Dust - PVC static electricity

[SteveI]

Some great ideas on dust collection, but a question about the piping.

I notice some people are using PVC piping as well as the flexible hoses - and in some cases metal ducting.

It has been suggested to me that the PVC (stormwater etc) presents a fire/flash risk because of a static electricity build-up. (Fine dust can be explosive)

The PVC is attractive because of cost, availability and ease of getting airtight joints, but is anyone aware of literature on the static electricity side - and whether there are solutions (such as earthing straps)??

[silentC]

Hi Steve, try this one: http://www.woodworkforums.ubeaut.com...ust+pvc+static

And a range of opinions: http://www.woodweb.com/knowledge_bas...ollection.html

Hotly debated issue I think....

[SteveI]

Thanks - useful -

The use of earthed screws protruding into the pipe looks like a viable safety measure.

Given the volume of dust I would be generating, and the stats on the amount of dust needed to cause an explosion, it seems to be a marginal issue

[Sturdee]

Steve,

I have had a DC setup in my workshop for 2 years with ducting to each machine including my Triton equipment. My ducting is 4" pvc drainage piping with flexible pvc from the blastgates to each machine.

When installing the system I read everywhere and have come to the conclusion that whilst static electricity can occur it would most likely happen in a commercial shop setup but not in a home workshop. I have never had any problemswith static electricity.


Peter.

[kenmil]

I have not earthed mine and I have never encountered static electricity. I am still waiting to hear the details of the first sawdust fire caused by static build-up. Sounds like an urban myth to me; I wouldn't worry about it.

[burn]

Hi Peoples,

I seem to be the lucky one! :mad:

Quite often, I will connect my Triton dust bucket and 1400watt K-Mart vaccum cleaner and just hold the end of the black spring tubing to the top of the vaccum cleaner's floor head (on the end of the alum. tube) and I ALMOST ALWAYS get a static build-up in the bucked.

Essentially I'm interposing the bucket between the vaccum and it's floor head attachment. I can see stray dust charged and sticking to the outside of the bucket ... I tend to be very careful when I empty the bucket as I can get a nasty SNAP.

Burn

[Sturdee]

Burn

I think we are talking at cross purposes for we are talking about a proper dust collector with fixed ducting and hoses fixed to all machines not the Triton dustbucket and vacuum cleaner.

I use my dust bucket and vacuum for general cleanups etc. and I don't get static but I connect the bucket direct to the flexible hose of the vacuum and not the alum tube. Try it this way and if that does not improve it then may be your vacuum cleaner is at fault.


Peter.

[GeoffS]

I get some quite powerful bites from my shop vac when vaccuuming the floor but have never got a bite from my PVC ducting. The shop vac has a nasty habit of rolling into the back of my bare legs!!!
The other item that bites is my Triton table when using the planer attachment - I suspect that is the plastic belt drive in the planer.
I believe that the dust density we generate and the short runs involved make the risks very low, if they exist at all.
Not quite an 'urban myth' but rather like worrying about being attacked by a tiger when you live in Melbourne.

Cheers

[Wayne Davy]

I have approx 20m of 6" PVC main duct plus some smaller stuff all connected to my Cyclone. I have never, every got a zap and I am not worried about an explosion from a dust cloud period!!!

[ozwinner]

Try this site.

http://home.att.net/~waterfront-woods/

[kenmil]

Hmmm...typical "academic theory" with no practical example. Like I said in my original reply, I await details of the last home workshop that exploded.:confused: