Yesterday in the mail there came a catalog I've never seen before, a
company called Leichtung Workshops out of Casper, WY. Has anybody on
the wreck bought from them and what have your experiences been?
Some of their stuff is priced the same as anybody else's ($37 for a
set of 3 plug cutters, same price as the Veritas at my local pro
shop). But what caught my eye were their prices on clamps. It was
literally 2 hours after I had just bought a couple Jorgensen 6" bar
clamps at my local hardware retailer for $9.99 each that the Leichtung
catalog came advertising a no-name brand for $3.99 and 36" for $8.99
(vs. $24.99 locally). Their version of a band clamp is $18.99 vs. $38
at the Rockler outlet.
So is this just another outlet like Harbor tool, selling cheaply made
knock offs? Or is their stuff decent? Thanks in advance.
In article <[email protected]>, George
<[email protected]> wrote:
> As the saying goes "you can't be first, but you can be next"...
> http://www.chem.leeds.ac.uk/delights/texts/expt_6.html
No mention at all of static electricity.
> http://www.safteng.net/Incident_Alert_Archives/industrial_accidents%201.htm
"The bin was collecting dust from the plant when the sawdust was
ignited by a spark. The spark was probably caused by a metal fragment
or nail striking the machinery."
Not static electricity. The other reference on the page is spontaneous
combustion, not explosion.
> http://www.gov.on.ca/lab/english/hs/alerts/i15.html
Explosion caused by existing fire in the hopper, not static electricity.
> http://www.engcollab.com/articles/understanding1.htm (safety info)
... but again, no example of an explosion caused by static electricity.
djb
--
There are no socks in my email address.
"Quando Omni Flunkus Moritati"
well, the "potential" is there but so is the potential for a wheel to
fall off an airplane and land on your car (which has happened). You
cannot protect against every possibility although there are those that
try. I have metal ductwork because I find it easier to work with but if
I had PVC I would only ground it to stop it discharging to me.
BRuce
Edwin Pawlowski wrote:
> "George" <[email protected]> wrote in message
> news:[email protected]...
>
>>I don't know what their grounding kit consists of or how effective it
>>is...BUT, explosions are a real possibility. The conditions would require
>>very fine particles of airborne sawdust in a high concentration and a
>
> static
>
>>electric discharge, and voila, you get the same result as grain elevators
>>experience every so often.
>
>
>
> The theory has been bandied about here for years. No one, however, has been
> able to find a single case of an explosion actually happening in a small
> shop. A little documentation would go a long way to convince us of a real
> potential problem.
> Ed
>
>
--
---
BRuce
"George" <[email protected]> wrote
: Like I said in my previous post, an ESD-caused sawdust fire or explosion
: would be most likely with a high concentration of FINE (very fine)
sawdust,
: like from sanding, rather than what your table saw or planer generates.
Edited from a 1977 posting to rec.ww. I fear that I no longer have details
of the actual source.
'.........................................................an OSHA required
data sheet.....
lists the safety requirements of hazardous material. It states therein that
the
Least Explosion Level (LEL) for wood dust is 40 grams per cubic meter of
air.
If there are 453.5 grams in a pound and 35.31 cubic feet in a cubic meter
then
this calculates out to 0.0025 pounds per cubuc foot of air.
If you have a typical 1-1/2 horsepower dust collection unit and nothing else
connected to it you can probably draw 1100 cfm according to the
manufacturers
rating. So, at 0.0025 pounds per cubic foot of air, you are going to need
to
sand off 2.75 pounds of wood per minute to reach the minimum dust explosion
level in your ductwork.
How does that relate to in the real world? The book says red oak has a
density
of 43 to 63 pounds per cubic foot. If we use 53 pounds as the average and
divide 2.75 pounds by 53 pounds per cubic foot we get 0.052 cubic feet of
oak
to reach LEL in our ductwork. If we were sanding a red oak 4" x 4" on the
sander, we would have to sand away .468 feet of 4x4 per minute or a little
over 5-1/2 inches if 4x4 oak per minute to reach LEL. Unless you have the
Tim
Allen memorial sander in your shop, I don't think that a home size workshop
can produce enough dust to get to the minimum explosive level.
Now, When you start moving thousands of pounds per minute of wood dust
through
a dust collection system, you can relate it to a grain elevator.'
Jeff G
--
Jeff Gorman, West Yorkshire, UK
Email address is username@ISP
username is amgron
ISP is clara.co.uk
Website www.amgron.clara.net
On Thursday, December 17, 2015 at 1:23:37 PM UTC-5, Trenbidia wrote:
> On Thu, 17 Dec 2015 09:52:55 -0800, mscottgruber wrote:
>
> >> Yesterday in the mail there came a catalog I've never seen before, a
> >> company called Leichtung Workshops out of Casper, WY. Has anybody on
> >> the wreck bought from them and what have your experiences been?
>
> I did - a long time ago. The company has been sold to Woodworkers Supply
> in Casper. I've also ordered from them, but again, it was a long time
> ago. Used to stop and browse their store any time we drove through
> Casper.
>
> So any old reviews you see about Leichtung no longer apply. But I never
> had any problems with Woodworkers Supply. But it may have changed hands
> as well - I don't know.
>
>
>
> --
> Nobody expects the Spanish Inquisition!
Love it when a 15 year old thread comes back to life :)
On Tue, 9 Dec 2003 23:07:10 -0500, "George" <[email protected]>
wrote:
> In
>the manufacture of electronic products, ESD protection is provided with much
>higher resistances. Many of the 3M products to reduce damage due to static
>use about 1,000,000 ohms to ground (or even 10,000,000 ohms).
I work in the electronics biz (telco), and we do all kinds of things
to contain ESD. For an entirely different reason. <G> Reasons for
that resistance include SLOWLY discharging the static electricity.
>In spite of how the tone of our exchange may have sounded to you, I fall in
>the "better safe than sorry" camp...if you re-read my original posting on
So do I, which is why I originally installed ground wires. When I
replumbed after a shop rearrange, I removed the existing internal
wires, and thought about driving screws in from the outside. After
using it ungrounded for a while, I saw no reason to bother to ground
it.
Barry
Ian Dodd wrote:
>
About 15 or so years ago I bought a doweling jig from them. Can't
remember what I
paid or if the price was inline with other companies products, but the
jig
is very well made without any "cheapness" in design or materials. I
think they
are basically just another one of the "boutique" type shops with a few
of their own
products, a few of the popular products from others, and with a
smattering of cheesy
offshore products thrown in for good measure.
-Bruce
> Yesterday in the mail there came a catalog I've never seen before, a
> company called Leichtung Workshops out of Casper, WY. Has anybody on
> the wreck bought from them and what have your experiences been?
>
> Some of their stuff is priced the same as anybody else's ($37 for a
> set of 3 plug cutters, same price as the Veritas at my local pro
> shop). But what caught my eye were their prices on clamps. It was
> literally 2 hours after I had just bought a couple Jorgensen 6" bar
> clamps at my local hardware retailer for $9.99 each that the Leichtung
> catalog came advertising a no-name brand for $3.99 and 36" for $8.99
> (vs. $24.99 locally). Their version of a band clamp is $18.99 vs. $38
> at the Rockler outlet.
>
> So is this just another outlet like Harbor tool, selling cheaply made
> knock offs? Or is their stuff decent? Thanks in advance.
-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----== Over 100,000 Newsgroups - 19 Different Servers! =-----
Ian Dodd wrote:
> Yesterday in the mail there came a catalog I've never seen before, a
> company called Leichtung Workshops out of Casper, WY. Has anybody on
> the wreck bought from them and what have your experiences been?
About 15 - 20 years ago Leichtung, with the woodworkers I know, was
respected for quality merchandise. I haven't heard much about them in
recent years. Trying their web site at:
http://www.leichtung.com/cgi-bin/HOME.exe
it brings up "Woodworker's Supply". I suspect, somewhere along the line,
Leichtung was bought out and now "they" are trying to revive the name.
--
Jack Novak
Buffalo, NY - USA
(Remove "SPAM" from email address to reply)
Mike G wrote:
> You can rest easy now George. Trendlines went tits up several years ago.
> Their golf line is, as far as I know, gone. Their woodworking supply branch
> became Woodworkers Warehouse. I do a lot of trade with Woodworkers Warehouse
> and they have always been great people to deal with.
> --
Interesting... A few weeks ago I accessed Woodworker Warehouse's web page. It
worked, and I was almost certain there was a blurb at the bottom of the page
saying that they were a division of Trendlines. I checked the page today at:
http://www.woodworkerswarehouse.com/
We did have on franchised store in the Buffalo area. It looks like Rockler's
will now be the sole player. :-(
Where's Rob Lee? ;-)
--
Jack Novak
Buffalo, NY - USA
(Remove "SPAM" from email address to reply)
On Mon, 8 Dec 2003 20:46:23 -0500, "George" <[email protected]>
wrote:
> Since any dust collection system will cost at
>least $200, why are you kicking and screaming over $5-10 worth of wire to
>make it safer? Just curious...
In my case it had nothing to do with cost. I GROUNDED my system. I
pulled the wires out after getting tired of semi-weekly clogs caused
by jointer and planer chips and offcuts getting stuck in the wires. I
haven't had a clog since I pulled the wires out.
I can also see no noticeable difference in static electricity buildup
or the other performance aspects of the system. My ground wires were
grounded at copper cold water pipes which are in turn grounded to the
same 8' ground rod my radios are. The connections were soldered to
the pipes.
If you want to ground yours, feel free. Until someone comes up with
documented evidence, or for that matter, documented conjecture on the
part of a fire inspector that grounding would have prevented a WOOD
SHOP (NOT plastic, grain dust, etc...) explosion, I'll continue to
question "safer". I'd even go with "better safe than sorry" thinking,
if the wires didn't cause so many clogs.
Barry
Finally, quantitative proof! (Good analysis)
:-)
Thanx
Renata
On Wed, 10 Dec 2003 07:32:59 -0000, "Jeff Gorman" <[email protected]>
wrote:
>
>"George" <[email protected]> wrote
>
>: Like I said in my previous post, an ESD-caused sawdust fire or explosion
>: would be most likely with a high concentration of FINE (very fine)
>sawdust,
>: like from sanding, rather than what your table saw or planer generates.
>
>Edited from a 1977 posting to rec.ww. I fear that I no longer have details
>of the actual source.
>
>'.........................................................an OSHA required
>data sheet.....
> lists the safety requirements of hazardous material. It states therein that
>the
> Least Explosion Level (LEL) for wood dust is 40 grams per cubic meter of
>air.
>
>If there are 453.5 grams in a pound and 35.31 cubic feet in a cubic meter
>then
> this calculates out to 0.0025 pounds per cubuc foot of air.
>
>If you have a typical 1-1/2 horsepower dust collection unit and nothing else
> connected to it you can probably draw 1100 cfm according to the
>manufacturers
> rating. So, at 0.0025 pounds per cubic foot of air, you are going to need
>to
> sand off 2.75 pounds of wood per minute to reach the minimum dust explosion
> level in your ductwork.
>
>How does that relate to in the real world? The book says red oak has a
>density
> of 43 to 63 pounds per cubic foot. If we use 53 pounds as the average and
> divide 2.75 pounds by 53 pounds per cubic foot we get 0.052 cubic feet of
>oak
> to reach LEL in our ductwork. If we were sanding a red oak 4" x 4" on the
> sander, we would have to sand away .468 feet of 4x4 per minute or a little
> over 5-1/2 inches if 4x4 oak per minute to reach LEL. Unless you have the
>Tim
> Allen memorial sander in your shop, I don't think that a home size workshop
> can produce enough dust to get to the minimum explosive level.
>
>Now, When you start moving thousands of pounds per minute of wood dust
>through
> a dust collection system, you can relate it to a grain elevator.'
>
>Jeff G
>
>--
>Jeff Gorman, West Yorkshire, UK
>Email address is username@ISP
>username is amgron
>ISP is clara.co.uk
>Website www.amgron.clara.net
>
>
>
On Thu, 11 Dec 2003 18:42:20 -0500, "John Sellers"
<[email protected]> wrote:
>
>"Bob N" <[email protected]> wrote in message
>news:HtpBb.4569$%[email protected]...
>> Mike, as a benefit the brads should lower the impedance so you won't
>need to buy a preamp.
>>
>> Bob
>>
>
>I knew there were pickers here.
Oh, hell yes. Bob and I met on rec.music.makers.guitar.acoustic.
Great group of folks, have annual get togethers, good newsgroup to
check out.
Michael
On Friday, December 5, 2003 at 4:28:31 PM UTC-5, Ian Dodd wrote:
> Yesterday in the mail there came a catalog I've never seen before, a
> company called Leichtung Workshops out of Casper, WY. Has anybody on
> the wreck bought from them and what have your experiences been?
>
> Some of their stuff is priced the same as anybody else's ($37 for a
> set of 3 plug cutters, same price as the Veritas at my local pro
> shop). But what caught my eye were their prices on clamps. It was
> literally 2 hours after I had just bought a couple Jorgensen 6" bar
> clamps at my local hardware retailer for $9.99 each that the Leichtung
> catalog came advertising a no-name brand for $3.99 and 36" for $8.99
> (vs. $24.99 locally). Their version of a band clamp is $18.99 vs. $38
> at the Rockler outlet.
>
> So is this just another outlet like Harbor tool, selling cheaply made
> knock offs? Or is their stuff decent? Thanks in advance.
I have ordered tools from for my husband and he was happy with them.
On 2015-12-17 19:08:32 +0000, [email protected] said:
> On Thursday, December 17, 2015 at 1:23:37 PM UTC-5, Trenbidia wrote:
>> On Thu, 17 Dec 2015 09:52:55 -0800, mscottgruber wrote:
>>
>>>> Yesterday in the mail there came a catalog I've never seen before, a
>>>> company called Leichtung Workshops out of Casper, WY. Has anybody on
>>>> the wreck bought from them and what have your experiences been?
>>
>> I did - a long time ago. The company has been sold to Woodworkers Supply
>> in Casper. I've also ordered from them, but again, it was a long time
>> ago. Used to stop and browse their store any time we drove through
>> Casper.
>>
>> So any old reviews you see about Leichtung no longer apply. But I never
>> had any problems with Woodworkers Supply. But it may have changed hands
>> as well - I don't know.
>>
>>
>>
>> --
>> Nobody expects the Spanish Inquisition!
>
> Love it when a 15 year old thread comes back to life :)
I actually had forgotten about them, looks like Woodworkers Supply
folded them into the company and closed that name out
On Tue, 09 Dec 2003 13:41:00 GMT, "Rick" <[email protected]> wrote:
>BTW, you MUST use the "wire" from a string trimmer to connect your PVC duct
>to the PVC pipe driven into the dirt.
Hmm... I think I fukd up. Do I have to replace all the monofilament
fishing line? That'll take longer than a winter in Luigiland.
How 'bout if I shoot 16-gauge brads through the fishing line into the
PVC? That should improve the connectical disjointing of the charge
buoyancy, right?
Michael
"Mike G" <[email protected]> wrote in message
news:[email protected]...
> You can rest easy now George. Trendlines went tits up several years ago.
> Their golf line is, as far as I know, gone. Their woodworking supply
branch
> became Woodworkers Warehouse. I do a lot of trade with Woodworkers
Warehouse
> and they have always been great people to deal with.
> --
> Mike G.
Going tits up as well apparently!
--
© Jon Down ®
http://www.stores.ebay.com/jdpowertoolcanada
"Bob N" <[email protected]> wrote in message
news:HtpBb.4569$%[email protected]...
> Mike, as a benefit the brads should lower the impedance so you won't
need to buy a preamp.
>
> Bob
>
I knew there were pickers here.
John Sellers
On 12/24/2015 8:55 AM, Doug Miller wrote:
> [email protected] wrote in news:6cc61f6c-1fbe-4f7e-ac95-e3142dca24a8
> @googlegroups.com:
>
>> On Friday, December 5, 2003 at 4:28:31 PM UTC-5, Ian Dodd wrote:
> [...]
>> I have ordered tools from for my husband and he was happy with them.
>
> You just responded to a post from 12 years ago...
>
And I never saw it until YOU made a comment. Stuff happens, just let it go.
In article <[email protected]>,
[email protected] says...
> Yesterday in the mail there came a catalog I've never seen before, a
> company called Leichtung Workshops out of Casper, WY. Has anybody on
> the wreck bought from them and what have your experiences been?
I think they were independent at one point, but they're part of
Woodworker's Supply now.
http://www.woodworker.com
CharlesJ
--
========================================================================
Charles Jones | Works at HP, | email: [email protected]
Hewlett-Packard | doesn't speak | ICQ: 29610755
Loveland, Colorado | for HP | AIM: LovelandCharles
USA | |Jabber: [email protected]
If it isn't you'll be in hot water.
BTW, you MUST use the "wire" from a string trimmer to connect your PVC duct
to the PVC pipe driven into the dirt. Your connections may be made with
multiple nylon self-locking cable ties (only don't use the ones with the
metal locking tab ... use the all nylon ones). Be sure to coat all the
connections with a good quality teflon grease.
Rick
"Henry E Schaffer" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> Michael Baglio <mbaglio<NOSPAM> wrote:
> >... that only approved way to ground a PVC dust collection system is
> >run a wire from it to a PVC pipe driven into the dirt. :)
>
> Does it have to be a cold water PVC pipe? :-)
> --
> --henry schaffer
> [email protected]
You can rest easy now George. Trendlines went tits up several years ago.
Their golf line is, as far as I know, gone. Their woodworking supply branch
became Woodworkers Warehouse. I do a lot of trade with Woodworkers Warehouse
and they have always been great people to deal with.
--
Mike G.
[email protected]
Heirloom Woods
www.heirloom-woods.net
"George" <[email protected]> wrote in message
news:[email protected]...
> My only gripe about Leichtung Workshops is that if you encourage them in
any
> way (like buying from them), they will bury you in catalogs. They aren't
as
> bad as Trendlines in that regard, but I won't purchase from them again.
> (Trendlines is worse because they ASSUME that all woodworkers MUST love
> golf, so they bury you in woodworking and golfing catalogs. And it is
> virtually impossible to get off any unwanted list they decide to add you
> to.) Personally, I don't like buying from companies that are strictly
> marketing companies and aren't really into whatever it is that they sell
and
> that is my perception of Leichtung and Trendlines.
>
> "Ian Dodd" <[email protected]> wrote in message
> news:[email protected]...
> > Yesterday in the mail there came a catalog I've never seen before, a
> > company called Leichtung Workshops out of Casper, WY. Has anybody on
> > the wreck bought from them and what have your experiences been?
> >
> > Some of their stuff is priced the same as anybody else's ($37 for a
> > set of 3 plug cutters, same price as the Veritas at my local pro
> > shop). But what caught my eye were their prices on clamps. It was
> > literally 2 hours after I had just bought a couple Jorgensen 6" bar
> > clamps at my local hardware retailer for $9.99 each that the Leichtung
> > catalog came advertising a no-name brand for $3.99 and 36" for $8.99
> > (vs. $24.99 locally). Their version of a band clamp is $18.99 vs. $38
> > at the Rockler outlet.
> >
> > So is this just another outlet like Harbor tool, selling cheaply made
> > knock offs? Or is their stuff decent? Thanks in advance.
>
>
"George" <[email protected]> wrote in message
news:[email protected]...
> I don't know what their grounding kit consists of or how effective it
> is...BUT, explosions are a real possibility. The conditions would require
> very fine particles of airborne sawdust in a high concentration and a
static
> electric discharge, and voila, you get the same result as grain elevators
> experience every so often.
The theory has been bandied about here for years. No one, however, has been
able to find a single case of an explosion actually happening in a small
shop. A little documentation would go a long way to convince us of a real
potential problem.
Ed
On 09 Dec 2003, Michael Baglio <mbaglio spake unto rec.woodworking:
>
>>BTW, you MUST use the "wire" from a string trimmer to connect your PVC
>>duct to the PVC pipe driven into the dirt.
> How 'bout if I shoot 16-gauge brads through the fishing line into the
> PVC? That should improve the connectical disjointing of the charge
> buoyancy, right?
What are you, a child? If you use differentially valented materials,
i.e. nylon filament and brads, on humid days the moisture in the air will
set up a battery-like effect, and the ions in the air will rust the top of
your table saw down to the trunnions before you can grab the WD-40.
If I were you, I'd bring in a Feng-Shui master to make sure your
ductwork isn't constricting the flow of positive energy through your
personal space. You might want to get your chakras aligned as well, just
to be on the safe side.
[email protected] wrote in news:6cc61f6c-1fbe-4f7e-ac95-e3142dca24a8
@googlegroups.com:
> On Friday, December 5, 2003 at 4:28:31 PM UTC-5, Ian Dodd wrote:
[...]
> I have ordered tools from for my husband and he was happy with them.
You just responded to a post from 12 years ago...
On Sun, 7 Dec 2003 00:20:51 -0500, "George" <[email protected]>
wrote:
>I don't know what their grounding kit consists of or how effective it
>is...BUT, explosions are a real possibility.
Here we go... <G>
Please point us to a documented case of a wood shop dust collector
explosion due to static electricity. Ciggies, glowing embers or
glowing metal shavings don't count. If it's not on the web, I'll
volunteer to go get a copy of the news article from my local
university library and put it up on the web.
I'll simply need the date and name of the paper, TV, or radio entity
that published it. I'll do the rest to get it on the web.
FWIW, I pulled my ground wires out of my DC pipes, as they caused
clogging if an offcut or large chip landed the right way.
Barry
I got my cabinet saw through them. The sales guy did alot of leg work to get
me just what I wanted at amizon's prices. Sadly, he is no longer there.
I recently mentioned to one of their managers that the "dust collection
grounding kit" was snake oil. He could have said "it make some folks feel
safer" but instead he insisted that we "personally" knew people who had
experience explosions in a home shop. I lost all respect.
That said, they are better than nothing. It's still nice to be able to see
and touch in theis one-horse town.
"Howard Ruttan" <[email protected]> wrote in message
news:[email protected]...
>
> "Mike G" wrote ...
> > You can rest easy now George. Trendlines went tits up several years ago.
> > Their golf line is, as far as I know, gone. Their woodworking supply
> branch
> > became Woodworkers Warehouse. I do a lot of trade with Woodworkers
> Warehouse
> > and they have always been great people to deal with.
>
> ... which is, however, not everyone's experience with WWW.
>
> --
>
> Cheers,
> Howard
>
> ----------------------------------------------------------
> Working wood in New Jersey - [email protected]
> Visit me in the woodshop - www.inthewoodshop.org
>
>
In article <[email protected]>,
Michael Baglio <mbaglio<NOSPAM> wrote:
>... that only approved way to ground a PVC dust collection system is
>run a wire from it to a PVC pipe driven into the dirt. :)
Does it have to be a cold water PVC pipe? :-)
--
--henry schaffer
[email protected]
On Thursday, December 17, 2015 at 1:23:37 PM UTC-5, Trenbidia wrote:
> On Thu, 17 Dec 2015 09:52:55 -0800, mscottgruber wrote:
>
> >> Yesterday in the mail there came a catalog I've never seen before, a
> >> company called Leichtung Workshops out of Casper, WY. Has anybody on
> >> the wreck bought from them and what have your experiences been?
>
> I did - a long time ago. The company has been sold to Woodworkers Supply
> in Casper. I've also ordered from them, but again, it was a long time
> ago. Used to stop and browse their store any time we drove through
> Casper.
>
> So any old reviews you see about Leichtung no longer apply. But I never
> had any problems with Woodworkers Supply. But it may have changed hands
> as well - I don't know.
>
>
>
> --
> Nobody expects the Spanish Inquisition!
oops, 12...dang it!
On Tue, 09 Dec 2003 18:08:55 GMT, Michael Baglio
<mbaglio<NOSPAM>@nc.rr.com> wrote:
>On Tue, 09 Dec 2003 13:41:00 GMT, "Rick" <[email protected]> wrote:
>
>>BTW, you MUST use the "wire" from a string trimmer to connect your PVC duct
>>to the PVC pipe driven into the dirt.
>
>Hmm... I think I fukd up. Do I have to replace all the monofilament
>fishing line? That'll take longer than a winter in Luigiland.
I've heard genuine wool thread, NOT cotton, will also work well.
Don't forget to grease the connections with non-petroleum lube. I
hear KY works well at a fair price. You could probably steal a tube
when the doctor is out of the room during your next physical.
Barry
On Tue, 09 Dec 2003 03:41:15 GMT, Mark & Juanita
<[email protected]> wrote:
>In article <[email protected]>, [email protected]
>says...
>> Since any dust collection system will cost at least $200, why are you
>> kicking and screaming over $5-10 worth of wire to make it safer?
>
> Not the $5 to $10 but the 30 to 40 hours of time it's going to take to
>wrap, interconnect across gaps, and seal any holes if you run the
>grounding inside the pipe, all for a very dubious benefit. The other
>problem is the fact that if you run the wire around the outside of the
>pipe, the only thing you will do is protect yourself from uncomfortable
>discharges when coming in contact with the pipe --
And if that actually _worked_, you'd think by now somebody would have
posted a pic of their NEW! IMPROVED! system--
--pvc pipes totally encased in aluminum foil. :)
"I'm grounded NOW, baby!!!"
M--
In article <[email protected]>, [email protected]
says...
> We'll see if the 5-6 links I posted in response actually do post...but
> another thought came to mind. Since any dust collection system will cost at
> least $200, why are you kicking and screaming over $5-10 worth of wire to
> make it safer? Just curious...
>
Not the $5 to $10 but the 30 to 40 hours of time it's going to take to
wrap, interconnect across gaps, and seal any holes if you run the
grounding inside the pipe, all for a very dubious benefit. The other
problem is the fact that if you run the wire around the outside of the
pipe, the only thing you will do is protect yourself from uncomfortable
discharges when coming in contact with the pipe -- as you alluded to in
your original post, the plastic pipe is non-conductive, therefore the
charge is distributed across the entire pipe and thus will not fully
discharge, particularly if the static is being generated from the
friction of the sawdust on the inside of the pipe. Grounding the inside
of the pipe leads to other theoretical problems: a) you cannot wrap a
conductor around the inside of the pipe, thus one must lay the conductor
inside the pipe. b) The problem here is since one is laying a conductor
along a non-conductive surface that is becoming electrically charged,
one could postulate that you are actually creating an environment in
which you have actually increased the potential for explosion by
providing a discharge path for a spark that could occur from the
potential generated across the diameter of the pipe, discharged to the
grounded wire inside the pipe. This could be further excacerbated in a
case in which the wire could become airborne due to the airflow in the
pipe, thus isolating the wire from the pipe until enough potential is
achieved to generate a spark from the pipe to the airborne wire.
> Like I said in my previous post, an ESD-caused sawdust fire or explosion
> would be most likely with a high concentration of FINE (very fine) sawdust,
> like from sanding, rather than what your table saw or planer generates.
>
Given your first link, how much sanding dust would be required to be
generated to achieve sufficient concentration for an explosion? I
cannot picture any workshop equipment capable of generating sufficient
volume and concentration of sawdust to ignite. Further, that experiment
requires a candle to ignite, this is not equivalent to the low amount of
energy imparted by a static discharge -- the duration of discharge is
too short to sustain combustion. i.e., what you have posted does not
constitute proof of your assertion.
>
>
On Tue, 9 Dec 2003 22:52:27 -0500, "George" <[email protected]>
wrote:
>
>"K.-Benoit Evans" <[email protected]> wrote in message
>news:[email protected]...
>> Unfortunately, the link at the end of the following citation no longer
>> works, but it did when I excerpted the article a couple of years ago.
>
>Do you know who did the study and when??? You say it was published a
>"couple of year ago"...any idea of when the study occurred?
here's the updated link.
http://mywebpages.comcast.net/rodec/woodworking/articles/DC_myths.html
On Sun, 07 Dec 2003 13:41:44 GMT, B a r r y B u r k e J r .
<[email protected]> wrote:
>On Sun, 7 Dec 2003 00:20:51 -0500, "George" <[email protected]>
>wrote:
>
>>I don't know what their grounding kit consists of or how effective it
>>is...BUT, explosions are a real possibility.
>
>Here we go... <G>
Now Barry... don't rain on the guy's parade. Simply instruct the nice
man that only approved way to ground a PVC dust collection system is
run a wire from it to a PVC pipe driven into the dirt. :)
Michael
On Mon, 8 Dec 2003 20:26:55 -0500, "George" <[email protected]>
wrote:
>As the saying goes "you can't be first, but you can be next"...
>http://www.chem.leeds.ac.uk/delights/texts/expt_6.htm
We know. <G> How would grounding change this?
>http://www.safteng.net/Incident_Alert_Archives/industrial_accidents%201.htm
A plastic insulation factory. Where is the wood shop explosion?
>http://www.gov.on.ca/lab/english/hs/alerts/i15.html
The sawdust was already on fire from another source. How would
grounding change this?
>http://www.engcollab.com/articles/understanding1.htm (safety info)
Where is the wood shop explosion?
We would like to see an actual WOOD DUST, not insulation, grain dust,
or plastic explosion caused by STATIC ELECTRICITY, not glowing
sharpening embers, cigarettes, torches, etc... that would have been
prevented with an internal ground wire.
Barry
Unfortunately, the link at the end of the following citation no longer
works, but it did when I excerpted the article a couple of years ago.
A research scientist at MIT has looked into this matter very carefully,
both anecdotally and empirically. In the summary of his quite long
report, he says:
"...I have read more than a dozen research
papers on this topic recently. The thing I am most struck by is how
hard these guys have to work to get dust explosions in the lab. It is
not hard to get ignition if one makes a very carefully controlled,
nonmoving cloud with just the right dust mix, and introduces a spark
from a very carefully designed sparking mechanism. But no one seems to
be able in lab sized experiments to get electrostatic discharge
ignition of even very highly combustible dusts in remotely realistic
situations, and they do try. Is is possible? I presume so, but it is
extremely difficult."
"...there has never, to my knowledge, been a documented case of an
explosion problem with PVC in the home shop or a case of an explosion
in a filter bag in a home shop. A friend of mine who is a professional
cabinet maker asked his fire inspector what he thought about the hazard
of PVC ducts, and the fire inspector said he was far more concerned
about people keeping lighter fluid under the kitchen sink. The fire
inspector was intrigued and checked whatever registry of fire
information he had available and came back and said he could not find
one reference to a problem in a small shop with PVC ducts."
"In all the years that this has been debated on the Web, not one
verifiable report has surfaced of an exploding home shop dust
collector. I know full well that anecdotal evidence does not make good
science, and just because I don't know of a problem caused by an
electrical discharge in a home shop DC does not make it impossible.
But, such evidence is certainly food for thought, and at least shows
that such events, if they exist at all, are very rare."
Near the end of the report, there is an explanation of several common
MYTHS (untrue, unfounded beliefs) about home workshop dust collection.
That list (without the accompanying explanations) is as follows:
Myths--the following assertions are NOT true
1. PVC ducts are dangerous. FALSE
2. You can ground PVC. FALSE
3. The only thing of concern in a dust collector are the ducts. FALSE
4. The external ground wire works by reducing the static on the outside
of the PVC. FALSE
5. The external wire must be bare. FALSE
6. Grounded screws can not help as they are too far apart. FALSE
7. Grounding works by removing charge from the dust. FALSE
8. Metal ducts keep the dust from charging. FALSE
9. Any spark will ignite the right dust mixture. FALSE
10. Grounding PVC works by removing charge at a point, and since charge
must be uniformly distributed, it therefore removes charge everywhere.
FALSE
11. Getting a discharge outside the ducts, say to your finger, means
you also have discharges inside the ducts. FALSE
The full report can be found at:
<http://www.gis.net/~dheaton/woodworking/articles/DC_myths.shtml>
--
Regards,
Benoit Evans
In article <[email protected]>,
"George" <[email protected]> wrote:
> I don't know what their grounding kit consists of or how effective it
> is...BUT, explosions are a real possibility. The conditions would require
> very fine particles of airborne sawdust in a high concentration and a static
> electric discharge, and voila, you get the same result as grain elevators
> experience every so often. I am an electrical engineer and have used a
> static electric voltmeter to track down static problems in the manufacture
> of electronic products and have found charges in the neighborhood of
> 5,000-10,000 volts cause by airflow across non-conductive plastic (polymer)
> surfaces.
Please do your homework and read the archived posts on this subject. The
possibilty of a wood dust explosion in a home workshop are practically
less than nil (perhaps even lower!)
As for your large static charges on plastic, any high school physics
teacher could tell you the same thing about his classroom Van de Graff
generator and all it could do was make his hair stand on end. No
explosions and no student deaths by electrocution.
And the hugh charge built up on my body when I shuffle across the room
in winter doen't set the house on fire when i discharge it to the door
knob. (It does make me jump though--and that's all the charge on
ductwork in the shop will do too.)
Of course you are right that such charges could fire a microprocessor
chip--that's why they're often sold with a wrist strap grounding cable
so the person installing them want accidentally ruin them.
Dust collection in a shop only needs grounding if static discharges from
ductwork to the human operator are undesired. There is NO danger of a
"grain elevator" type explosion--unless your shop is extremely large and
full of tons of dust with hugh volumes of airborne particles.
--
Regards,
Benoit Evans
"George" <[email protected]> wrote in message >
http://www.engcollab.com/articles/understanding1.htm (safety info)
I like this one:
1.. Dust collectors shall be located outside of buildings. Dust collectors
may be located inside of buildings if they are located near an outside wall,
are vented to the outside through straight reinforced ducts not exceeding
10 feet in length, and have explosion vents designed according to
information in NFPA 68, Venting of Deflagrations. Some think that installing
an explosion vent on a dust collector prevents an explosion. This is not the
case. The vent relieves the pressure of an explosion. Dust collectors can be
installed safely inside buildings only under one of the following
conditions:
How many wood shops have the DC outside? Or have vents from reinforced
ducts? I don't think this applies to us.
Sorry, Still no real information. I won't be next because no one has been
first yet.
Ed
[email protected]
http://pages.cthome.net/edhome
On Thu, 17 Dec 2015 09:52:55 -0800, mscottgruber wrote:
>> Yesterday in the mail there came a catalog I've never seen before, a
>> company called Leichtung Workshops out of Casper, WY. Has anybody on
>> the wreck bought from them and what have your experiences been?
I did - a long time ago. The company has been sold to Woodworkers Supply
in Casper. I've also ordered from them, but again, it was a long time
ago. Used to stop and browse their store any time we drove through
Casper.
So any old reviews you see about Leichtung no longer apply. But I never
had any problems with Woodworkers Supply. But it may have changed hands
as well - I don't know.
--
Nobody expects the Spanish Inquisition!
On Tue, 9 Dec 2003 22:28:49 -0500, "George" <[email protected]>
wrote:
>
>"B a r r y B u r k e J r ." <[email protected]> wrote
>in message news:[email protected]...
>> On Mon, 8 Dec 2003 20:26:55 -0500, "George" <[email protected]>
>> wrote:
>>
>> >http://www.gov.on.ca/lab/english/hs/alerts/i15.html
>>
>> The sawdust was already on fire from another source. How would
>> grounding change this?
>
>What makes you say that? It refers to a rash of explosions and fires caused
>by various spark sources throughout Canada and it does name static discharge
>as a source of ignition. If your concern is that sparking usually occurs to
>ground, grounding multiple points on a non-conductive (i.e., charge-holding)
>material would minimize its ability to hold a charge at all.
>
><<<SNIP>>>
>> Where is the wood shop explosion?
>>
>> We would like to see an actual WOOD DUST, not insulation, grain dust,
>> or plastic explosion caused by STATIC ELECTRICITY, not glowing
>> sharpening embers, cigarettes, torches, etc... that would have been
>> prevented with an internal ground wire.
>>
>So, I guess you're saying that since no SPECIFIC idiot at a SPECIFIC address
>is named that one might as well "run with scissors" (I've never seen a
>documented case of THAT either...my assumption is that most of the Darwin
>Awards for that were already handed out about two generations ago)??? If
>you've ever seen a dust explosion of any sort, it results in a fireball and
>if caused by static discharge there would be no ignition source to be found
>(unlike embers, torches, cigarettes, etc)...as long as you don't live near
>me or my relatives or friends, do as you wish with the information and I
>truly DO wish you the best of luck.
>
the point is that despite lots of chicken little running around, there
are no documented cases of home shop dust collection systems exploding
from static electricity generated by plastic pipes. none. zip. zilch.
plenty of industrial woodshop and flour mill and so on dust collection
explosions... mostly caused by things other than static from plastic
pipes. IIRC, plastic pipes aren't allowed in industry for that very
reason. they actually move enough dust with enough air for hot static
discharge to be possible. they also have 24" pipe and 40 HP blowers
sucking sawdust from dozens to hundreds of machines simultaneously.
my measly 2HP dust collector and 40 feet of 4" plastic pipe isn't
gonna blow. nope.
Bridger
On Mon, 8 Dec 2003 20:26:55 -0500, "George" <[email protected]>
brought forth from the murky depths:
>As the saying goes "you can't be first, but you can be next"...
>http://www.chem.leeds.ac.uk/delights/texts/expt_6.html
Bogus. Not a DC.
>http://www.safteng.net/Incident_Alert_Archives/industrial_accidents%201.htm
Bogus. Not a DC.
>http://www.gov.on.ca/lab/english/hs/alerts/i15.html
Hey, a real industrial fire! Hmmm, 8 employees? LARGE installation.
But it's not a wood shop dust collector explosion.
>http://www.engcollab.com/articles/understanding1.htm (safety info)
Warnings but no cite of actual explosion.
>"B a r r y B u r k e J r ." <[email protected]> wrote
>> Please point us to a documented case of a wood shop dust collector
>> explosion due to static electricity. Ciggies, glowing embers or
--
Sex is Evil, Evil is Sin, Sin is Forgiven.
Gee, ain't religion GREAT?
---------------------------------------------
http://diversify.com Sin-free Website Design
On Tue, 9 Dec 2003 22:28:49 -0500, "George" <[email protected]>
wrote:
>
>"B a r r y B u r k e J r ." <[email protected]> wrote
>in message news:[email protected]...
>> On Mon, 8 Dec 2003 20:26:55 -0500, "George" <[email protected]>
>> wrote:
>>
>> >http://www.gov.on.ca/lab/english/hs/alerts/i15.html
>>
>> The sawdust was already on fire from another source. How would
>> grounding change this?
>
>What makes you say that?
"Recently, firefighters were trying to remove smouldering sawdust from
the hopper of a dust collector when an explosion blew burning
materials out of the equipment. Six firefighters and eight workers
suffered serious burns and cuts. The explosion happened 36 minutes
after the fire apparatus arrived."
Read the first sentence.
Barry
<[email protected]> wrote:
[Woodworkers Warehouse]Going tits up as well apparently!
I'm not surprised. I just made a major purchase ($1600 for a table
saw). I made an attempt to buy it at the local Woodworkers Warehouse,
but finally gave up and ordered it through Amazon.
I went to the store. Had some questions about different models. The
salesperson was completely clueless. Person one went away and said he
would send over somebody who knew more. He then proceeded to leave me
alone. Eventually somebody else came over who knew even less than the
first person. What little information they gave me I knew to be
incorrect.
I asked about getting it delivered. I was told they don't deliver. I
asked if he knew anybody who might be able to deliver it for me.
Anybody in a business like this should at least be able to give me
somebody's business card along with, "I know this guy has a truck and
doesn't mind picking up a few bucks on the side", but he couldn't even
do that.
So, what did I get? No information, no assistance, a higher base price
(not to mention having to pay sales tax), and no delivery. Amazon
delivered it to my garage for less money and were helpful on the phone
when I had questions.
I'm all for dealing locally, but there are limits to how far I'm willing
to go to cater to a local merchant. If WW is going out of business, I'm
not surprised, and I won't miss them.
On Fri, 05 Dec 2003 23:54:56 GMT, Nova <[email protected]>
whined:
>We did have on franchised store in the Buffalo area. It looks like Rockler's
>will now be the sole player. :-(
>
>Where's Rob Lee? ;-)
What are you complaining about, Jack? You're, what, less than an hour
away from their Burlington store?
Luigi
Replace "no" with "yk" for real email address
"Mike G" wrote ...
> You can rest easy now George. Trendlines went tits up several years ago.
> Their golf line is, as far as I know, gone. Their woodworking supply
branch
> became Woodworkers Warehouse. I do a lot of trade with Woodworkers
Warehouse
> and they have always been great people to deal with.
... which is, however, not everyone's experience with WWW.
--
Cheers,
Howard
----------------------------------------------------------
Working wood in New Jersey - [email protected]
Visit me in the woodshop - www.inthewoodshop.org
My only gripe about Leichtung Workshops is that if you encourage them in any
way (like buying from them), they will bury you in catalogs. They aren't as
bad as Trendlines in that regard, but I won't purchase from them again.
(Trendlines is worse because they ASSUME that all woodworkers MUST love
golf, so they bury you in woodworking and golfing catalogs. And it is
virtually impossible to get off any unwanted list they decide to add you
to.) Personally, I don't like buying from companies that are strictly
marketing companies and aren't really into whatever it is that they sell and
that is my perception of Leichtung and Trendlines.
"Ian Dodd" <[email protected]> wrote in message
news:[email protected]...
> Yesterday in the mail there came a catalog I've never seen before, a
> company called Leichtung Workshops out of Casper, WY. Has anybody on
> the wreck bought from them and what have your experiences been?
>
> Some of their stuff is priced the same as anybody else's ($37 for a
> set of 3 plug cutters, same price as the Veritas at my local pro
> shop). But what caught my eye were their prices on clamps. It was
> literally 2 hours after I had just bought a couple Jorgensen 6" bar
> clamps at my local hardware retailer for $9.99 each that the Leichtung
> catalog came advertising a no-name brand for $3.99 and 36" for $8.99
> (vs. $24.99 locally). Their version of a band clamp is $18.99 vs. $38
> at the Rockler outlet.
>
> So is this just another outlet like Harbor tool, selling cheaply made
> knock offs? Or is their stuff decent? Thanks in advance.
Trendlines used to be or still is connected with Post Tools...I am out of
California these days, so is Post Tools still around?
"Nova" <[email protected]> wrote in message
news:[email protected]...
> Mike G wrote:
>
> > You can rest easy now George. Trendlines went tits up several years ago.
> > Their golf line is, as far as I know, gone. Their woodworking supply
branch
> > became Woodworkers Warehouse. I do a lot of trade with Woodworkers
Warehouse
> > and they have always been great people to deal with.
> > --
>
> Interesting... A few weeks ago I accessed Woodworker Warehouse's web
page. It
> worked, and I was almost certain there was a blurb at the bottom of the
page
> saying that they were a division of Trendlines. I checked the page today
at:
>
> http://www.woodworkerswarehouse.com/
>
> We did have on franchised store in the Buffalo area. It looks like
Rockler's
> will now be the sole player. :-(
>
> Where's Rob Lee? ;-)
>
> --
> Jack Novak
> Buffalo, NY - USA
> (Remove "SPAM" from email address to reply)
>
>
I don't know what their grounding kit consists of or how effective it
is...BUT, explosions are a real possibility. The conditions would require
very fine particles of airborne sawdust in a high concentration and a static
electric discharge, and voila, you get the same result as grain elevators
experience every so often. I am an electrical engineer and have used a
static electric voltmeter to track down static problems in the manufacture
of electronic products and have found charges in the neighborhood of
5,000-10,000 volts cause by airflow across non-conductive plastic (polymer)
surfaces.
The safest thing to do would be to build your ductwork from metal and ground
it. If you use non-conductive plastic, you'd have to distribute numerous
grounds along it's length and the spacing would depend on the duct material.
"Stephen Meier" <[email protected]> wrote in message
news:[email protected]...
> I got my cabinet saw through them. The sales guy did alot of leg work to
get
> me just what I wanted at amizon's prices. Sadly, he is no longer there.
>
> I recently mentioned to one of their managers that the "dust collection
> grounding kit" was snake oil. He could have said "it make some folks feel
> safer" but instead he insisted that we "personally" knew people who had
> experience explosions in a home shop. I lost all respect.
>
> That said, they are better than nothing. It's still nice to be able to see
> and touch in theis one-horse town.
>
> "Howard Ruttan" <[email protected]> wrote in message
> news:[email protected]...
> >
> > "Mike G" wrote ...
> > > You can rest easy now George. Trendlines went tits up several years
ago.
> > > Their golf line is, as far as I know, gone. Their woodworking supply
> > branch
> > > became Woodworkers Warehouse. I do a lot of trade with Woodworkers
> > Warehouse
> > > and they have always been great people to deal with.
> >
> > ... which is, however, not everyone's experience with WWW.
> >
> > --
> >
> > Cheers,
> > Howard
> >
> > ----------------------------------------------------------
> > Working wood in New Jersey - [email protected]
> > Visit me in the woodshop - www.inthewoodshop.org
> >
> >
>
>
As the saying goes "you can't be first, but you can be next"...
http://www.chem.leeds.ac.uk/delights/texts/expt_6.html
http://www.safteng.net/Incident_Alert_Archives/industrial_accidents%201.htm
http://www.gov.on.ca/lab/english/hs/alerts/i15.html
http://www.engcollab.com/articles/understanding1.htm (safety info)
"B a r r y B u r k e J r ." <[email protected]> wrote
in message news:[email protected]...
> On Sun, 7 Dec 2003 00:20:51 -0500, "George" <[email protected]>
> wrote:
>
> >I don't know what their grounding kit consists of or how effective it
> >is...BUT, explosions are a real possibility.
>
> Here we go... <G>
>
> Please point us to a documented case of a wood shop dust collector
> explosion due to static electricity. Ciggies, glowing embers or
> glowing metal shavings don't count. If it's not on the web, I'll
> volunteer to go get a copy of the news article from my local
> university library and put it up on the web.
>
> I'll simply need the date and name of the paper, TV, or radio entity
> that published it. I'll do the rest to get it on the web.
>
> FWIW, I pulled my ground wires out of my DC pipes, as they caused
> clogging if an offcut or large chip landed the right way.
>
> Barry
We'll see if the 5-6 links I posted in response actually do post...but
another thought came to mind. Since any dust collection system will cost at
least $200, why are you kicking and screaming over $5-10 worth of wire to
make it safer? Just curious...
Like I said in my previous post, an ESD-caused sawdust fire or explosion
would be most likely with a high concentration of FINE (very fine) sawdust,
like from sanding, rather than what your table saw or planer generates.
"B a r r y B u r k e J r ." <[email protected]> wrote
in message news:[email protected]...
> On Sun, 7 Dec 2003 00:20:51 -0500, "George" <[email protected]>
> wrote:
>
> >I don't know what their grounding kit consists of or how effective it
> >is...BUT, explosions are a real possibility.
>
> Here we go... <G>
>
> Please point us to a documented case of a wood shop dust collector
> explosion due to static electricity. Ciggies, glowing embers or
> glowing metal shavings don't count. If it's not on the web, I'll
> volunteer to go get a copy of the news article from my local
> university library and put it up on the web.
>
> I'll simply need the date and name of the paper, TV, or radio entity
> that published it. I'll do the rest to get it on the web.
>
> FWIW, I pulled my ground wires out of my DC pipes, as they caused
> clogging if an offcut or large chip landed the right way.
>
> Barry
"B a r r y B u r k e J r ." <[email protected]> wrote
in message news:[email protected]...
> On Mon, 8 Dec 2003 20:26:55 -0500, "George" <[email protected]>
> wrote:
>
> >http://www.gov.on.ca/lab/english/hs/alerts/i15.html
>
> The sawdust was already on fire from another source. How would
> grounding change this?
What makes you say that? It refers to a rash of explosions and fires caused
by various spark sources throughout Canada and it does name static discharge
as a source of ignition. If your concern is that sparking usually occurs to
ground, grounding multiple points on a non-conductive (i.e., charge-holding)
material would minimize its ability to hold a charge at all.
<<<SNIP>>>
> Where is the wood shop explosion?
>
> We would like to see an actual WOOD DUST, not insulation, grain dust,
> or plastic explosion caused by STATIC ELECTRICITY, not glowing
> sharpening embers, cigarettes, torches, etc... that would have been
> prevented with an internal ground wire.
>
So, I guess you're saying that since no SPECIFIC idiot at a SPECIFIC address
is named that one might as well "run with scissors" (I've never seen a
documented case of THAT either...my assumption is that most of the Darwin
Awards for that were already handed out about two generations ago)??? If
you've ever seen a dust explosion of any sort, it results in a fireball and
if caused by static discharge there would be no ignition source to be found
(unlike embers, torches, cigarettes, etc)...as long as you don't live near
me or my relatives or friends, do as you wish with the information and I
truly DO wish you the best of luck.
"K.-Benoit Evans" <[email protected]> wrote in message
news:[email protected]...
> Unfortunately, the link at the end of the following citation no longer
> works, but it did when I excerpted the article a couple of years ago.
Do you know who did the study and when??? You say it was published a
"couple of year ago"...any idea of when the study occurred?
>
> A research scientist at MIT has looked into this matter very carefully,
> both anecdotally and empirically. In the summary of his quite long
> report, he says:
>
> "...I have read more than a dozen research
> papers on this topic recently. The thing I am most struck by is how
> hard these guys have to work to get dust explosions in the lab. It is
> not hard to get ignition if one makes a very carefully controlled,
> nonmoving cloud with just the right dust mix, and introduces a spark
> from a very carefully designed sparking mechanism. But no one seems to
> be able in lab sized experiments to get electrostatic discharge
> ignition of even very highly combustible dusts in remotely realistic
> situations, and they do try. Is is possible? I presume so, but it is
> extremely difficult."
>
> "...there has never, to my knowledge, been a documented case of an
> explosion problem with PVC in the home shop or a case of an explosion
> in a filter bag in a home shop. A friend of mine who is a professional
> cabinet maker asked his fire inspector what he thought about the hazard
> of PVC ducts, and the fire inspector said he was far more concerned
> about people keeping lighter fluid under the kitchen sink. The fire
> inspector was intrigued and checked whatever registry of fire
> information he had available and came back and said he could not find
> one reference to a problem in a small shop with PVC ducts."
>
> "In all the years that this has been debated on the Web, not one
> verifiable report has surfaced of an exploding home shop dust
> collector. I know full well that anecdotal evidence does not make good
> science, and just because I don't know of a problem caused by an
> electrical discharge in a home shop DC does not make it impossible.
> But, such evidence is certainly food for thought, and at least shows
> that such events, if they exist at all, are very rare."
>
> Near the end of the report, there is an explanation of several common
> MYTHS (untrue, unfounded beliefs) about home workshop dust collection.
> That list (without the accompanying explanations) is as follows:
>
> Myths--the following assertions are NOT true
>
> 1. PVC ducts are dangerous. FALSE
My experience was related to high static charges on G10, a printed circuit
board material. Not too many raw materials are dangerous. THAT usually
depends on one's design.
>
> 2. You can ground PVC. FALSE
Since PVC doesn't conduct electricity, you cannot ground PVC. Since a
static charge does not flow (definition of static), the distance from ground
potential is what is important...I'd bond a wire to the PVC in multiple
locations to ground to hold the static charge to a very low voltage. It is
true that you would not eliminate static charge altogether by doing
something like this.
>
> 3. The only thing of concern in a dust collector are the ducts. FALSE
Agreed. One should look at the entire system. I would hope that the
manufacturers have already taken due care to make certain that the collector
itself cannot become a source of ignition.
>
> 4. The external ground wire works by reducing the static on the outside
> of the PVC. FALSE
Depends on implementation. See #2 above.
>
> 5. The external wire must be bare. FALSE
Agreed.
>
> 6. Grounded screws can not help as they are too far apart. FALSE
Agreed...that was my suggestion
>
> 7. Grounding works by removing charge from the dust. FALSE
Agreed. We are only talking about a charge on the PVC. I do not know if
the dust can even hold a charge (I tend to doubt it, however).
>
> 8. Metal ducts keep the dust from charging. FALSE
See #7 above. If the dust can charge, it'd be from the airflow and not the
PVC. But, also, if the dust can charge, no individual particle could hold a
charge sufficient to ignite the sawdust.
>
> 9. Any spark will ignite the right dust mixture. FALSE
I have NO knowledge of what kind of spark is required for various dust
mixtures.
>
> 10. Grounding PVC works by removing charge at a point, and since charge
> must be uniformly distributed, it therefore removes charge everywhere.
> FALSE
Agreed. This is a rather weird idea for something that is non-conductive.
>
> 11. Getting a discharge outside the ducts, say to your finger, means
> you also have discharges inside the ducts. FALSE
Agreed in principle, but due to the thickness of ductwork it is likely to be
able to conduct through the thickness of the duct meaning that what is
inside could experience sparking as well.
>
> The full report can be found at:
>
> <http://www.gis.net/~dheaton/woodworking/articles/DC_myths.shtml>
>
> --
> Regards,
>
> Benoit Evans
So, your system uses PVC ducts and you ran internal ground wires (which you
have since removed)? I could see where that would cause you some grief. In
the manufacture of electronic products, ESD protection is provided with much
higher resistances. Many of the 3M products to reduce damage due to static
use about 1,000,000 ohms to ground (or even 10,000,000 ohms). I've never
put an ohmmeter to a piece of PVC (plus I'm sure it would vary by
manufacturer as any impurities would change the resistance) but I'd
investigate putting the ground wire on the outside...worst case you could
even use small self-tapping screws to bring a ground from the outside to the
inside and I wouldn't think that would cause the dust collection system to
clog.
In spite of how the tone of our exchange may have sounded to you, I fall in
the "better safe than sorry" camp...if you re-read my original posting on
this, I merely stated that it was possible based on several factors. I
don't think that it is highly likely for very many home woodworkers because
most won't generate the concentration of dust nor the fineness.
"B a r r y B u r k e J r ." <[email protected]> wrote
in message news:[email protected]...
> On Mon, 8 Dec 2003 20:46:23 -0500, "George" <[email protected]>
> wrote:
>
> > Since any dust collection system will cost at
> >least $200, why are you kicking and screaming over $5-10 worth of wire to
> >make it safer? Just curious...
>
> In my case it had nothing to do with cost. I GROUNDED my system. I
> pulled the wires out after getting tired of semi-weekly clogs caused
> by jointer and planer chips and offcuts getting stuck in the wires. I
> haven't had a clog since I pulled the wires out.
>
> I can also see no noticeable difference in static electricity buildup
> or the other performance aspects of the system. My ground wires were
> grounded at copper cold water pipes which are in turn grounded to the
> same 8' ground rod my radios are. The connections were soldered to
> the pipes.
>
> If you want to ground yours, feel free. Until someone comes up with
> documented evidence, or for that matter, documented conjecture on the
> part of a fire inspector that grounding would have prevented a WOOD
> SHOP (NOT plastic, grain dust, etc...) explosion, I'll continue to
> question "safer". I'd even go with "better safe than sorry" thinking,
> if the wires didn't cause so many clogs.
>
> Barry
"K.-Benoit Evans" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>,
> "George" <[email protected]> wrote:
>
>
> As for your large static charges on plastic, any high school physics
> teacher could tell you the same thing about his classroom Van de Graff
> generator and all it could do was make his hair stand on end. No
> explosions and no student deaths by electrocution.
>
You obviously, have not played with this equipment! When I was in high
school, I did connect a Van de Graff generator to a doorknob (teenage
pranks) and after seeing that I could zap an unsuspecting victim with about
a 7" "lightning bolt" (ESD) decided to add licopodium powder to the prank.
It IS impressive and it DOES ignite and is reminiscent of flash powder of
years gone by. For those unfamiliar with licopodium powder, it is about the
same fineness as flour and would represent a fine dust explosion or
ignition.
As for permanent harm, a Van de Graff generator doesn't generate sufficient
static charge for that, though lightning does.
"B a r r y B u r k e J r ." <[email protected]> wrote
in message news:[email protected]...
> On Tue, 9 Dec 2003 23:07:10 -0500, "George" <[email protected]>
> wrote:
>
> > In
> >the manufacture of electronic products, ESD protection is provided with
much
> >higher resistances. Many of the 3M products to reduce damage due to
static
> >use about 1,000,000 ohms to ground (or even 10,000,000 ohms).
>
> I work in the electronics biz (telco), and we do all kinds of things
> to contain ESD. For an entirely different reason. <G> Reasons for
> that resistance include SLOWLY discharging the static electricity.
>
> Barry
Not to mention worker safety (in case of other fault conditions), otherwise
the assembly labor would likely be barefoot on copper ground plates to save
$3 ICs... For production, one of the nicer solutions is ionizers.