Tips for Installing a Dust Collection System - Page 3 - Router Forums
 88Likes
Reply
 
LinkBack Thread Tools Display Modes
post #21 of 122 (permalink) Old 06-26-2015, 01:17 AM
Registered User
 
sunnybob's Avatar
 
Join Date: Apr 2015
Country: Cyprus
First Name: Bob
Posts: 1,788
 
Default

out of curiosity, I have just gone to the workshop and conducted a quick experiment with foil tape.

This is obviously a spur of the moment test, but the results surprised even me.

Using my test meter on a metal paintbrush section I got the following results.
meter leads test to 0.3 ohm.
metal paintbrush body tests to 0.3 ohm (perfect, as I would expect as the leads are only two inches apart)
single layer of foil under one test lead tests to 0.3 ohm (perfect, no loss)
double layer foil tests to 0.4 ohm (not so good, a significant loss of continuity)
triple layer foil tests to wildly varying numbers right up to infinity that would be an instant fail on any installation I have ever tested.

Conclusions; do NOT use foil tape in any area regarded as electrically sensitive unless you make sure there is no more than 1 complete turn of tape to stop the draught.
More than three turns would be a capacitor because the glue is storing the electric
sunnybob is online now  
Sponsored Links
Advertisement
 
post #22 of 122 (permalink) Old 06-26-2015, 01:22 AM
Registered User
 
DaninVan's Avatar
 
Join Date: Dec 2011
Country: Canada
First Name: Dan
Posts: 13,831
 
DaninVan is offline  
post #23 of 122 (permalink) Old 06-26-2015, 03:08 AM
Moderation Team
 
Cherryville Chuck's Avatar
 
Join Date: Sep 2010
Country: Canada
First Name: Charles
Posts: 14,857
 
Default

Quote:
Originally Posted by sunnybob View Post
out of curiosity, I have just gone to the workshop and conducted a quick experiment with foil tape.

This is obviously a spur of the moment test, but the results surprised even me.

Using my test meter on a metal paintbrush section I got the following results.
meter leads test to 0.3 ohm.
metal paintbrush body tests to 0.3 ohm (perfect, as I would expect as the leads are only two inches apart)
single layer of foil under one test lead tests to 0.3 ohm (perfect, no loss)
double layer foil tests to 0.4 ohm (not so good, a significant loss of continuity)
triple layer foil tests to wildly varying numbers right up to infinity that would be an instant fail on any installation I have ever tested.

Conclusions; do NOT use foil tape in any area regarded as electrically sensitive unless you make sure there is no more than 1 complete turn of tape to stop the draught.
More than three turns would be a capacitor because the glue is storing the electric
Bob your measurements of the continuity of layer after layer of tape I'm sure are correct, especially if the layers were separated from each other as opposed to a continuous loop 3 layers thick, but the end of one pipe is crimped so that it will slide into the end of the next pipe. There is approximately 2" of overlap between the two. The tape only prevents suction loss. It has no effect on the continuity of current from one pipe to the next. It would be a factor if you were grounding from the outside layer of the tape.
cocobolo1 likes this.

Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.
Cherryville Chuck is online now  
Sponsored Links
Advertisement
 
post #24 of 122 (permalink) Old 06-26-2015, 03:55 AM
Registered User
 
sunnybob's Avatar
 
Join Date: Apr 2015
Country: Cyprus
First Name: Bob
Posts: 1,788
 
Default

granted under those circumstances. What concerned me was the use of plastic elbows which are non conducting.
If you have a grounded metal tube sealed into a plastic elbow with foil tape, the plastic elbow disconnects each section from each other. Under those circumstances, a metal conductor should be used to bridge the plastic elbow and re connect with the next metallic section and not rely on a piece of foil tape to do the job.

But it is worth bearing in mind the capacitor effect, and not winding the foil tape around more than is absolutely neccessary to seal the tube (1 turn)

I originally had 4" metal for my dust collection system, small as it is, but the cost of fitting 5 blast gates (1 for for each appliance) turned me to a smaller, 63mm clear plastic tube and elbows with blast gates for each. Still not cheap, but a much nicer appearance and more space behind the machines.

Until now, I had not considered static a problem on my system. I still think the risk is extremely low for me, where the system doesnt run all day, and I am quite paranoid about using the floor vac at the end of each day, sometimes twice if theres been a lot of activity (sawdust in the house is a BIG BIG issue!!!), but I shall study the problem, and may well end up earthing the tubing
sunnybob is online now  
post #25 of 122 (permalink) Old 06-26-2015, 05:40 AM
Registered User
 
sunnybob's Avatar
 
Join Date: Apr 2015
Country: Cyprus
First Name: Bob
Posts: 1,788
 
Default

well, I've studied my system, and i dont think there is any point in adding ground wiring to it.
Its only a 12 ft long run, with 5 outlets. Theres a cyclone (all plastic) at the end of the run between the tube and the vacuum unit, which also has an air filter between the void and the electric motor.
the plastic cyclone feeds dust down into a sealed plastic bucket. Plastic flexible hose connects everything to everything. Although there are metal clips holding the pipe to the wall, they are held with screws into plastic plugs. there are even wooden spacer blocks behind each clip.

So, theres no way any mains electricity can reach any part of the system or travel along it. Any static could only come from inside the pipe itself, and the travelling time of the dust moving 12 ft is just not measurable. I dont believe it would be possible for enough friction to form to produce any static.
I think I'm good to go. (G)
Herb Stoops likes this.
sunnybob is online now  
post #26 of 122 (permalink) Old 06-26-2015, 05:45 AM
Forum Contributor
 
Stick486's Avatar
 
Join Date: Jan 2013
Country: United States
First Name: Stick
Posts: 24,527
 
Default

simplify the thought process...

every place there is combustible dust static electricity is an issue....
the possibility exists...
choose to blow it off, ignore it, gamble, play chicken (w/ yours and other's) w/ life, limb and propertybelieve ''not me,'' or it's all just rhetoric and if the day ''should'' arrive enjoy the I tol'ja so's...

https://www.osha.gov/dsg/combustibledust/index.html
https://www.osha.gov/dts/shib/shib073105.html
NFPA 652: Standard on Combustible Dusts

A wide variety of materials that can be explosible in dust form exist in many industries. Examples of these materials include: food (e.g., candy, sugar, spice, starch, flour, feed), grain, tobacco, plastics, wood, paper, pulp, rubber, pesticides, pharmaceuticals, dyes, coal, metals (e.g., aluminum, chromium, iron, magnesium, and zinc). These materials are used in a wide range of industries and processes, such as agriculture, chemical manufacturing, pharmaceutical production, furniture, textiles, fossil fuel power generation, recycling operations, and and metal working and processing which includes additive manufacturing and 3D printing.
TwoSkies57, Pots43 and arby157 like this.

This would have been the week that I'd have finished chewing thru the restraints...
If only new layers hadn't been added....

Stick....
Forget the primal scream, just ROAR!!!
"SNORK Mountain Congressional Library and Taxidermy”
Stick486 is offline  
post #27 of 122 (permalink) Old 06-26-2015, 07:23 AM
Registered User
 
schnewj's Avatar
 
Join Date: Nov 2013
Country: United States
First Name: Bill
Posts: 2,323
 
Default

Quote:
Originally Posted by Stick486 View Post
simplify the thought process...

every place there is combustible dust static electricity is an issue....
the possibility exists...
choose to blow it off, ignore it, gamble, play chicken (w/ yours and other's) w/ life, limb and propertybelieve ''not me,'' or it's all just rhetoric and if the day ''should'' arrive enjoy the I tol'ja so's...

https://www.osha.gov/dsg/combustibledust/index.html
https://www.osha.gov/dts/shib/shib073105.html
NFPA 652: Standard on Combustible Dusts

A wide variety of materials that can be explosible in dust form exist in many industries. Examples of these materials include: food (e.g., candy, sugar, spice, starch, flour, feed), grain, tobacco, plastics, wood, paper, pulp, rubber, pesticides, pharmaceuticals, dyes, coal, metals (e.g., aluminum, chromium, iron, magnesium, and zinc). These materials are used in a wide range of industries and processes, such as agriculture, chemical manufacturing, pharmaceutical production, furniture, textiles, fossil fuel power generation, recycling operations, and and metal working and processing which includes additive manufacturing and 3D printing.
Stick,

It's not that I'm disagreeing with anything you have said, and I agree with "belts and suspenders" in this case. However, The real danger of explosions is evident in commercial operations where the use of the dust systems is a continuous operation. The possibilities of static discharge are probable and possible.

However, in a hobby or small shop operation where continuous operations are unlikely the probabilities of a static event are very low.

I have never, in all of my research, ever come across a documented event in a small workshop that caused a fire or explosion due to static discharge in the ducting. I am not saying that there aren't any but I have never found a credible documented case.

That is why in my first post I asked if anyone who has knowledge of such an event to provide me with the details.

I spent 30 years of a much longer career as Safety Engineer for a large aerospace company. My first assignment was to oversee the construction, testing and operations of a building that had a self contained "Mix Room" and three spray cells.

We sprayed primer on a 27 foot by 100+ foot Aluminum tank and then coated it with a cork based mixture in a heptane slurry.

The mix room is where the slurry was made.

We dealt with Heptane, Toluene, Alcohol, and Methyl Ethyl Ketone in the processes. Needless to say, grounding and static was a big issue, right down to the non-conductive flooring and the use of wrist stats for static.

We never had an incident and thank God we eventually did away with the some of the processes.

My point to the ramble is that I have extensive experience in grounding and the techniques involved. Sonnybob is astute in his observations, but for a hobby shop I just don't see a high level of concern over static in the dust system.

I would, personally ground my own systems, but not for the fear of a static discharge fire and certainly not an explosion, but to keep from getting my fingers zapped.

Bottom line, ground the system, it's not "rocket science", if anything it will keep you from getting zapped when you get near the ducts or machinery.

Bill
jw2170, Stick486 and Herb Stoops like this.

Hi, sorry I missed you. I have gone to find myself, but if I return before I get back, please ask me to wait.

Nothing ever gets built on schedule or within budget.

Tool Storage Bait and Tackle, LLC.
schnewj is offline  
post #28 of 122 (permalink) Old 06-26-2015, 08:04 AM
Forum Contributor
 
Stick486's Avatar
 
Join Date: Jan 2013
Country: United States
First Name: Stick
Posts: 24,527
 
Default

I worked in the R&D department of an explosives/munitions facility for a number of years...
not to mention the years of grain mill work... (millwright)
static being an issue is a very real thing...

as long as static is an issue.. would it be be prudent to cover your butt...
single digit humidity here enlarges the issues...
even if there are no fire/explosions, static discharges to a person get to be very annoying...
forbid if you should be wearing a pacemaker...

preventative medicine here goes a long ways...
doesn't take much to accomplish either...
ask Ray what it was like when got a shock and his hearing aide went nuts...
his screams were something else...

This would have been the week that I'd have finished chewing thru the restraints...
If only new layers hadn't been added....

Stick....
Forget the primal scream, just ROAR!!!
"SNORK Mountain Congressional Library and Taxidermy”
Stick486 is offline  
post #29 of 122 (permalink) Old 06-26-2015, 10:27 AM
Registered User
 
schnewj's Avatar
 
Join Date: Nov 2013
Country: United States
First Name: Bill
Posts: 2,323
 
Default

Quote:
Originally Posted by Stick486 View Post
preventative medicine here goes a long ways...doesn't take much to accomplish either...
ask Ray what it was like when got a shock and his hearing aide went nuts...his screams were something else...
Exactly the reason(s) that I advocate doing it (LOL). However, in a small wood shop I still don't believe that not grounding the ducting is a fire or explosion waiting to happen.

Working as a millwright and especially in the explosives field speaks volumes on your expertise on grounding and static. I dealt with low order ordinance in my job and we were extremely careful about grounding and static discharges. I can only imagine what it was like in the munitions operations.

Bill

Hi, sorry I missed you. I have gone to find myself, but if I return before I get back, please ask me to wait.

Nothing ever gets built on schedule or within budget.

Tool Storage Bait and Tackle, LLC.
schnewj is offline  
post #30 of 122 (permalink) Old 06-26-2015, 11:11 AM
Forum Contributor
 
Stick486's Avatar
 
Join Date: Jan 2013
Country: United States
First Name: Stick
Posts: 24,527
 
Default

Quote:
Originally Posted by schnewj View Post
Exactly the reason(s) that I advocate doing it (LOL). However, in a small wood shop I still don't believe that not grounding the ducting is a fire or explosion waiting to happen.

I can only imagine what it was like in the munitions operations.

Bill
so no sweat on the fire and explosions... protect the people/children in the shop... but do something about it...
I would not want to be party to screwing up somebody's pacemaker..
the drier the air the more it's an issue...

Ray was in a itty bitty shop...
one worker and 4 audience.. and it wasn't Ray that was working but his screams, him hitting the floor and grabbing his head sure got our adrenaline pumping...
apparently the static shock caused some kind of feed back in the hearing aide.. WHEW!!!

I built the assembly stations people used...
at 1st it was brute force defense.. major not so good...
next it was deflection.. better but there were some very serious issues...
then it became redirect, deflect and absorption.... got pretty good at it... earned some very nice bonuses and rate increases...
incident rate dropped to about ziltch...

the cool part of the job was to build a station.. custom make an explosive charge for it and go blow it up...
successes were treated to still larger charges to find it's limits... some of those explosions were spectacular....
failures were analyzed and re-engineered and run through the gambit...
building drying kilns, ovens and storage bunkers were another trip...
came pretty proficient at air and air over hydraulic systems... SS heat exchangers. radiant heat, air drying and a few other odds and ends.....
Rogerdodge likes this.

This would have been the week that I'd have finished chewing thru the restraints...
If only new layers hadn't been added....

Stick....
Forget the primal scream, just ROAR!!!
"SNORK Mountain Congressional Library and Taxidermy”
Stick486 is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Router Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 4 (0 members and 4 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Index of Dust Collection Solutions and Comments allthunbs Shop Safety 28 03-14-2014 01:40 AM
Review - Rockler Dust Collection Separator (Small) Cochese Shop Safety 38 09-08-2012 09:22 PM
Oak Park Dust Collection kawisser Table-mounted Routing 3 08-18-2011 07:32 PM
Dust collection system for Router Table yhadar Lobby 2 12-31-2004 01:37 PM

Posting Rules  
You may not post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome