jj

jtpr

25/07/2012 8:54 AM

PVC for dust collection, is it safe?

I asked a long time ago about duct work for DC in my shop, 2 years later I'=
m finally ready to do it. I have a 1.5hp single stage collector and I want=
to get the 4" hoses off the floor. I would really like to use 4" PVC to d=
o this as it is a whole lot easier, accessible, and cheaper. But what abou=
t static? Is it really that unsafe? Can it be grounded? This is a small =
shop, 20x20 and I will probably just be going to my table saw and planer to=
start. If the PVC is really not safe, then what is wrong with the 30 gaug=
e metal stuff at HD? I can't believe I have the horsepower in this machine=
to buckle it, but maybe I'm wrong. It's just that going to Woodcraft for =
duct work is VERY expensive, and ordering online is a PITA whenever I need =
something. =20

Thanks again for the input.

-Jim


This topic has 26 replies

jj

jtpr

in reply to jtpr on 25/07/2012 8:54 AM

26/07/2012 11:18 AM

On Thursday, July 26, 2012 1:16:26 PM UTC-4, Mike Marlow wrote:
> Leon wrote:
> > On 7/26/2012 11:02 AM, Dr. Deb wrote:
> >> jtpr wrote:
> >>
> >>> I asked a long time ago about duct work for DC in my shop, 2=
years
> >>> later I'm finally ready to do it. I have a 1.5hp single=
stage
> >>> collector and I want to get the 4" hoses off the floor.=
I would
> >>> really like to use 4" PVC to do this as it is a whole l=
ot easier,
> >>> accessible, and cheaper. But what about static? Is it real=
ly that
> >>> unsafe? Can it be grounded? This is a small shop, 20x20 an=
d I
> >>> will probably just be going to my table saw and planer to st=
art. If the=20
> >>> PVC is really not safe, then what is wrong with the 30 gauge
> >>> metal stuff at HD? I can't believe I have the horsepowe=
r in this
> >>> machine to buckle it, but maybe I'm wrong. It's jus=
t that going to
> >>> Woodcraft for duct work is VERY expensive, and ordering onli=
ne is a
> >>> PITA whenever I need something. Thanks again for the input.
> >>>
> >>> -Jim
> >>
> >>
> >> Mythbusters did a show on trying to get enough static electricty=
off
> >> a piecss of PVC pipe to cause an explosion. The listed it as
> >> "Thoroughly Busted."
> >>
> >> Deb
> >>
> >
> >
> > I would have thought the PVC would have only let off a spark rather
> > than being thoroughly busted.
>=20
> Well - it was thoroughly busted - but... even if there were a static issu=
e,=20
> it would bee too small, in to difuse an environment, to matter at all. W=
hat=20
> most people overlook is that it's not about the static discharge, it&=
#39;s about=20
> the concentration of the material in question, in the air. You have to h=
ave=20
> a minimul concentration in the air before you can expect a problem.
>=20
> --=20
>=20
> -Mike-
> [email protected]

OK, well, I'm going with the PVC from the Depot. I bought a 2' piece and s=
topped at WoodCraft and found an adapter to hook it to my 4" flexible hose.=
I already had bought the cyclone top thingy they sell that goes on a meta=
l 30 gallon trash can and it works great. I think I'm rocking now.

I gave all my oak to the woodworker down the street that I don't like.

-Jim

PS, thank you for all the input.

Rr

RonB

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 9:25 PM

On Wednesday, July 25, 2012 3:30:23 PM UTC-5, -MIKE- wrote:

> >
>
> You'll be fine as long as you never run any oak saw dust through it. Oak
> rust will rot that mofo from the inside out and the resulting explosion
> will send shrapnel up to a mile, killing everyone in sight.
>
>

You just had to do that didn't you Mike. We came this far without any crazy crash, burn and obliterated statements - then this.

I know - the devil made you......

Jeeeeesssshhhhh!

RonB

Sk

Swingman

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 3:40 PM

On 7/25/2012 3:30 PM, -MIKE- wrote:
> On 7/25/12 10:54 AM, jtpr wrote:
>> I asked a long time ago about duct work for DC in my shop, 2 years
>> later I'm finally ready to do it. I have a 1.5hp single stage collector
>> and I want to get the 4" hoses off the floor. I would really like to use
>> 4" PVC to do this as it is a whole lot easier, accessible, and cheaper.
>> But what about static? Is it really that unsafe? Can it be grounded?
>> This is a small shop, 20x20 and I will probably just be going to my
>> table saw and planer to start. If the PVC is really not safe, then what
>> is wrong with the 30 gauge metal stuff at HD? I can't believe I have the
>> horsepower in this machine to buckle it, but maybe I'm wrong. It's just
>> that going to Woodcraft for duct work is VERY expensive, and ordering
>> online is a PITA whenever I need something.
>>
>> Thanks again for the input.
>>
>> -Jim
>>
>
> You'll be fine as long as you never run any oak saw dust through it. Oak
> rust will rot that mofo from the inside out and the resulting explosion
> will send shrapnel up to a mile, killing everyone in sight.

It will also negate your homeowner's insurance, and turn all your cherry
brown ...

--
www.eWoodShop.com
Last update: 4/15/2010
KarlCaillouet@ (the obvious)
http://gplus.to/eWoodShop

Pp

Puckdropper

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 4:08 PM

jtpr <[email protected]> wrote in
news:[email protected]:

> I asked a long time ago about duct work for DC in my shop, 2 years
> later I'm finally ready to do it. I have a 1.5hp single stage
> collector and I want to get the 4" hoses off the floor. I would
> really like to use 4" PVC to do this as it is a whole lot easier,
> accessible, and cheaper. But what about static? Is it really that
> unsafe? Can it be grounded? This is a small shop, 20x20 and I will
> probably just be going to my table saw and planer to start. If the
> PVC is really not safe, then what is wrong with the 30 gauge metal
> stuff at HD? I can't believe I have the horsepower in this machine to
> buckle it, but maybe I'm wrong. It's just that going to Woodcraft for
> duct work is VERY expensive, and ordering online is a PITA whenever I
> need something.
>
> Thanks again for the input.
>
> -Jim
>

Trying to stir up some discussion? We've talked about static from dust
collection quite a bit...

PVC has two basic issues: It can be brittle and the static is annoying.
Since the PVC will be on the suction side, if it does become brittle and
break, the pieces will be sucked into the collector. The static is only
dangerous if by virtue of a static shock you react and hit something.

Grounding PVC is done more for eliminating the annoyance factor than
anything else.

Some suggest going with 6" PVC for better flow, if your DC can handle it.
It's much harder to find in reasonably priced quantities, though.

Puckdropper
--
Make it to fit, don't make it fit.

Pp

Puckdropper

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 7:26 PM

dpb <[email protected]> wrote in news:[email protected]:

*snip*

>
> OBTW -- on the 30-ga HVAC stuff--I've not tried it on a 2 hp collector
> but it will all depend on what pressure drop your fan will pull. At
> worst buy a section, hook it up to the inlet directly and do a block
> test and see if you can collapse it or not.

If you're worried about collapsing, a simple pressure relief damper can be
installed at the end of the run. All it is is basically a damper that can
turn freely that is weighted at one end. In normal operation, the damper
stays closed for maximum draw from the outlets. In a clogged/choked
condition, the damper opens to take the pressure off the pipe.

Puckdropper
--
Make it to fit, don't make it fit.

Pp

Puckdropper

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 11:32 PM

-MIKE- <[email protected]> wrote in news:jupl0r$luv$1
@speranza.aioe.org:

>
> You'll be fine as long as you never run any oak saw dust through it. Oak
> rust will rot that mofo from the inside out and the resulting explosion
> will send shrapnel up to a mile, killing everyone in sight.
>
>

Who's sight? If he just closes his eyes immediately after the oak rust
explosion, will everyone be safe?

Save us, man! Close your eyes!

Puckdropper
--
Make it to fit, don't make it fit.

LJ

Larry Jaques

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 2:32 PM

On Wed, 25 Jul 2012 13:44:13 -0700, "CW" <[email protected]> wrote:

>
>
>"-MIKE-" wrote in message news:[email protected]...
>
>
>
>You'll be fine as long as you never run any oak saw dust through it. Oak
>rust will rot that mofo from the inside out and the resulting explosion
>will send shrapnel up to a mile, killing everyone in sight.
>==================================================================
>Except Rambo.

That goes without saying. Also, it won't harm Superman or the
Terminator, either in governator form or in mufti.

--
In the depth of winter, I finally learned
that within me there lay an invincible summer.
-- Albert Camus

tn

tiredofspam

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 2:52 PM

On 7/25/2012 11:54 AM, jtpr wrote:
> I asked a long time ago about duct work for DC in my shop, 2 years later I'm finally ready to do it. I have a 1.5hp single stage collector and I want to get the 4" hoses off the floor. I would really like to use 4" PVC to do this as it is a whole lot easier, accessible, and cheaper. But what about static? Is it really that unsafe? Can it be grounded? This is a small shop, 20x20 and I will probably just be going to my table saw and planer to start. If the PVC is really not safe, then what is wrong with the 30 gauge metal stuff at HD? I can't believe I have the horsepower in this machine to buckle it, but maybe I'm wrong. It's just that going to Woodcraft for duct work is VERY expensive, and ordering online is a PITA whenever I need something.
>
> Thanks again for the input.
>
> -Jim
>
PVC is safe.
I use it for a 2" system for small stuff, jointer,planer, 6x48 belt ,
sander , band saw, and the bottom of my TS saw to clear out the
droppings, drill press, router table

In all about 80 feet of pvc... no problems.
A regular DC with 4" won't be a problem, there are many out there.

If you really want a good system, bend your own pipe. Lookup on the
internet there are small boxes people make so they can heat the pipe
evenly. It keeps the heat in so it won't cool as they rotate it.

Then make some nice long bends....

Piece of cake... I did something similar for kicks to see if it would
work as easily as they showed.... yes it does.

One day I'll get around to a full size cyclone... after I find a motor/
blade for a good price.

EP

Ed Pawlowski

in reply to jtpr on 25/07/2012 8:54 AM

27/07/2012 5:25 PM

On Fri, 27 Jul 2012 06:51:42 -0500, Leon <lcb11211@swbelldotnet>
wrote:



> The thing to be more concerned about is are there any
>combustible vapors lingering around.

Not to worry with a good duct collector. When you fart, it sucks it
up and the vapors are gone.

MM

"Mike Marlow"

in reply to jtpr on 25/07/2012 8:54 AM

26/07/2012 1:16 PM

Leon wrote:
> On 7/26/2012 11:02 AM, Dr. Deb wrote:
>> jtpr wrote:
>>
>>> I asked a long time ago about duct work for DC in my shop, 2 years
>>> later I'm finally ready to do it. I have a 1.5hp single stage
>>> collector and I want to get the 4" hoses off the floor. I would
>>> really like to use 4" PVC to do this as it is a whole lot easier,
>>> accessible, and cheaper. But what about static? Is it really that
>>> unsafe? Can it be grounded? This is a small shop, 20x20 and I
>>> will probably just be going to my table saw and planer to start. If the
>>> PVC is really not safe, then what is wrong with the 30 gauge
>>> metal stuff at HD? I can't believe I have the horsepower in this
>>> machine to buckle it, but maybe I'm wrong. It's just that going to
>>> Woodcraft for duct work is VERY expensive, and ordering online is a
>>> PITA whenever I need something. Thanks again for the input.
>>>
>>> -Jim
>>
>>
>> Mythbusters did a show on trying to get enough static electricty off
>> a piecss of PVC pipe to cause an explosion. The listed it as
>> "Thoroughly Busted."
>>
>> Deb
>>
>
>
> I would have thought the PVC would have only let off a spark rather
> than being thoroughly busted.

Well - it was thoroughly busted - but... even if there were a static issue,
it would bee too small, in to difuse an environment, to matter at all. What
most people overlook is that it's not about the static discharge, it's about
the concentration of the material in question, in the air. You have to have
a minimul concentration in the air before you can expect a problem.

--

-Mike-
[email protected]

tn

tiredofspam

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 4:40 PM

On 7/25/2012 4:30 PM, -MIKE- wrote:

>
> You'll be fine as long as you never run any oak saw dust through it. Oak
> rust will rot that mofo from the inside out and the resulting explosion
> will send shrapnel up to a mile, killing everyone in sight.
>
>
Geez you're killing me... :-)

Cc

"CW"

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 1:44 PM



"-MIKE-" wrote in message news:[email protected]...



You'll be fine as long as you never run any oak saw dust through it. Oak
rust will rot that mofo from the inside out and the resulting explosion
will send shrapnel up to a mile, killing everyone in sight.
==================================================================
Except Rambo.

GR

"G. Ross"

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 12:18 PM

jtpr wrote:
> I asked a long time ago about duct work for DC in my shop, 2 years later I'm finally ready to do it. I have a 1.5hp single stage collector and I want to get the 4" hoses off the floor. I would really like to use 4" PVC to do this as it is a whole lot easier, accessible, and cheaper. But what about static? Is it really that unsafe? Can it be grounded? This is a small shop, 20x20 and I will probably just be going to my table saw and planer to start. If the PVC is really not safe, then what is wrong with the 30 gauge metal stuff at HD? I can't believe I have the horsepower in this machine to buckle it, but maybe I'm wrong. It's just that going to Woodcraft for duct work is VERY expensive, and ordering online is a PITA whenever I need something.
>
> Thanks again for the input.
>
> -Jim
>
Get some thin wall PVC drain pipe. You may need to wrap the ends of
the gates with duct tape to get them to fit. I've used this for 12
years with no problems. Do not seal all the joints as you WILL have
to open it up eventually to get something out. I initially ran copper
wire through it, grounding it to the machines and the collector. Had
so much trouble with curlies catching on it and stopping it up that I
removed it about 5 years ago and have never had any problems since.

Get a 20 or 30 gal fiber barrel with a metal lid, cut holes for two
elbows to fit inside, turned in opposite directions. Connect the
collector to one side and the duct to the other using flexible hose.
Much easier to catch the trash and emptying it out of the barrel than
out of the collector, and it stops large chips from banging on the
turbine. Some fine dust will go through, I have to empty the bag
every couple of years.

I have 5 gates and 4 outlets for 2 1/4 " (?) hose for sweeping and
catching dust at the lathe. A small round Tupperware container fits
nicely in the outlet when it is not being used.

--
G.W. Ross

Everywhere is walking distance if you
have the time. --Steven Wright





Ll

Leon

in reply to jtpr on 25/07/2012 8:54 AM

26/07/2012 12:04 PM

On 7/26/2012 11:02 AM, Dr. Deb wrote:
> jtpr wrote:
>
>> I asked a long time ago about duct work for DC in my shop, 2 years later
>> I'm finally ready to do it. I have a 1.5hp single stage collector and I
>> want to get the 4" hoses off the floor. I would really like to use 4" PVC
>> to do this as it is a whole lot easier, accessible, and cheaper. But what
>> about static? Is it really that unsafe? Can it be grounded? This is a
>> small shop, 20x20 and I will probably just be going to my table saw and
>> planer to start. If the PVC is really not safe, then what is wrong with
>> the 30 gauge metal stuff at HD? I can't believe I have the horsepower in
>> this machine to buckle it, but maybe I'm wrong. It's just that going to
>> Woodcraft for duct work is VERY expensive, and ordering online is a PITA
>> whenever I need something.
>>
>> Thanks again for the input.
>>
>> -Jim
>
>
> Mythbusters did a show on trying to get enough static electricty off a
> piecss of PVC pipe to cause an explosion. The listed it as "Thoroughly
> Busted."
>
> Deb
>


I would have thought the PVC would have only let off a spark rather than
being thoroughly busted.

kk

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 10:42 PM

On Wed, 25 Jul 2012 11:09:00 -0500, dpb <[email protected]> wrote:

>On 7/25/2012 10:54 AM, jtpr wrote:
>...
>
>4" PVC to do this as it is a whole lot easier, accessible, and cheaper.
>But what about static? Is it really that unsafe? Can it be grounded?
>
>...
>
>There is no evidence whatever that any small diameter dust collection
>system has had an explosion or fire sparked by static discharge in plastic.
>
>It _will_ shock on occasion like the olden days of wool carpets and dry
>indoor conditions.
>
>You can attempt to minimize that by wrapping w/ wire and grounding but
>since the material is nonconductive it's of marginal benefit.
>
>The biggest pita w/ it is twofold --
>
>1) The fittings for 4" dust collection aren't the same size as Sch 40
>fittings so you have to adapt everything, and

I found some adapters (Rockler) that adapt drainage (schedule 20?) PVC to dust
collector stuff. The problem I have is that I've found that 4" dust
collection hardware doesn't fit 4" dust collection hardware. Indeed,
different tools have different sized ports. Grr.

Ll

Leon

in reply to jtpr on 25/07/2012 8:54 AM

27/07/2012 6:51 AM

On 7/26/2012 12:16 PM, Mike Marlow wrote:
> Leon wrote:
>> On 7/26/2012 11:02 AM, Dr. Deb wrote:
>>> jtpr wrote:
>>>
>>>> I asked a long time ago about duct work for DC in my shop, 2 years
>>>> later I'm finally ready to do it. I have a 1.5hp single stage
>>>> collector and I want to get the 4" hoses off the floor. I would
>>>> really like to use 4" PVC to do this as it is a whole lot easier,
>>>> accessible, and cheaper. But what about static? Is it really that
>>>> unsafe? Can it be grounded? This is a small shop, 20x20 and I
>>>> will probably just be going to my table saw and planer to start. If the
>>>> PVC is really not safe, then what is wrong with the 30 gauge
>>>> metal stuff at HD? I can't believe I have the horsepower in this
>>>> machine to buckle it, but maybe I'm wrong. It's just that going to
>>>> Woodcraft for duct work is VERY expensive, and ordering online is a
>>>> PITA whenever I need something. Thanks again for the input.
>>>>
>>>> -Jim
>>>
>>>
>>> Mythbusters did a show on trying to get enough static electricty off
>>> a piecss of PVC pipe to cause an explosion. The listed it as
>>> "Thoroughly Busted."
>>>
>>> Deb
>>>
>>
>>
>> I would have thought the PVC would have only let off a spark rather
>> than being thoroughly busted.
>
> Well - it was thoroughly busted - but... even if there were a static issue,
> it would bee too small, in to difuse an environment, to matter at all. What
> most people overlook is that it's not about the static discharge, it's about
> the concentration of the material in question, in the air. You have to have
> a minimul concentration in the air before you can expect a problem.
>



Exactly! You are going to get the spark, that is a certainty especially
if you see any dust collecting/sticking like a magnet on the outside of
the pipe/hose. The thing to be more concerned about is are there any
combustible vapors lingering around.

ME

Martin Eastburn

in reply to jtpr on 25/07/2012 8:54 AM

30/07/2012 11:02 PM

If the plastic fails it might shard and be dangerous.
Wonder about long term after n-flexes or n-hits in corners.
Martin

On 7/27/2012 6:51 AM, Leon wrote:
> On 7/26/2012 12:16 PM, Mike Marlow wrote:
>> Leon wrote:
>>> On 7/26/2012 11:02 AM, Dr. Deb wrote:
>>>> jtpr wrote:
>>>>
>>>>> I asked a long time ago about duct work for DC in my shop, 2 years
>>>>> later I'm finally ready to do it. I have a 1.5hp single stage
>>>>> collector and I want to get the 4" hoses off the floor. I would
>>>>> really like to use 4" PVC to do this as it is a whole lot easier,
>>>>> accessible, and cheaper. But what about static? Is it really that
>>>>> unsafe? Can it be grounded? This is a small shop, 20x20 and I
>>>>> will probably just be going to my table saw and planer to start. If
>>>>> the
>>>>> PVC is really not safe, then what is wrong with the 30 gauge
>>>>> metal stuff at HD? I can't believe I have the horsepower in this
>>>>> machine to buckle it, but maybe I'm wrong. It's just that going to
>>>>> Woodcraft for duct work is VERY expensive, and ordering online is a
>>>>> PITA whenever I need something. Thanks again for the input.
>>>>>
>>>>> -Jim
>>>>
>>>>
>>>> Mythbusters did a show on trying to get enough static electricty off
>>>> a piecss of PVC pipe to cause an explosion. The listed it as
>>>> "Thoroughly Busted."
>>>>
>>>> Deb
>>>>
>>>
>>>
>>> I would have thought the PVC would have only let off a spark rather
>>> than being thoroughly busted.
>>
>> Well - it was thoroughly busted - but... even if there were a static
>> issue,
>> it would bee too small, in to difuse an environment, to matter at
>> all. What
>> most people overlook is that it's not about the static discharge, it's
>> about
>> the concentration of the material in question, in the air. You have
>> to have
>> a minimul concentration in the air before you can expect a problem.
>>
>
>
>
> Exactly! You are going to get the spark, that is a certainty especially
> if you see any dust collecting/sticking like a magnet on the outside of
> the pipe/hose. The thing to be more concerned about is are there any
> combustible vapors lingering around.

dn

dpb

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 11:09 AM

On 7/25/2012 10:54 AM, jtpr wrote:
...

4" PVC to do this as it is a whole lot easier, accessible, and cheaper.
But what about static? Is it really that unsafe? Can it be grounded?

...

There is no evidence whatever that any small diameter dust collection
system has had an explosion or fire sparked by static discharge in plastic.

It _will_ shock on occasion like the olden days of wool carpets and dry
indoor conditions.

You can attempt to minimize that by wrapping w/ wire and grounding but
since the material is nonconductive it's of marginal benefit.

The biggest pita w/ it is twofold --

1) The fittings for 4" dust collection aren't the same size as Sch 40
fittings so you have to adapt everything, and

2) It does and will collect from static charge.

But, there are thousands of applications and I've used drain/waste PVC
w/ the molded-in fittings for the main laterals here as it's
lighter/cheaper and the 10-ft joints are convenient in small shop areas.

I didn't bother to glue joints, they fit well enough to not leak
significantly and can rearrange if desired/needed.

BTW, be sure you use sweeps and larger radius fittings rather than
ordinary tight elbows for less pressure drop and fewer hangups. Also
keep the amount of flex hose to the bare minimum possible--it's the
biggest sucker-upper of airflow you can have other than a block gate.

OBTW -- on the 30-ga HVAC stuff--I've not tried it on a 2 hp collector
but it will all depend on what pressure drop your fan will pull. At
worst buy a section, hook it up to the inlet directly and do a block
test and see if you can collapse it or not.

--

dn

dpb

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 3:03 PM

On 7/25/2012 2:26 PM, Puckdropper wrote:
> dpb<[email protected]> wrote in news:[email protected]:
>
> *snip*
>
>>
>> OBTW -- on the 30-ga HVAC stuff--I've not tried it on a 2 hp collector
>> but it will all depend on what pressure drop your fan will pull. At
>> worst buy a section, hook it up to the inlet directly and do a block
>> test and see if you can collapse it or not.
>
> If you're worried about collapsing, a simple pressure relief damper can be
> installed at the end of the run. All it is is basically a damper that can
> turn freely that is weighted at one end. In normal operation, the damper
> stays closed for maximum draw from the outlets. In a clogged/choked
> condition, the damper opens to take the pressure off the pipe.
...

Oh, gee, and take all the suspense out??? :)

--

Mm

-MIKE-

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 3:30 PM

On 7/25/12 10:54 AM, jtpr wrote:
> I asked a long time ago about duct work for DC in my shop, 2 years
> later I'm finally ready to do it. I have a 1.5hp single stage collector
> and I want to get the 4" hoses off the floor. I would really like to use
> 4" PVC to do this as it is a whole lot easier, accessible, and cheaper.
> But what about static? Is it really that unsafe? Can it be grounded?
> This is a small shop, 20x20 and I will probably just be going to my
> table saw and planer to start. If the PVC is really not safe, then what
> is wrong with the 30 gauge metal stuff at HD? I can't believe I have the
> horsepower in this machine to buckle it, but maybe I'm wrong. It's just
> that going to Woodcraft for duct work is VERY expensive, and ordering
> online is a PITA whenever I need something.
>
> Thanks again for the input.
>
> -Jim
>

You'll be fine as long as you never run any oak saw dust through it. Oak
rust will rot that mofo from the inside out and the resulting explosion
will send shrapnel up to a mile, killing everyone in sight.


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

Ff

FrozenNorth

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 4:45 PM

On 7/25/12 4:44 PM, CW wrote:
>
>
> "-MIKE-" wrote in message news:[email protected]...
>
>
> You'll be fine as long as you never run any oak saw dust through it. Oak
> rust will rot that mofo from the inside out and the resulting explosion
> will send shrapnel up to a mile, killing everyone in sight.
> ==================================================================
> Except Rambo.
and Chuck Norris. :-)

--
Froz...


The system will be down for 10 days for preventive maintenance.

Mm

-MIKE-

in reply to jtpr on 25/07/2012 8:54 AM

25/07/2012 11:54 PM

On 7/25/12 11:25 PM, RonB wrote:
> On Wednesday, July 25, 2012 3:30:23 PM UTC-5, -MIKE- wrote:
>
>> &gt;
>>
>> You&#39;ll be fine as long as you never run any oak saw dust through it. Oak
>> rust will rot that mofo from the inside out and the resulting explosion
>> will send shrapnel up to a mile, killing everyone in sight.
>>
>>
>
> You just had to do that didn't you Mike. We came this far without any crazy crash, burn and obliterated statements - then this.
>
> I know - the devil made you......
>
> Jeeeeesssshhhhh!
>
> RonB
>

Did you know SawStop was designed totally on Google Sketchup, the best
CAD program in the world? :-)


--

-MIKE-

"Playing is not something I do at night, it's my function in life"
--Elvin Jones (1927-2004)
--
http://mikedrums.com
[email protected]
---remove "DOT" ^^^^ to reply

dn

dpb

in reply to jtpr on 25/07/2012 8:54 AM

26/07/2012 1:09 PM

On 7/26/2012 12:16 PM, Mike Marlow wrote:
...

> Well - it was thoroughly busted - but... even if there were a static issue,
> it would bee too small, in to difuse an environment, to matter at all. What
> most people overlook is that it's not about the static discharge, it's about
> the concentration of the material in question, in the air. You have to have
> a minimul concentration in the air before you can expect a problem.

The biggest problem in woodshop dust explosion (getting one, that is) is
that the particle sizes are far too large if there is enough mass and
it's essentially impossible to generate enough mass by sanding to reach
the necessary stoichiometry (concentration). I estimated once that to
reach the level w/ sanding a 1-ft square board in a very small 250 cfm
system it would require something like removing almost 3/16" of material
a minute over the entire surface to reach the 0.003 lb/cuft estimated by
US FPL as the lower critical concentration for an explosion.

Then in PVC, while it builds a great charge, owing to it being an
insulator it is virtually impossible to get an actual discharge spark of
any energy content to speak of as only a very small portion of the
charge will travel to the discharge point. This is different than a
conductive surface that allows for charge transport through the material.

So you can get the annoying static charge that makes hair stand on end
and collects dust, etc., etc., etc., but can't get an energetic charge
to light it off even if could get the dust concentration.

Where there's more hazard is in the collections but it's not explosion
it's a smoldering spark that finally bursts to flame if a metal chunk
hits a metal fan and makes a hot flying chunk...

I came close in the base of the PM66 once when hit a wood screw and it
did the nasty...

--

Jj

Jack

in reply to jtpr on 25/07/2012 8:54 AM

07/08/2012 9:26 AM

On 7/31/2012 12:02 AM, Martin Eastburn wrote:
> If the plastic fails it might shard and be dangerous.
> Wonder about long term after n-flexes or n-hits in corners.
> Martin

Mine has been in use since 1976. Not a problem, and it is the cheap
schedule 20 stuff. I only suck super fine dust through it though,
anything bigger falls into a drum before it gets to the filter or the
piping. I would not hesitate to suck the bigger sawdust through the
pipe though, no worries there.

--
Jack
Add Life to your Days not Days to your Life.
http://jbstein.com
>
> On 7/27/2012 6:51 AM, Leon wrote:
>> On 7/26/2012 12:16 PM, Mike Marlow wrote:
>>> Leon wrote:
>>>> On 7/26/2012 11:02 AM, Dr. Deb wrote:
>>>>> jtpr wrote:
>>>>>
>>>>>> I asked a long time ago about duct work for DC in my shop, 2 years
>>>>>> later I'm finally ready to do it. I have a 1.5hp single stage
>>>>>> collector and I want to get the 4" hoses off the floor. I would
>>>>>> really like to use 4" PVC to do this as it is a whole lot easier,
>>>>>> accessible, and cheaper. But what about static? Is it really that
>>>>>> unsafe? Can it be grounded? This is a small shop, 20x20 and I
>>>>>> will probably just be going to my table saw and planer to start. If
>>>>>> the
>>>>>> PVC is really not safe, then what is wrong with the 30 gauge
>>>>>> metal stuff at HD? I can't believe I have the horsepower in this
>>>>>> machine to buckle it, but maybe I'm wrong. It's just that going to
>>>>>> Woodcraft for duct work is VERY expensive, and ordering online is a
>>>>>> PITA whenever I need something. Thanks again for the input.
>>>>>>
>>>>>> -Jim
>>>>>
>>>>>
>>>>> Mythbusters did a show on trying to get enough static electricty off
>>>>> a piecss of PVC pipe to cause an explosion. The listed it as
>>>>> "Thoroughly Busted."
>>>>>
>>>>> Deb
>>>>>
>>>>
>>>>
>>>> I would have thought the PVC would have only let off a spark rather
>>>> than being thoroughly busted.
>>>
>>> Well - it was thoroughly busted - but... even if there were a static
>>> issue,
>>> it would bee too small, in to difuse an environment, to matter at
>>> all. What
>>> most people overlook is that it's not about the static discharge, it's
>>> about
>>> the concentration of the material in question, in the air. You have
>>> to have
>>> a minimul concentration in the air before you can expect a problem.
>>>
>>
>>
>>
>> Exactly! You are going to get the spark, that is a certainty especially
>> if you see any dust collecting/sticking like a magnet on the outside of
>> the pipe/hose. The thing to be more concerned about is are there any
>> combustible vapors lingering around.


LJ

Larry Jaques

in reply to jtpr on 25/07/2012 8:54 AM

26/07/2012 5:38 PM

On Thu, 26 Jul 2012 12:04:11 -0500, Leon <lcb11211@swbelldotnet>
wrote:

>On 7/26/2012 11:02 AM, Dr. Deb wrote:
>> jtpr wrote:
>>
>>> I asked a long time ago about duct work for DC in my shop, 2 years later
>>> I'm finally ready to do it. I have a 1.5hp single stage collector and I
>>> want to get the 4" hoses off the floor. I would really like to use 4" PVC
>>> to do this as it is a whole lot easier, accessible, and cheaper. But what
>>> about static? Is it really that unsafe? Can it be grounded? This is a
>>> small shop, 20x20 and I will probably just be going to my table saw and
>>> planer to start. If the PVC is really not safe, then what is wrong with
>>> the 30 gauge metal stuff at HD? I can't believe I have the horsepower in
>>> this machine to buckle it, but maybe I'm wrong. It's just that going to
>>> Woodcraft for duct work is VERY expensive, and ordering online is a PITA
>>> whenever I need something.
>>>
>>> Thanks again for the input.
>>>
>>> -Jim
>>
>>
>> Mythbusters did a show on trying to get enough static electricty off a
>> piecss of PVC pipe to cause an explosion. The listed it as "Thoroughly
>> Busted."
>>
>> Deb
>>
>
>
>I would have thought the PVC would have only let off a spark rather than
>being thoroughly busted.

I didn't think PVC pipe -wore- bras.

--
It takes as much energy to wish as to plan.
--Eleanor Roosevelt

DD

"Dr. Deb"

in reply to jtpr on 25/07/2012 8:54 AM

26/07/2012 11:02 AM

jtpr wrote:

> I asked a long time ago about duct work for DC in my shop, 2 years later
> I'm finally ready to do it. I have a 1.5hp single stage collector and I
> want to get the 4" hoses off the floor. I would really like to use 4" PVC
> to do this as it is a whole lot easier, accessible, and cheaper. But what
> about static? Is it really that unsafe? Can it be grounded? This is a
> small shop, 20x20 and I will probably just be going to my table saw and
> planer to start. If the PVC is really not safe, then what is wrong with
> the 30 gauge metal stuff at HD? I can't believe I have the horsepower in
> this machine to buckle it, but maybe I'm wrong. It's just that going to
> Woodcraft for duct work is VERY expensive, and ordering online is a PITA
> whenever I need something.
>
> Thanks again for the input.
>
> -Jim


Mythbusters did a show on trying to get enough static electricty off a
piecss of PVC pipe to cause an explosion. The listed it as "Thoroughly
Busted."

Deb


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