AWGB Woodturning Forum

General Category => General Discussion => Topic started by: Mike313 on December 11, 2019, 11:14:54 PM

Title: Video about the danger (or otherwise) of static in dust extraction systems
Post by: Mike313 on December 11, 2019, 11:14:54 PM

Hi Folks,
I thought some might be interested in this video. Just flagging it - I'm not saying I agree or disagree - just that it might make interesting viewing:

https://www.youtube.com/watch?v=WJ8NMYlhaLQ

Mike.

Title: Re: Video about the danger (or otherwise) of static in dust extraction systems
Post by: Doug Barratt on December 12, 2019, 07:35:38 AM

You don’t need to go to the trouble of copper wire & screws just stick aluminium tape along the length of the plastic ducting & connect that to earth, it will stop the build up of static.

I also have never heard of a fire caused by static in a small extraction system but I’ve had enough static shocks to now have my system earthed.

Title: Re: Video about the danger (or otherwise) of static in dust extraction systems
Post by: Twisted Trees on December 12, 2019, 04:08:42 PM

I actually found galvanised was cheaper than PVC and solves the problem intrinsically. dust fires from static sparks? possibly in flour mills where there is a lot of fine dust, but I tend to avoid sanding enough to create an explosive cloud! also never heard of anyone having the problem, except when using the same sanding belt for wood and metal.

Title: Re: Video about the danger (or otherwise) of static in dust extraction systems
Post by: burywoodturners on December 12, 2019, 08:27:54 PM

Try this https://en.wikipedia.org/wiki/Dust_explosion#Sources_of_ignition (https://en.wikipedia.org/wiki/Dust_explosion#Sources_of_ignition). There are may others on youtube
Ron

Title: Re: Video about the danger (or otherwise) of static in dust extraction systems
Post by: Twisted Trees on December 12, 2019, 11:17:44 PM

Quote from: burywoodturners on December 12, 2019, 08:27:54 PM

Try this https://en.wikipedia.org/wiki/Dust_explosion#Sources_of_ignition (https://en.wikipedia.org/wiki/Dust_explosion#Sources_of_ignition). There are may others on youtube
Ron

All the examples cited do not include sawdust, so yes it is a potential risk but not seen specific sawdust examples yet...

Title: Re: Video about the danger (or otherwise) of static in dust extraction systems
Post by: hughie on December 12, 2019, 11:41:53 PM

I use PVC on my dust collector and  agree with the comments on the video. I have a background of over 20-30 years in Engineering  across 3 continents with dust and dust collectors and it that time I have only seen one dust fire. The ignition point in the fire was not static but rather a  hot slag sucked by the dust collector as it was being used to remove welding fumes.
But I have had many a conversation about this with little or no avail as to finding a point of agreement and so like wise I dont do 'the discussion' any more

Title: Re: Video about the danger (or otherwise) of static in dust extraction systems
Post by: The Bowler Hatted Turner on December 13, 2019, 10:00:12 PM

I have seen 2 dust explosions in my time, the first when I worked in a furniture manufacturers after I left the forces, it was caused by a lighted cigarette
butt being sucked up the sweep up port. That was quite exciting at the time, but the more exciting one that I have witnessed (and I swear I didn't have that much to do with it) was when I was still in the forces and one time on exercise we taped a thunder flash to a bag of flour, from 1/4 mile away in the dark that looked like a nuclear explosion. I do miss those days sometimes.... ;D ;D ;D ;D ;D