
>
> I bought a dust collector tonight. What is the idea behind grounding the
> hose? I assume to reduce friction. So do I connect it to a pipe and hook
> it to the tool itself or what?
>
> Thanks...
Astriapo wrote:
> I bought a dust collector tonight. What is the idea behind grounding
> the hose? I assume to reduce friction. So do I connect it to a pipe
> and hook it to the tool itself or what?
>
> Thanks...
If you are using plastic pipes the idea is to eliminate static buildup
caused by the material in the pipe rubbing on the walls.
It should be sufficient to ground the hose clamp at the dust collecor
end. If the hose attachment is metal and in contact with the blower
motor housing it is likely to be grounded already.
A simple check is to run the system and suck up a bunch of dust, then
touch the hoses while in your stocking feet. If you don't get a jolt
you can probably leave it alone.
If you don't think you have a static problem in your workshop... what do
you think is holding all that dust on the walls?
HOWEVER... having said that, getting a dust cloud to explode in a home
workshop environment is next to impossible.
I agree with Vic. I went to all the bother of running a ground wire through
an extensive duct system. I dont think I would do it a second time.
Tom
"Vic Baron" <[email protected]> wrote in message
news:DXcaf.8991$q%[email protected]...
>
> "Astriapo" <[email protected]> wrote in message
> news:[email protected]...
>>
>> I bought a dust collector tonight. What is the idea behind grounding
>> the hose? I assume to reduce friction. So do I connect it to a pipe
>> and hook it to the tool itself or what?
>>
>
>
> Gee - I'm really sorry you asked that question. Prepare for a lot of pro's
> and cons. For in depth information, search for info. Otherwise, *some*
> people content that static electricity could generate a spark which will
> ignite the dust in the hoses and start a fire in your workshop. Others
> quickly point out that there is NOT ONE documented case of this happening
> in
> a home workshop. Dust explosions in a commercial environment are another
> matter but still not relative to the dust collector and static
> electricity.
>
> If you want to do it, run a copper wire through the hoses and ground them.
> I
> did it that way and it was a real PITA. When I moved and redid the system,
> I
> did not ground the hoses/pipes.
>
> IMHO, ignore the grounding - it really falls under the urban legend
> heading.
>
> Vic
>
>
"Buster" <[email protected]> wrote in message
news:%deaf.396481$tl2.700@pd7tw3no...
> You'd be surprised how much static is built up on the system. If you're
> moving it around the shop at all you'll want to ground it so you don't get
> shocked every time you touch it... and continuously while your touching
> it.
>
> As the other reply points out people worry about dust explosions and such,
> I agree with him I don't think it's a real danger.
Of course, grounding non-conducting material is a bit iffy. If don't want
to get shocked, you should be "grounding" the outside.
Now metal ducts and the odd woodscrew represent a real sparking danger.
"Mike Berger" <[email protected]> wrote in message
news:[email protected]...
> My shop vac pushes enough air to ionize ne-2 neon lights and make
> them glow. It gets very dry here in the midwest during the winter.
> This is NOT urban legend. We see sparks and grain dust explosions
> every year. It's not a big stretch to imagine a fire from sawdust.
> People in this newsgroup have ignited it with sparks or hot metal
> particles.
>
> Vic Baron wrote:
>
>> IMHO, ignore the grounding - it really falls under the urban legend
>> heading.
>>
" 'Our preliminary information shows that there have been 150 dust
explosions resulting in more than 80 deaths over the past two decades,' CSB
representative Dan Horowitz says. Hoyle, who is heading the investigation,
traveled to Baltimore in October to attend a meeting of NFPA's Technical
Committee on Handling and Conveying of Dusts, Vapors, and Gases, which has
jurisdiction over NFPA 654."
You need to do something. It would seem half the explosions in the US are
happening where you live.
The folks at NFPA will remind you that proper particle composition, size,
dispersal but overall confinement, and the availability of oxygen don't
guarantee an explosion. Even the ignition source has to fall within a fairly
narrow set of parameters.
That's why dust explosions so rare. Now explosions resulting from "dust"
off-gassing, like plastics and such are more common, but they're not really
dust explosions, nor are they so picky in their conditions.
[...snip...]
>
>Gee - I'm really sorry you asked that question. Prepare for a lot of pro's
>and cons. For in depth information, search for info. Otherwise, *some*
>people content that static electricity could generate a spark which will
>ignite the dust in the hoses and start a fire in your workshop. Others
>quickly point out that there is NOT ONE documented case of this happening in
>a home workshop.
[...snip...]
FWIW, I do recall seeing a mention of this in Sandor N.'s book on dust
collection a few years back. He stated in that edition that insurance
companies said they have documented evidence this does happen. Whether
you believe that or not, it might be wise to be sure you don't do
something the insurance companies can use to avoid paying out on a
claim.
There's a new edition of that book out, I guess. I wonder what he says
now?
Anyway, on Bill Pentz web site on dust collection
(http://billpentz.com//woodworking/cyclone/index.cfm) I believe he
says something about using metallic tape for grounding as being easier
than wire.
On Wed, 02 Nov 2005 19:23:39 -0500, Astriapo <[email protected]>
wrote:
>
>I bought a dust collector tonight. What is the idea behind grounding
>the hose? I assume to reduce friction. So do I connect it to a pipe
>and hook it to the tool itself or what?
>
>Thanks...
please be careful to properly ground the system. instructions are at:
<http://groups.google.com/group/rec.woodworking/msg/fbf227e350673fea?output=gplain>
On Thu, 03 Nov 2005 10:27:15 -0600, Mike Berger <[email protected]>
wrote:
>My shop vac pushes enough air to ionize ne-2 neon lights and make
>them glow. It gets very dry here in the midwest during the winter.
>This is NOT urban legend. We see sparks and grain dust explosions
>every year. It's not a big stretch to imagine a fire from sawdust.
>People in this newsgroup have ignited it with sparks or hot metal
>particles.
if you have evidence of a static electricity induced explosion in a
home shop dust collection system, post it here. you'll make history-
it will be the first and only time such evidence has come to light.
wanna be famous? go for it....
Astriapo wrote:
> joe2 wrote:
>
>> Tom Woodman Wrote:
>>
>>> If you don't think you have a static problem in your workshop... what
>>> do
>>> you think is holding all that dust on the walls?
>>
>>
>>
>> Spider webs. :)
>>
>>
> I was just wondering where the myth began then? Sounds like a job for
> Myth Busters...
And someone has already posted that on their website, so I can't ask
again. Sniff.
"Astriapo" <[email protected]> wrote in message
news:[email protected]...
>
> I bought a dust collector tonight. What is the idea behind grounding
> the hose? I assume to reduce friction. So do I connect it to a pipe
> and hook it to the tool itself or what?
>
Gee - I'm really sorry you asked that question. Prepare for a lot of pro's
and cons. For in depth information, search for info. Otherwise, *some*
people content that static electricity could generate a spark which will
ignite the dust in the hoses and start a fire in your workshop. Others
quickly point out that there is NOT ONE documented case of this happening in
a home workshop. Dust explosions in a commercial environment are another
matter but still not relative to the dust collector and static electricity.
If you want to do it, run a copper wire through the hoses and ground them. I
did it that way and it was a real PITA. When I moved and redid the system, I
did not ground the hoses/pipes.
IMHO, ignore the grounding - it really falls under the urban legend heading.
Vic
"It gets very dry here in the midwest during the winter. This is NOT urban
legend"
Here we go again. I too, live in the mid-west and have had an ungrounded
plastic piped system about 20 years, no sign of static problem. We are
talking home shop here, not commercial shop. A post a couple of year ago,
using Gov. figures, estimated that you would have to reduce a 6" pc of Oak
4x4 to dust in about one minute to get a great enough concentration to
cause an explosion.
Walt Conner
Vic Baron Wrote:
> "Astriapo" [email protected] wrote in message
> news:[email protected]...
>
> I bought a dust collector tonight. What is the idea behind grounding
> the hose? I assume to reduce friction. So do I connect it to a pipe
> and hook it to the tool itself or what?
>
>
>
> Gee - I'm really sorry you asked that question. Prepare for a lot of
> pro's
> and cons. For in depth information, search for info. Otherwise, *some*
> people content that static electricity could generate a spark which
> will
> ignite the dust in the hoses and start a fire in your workshop. Others
> quickly point out that there is NOT ONE documented case of this
> happening in
> a home workshop. Dust explosions in a commercial environment are
> another
> matter but still not relative to the dust collector and static
> electricity.
>
> If you want to do it, run a copper wire through the hoses and ground
> them. I
> did it that way and it was a real PITA. When I moved and redid the
> system, I
> did not ground the hoses/pipes.
>
> IMHO, ignore the grounding - it really falls under the urban legend
> heading.
>
> Vic
Gents,
I have no knowledge of static electric build-up causing explosions.
However, please be advised that static electric in an ungrounded vacuum
system can be substantial. Just last week, my son "fried" a Dewalt
plunge router while using its dust collection connection in
conjunction with his home vacuum system.
He was running the router while connected to his operating home vacuum
sytem. The plastic hose connected to the vac and the router was draped
over his shoulder. After running the setup for only 10 to 20 seconds,
he felt a tremendous shock in his shoulder at which time the router
stopped running. Previously, he had used the router extensively with
the home vacuum in another location where the vacuum outlet was
grounded.
The router was deemed not repairable by the Dewalt service center. The
center personnel stated that the router had been damaged by an external
electric source; the router checked out as properly insulated.
Please be careful.
--
Jerry S
"Mike Berger" <[email protected]> wrote in message
news:[email protected]...
> My shop vac pushes enough air to ionize ne-2 neon lights and make
> them glow. It gets very dry here in the midwest during the winter.
> This is NOT urban legend. We see sparks and grain dust explosions
> every year. It's not a big stretch to imagine a fire from sawdust.
> People in this newsgroup have ignited it with sparks or hot metal
> particles.
>
> Vic Baron wrote:
>
> > IMHO, ignore the grounding - it really falls under the urban legend
heading.
> >
Static charge and sawdust fires from hot metal are two different animals.
Grain and dust explosions in commercial environment are not the same thing.
I repeat - sawdust explosions from static charge in a home workshop are the
stuff of urban legend.
Vic
[email protected] wrote:
> On Wed, 02 Nov 2005 19:23:39 -0500, Astriapo <[email protected]>
> wrote:
>
>>
>>I bought a dust collector tonight. What is the idea behind grounding
>>the hose? I assume to reduce friction. So do I connect it to a pipe
>>and hook it to the tool itself or what?
>>
>>Thanks...
>
>
> please be careful to properly ground the system. instructions are at:
> <http://groups.google.com/group/rec.woodworking/msg/fbf227e350673fea?ou
> tput=gplain>
>
I want to see the Video of freehand panel routing on a table mounted
router.
My shop vac pushes enough air to ionize ne-2 neon lights and make
them glow. It gets very dry here in the midwest during the winter.
This is NOT urban legend. We see sparks and grain dust explosions
every year. It's not a big stretch to imagine a fire from sawdust.
People in this newsgroup have ignited it with sparks or hot metal
particles.
Vic Baron wrote:
> IMHO, ignore the grounding - it really falls under the urban legend heading.
>
Lobby Dosser wrote:
> [email protected] wrote:
>
>
>>On Wed, 02 Nov 2005 19:23:39 -0500, Astriapo <[email protected]>
>>wrote:
>>
>>
>>>I bought a dust collector tonight. What is the idea behind grounding
>>>the hose? I assume to reduce friction. So do I connect it to a pipe
>>>and hook it to the tool itself or what?
>>>
>>>Thanks...
>>
>>
>>please be careful to properly ground the system. instructions are at:
>><http://groups.google.com/group/rec.woodworking/msg/fbf227e350673fea?ou
>>tput=gplain>
>>
>
>
> I want to see the Video of freehand panel routing on a table mounted
> router.
I could probably do that... Isn't the wheel on top of the bit there so
your wood can use it at a guide. Plunge in and push forward...
On Fri, 4 Nov 2005 08:06:27 -0500, "George" <George@least> wrote:
>
>"Mike Berger" <[email protected]> wrote in message
>news:[email protected]...
>> My shop vac pushes enough air to ionize ne-2 neon lights and make
>> them glow. It gets very dry here in the midwest during the winter.
>> This is NOT urban legend. We see sparks and grain dust explosions
>> every year. It's not a big stretch to imagine a fire from sawdust.
>> People in this newsgroup have ignited it with sparks or hot metal
>> particles.
>>
>> Vic Baron wrote:
>>
>>> IMHO, ignore the grounding - it really falls under the urban legend
>>> heading.
>>>
>
>" 'Our preliminary information shows that there have been 150 dust
>explosions resulting in more than 80 deaths over the past two decades,' CSB
>representative Dan Horowitz says. Hoyle, who is heading the investigation,
>traveled to Baltimore in October to attend a meeting of NFPA's Technical
>Committee on Handling and Conveying of Dusts, Vapors, and Gases, which has
>jurisdiction over NFPA 654."
>
>You need to do something. It would seem half the explosions in the US are
>happening where you live.
>
>The folks at NFPA will remind you that proper particle composition, size,
>dispersal but overall confinement, and the availability of oxygen don't
>guarantee an explosion. Even the ignition source has to fall within a fairly
>narrow set of parameters.
>
>That's why dust explosions so rare. Now explosions resulting from "dust"
>off-gassing, like plastics and such are more common, but they're not really
>dust explosions, nor are they so picky in their conditions.
>
OK, let's get a look at that preliminary data.
how many of those were in home shop dust collectors?
how many of them were caused by static discharge?
I'll guess none.
On Wed, 02 Nov 2005 19:23:39 -0500, Astriapo <[email protected]>
wrote:
>
>I bought a dust collector tonight. What is the idea behind grounding
>the hose? I assume to reduce friction. So do I connect it to a pipe
>and hook it to the tool itself or what?
>
>Thanks...
The incorrect idea is that by "grounding" the plastic piping, static
charge can be eliminated.
When two things in contact with each other are separated, electrons
can be stripped from one of them and deposited on the other. In this
case, the objects are 1) the piping and 2) air/dust. If either or
both of the objects are insulators then the resulting electrical
charges have no place to go and thus remain in place, i.e. they are
"static."
If the process is continous, as it is when air/dust is flowing through
the piping, the charges continue to build. They cannot build without
limit however because there is no perfect insulator so when the
potential difference (voltage) becomes high enough the insulative
properties will be overcome and the charge will discharge. This can
happen rapidly, via a spark (think lightning) or more likely, by
gradual discharge.
The myth in woodworking is that "ungrounded" piping will generate
static charge buildup sufficient to create a spark inside the piping
that will ignite the combustible dust. There is no documented
evidence of this ever happening.
Furthermore, even if there was, there is no way to "ground" an
insulator. It's an "insulator", by definition a poor conductor of
electricity, and attaching a wire to it, or running a wire through it
cannot prevent the buildup of charge in areas not directly in contact
with the wire. The best this wire can do is to insure that the
equipment at each end is at the same potential, something that should
already be the case due to the equipment-grounding conductor in the
power wiring.
Can you be shocked by static charge buildup in your shop? Sure. I'm
in AZ where the RH can be under 10% and dry air is a better insulator
than damp air. If I'm wearing rubber soled shoes and vacuum up a large
volume of dust, using my all-plastic (double insulated) vac, the
vacuum and I get charged up. If I then touch the metal frame of a
piece of grounded equipment I will get a shock. There might even be a
tiny spark. Does anyone think that this spark will ignite the dust in
the air and burn down my garage?
If I turn off the vacuum and wait just a few seconds, I can touch the
grounded equipment and not be shocked. This shows that the insulators
are not perfect and that the charge is slowly dissipated. Note that
this is a continuous process, which is why you don't get shocked every
time you run a vacuum; if the charge buildup is small, for example
when you're not sucking up sawdust, but just air, the charge is
dissipating as fast as it is generated.
Tip: If possible (and I remember to do it) I just keep one hand on a
piece of grounded equipment when I suck up a pile of stuff. Absent
that, I bend over and touch the concrete floor with a bare hand before
touching anything else. This dissipates the charge slowly and
painlessly.
On Thu, 03 Nov 2005 22:03:14 -0500, Astriapo <[email protected]>
wrote:
>Astriapo wrote:
>> I was just wondering where the myth began then? Sounds like a job for
>> Myth Busters...
>And someone has already posted that on their website, so I can't ask
>again. Sniff.
Has anyone ever suggested "woodshop PVC pipe dust collector explosion"
to Adam & Jamie? <G>
In order for an explosion from a static electric discharge to ignite
sawdust in the air, the concentration in the air would need to be on the
order of not being able to see your hand in front of your face! It is
not possible to have that concentration of sawdust in the air and still
be breathing.
I have no personal experience, this is according to everything I've ever
read on the subject. Grain explosions occur in very confined areas in
silos with very high concentrations of dust, to a degree simply not
possible in a shop (commercial or hobby).
Mike Berger wrote:
> My shop vac pushes enough air to ionize ne-2 neon lights and make
> them glow. It gets very dry here in the midwest during the winter.
> This is NOT urban legend. We see sparks and grain dust explosions
> every year. It's not a big stretch to imagine a fire from sawdust.
> People in this newsgroup have ignited it with sparks or hot metal
> particles.
>
> Vic Baron wrote:
>
>> IMHO, ignore the grounding - it really falls under the urban legend
>> heading.
>>
--
Joseph Connors
The New Golden Rule:
Those with the gold, make the rules!