I'm not a fan of, nor do I recommend a standard "dust collector" in a knife shop. At one time I had one installed (like you it was given to me)....and nearly lost my shop! I thought I was taking all care and diligence, but somehow a spark must have gotten to the collection bag, and things went up in flames in short order. I was fortunate in that the collection unit (the motor and bag) were housed in a small "lean to" on the outside of the shop, and I saw the smoke right away...but by the time I got out the door and to it, the unit was burned beyond saving. Had that unit been inside the shop, and not in my direct line of sight, I would have lost the entire shop!

Afterward, I ripped out all the duct work, and have since used 5 gallon buckets, full of soapy water, that hang under each grinder. I also fabricated "dust suckers" that filter/recirculate the air in the shop.

Now, if all that doesn't deter you from installing a dust collector in your shop, then at a bare minimum, FIND, PURCHASE, AND INSTALL INDUSTRIAL SPARK ARRESTORS WITHIN THE SYSTEM! Even that isn't a guarantee... I personally know of 3 different knifemakers who have very high end industrial dust collectors in their shops, with spark arrestors installed, who have had fires in their systems from grinding titanium or zirconium.

Hi, Ed~

Thanks for your helpful perspective and caution. I did not realize just how combustible dust can be until reading your post and then looking up some OSHA material. Since my shop is a two-car garage worship attached to my home, the fire concern is very real.

I discovered this summer that my little 1x30 set up by a window box fan filter still managed to get fine dust over the entire workshop. Just purchased a 2x72 and plan to use water buckets and a full-face respirator. Even after I blow the shop dust out I’m not comfortable with five children going in and out of it.

Three questions:

1. If the filtration system was exclusively for handle material rather than metal (sparks) would it still give you pause?

2. Would you mind sending a link to the type of “dust suckers” you are referring to?

3. Are there any options for using a collector without the collection bag?

Thanks again.

Greg

Greg,

Dust Is Dangerous! Wood and metal dust combined is explosive! Put aluminum in the mix you better dig your grave first! There is a great DVD by Dan Johnson (Bader CEO) published by the ABS called "Belts , Wheels and Grinding" Section 12 Dust concerns & management.

The DVD is from 22nd Batson symposium at Tannehill April 2010. Well worth the cost and time to view. Hope this helps.

Albert

Excellent topic, thanks for posting the question Greg. The answers are very helpful as I am setting up my shop this winter.

Albert and James~

Thank you for the helpful feedback and reference to the "Belts, Wheels and Grinding" DVD which I plan to watch.

The two ABS experts who responded (one online and one privately) gave different opinions:

1. Dangerous and never recommended.

2. Lung/Eye health risk is greater than a smoldering fire by a long shot, but don't use a collection bag and get an industrial spark trap.

When it comes to safety priorities there are no guarantees and I think that we interpret threats differently in light of our own life experiences. The trouble with this case is that I have no relevant experience. I'm going to play it safe and go with Ed's advice for the time being while trying becoming more educated on the subject.

Blessings,

Greg Cumbee

Winchester, VA

|quoted:

Greg,

Dust Is Dangerous! Wood and metal dust combined is explosive! Put aluminum in the mix you better dig your grave first! There is a great DVD by Dan Johnson (Bader CEO) published by the ABS called "Belts , Wheels and Grinding" Section 12 Dust concerns & management.

The DVD is from 22nd Batson symposium at Tannehill April 2010. Well worth the cost and time to view. Hope this helps.

Albert

Greg,

Great topic! I wonder this too as I'm building a new shop and have a dust collector in storage awaiting installation... I've heard about the dangers before... but I can't help to wonder what it might be like to work in a cleaner shop.

Does anyone here have experience with routing the duct through a water filled container? I saw this while studying in Idaho this time last year and it seemed very effective.

Thank you to the original poster for raising the topic. I spent a large part of last year revamping my home garage / workshop including building a dedicated grinding room as I was sick and tired of having to spend an hour or more cleaning dust off everything every time I used the grinders.

My workshop is still used as a double garage, housing two cars at night so I had to position almost all of my equipment against the side and rear walls. My grinders were originally positioned right next to the main garage door to try minimise dust in the shop by grinding with the large door rolled up, it wasnt very effective. Given that the garage still houses two cars, I built the grinding room at the back of the garage in the corner. It is not a big space - 3M x 2M but is big enough to house my Jones and Shipman surface grinder and my grinding bench with two TW90 clones and a double ended swivelling disc grinder. Instead of installing a swinging door which would take up space I didnt have I utilised PVC flap curtains - as used in cold storage / spraypaint booths / welding booths / warehouses etc - it is very effective in keeping the dust inside the room.

The idea was that once the room was built I would add a dust collection system outside and piped into the room - initially I considered being able to use the system when grinding both wood and metal - but I decided against it having seen the effects of a hot spark in dust filled environments (ie: potentially disastrous) and since my shop is mostly underneath my house - I dont need any fires / explosions.

Steel dust is fairly easy to catch in a water bucket and with some carefully positioned strong magnets at the back of the grinders. the really fine stuff which makes it into the air will be collected by an additional pleated filter based air filtration unit hanging overhead.

The dust extraction system will be used when grinding & shaping handle materials -> Micarta / natural woods / G10 / Carbon Fiber / Bone / Horn - are all very unpleasant substances and most make a serious amount of fine dust which gets everywhere (NB: as far as PPE I use safety glasses and a proper respirator (3M 7502 with 6059 filters and pre filters) to protect my lungs when grinding).

As most machinery is not cheap in South Africa, I was lucky to find and purchase a 2Hp woodworking dust extractor (with a second unit disassembled for spares), including a 1micron filter at an absolute bargain price second hand.

I will be adding a cyclone to the unit, with blast gates at each inlet to maximise suction. The dust extractor with cyclone will be wall mounted with 4" - 6" ducting installed and running to the wood Bandsaw, grinders, drill press and Mill-Drill. ( I take a lot of inspiration for the system from Van Barnett and what he has done in his latest shop - it looks like a surgery.

I was very lucky to get a set of two electrically activated blast gates / valves from a friend - these will be fitted as close to the dust extractor as possible with remote power switches at the grinders. The switches will be wired in such a way that the dust extractor and relevant blast gate / valve will only be activated / opened when the wood/micarta setting is selected, but will be isolated / siwtched off and the vaccuum line sealed when the steel setting is selected.

I think I need to get hold of the DVD mentioned above.

Thanks

Kind Regards and all the best to everyone for 2018.

Rick

Rick Afonso

Apprentice Smith

Cape Town, South Africa

Great topic and great information. Thanks guys.