Thread: Dust Extraction / Control used by woodturners

Originally Posted by mick59wests

After reading Bill Pentz and most things on the Dust Extraction Forum (as well as asking questions with my own thread) I am currently planning to get a ClearVue Cyclone and run 6" piping to my lathe and other machines. Our very own BobL is very respected on the Dust Extraction forum and this also falls in line with his recommendations. The basic health issue seems to be so called invisible dust (stuff smaller than say 5 microns) and getting rid of it at source.

However, in furthering my research, I'd be interested to know what other woodturners do and what they think of their own setup and the health risks.

1. Cyclone: I built my own on the Pentz design with min diam 6" runs, the ducting doesn't have to be round. No sharp bends. The ClearVue is also a good solution, if you can afford it. I have one comment on that design which I can share off forum.
2. Inlet Port Design: As important as the cyclone. Don't forget about the bandsaw.
3. Filtered Respirator Mask/Hood: I made my own.

Mick,

A number of woodworkers I speak to with dust issues seem to think that the only solution is a BP cyclone whereas it makes more sense to think of what minimum air flow and air speed is needed to tackle fine dust. Bill Pentz (BP) himself clearly states that a target air flow (1000 CFM) and air speed (in the duct of 400 FPM)is more fundamental target than how this is obtained.

A modern 3HP DC with a 13" impeller will achieve 1250 CFM and thus in excess of 4000 fpm using 6" ducting, provided the ducting runs are kept short, filter bags kept clean, and, as NeilS says, more important than most folks think, the machine ports are made big enough to utilize the sucking power of the DC. Not all 3HP DCs are the same. Those with the impellers attached direct to the bag housing will perform slightly better than those using flexy or a tortuous connection between the two.

The reason BP recommends more HP, a bigger impeller is that he wants to ensure that his recommendation can cater for a larger workspaces (hence longer ducting runs) and he recommends a cyclone so as not to worry about cleaning bags. If a woodworker is generating large amounts of dust using large belt sanders, thicknessers, tablesaws etc continually changing bags definitely becomes a PITA. However, for turners turning small staff the amount of dust being generated is relatively low so the necessity of cleaning bags is less of a problem.

The 6" ducting is a no brainer as 4" ducting simply cannot carry more than about 450 cfm under the pressures generated available by conventional impellers. Few people know than it takes 3 ,4" ducts to carry the same amount of air as 1, 6" duct.

The other thing that I see turners focussing on are the chips coming off items being turned (which even 2000 CFM may not capture) which have a very low health risk whereas they should be focussing on the finer dust which can be captures direct from the source when objects being turned are small. For larger objects like large platters/bowls or long work multiple 6" ducts should be used to ensure capture at source.

The Dust forum here has a lot of information about ways of handling dust but not much specific to turners.
This thread https://www.woodworkforums.com/f200/a...cussed-157526/ shows the development and testing of a high efficiency bell mouth hood for a small WW lathe.
Unfortunately the thread gets side tracked and does not get back on track until post #29 which is where the real discussion related to hood for lathes kicks off.

When sanding I use 3 methods: (1) a dusty with a Carbatec Big Gulp sitting close to the piece. I can see the visible stream going into it. (2) A powered filtered visor. (3) A box-type scrubber hanging from the ceiling. That's to catch some of the remaining small particles that hang around while I move onto finishing.

Originally Posted by BobL

The Dust forum here has a lot of information about ways of handling dust but not much specific to turners.
This thread https://www.woodworkforums.com/f200/a...cussed-157526/ shows the development and testing of a high efficiency bell mouth hood for a small WW lathe.
Unfortunately the thread gets side tracked and does not get back on track until post #29 which is where the real discussion related to hood for lathes kicks off.

Bob,
thanks for the above - I had read this and have book-marked it for when I am that ready. I have done a lot more research since I started my thread and have very much appreciated your expertise and time spent in helping

Ern and Neil - thanks for the replies. This also makes me feel more confident I am heading down the right path BUT I WOULD LOVE TO KNOW WHAT OTHERS DO AS WELL

thanks

Mick

Sanding of course generates most of the fine particles so some folk wet-sand with water. I tried that once with a piece of blackwood and IMO it reduced the 'iridescence' that blackwood often displays when finished.

One thing that I found to help out with Dust, put the dusty out of the main shed/workspace. Mine is housed in it's own little shed, behind the new shed.

So my full system is Dusty, Big Gulp at the lathe, Air Filter, P2 3m Half face mask for sanding, Plenty of ventilation:Fan behind me, open windows and door and an extraction fan in the roof under the Whirlybird. Not perfect, but I can turn and sand redgum all day and have clear mucus.

just to make this a bit harder, what do people do who turn bowls at 90 degrees to the lathe (ie: a swivel head) do. If using a 'big gulp' (or better still BobLs) flange shape has anyone set this up so it can be moved close to the bowl when turning or am I over engineering (at least in thought

thanks

Mick

Originally Posted by mick59wests

just to make this a bit harder, what do people do who turn bowls at 90 degrees to the lathe (ie: a swivel head) do.

I hang the inlet on the outboard banjo with the mouth adjusted very close to and below the work piece; so close that occasionally it sucks onto the piece...

I move the inlet into a different position for working on the outside and inside of a bowl.

This is what I use. The “head” can be rotated 360 from straight down to straight up. The pickup (oval) can also be rotated 360, and of course the main post from the banjo can be rotated 360 or adjusted to any height. The shop built extra banjo only takes a few tee nuts and adjusting knobs.
I made the shop banjo for times when I want to use the lathe banjo as a rest of a drill when power sanding.
The Velcro additions allow for almost any size shape. In the case of bowls, platters, etc it allows maximum flow where your are sanding; for a bowl sanding on the inside the outside is choked off to force full flow from the interior side.
Being able to mount through the bottom of the banjo is helpful if you have a sanding disc for your lathe as the head can be placed directly under the sanding action.
May give you some ideas anyway.
The main pickup is a floor register box which goes oval when you snip off the rectangular mount (about $3).

For respirators I use the 3M which filters down to 0.3 microns at 100% efficiency.

NCPaladin,

fantastic stuff . That is the type of flexibility I am thinking of. Much appreciated for the photos - they speak a thousand words

cheers

Mick

Before I could afford a dusty I built an extraction system with stuff from a building salvage yard: a kitchen exhaust fan, some 8" gal ducting and some 8" flex duct that had to be bought new. The fan went into the wall behind me, the gal duct overhead resting on a rail and then the flex duct dropped down on the lathe far side. The opening could be pulled into position behind the workpiece with the inevitable bit of coathanger wire. Suction worked better with half of the opening blocked off.

Great idea on attaching to the Banjo for collection underneath

Originally Posted by NCPaladin

For respirators I use the 3M which filters down to 0.3 microns at 100% efficiency.

Not a big deal but no air filter is able to achieve a 100% efficiency and any that claims of 100% efficiency means they either don't have the measurement capability (obviously not in the case of 3M) or the filter must be blocked. My reading of the 3M filter specs is the best have 99.97% filtration which is more than adequate for woodworking but the problem with respirators is rarely the filters but the fit around the human head and the fact that at some stage or other the respirator has to be removed.

A question I often get asked is "how much dust should I be worried about"

For a sobering post with a very telling photo take a look at this post.

I see way more dust than this on woodturners clothing after about 10 minutes worth of turning.

This is why relying on respirators alone is not a good idea. if only a respirator is worn then clothing should be removed and washed before removing the respirator. Continuing to wear dusting clothing is like walking around with a pot of dust under your bodily air intakes. Even small movements will fluff clothing together with the fact that the warm human body acts like a chimney and generates rising air currents which sweep fine dust off clothing past the head. This fume of dust coming of dusty clothing can persist for hours or even days afterwards.

Well, maybe it is time to post this clip again.

robo hippy BOWL SANDING HOOD - YouTube

My next model will be a 300 gallon or so tank that stays up all the time, and baffles to put in depending on what I am turning. You can also buy sheet stock of plastic and build your own. Helps some what with chip containment.

I turn 99% green wood, so turning doesn't generate dust for me, only sanding does. I have a 24 by 36 foot shop, so about 7 by 12 meters (I still haven't gone metric). For a shop this size, especially if I have 2 machines running at the same time, I need 3 hp on my dust collector. I might have gotten away with a 2 hp collector, but it would be pretty minimal. My lathe room is 10 meters from the collector, and the duct design people said I had to drop down to 5 inch pipe by the time I got there. I think I could have gotten away with 6 inch no problem.

Cyclone systems: The main reason to get one of these, and there are plenty of do it yourself set ups, is so that whatever goes through the lines, will drop down into the barrel before it gets a chance to go through your impeller blades. I had a little 1 hp model that was on a cart and I dragged it from one machine to the next. I sucked up all sorts of things from small cut off pieces of wood, to rags, shavings, a light bulb, and other things. I bent the impeller blades a couple of times and the cart would start to dance around the shop. The shavings and rags would clog up the impeller blade, and cut off all suction. Had to stop and clean it out. Quite a bit of bother. Now, with the cyclone, the only thing in the filter is dust, and very fine dust at that.

Bag or paper filter: Some what new on the market are pleated paper filters. The newer ones go down to 0.5 microns, which is really fine. Old cloth bags used to go down to 5 microns, which is fairly big chunks. The advantage of the paper filters is that in the same space of one bag, you get several times the surface area for air to vent back out into the shop, which keeps air flow in your lines at a higher level. If you have the fine filters, there is no dust put back into the shop. The better systems don't make much noise, so it isn't necessary to move it outside the shop unless you want more floor space. Some of these units have a very little foot print. If it is outside, and you don't have neighbors close by or down wind, you can take the bag off and just let it blow out.

You do want a remote switch. The radio frequency ones are the best rather than the line of site ones because then you don't have to point it at the collector. I have 2. One out in the shop for my flat work machines, and one on a clip on the wall in my turning room. I lost one to the shavings and learned my lesson that one time.

robo hippy