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mick59wests
18th October 2013, 07:08 PM
To all of you fellow woodturners,

I am about to move from a place where my turning was basically done on a small porch. I did not use any dust extraction but used a mask (and recently upgraded to a Paftec Cleanspace2 powered respirator). However, I am moving shortly and the new place has a real shed :).

I have been researching dust extraction/control and health risks, especially as I will be in a much more enclosed setup. 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.

Thanks in advance

Mick

NeilS
19th October 2013, 09:20 AM
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.





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.
Inlet Port Design: As important as the cyclone. Don't forget about the bandsaw.
Filtered Respirator Mask/Hood: I made my own.

BobL
19th October 2013, 11:51 AM
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 http://www.woodworkforums.com/f200/air-speeds-around-duct-openings-blades-nb-invisible-dust-discussed-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.

rsser
19th October 2013, 12:15 PM
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.

mick59wests
19th October 2013, 05:23 PM
The Dust forum here has a lot of information about ways of handling dust but not much specific to turners.
This thread http://www.woodworkforums.com/f200/air-speeds-around-duct-openings-blades-nb-invisible-dust-discussed-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

rsser
20th October 2013, 05:58 AM
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.

Pat
20th October 2013, 07:26 AM
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.

mick59wests
20th October 2013, 08:54 AM
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

NeilS
20th October 2013, 09:36 AM
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...:o

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

NCPaladin
21st October 2013, 03:30 AM
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.

mick59wests
21st October 2013, 08:58 AM
NCPaladin,

fantastic stuff :2tsup::2tsup:. That is the type of flexibility I am thinking of. Much appreciated for the photos - they speak a thousand words

cheers

Mick

rsser
23rd October 2013, 08:39 AM
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.

BobL
23rd October 2013, 11:45 AM
Great idea on attaching to the Banjo for collection underneath :2tsup:


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.

BobL
23rd October 2013, 12:11 PM
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 (http://www.woodworkforums.com/f200/how-much-dust-too-much-155151/).

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.

robo hippy
25th October 2013, 04:48 AM
Well, maybe it is time to post this clip again.

robo hippy BOWL SANDING HOOD - YouTube (http://www.youtube.com/watch?v=AZsVc7qVx7A)

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

BobL
25th October 2013, 11:19 AM
. . . . 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.

At the normal pressures generated by a 3HP DC the most a 4" pipe can carry is around 400 CFM, a 5" can carry no more than about 700 CFM and a 6" can carry 1250 CFM so only 6" meets the 1000 cfm specification needed to grab all fine dust at source which is especially for lathe work.


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.

I have tested around 25 different working dust extractors and found that found what the manufacturers say about micron ratings of bags and filters to only be correct more or less for new filters and bags. almost all new filters and bags actually let thru a lot of dust and need a few hours of use to start filtering properly. All filters require some hours of use to achieve optimum filtering "conditioning" or impregnation with fine dust before they reach optimum performance which is generally much better that manufacturers specification. There are many different types of bags ranging from thing coarse cotton type to thick needlefelt. A well maintained coarse cotton bag is limited to around 80% efficiency below 5 microns, whereas I have found that thick needlefelt bags capture dust as efficiently as paper filters with paper filters averaging 92% at 0.3 microns and needlefelt bags averaging 96.8%. Paper filters will indeed clog more slowly than bags because they have a larger surface area.

The particle filtering efficiency of bags and paper filters is actually not that relevant for most woodworkers compared to the problems I have seen with leaks. Almost all DCs I have measured have a visible leak, and some have many leaks, and this is THE primary reason for vent or placing the dust extractor outside. I realize this is not a solution for North Americans but it is viable for most australians.

I could write a book on DC leaks. They start with poorly constructed and sealed impeller housings, then I see many leaks in the junctions or ducting between the impeller and the bag housing. The biggest source of leaks are around the filter and bag clamps, the most common being the leaks around the rucks in the plastic collection bag but also in the cloth or pleated filter junctions. In most cases these were clearly visible to anyone that bothered to look but often they were not visible but still managed to let forth a veritable torrent of invisible fine dust sufficient to contaminate a shed well beyond OHS limits, some within minutes of use. Then there are leaks in the bags and filters. I saw a number of new plastic collection bags with a small amount of dust and chips in them that had many pinholes in the bag. The reason for this is that the DC had been run with the bag near empty without collecting much dust so the plastic collection bag had been continually battered by the strong air flow from the DC against the DC base and frame punching many small holes in the bag. Hence it is better if plastic collection bags are not completely emptied but left about 20% full so that they are not easily moved and then do not get bashed around as much. the other thing I observed was that DCs that were moved to machines tended to have more leaks than those that were kept stationary

NeilS
27th October 2013, 11:12 AM
Valuable contribution to the topic there, Bob, particularly your observations on leaks.

I have suspected that leaks could be the weak point in my DC system. However, without the benefit of dust measuring equipment I have no way of getting a reading on that.

Bob, have you written elsewhere on the measuring equipment that you are using?

BobL
27th October 2013, 04:12 PM
Valuable contribution to the topic there, Bob, particularly your observations on leaks.

I have suspected that leaks could be the weak point in my DC system. However, without the benefit of dust measuring equipment I have no way of getting a reading on that.
Cyclones have a clear advantage as far as leaks go because the collection bag/chamber is under negative pressure. Only the dusting on the down flow side of the impeller is pressurised which can be reliably sealed and have it stay sealed. Most leaks on DCs occur around or in the collection bag which being positively pressured causes problems


Bob, have you written elsewhere on the measuring equipment that you are using?

I'm using an ARTI 6 channel particle counter with micron particle size ranges of <0.3. 0.3 - 0.5, 0.5 - 0.7, 0.7 - 1.0, 1.0 - 2.0, 2.0 - 5.0 , >5.0.
FOr air flow I'm using a TSI digital and Kurz Analog hotwire anemometers.
The TSI has a max range of 20m/s and the Kurz is 30 m/s so I use test pipes with larger diameters to measure higher air speeds.

robo hippy
28th October 2013, 06:46 AM
Bob,
Interesting points. Leaks are a huge problem and probably account for more flow loss than the corrugated type tubing/pipes. When I set up my centralized system, they recommended taping all seams as they supplied snap lock type sections of metal pipe. They also said to tape and/or silicone caulk all joints. For their hook ups at the machine, all had neoprene type gaskets at all junctions, so they should have been pretty clean.

I am not sure about how accurate the micron rating is on the various filters. The old cloth bags were 5 micron at best (mine was about 20 years ago). Every time I started it up, there would be a dust plume from the bag. I do think that the ratings are better on the newer machines. I guess it comes down to design and 'respectability' of the manufacturer. Like Mark Twain said, "There are 3 kinds of lies in this world, lies, damned lies, and statistics". One turner here, I think but, am not sure, he was the guy who started Clear View cyclones tested a bunch of different dust collectors. Almost none of them matched the manufacturer's specs, and some didn't even come close. One manufacturer even threatened him with a law suit if he didn't retract his statements.

I don't know if you did a comparison chart, but I would be interested in seeing it.

robo hippy

NeilS
28th October 2013, 09:22 AM
I'm using an ARTI 6 channel particle counter with micron particle size ranges of <0.3. 0.3 - 0.5, 0.5 - 0.7, 0.7 - 1.0, 1.0 - 2.0, 2.0 - 5.0 , >5.0.
For air flow I'm using a TSI digital and Kurz Analog hotwire anemometers.


Thanks, Bob.

BobL
28th October 2013, 11:56 AM
Bob,
Interesting points. Leaks are a huge problem and probably account for more flow loss than the corrugated type tubing/pipes.
In terms of loss of flow rate, lt depends where the leaks are. The leaks I was referring to are on the positive pressure side of the system ie after the impeller, and these will actually assist flow at the input side of the system.


When I set up my centralized system, they recommended taping all seams as they supplied snap lock type sections of metal pipe. They also said to tape and/or silicone caulk all joints. For their hook ups at the machine, all had neoprene type gaskets at all junctions, so they should have been pretty clean.
I probably should be more rigorous about this but I don't worry too much about leaks on the input side as they under negative pressure still collect dust from the shed. About half my junctions are taped and these tend to be those that are likely to be more permanent. If there is a chance I will be modifying junctions I usually leave them untaped.


I am not sure about how accurate the micron rating is on the various filters. The old cloth bags were 5 micron at best (mine was about 20 years ago). Every time I started it up, there would be a dust plume from the bag. I do think that the ratings are better on the newer machines.
It took me a while to work this out but the classic "dust plume from the bag on startup" is in many cases mostly not from the bag. That is the dust that has settled out around the DC either from leaks, or the failure of the DC to capture fine dust at source (most likely), or from something else like using a vacuum cleaner. After some use, most vacuum cleaners (even really expensive ones) output more fine dust than they collect. They do this because the motor cooling look minces larger dust particles into finer ones. This plume of dust from a filter/bag is a good measure of what is not being collected at source and a sure sign that a DC is not up to spec. Sometimes this is due to the small ports being used on machines being too constrictive to air flow. A good test of any DC system is to lay out a large clean (ie just washed) cloth after doing a days worth of woodwork and leave it for a few days. Then carefully collect it up and take it outside in full view of early morning or late evening light and shake it and see how much dust comes of. Bear in mind you might only be seeing a few percent of the actual dust as most of it will be invisible.

The single number micron ratings of bags/filters (ie 5 microns) is effecfively useless without the efficiency at that micron rating, and whether those ratings are for a new or conditioned bag. The filter/bag conditioning process is so variable (wood type, WW activity, humidity ext) that it would be impractical for manufacturers to provide any sort of accuracy for a conditioned bag. A new bag rating may also not be indicative of it conditioned performance which might still be OK even though it is relatively porous when new. But as I said before all this seems secondary to stuff like leaks and poor collection at source.

Perhaps more significant than micron ratings are manufacturers claims on DC Air flow. I have communicated with many wood workers who ask me what I think about (generic) 2HP DCs. Most of them have skim read Bill Pentz website and picked up on the 1000 cfm requirement for fine dust control and then read on retail websites that their 2HP has a flow rate of 1200 CFM but his is complete bollocks on a variety of fronts. The most I have measure on 3 of these as supplied by the retailer is 600 cfm. I have seen the measurement protocols for a manufacturer of these generic DCs and the test is not for the DC it is for the impeller alone, ie no adapters to 100 mm hose on the input side, no filters or bag housing, no flexy connection to the bag housing AND they perform a single point measurement in the middle of the exit so there is no allowance for wall friction which can be of the order of a 25% reduction to real flow. The real flow of those 2HP DCs as supplied by the retailer using one of the 2, 100 diameter input ports is ~400 cfm. Using both of the 100 mm diameter inputs the flow is <600 cfm - the only wood working machine this is probably adequate for is a drill press .


. . . . . Almost none of them matched the manufacturer's specs, and some didn't even come close. One manufacturer even threatened him with a law suit if he didn't retract his statements.
I don't know if you did a comparison chart, but I would be interested in seeing it.

If you read my threads in the DUST forum you can see that I report on a number of DCs and VCs but I do not mention any brand names because of what BP experienced. What I do feel safe about saying is none of the DCs I have measured for flow rates measure up to the manufacturers claims.

mick59wests
28th October 2013, 09:14 PM
come on you fellow wood turners,

this is not an inquisition. I (and I expect many others) would like to know what others are actually doing in regards to dust extraction to get a more balanced feeling for 'what is normal'. I would also like to know what others think about what they are doing. I know the path I am currently thinking of but want to get a broader view. I'd hate to think I went down a religious path (no offence intended) but I expect most people will get my drift.

thanks

Mick

rsser
28th October 2013, 10:11 PM
Mick, I would expect after BobL's informed posts many of us are thinking something like '#####, my kit is not up to speed and/or I've overlooked something' and so will be reluctant to admit to our failures.

For your own setup, there's all the info you need here and elsewhere on the web.

Set it up and let us know what you opted for and why.

BobL
28th October 2013, 10:47 PM
How about, unless invited, I agree to butt out of any criticism or comments on members setups?

mick59wests
29th October 2013, 09:52 AM
How about, unless invited, I agree to butt out of any criticism or comments on members setups?

Bob - I hope you do not as there is no doubt that you are making an extremely valuable contribution and I for one am extremely grateful (even if sometimes it may not seem that way :D ).

I also suspected what Ern is saying ie: many feel what they have done is 'not really good enough' so are reluctant to comment. From that view, it makes me feel more confident that I am going down the right path of trying to achieve the magic numbers to get fine dust extraction at the source.


cheers


Mick

rsser
29th October 2013, 12:20 PM
Yeah, I'm with Mick. Friendly and informed comment is invaluable, and I've learned a lot from Bob's posts.

Eg. while I knew that some folk have contracted an asbestos-related disease via the clothes of a worker exposed to the stuff I never made the connection with wood dust :doh:

Just to add regarding my complete setup: after a number of years I was seeing dust settle both in the workshop and in the workshop annexe which houses the dusty. Following a query about the life of pleated paper cartridges, Bob suggested I check for leaks. Bingo, the rubber sealing ring at its bottom was leaking.

And I replaced the prefilter on the box scrubber. The original type was no longer available. The replacement is not working as well and again that looks to be due to a poor seal.

BobL
29th October 2013, 03:07 PM
Yeah, I'm with Mick. Friendly and informed comment is invaluable, and I've learned a lot from Bob's posts. Eg. while I knew that some folk have contracted an asbestos-related disease via the clothes of a worker exposed to the stuff I never made the connection with wood dust :doh:
The risk is nowhere near as high for second/third party exposures with wood dust as it is for asbestos otherwise we'd be seeing clear problems with turners families. My concern is more with the turners than only wear masks as a form of dust control and end up with many grams of fine dust on and in their clothing and continue to wear the clothing for hours after turning.

Here is another sobering piece of information showing relative exposure by different woodworking occupations.
I have posted this before but I cannot find it so I will post it again here.
The Australian Standard for wood exposure is 1 mg/m for hardwood and 5 mg/m3 for softwoods but these are considered too high in terms of world's best practice.
This chart also does not take into account "particle sizes" since fewer fine particles will have lower mg/m3 but in turn are likely to cause more health problems than larger particles.
For example the European Medical Standard for wood dust exposure is 0.1 mg/m3 for particles 10 microns or smaller and turning typically produces a lot of very fine dust
The average exposure for turners well above the recommended OHS levels.
Maximum levels are the highest of all specific wood machinery type operators and even the minimum exposure is above the recommended hardwood level.
http://www.woodworkforums.com/attachment.php?attachmentid=291295&stc=1

cornucopia
29th October 2013, 07:12 PM
I have been turning for 15 years and luckily in my first year of turning I met a retired production turner who warned me about dust and scared me into taking it seriously

I use three ways to help control dust:
1. I wear a trend respirator helmet all day long
2.I have a microclean air scrubber running all day and an hour after i finish working.
3.I have a 2hp cyclone extractor (http://www.axminster.co.uk/axminster-industrial-series-ub-2200veck-cyclone-extractor-prod795037/) which sits just outside of my workspace and is ducted in with 2.5m of 8" duct

I use the extractor when i'm sanding and if i'm turning something very dusty

I would value any advice on one thing and that is that at the end of the 8" duct I put a Y piece on with two 4" ports, I tend to cap one port and use a metre of 4" bendy hose from one of those ports to the closet point that the dust is leaving the workpiece.
would i be better trying to find a larger diameter bendy hose and doing away with the y piece? or using two bendy 4" hose's and not capping one port off?

here's a pic of me at the lathe that shows the end of the duct and the y piece, the bendy hose is on the shelf at the back.
http://i690.photobucket.com/albums/vv262/a-cornucopia/P1200023_zps423e208d.jpg (http://s690.photobucket.com/user/a-cornucopia/media/P1200023_zps423e208d.jpg.html)

BobL
29th October 2013, 08:34 PM
I use three ways to help control dust:
1. I wear a trend respirator helmet all day long
2.I have a microclean air scrubber running all day and an hour after i finish working.
3.I have a 2hp cyclone extractor (http://www.axminster.co.uk/axminster-industrial-series-ub-2200veck-cyclone-extractor-prod795037/) which sits just outside of my workspace and is ducted in with 2.5m of 8" duct


Firstly good on you for taking dust seriously.

If a cyclone was setup and working right you would not need either respirator or an air scrubber.
I can expand on this if you would like more details.

Any DC/cyclone sitting just outside a workspace doesn't help dust problems much as the DC/cyclone creates a negative pressure inside a workspace which draws any fine dust that exits the DC/cyclone back into the shed. A DC/cyclone should be where possible located outside on the wall opposite the major opening to the shed. This increased the possibility of fine dust being dispersed and carried away before it can get back into the shed. If this is not possible in your case then I can understand why you need to wear a respirator.

In terms of ducting and connectors the best way to increase flow (thus capturing more dust at source) is to remove all 4" ducting and ports as that just reduces flow. The most a 4" dust/port can transmit under the pressures generated by any conventional impeller used in DCs or cyclones is 400 CFM.

At 8"m the theoretical flow rate is ~1800 cfm but a 2HP with what looks like a 12" impeller will top out well before that, probably around 1350 CFM without any resistance. The Axminster cyclone design is quite an old one so I would expect it to significantly resist the flow so it will be less than this, but using 6" or more ducting should still generate a better flow than 2 x 4" individual ducts so you are better off using either 6" or 8" ducting. I seriously doubt whether you would get much more flow using 6" versus 8" ducting on that cyclone.

Using bigger ducting reduces air speed and increases flow which means more fine dust is collected but few chips may be collected. Some turners don't like this but remember that the big chips represent less risk than the fine dust in terms of respiratory problems.

cornucopia
30th October 2013, 01:43 AM
thank you for your reply

the impeller in this machine is just shy of 17" wide by 5" deep, i know this because after a few months of owning it it kept popping capacitors and i checked that the impeller could spin freely and the motor had no bearing issues. I also had to have a dedicated 16 amp supply fitted to it as when it starts up it needs the juice to get the impeller turning!!

I think i understand what you mean- so if i keep the 8" from the machine into my workshop but remove the 8" to 4" Y and try to find an 8" to 6" reducer and a 6" bendy hose i can improve the performance- is that right?

QuarkVI
30th October 2013, 07:52 AM
Hi,

Hopefully the following are appropriate questions for this thread:

As a new woodturner I am reading this with quite a bit of interest and trying to understand what I should consider as minimum requirements for dust control as a hobbyist. Needless to say this has to factor into the cost of the hobby, which is unfortunate when one is already scraping together for a lathe and tools but wisdom would dictate that one's health is more important. This is especially a concern to me as my son (12) has also joined me in the hobby.

I have no problems with accepting the dangers that wood dust poses but what isn't clear is how much exposure poses a risk - is it cumulative or can your body process some of it?
What would be the minimum requirements for a hobbyist turner spending less than 10 hours a week turning?
How effective is wet sanding at dust control i.e. if I wear a good dust mask while turning (and until dust settles) and then only wet sand will that provide adequate protection? (this is my current plan)

Any other cunning ideas? I have already chosen to do all my other woodworking with hand tools not only for reasons of cost but also due to OHS issues like noise and dust - simply safer, cheaper and easier to use hand tools and since I am not in a production environment I can amble along at my own pace. But there doesn't seem to be an analogue for turning. Was hoping that a good dust mask would be sufficient but this thread is starting to make me doubt that.

regards
Robin

BobL
30th October 2013, 09:16 AM
thank you for your reply

the impeller in this machine is just shy of 17" wide by 5" deep,
Is that the external diameter of the housing or of the actually impeller fan?
If it's the actual impeller and it is connected to the 2HP motor as per the axminster website then that is a mismatch as a 4 or 5HP motor is normally needed to fully utilise a 17" impeller and no wonder it is popping the breaker


I think i understand what you mean- so if i keep the 8" from the machine into my workshop but remove the 8" to 4" Y and try to find an 8" to 6" reducer and a 6" bendy hose i can improve the performance- is that right?
Correct, it will pick up fewer chips but grab more fine dust at source

BobL
30th October 2013, 09:44 AM
I have no problems with accepting the dangers that wood dust poses but what isn't clear is how much exposure poses a risk - is it cumulative or can your body process some of it?
What would be the minimum requirements for a hobbyist turner spending less than 10 hours a week turning?[QUOTE]

Yes it is sort of cumulative so risk for wood dust is thought to be proportional to concentration (mg/m3) x exposure (Hours exposed).
At 10 hours a week that is approximately 1/4 of a full time job.
From the table I posted earlier in this thread the average concentration is 33 mg/m3 so 1/4 of that is about 8 mg/m3 which is well above the OHS limit of 1 mg/m3 for hardwood and just above the 5 mg/m3 for softwoods and this doesn't take into account the fact that turning generates finer dusts than most other woodworking.
This is why, more than most other woodworkers, turners need good dust extraction.

What is less well understood is how dust triggers allergic reactions, some of which can be serious enough whereby wood workers cannot even touch some timbers. For some individuals and some timbers an allergic reaction can be triggered by much lower exposures than the OHS limits. How would you feel about not being able to turn for the rest of your life because you cannot even touch the wood? Suddenly the cost of reasonable dust extraction especially spread over a number of years starts to look real cheap.

[QUOTE]How effective is wet sanding at dust control i.e. if I wear a good dust mask while turning (and until dust settles) and then only wet sand will that provide adequate protection? (this is my current plan)
West sanding is very messy and generates rust on wood working machinery. Also unless the wet dust is collected once the water drys out any small disturbance of the dust will fill your shed fills up with the dust so it's not that helpful.


Any other cunning ideas? I have already chosen to do all my other woodworking with hand tools not only for reasons of cost but also due to OHS issues like noise and dust - simply safer, cheaper and easier to use hand tools and since I am not in a production environment I can amble along at my own pace. But there doesn't seem to be an analogue for turning. Was hoping that a good dust mask would be sufficient but this thread is starting to make me doubt that.

A good dust mask is not really sufficient. Best practice OHS is that PPE (like dust masks) should be used after all other OHS solutions (like dust extraction) have been implemented

It's not cunning but common sense that good ventilation and strategic location of the lathe can be very effective. Setting up a cross flow i.e. open door and window can reduce exposure even with light breezes. If there is no window or door cut large holes in the wall and install a grate or grille.
Aiding natural ventilation with a large extraction fan at the out take (not intake) will also help
Then on top of that wearing a mask is better than not wearing one but it is far from any sort of magic bullet.
Whether all this reduces the dust levels that work for you long term can only be determined by hard measurements.

cornucopia
30th October 2013, 06:15 PM
Is that the external diameter of the housing or of the actually impeller fan?
If it's the actual impeller and it is connected to the 2HP motor as per the axminster website then that is a mismatch as a 4 or 5HP motor is normally needed to fully utilise a 17" impeller and no wonder it is popping the breaker


Correct, it will pick up fewer chips but grab more fine dust at source

the actual fan, as I said I had to check it. The housing is around 22/24" from memory.
its not popping the breaker, every few months the capacitor on the side of the motor would fail, this fault was eventually tracked down to a faulty batch of capacitors and by moving the capacitor away from the motor so it could cool down more efficiently between stops and starts.

thank you for your help<o:p></o:p>

Colin62
7th November 2013, 07:35 PM
Using dust extraction while turning is not something that even occurred to me for many years after I started. Admittedly, I don't spend nearly as much time on the lathe as I'd like, but even so, reading these forums and particularly BobL's very helpful and informative posts, I've realised that I need to do something.

Basically, at the moment, I have no dust extraction, and if I've been sanding something large, I wander out the workshop in a cloud of dust, spitting. I'm at the stage where I am aware that it's not good enough to work like that, and I read most of the dust extraction threads, and am working my way up to investing in a system which will hopefully increase the length of time that I can enjoy my turning in a healthy way.

So, while I've not added to the knowledge or discussion, I've come out the closet and set the bar very low for others who may have been embarrassed that their dust control techniques were inadequate.

Thanks to BobL and the others who participate in the dust extraction threads - there is a huge amount of useful and practical advice there for those who are willing to look for it.

jefferson
12th November 2013, 11:07 AM
I have some very real dust problems in my shed that I need to quickly rectify. In the last month I have had severe reactions in turning sassafras, blackwood and cooiibar burl - asthma and skin allergies. I'd take some photos of my shed, but last time I did that I was told I was bragging. My shed is 25m by 9m, split into three sections - a 9m by 9m assembly area which has no dust control and gets very dusty. A mid section, around 3/5ths of 16m by 9 metres. This section of the shed contains: a Minimax CU 300 smart combo machine that runs 5inch dust ports. I've built 3 kitchens out of this machine in the last 18 months or so. The planer /thicknesser also gets a work out mainly on redgum. I use a 2hp dusty with a Gregory machinery 3ft pleated filter to capture dust on this machine. I also have a Sawstop cabinet saw with a shroud around the blade and a 4 inch outlet. (After reading about enlarging the port, I checked the inside of the machine yesterday. One third full of dust. ) The little Jet TS with dado head is in no better condition and given the stock removal rate, it fills up very quickly. I also have a woodwizz machine that is connected to 3inch ducting, then up to 4 inch to a separate 3hp DE. Needless to say, this one spits out a lot of dust. Thankfully, I don't use it too often. I also have 2 router tables, both very messy. One, a Triton table, the other a Carbatec one with a 4inch dust port on the fence. In one corner, I have an unconnected 3hp Carbatec cyclone that I've had waiting for installation for 3 years. Overhead, I have a very large swampy A/C which is great over summer as it blows almost everything out the doors. Plus the biggest Jet dust scrubber which also get very dirty. In the turning end of the shed (where I spend most of my time and have a decent wood fire installed) I have a number of lathes. Don't laugh. A Vicmarc VL 300 long bed, a VL 175 under a window, a s750 Stubby in the centre of the room. The two VLs are serviced by small Carbatec DEs, probably 3/4 hp with just one bag. Overhead, I have two large Microclene dust scrubbers, plus a small Jet version. I use a large 4 inch gulp chute for the Stubby. Plus my 19 inch bandsaw which I haven't got hooked up to any DE. Needless to say, there is a lot of dust everywhere. It's been so long that I've posted I've forgotten how to take pics which would probably explain it better - help please. So, can I run my 3 hp cyclone which I gather isn't very good throughout my shed? The longest run will be 16m to the VL 300. I also want a floor sweep as lots of dust and shavings end up on the floor, only to be stirred up by sweeping. I intend putting metal ducting throughout. I've gone to all this expense and the dust control is letting me down. When my mates come out each week to play on the lathes, we might have all three big ones going at once, sometimes even the VL 100 as well. I always have the Microclenes running when turning. And I hate dust masks. And I know for a fact that certain cuts on the lathe put lots of fine redgum dust in the air that I am breathing constantly. So what are the solutions? It seems I will have to vent outside, in spite of not wanting to loose heat from the fire over winter. We're not far from the snow here and the A/C in still running mid November. Will I need another cyclone just for the turning end of the shed? How good a job aren't my dust scrubbers doing as there is fine dust everywhere. It isn't too bad over summer as the A/C in the shed carries most of the bad stuff out the door and window. (As an aside I have two roller doors down the far end of the assembly area of the shed and lots of air comes in over the top of the doors.). A few of you have been to my shed and know the layout.

rsser
12th November 2013, 11:56 AM
Lot's of issues Jeff.

I'll just buy into the sweep and reactions.

I found the Carbatec 22" x 7" sweep close to useless (cat. no. M-015).

Got far better results out of a sweep they no longer sell but others might. The head has a skewed opening (about 25 x 10 cm) and it's fixed to a clear plakky tube that incorporates a handle, blast gate and union.

That's driven by a 2 HP dusty but over a fairly long line with hard bends and a lot of flexible duct. All 10 cm diam.

Re allergic reactions to certain woods, this appears to happen to a number of folk. A product of repeated exposure at a guess.

I'm looking at replumbing my setup to eliminate the Y-junction (replace it with quick-fit union) and reduce the length of flexiduct.

BobL
12th November 2013, 12:15 PM
I have some very real dust problems in my shed that I need to quickly rectify. In the last month I have had severe reactions in turning sassafras, blackwood and cooiibar burl - asthma and skin allergies. I'd take some photos of my shed, but last time I did that I was told I was bragging. My shed is 25m by 9m, split into three sections - a 9m by 9m assembly area which has no dust control and gets very dusty. A mid section, around 3/5ths of 16m by 9 metres.
I'm sorry to hear that you have a problem and it sounds like you really need to read what's going on in the Dust extraction forum.


This section of the shed contains: a Minimax CU 300 smart combo machine that runs 5inch dust ports. I've built 3 kitchens out of this machine in the last 18 months or so. The planer /thicknesser also gets a work out mainly on redgum. I use a 2hp dusty with a Gregory machinery 3ft pleated filter to capture dust on this machine.
Unfortunately the filter is irrelevant on this machine because the stock 2HP DC can only pull ~400 cfm thru 4" ducting which is simply insufficient to capture the very fine dust at the source of the problem. If a DC doesn't capture the dust it cannot filter it. The other problem with these DCs is they leak fine dust like there is no tomorrow so they should be placed outside the shed BUT they can only be used with short runs of ducting otherwise the flow drops away. I have done extensive testing and some modification on these DCs - have a look here (http://www.woodworkforums.com/f200/generic-2hp-dc-171247/).
5" ports are also too limited in flow to around 680 cfm (1000 cfm is considered a minimum at source) most DCs and cyclone flow rates clained by manufacturers are wrong by ~ 50%


I also have a Sawstop cabinet saw with a shroud around the blade and a 4 inch outlet. (After reading about enlarging the port, I checked the inside of the machine yesterday. One third full of dust.
Although it is an indication of a problem I would worry less about the dust you can see and more about that you cannot see.

A 3HP cyclone for that shed is just too small and will never be able to scavenge enough air from more than one machine. The carbatech models also use old cyclone designs so is a poor collector of fine dust at source. For your size shed you really needs a DC with a ~5HP motor and a 17" impeller and 8" ducting.

jefferson
12th November 2013, 12:47 PM
Thanks for the quick response Bob. Yea, you've confirmed I have a problem. I only have one circuit left on my single phase power board (50 amps max), so this will be testing. Do you think I can use the existing Cyclone (that I paid $3K for) for the woodworking machinery end (one machine at a time) and get a better cyclone (presumably a ClearVu) for the turning end? And what would you suggest for the main trunk line for the existing cyclone? 200mm? If I go the Clear Vu route for the turning end, will it run more than one machine at a time? Thanks in advance? You didn't say whether I wasted my money on the air scrubbers either. Presumably I did. And yes, I've read the last twenty odd pages in the Dust Collection section and invisible dust is important to me.

RETIRED
12th November 2013, 12:55 PM
Jeff. If you want to email the pics to me I will put them up for you.:cool:

jefferson
12th November 2013, 01:13 PM
, Annie has got the camera. I'll take some pics tomorrow and will send them down to you. I've just been down to the shed again and had a look in all the "dead" zones. Very fine dust settled in the corners, in spite of the 2 microclenes.

mick59wests
12th November 2013, 02:42 PM
I've just been down to the shed again and had a look in all the "dead" zones. Very fine dust settled in the corners, in spite of the 2 microclenes.

I am far from the expert, but I would expect that with so much dust being generated, nothing will pickup what gets into the corners and you will need to vac or sweep.

I'd be interested to know what others think of the microclenes as at the moment I intend to get one as part of my overall strategy.

cheers

Mick

BobL
12th November 2013, 02:59 PM
Thanks for the quick response Bob. Yea, you've confirmed I have a problem. I only have one circuit left on my single phase power board (50 amps max), so this will be testing. Do you think I can use the existing Cyclone (that I paid $3K for) for the woodworking machinery end (one machine at a time) and get a better cyclone (presumably a ClearVu) for the turning end? .
If you have an electrical power problem (and given the problem below) I would sell the unused cyclone and install a big cleavue with serious and extensive ducting throughout.


And what would you suggest for the main trunk line for the existing cyclone? 200mm? .
I would be wary about using 8" ducting on an older technology 3HP cyclone
The real flow rate of old tech systems with 6" ducting to machines is about 1250 CFM, this translates to a linear air speed of 3600 fpm in an 8" trunkline which is less than 4000 fpm so there will be a risk of sawdust dropout.


If I go the Clear Vu route for the turning end, will it run more than one machine at a time?
The bigger one should easily be able to do this.

Remember, when you dust extract from multiple machines the overall scavenging effect of fine dust from the shed is increased.
This is why a big CV can permanent leave open one of the inlets open at all times and continually scrub the shed of fine dust


You didn't say whether I wasted my money on the air scrubbers either. Presumably I did.

Scrubbers are realy useful for clearing a smallish space (like a small shed or booth) of ALL dust so that dust free finishes are required but they will struggle to keep up with continual dumping of large volumes of fine dust (e.g. from a lathes) into the shed and eventually become clogged and thus less effective. A well designed workshop and efficient DC system where the very fine dust is disposed of outside the shed will not need scrubbers inside for health purposes.

While you are at it you should to think about location of doors/windows and other openings in relation to the final ventilation of a DC. if you cannot arrange these strategically then you might need a stack to disperse the fine dust.

RETIRED
12th November 2013, 03:25 PM
, Annie has got the camera. I'll take some pics tomorrow and will send them down to you. I've just been down to the shed again and had a look in all the "dead" zones. Very fine dust settled in the corners, in spite of the 2 microclenes.No worries.

BobL
12th November 2013, 04:21 PM
, Annie has got the camera. I'll take some pics tomorrow and will send them down to you. I've just been down to the shed again and had a look in all the "dead" zones. Very fine dust settled in the corners, in spite of the 2 microclenes.

This is sure indication of insufficient DC air slow and hence fine dust being collected at source and highlights the problem with air filters/scrubbers. Air scrubbers generate relatively low air speeds and effectively end up mostly recirculating the same air over and over again and cannot reach out to the sides and corners of a shed quick enough to collect the fine dust from these areas. They work better in a small shed or a booth.

The very fine dust that settles is not a problem if it remains settled, but just walking past or moving something in the vicinity of this dust will continually "fluff" some of it back up into the air continually contaminating the shed. You may not even see it fluff up but rest assured that it does.

mick59wests
12th November 2013, 08:18 PM
Scrubbers are realy useful for clearing a smallish space (like a small shed or booth) of ALL dust so that dust free finishes are required but they will struggle to keep up with continual dumping of large volumes of fine dust (e.g. from a lathes) into the shed and eventually become clogged and thus less effective. A well designed workshop and efficient DC system where the very fine dust is disposed of outside the shed will not need scrubbers inside for health purposes.

I think of a 'scrubber' or air filtration as part of the strategy for removal of fine dust. I hope that I can remove at least 95% of fine dust at source more than 90% of the time. However, I never expect to remove 100% of it 100% of the time so the air filtration (and ventilation) is going to up my fine dust removal from around the 95% mark to closer to 99%. Is this a reasonable expectation or is the 99% more likely 96%?

So good to have expertise to call on with such a very important topic. Even the 'out there' posts are good to read :D

cheers

Mick

BobL
12th November 2013, 09:16 PM
I think of a 'scrubber' or air filtration as part of the strategy for removal of fine dust. I hope that I can remove at least 95% of fine dust at source more than 90% of the time. However, I never expect to remove 100% of it 100% of the time so the air filtration (and ventilation) is going to up my fine dust removal from around the 95% mark to closer to 99%. Is this a reasonable expectation or is the 99% more likely 96%?

It would be nice to be that prescriptive but every situation is different and some are quite different.

Using a drill press it appears that a decent DC will capture 99.99% of fine dust - therefore, air scrubber is completely unnecessary

Turning and sanding a small spindle on a lathe using a decent well setup DC will capture 99+% of the dust.
Turning a large bowl on a big lathe is going to spray stuff all over the place - depending on your DC you will be lucky to get 95% or maybe even 75% of the fine dust during the turning operations.

Now, how to get the rest out.
Using a scrubber will clear a bubble of air around the scrubber and that is about it - the size of the bubble will depend on how much dust there is and how long the scrubber is running for.
If the bubble is around the operator that is very useful but what about the rest of the shed.
Just running a scrubber for longer is not a solution if the amount of dust generated is greater than the capture rate, the non-captured dust fils the shed and eventually starts to settle in the corners and shadowed areas on shelving and low to ground etc. This settled dust cannot be picked up by the scrubber so so the next time you walk by or move that surface the fine dust will recontaminate the shed.
To get around this multiple scrubbers would be needed, but even then with only marginal improvement. It's always better to put more effort into capturing at source.

I have been asked about using a compressor to fluff up all the fine dust and run a scrubber overnight. I tried this and it sort of worked but it's very tricky to measure redeposited dust and I gave up on it after I blew some small machine parts onto the floor and lost some of them.

Running the DC after the last dust making activity has the benefit of replacing wood dust ladened internal air with cleaner external air. However, if there is only one opening from one side of a shed to the DC inlet then like the scrubber all that will be cleared is a tunnel of air between the opening and the DC inlet. To clear the air in the shed you can of course open all windows and doors on one side and all DC inlets on all machines which increases the size and numbers of tunnels. Better still would be to install vents on the walls near the dead areas so that air can be pulled from all areas of the shed during and after dust making activities.

jefferson
12th November 2013, 09:46 PM
Thanks Bob again for the help. I don't know how to get a paragraph break happening, so I can't make the read a little easier for you.

1. I won't sell the old cyclone. I reckon I can make it do for the saws in the main part of the shed. It's more the turning end that I'm worried about, particularly now that I have the s750 Stubby and have started turning larger platters.

And 2., you are right, the crap just does go everywhere. No way to capture it at source effectively.

Even worse when arrives here, it's everywhere.

So I'm thinking a Clearvu in the turning end of the shed, aided by two Microcleans above the VL 175 and the 300, with a down draft gate on the tail stock end of the Stubby permanently left open to scrub the air. (The Stubby is bolted to the floor under it's own power pendant. ) Plus another shroud behind the Stubby lathe to capture sanding dust, same for the other two lathes. That leaves four gates open at one time.

Or do I need blast gates?

Also, the Jet scrubber I'll leave high in the ceiling (which is useful in winter in bringing the heat down from the ceiling).

I assume I can vent the Clearvu inside the shed?

If not, I'll have to put up with the cold but that's got to be better than the dust.

As I said, I have one circuit left on the power board, including an existing 15amp one for the old cyclone and a new one as well. But no more.

And no, I don't want to build another shed outside the big one to house a cyclone. So I will have some noise issues to deal with as well.

The turning area is 9m by a little more than 6m, which should house all my turning gear but the cyclone. Oops, forgot the bandsaw, so gates will be needed.

Also forgot the floor sweep, lots of chips to get rid of.

Any other options to a ClearVu? Most of the stuff on the net seems heavy industrial.

I hope some of the other ClearVu owners can chip in with their thoughts. Or maybe I post over on the Dust Extraction forum>?

Thanks again.

pjt
13th November 2013, 01:14 AM
Hi Jeff,
It certainly does sound like you need to do some work to your dust collection, it might also be worth posting in the dust collection forum, it was only the headline that caught my eye as I don't normally visit the turning section.

As Bob has already said if you are looking at having multiple machines operating at once and still want to achieve acceptable airflow at each machine then a larger DE system is required, 5hp or more, really depends on total flow needed and total pressure losses within the system, things like pipe size, pipe length, cyclone, number of fittings, (gates,bends,etc) total length of hose, all effect pressure losses and you can be a bit smart with the control of it with a variable speed drive (VSD) you will be able to control the speed (airflow) for times when you want maximum flow (more than one machine operating) and turn it down for times when only one machine is in use thus saving power, this can be setup to be an automatic or manual change.

Other options to a CV are the Felder DE units the RL 200 has numbers that are right at were we want, (for one machine) although can't see at what pressure tho? also claims to emit lessthan 0.1mg/m3, I think Bob has posted before re what was allowable, seem to recall 25mg/m3 but not sure, Bob might confirm this, upshot of this is you may get away with not needing to vent outside in winter and quiet 70dB.

Floor sweep, I made this one up for Roy at his workshop
http://www.woodworkforums.com/f200/dust-extraction-upgrade-roy-schacks-workshop-172717/


Other operational things to consider, the jaws on a chuck act like a fan sucking in air/dust towards the centre and spraying it outwards in every direction, so preventing the dust from going over the back of the plate towards the chuck , for this to work you will need a close fitting dust shroud/hood located on the rear side of the plate, also, when sanding a plate if you sand in the top quandrant you will be directing the dust away from you and into a dust shroud if positioned at the rear of the machine.




Pete

BobL
13th November 2013, 10:48 AM
. . . .and you can be a bit smart with the control of it with a variable speed drive (VSD) you will be able to control the speed (airflow) for times when you want maximum flow (more than one machine operating) and turn it down for times when only one machine is in use thus saving power, . . . .
And noise.


Other options to a CV are the Felder DE units the RL 200 has numbers that are right at were we want, (for one machine) although can't see at what pressure tho? also claims to emit lessthan 0.1mg/m3, I think Bob has posted before re what was allowable, seem to recall 25mg/m3 but not sure, Bob might confirm this, upshot of this is you may get away with not needing to vent outside in winter and quiet 70dB.


The current OHS limit for OZ is the same as the US, 5 mg/m3 for softwoods and 1mg/m3 for hardwoods.
The Felder unit meets the European standard but none of these makes any allowance for real health culprit which is not the concentration of dust but the numbers of fine dust particles per cubic m.
If the 0.1mg/m3 was all in small particles that could still represent a millions of small particles per cubic metre
OR
If it could be one 0.1 mg particle of sawdust in a cubic meter of air i.e. harmless.

A more sensible standard mentions the particle size range e.g. the European medical standard is "0.1 mg/m3 (PM10) "
The means 0.1 mg/m3 for particles of 10 microns or smaller. Still not brilliant but better than nothing

NeilS
13th November 2013, 06:50 PM
For your size shed you really needs a DC with a ~5HP motor and a 17" impeller and 8" ducting.



We went to 5HP when we upgraded the DE at the local men's shed earlier in the year. Your workshop might even be larger, Jeff... :D

They already had a cyclone built to Bill Pentz' specs, so getting there step by step.

pjt
13th November 2013, 11:59 PM
And noise.



The current OHS limit for OZ is the same as the US, 5 mg/m3 for softwoods and 1mg/m3 for hardwoods.
The Felder unit meets the European standard but none of these makes any allowance for real health culprit which is not the concentration of dust but the numbers of fine dust particles per cubic m.
If the 0.1mg/m3 was all in small particles that could still represent a millions of small particles per cubic metre
OR
If it could be one 0.1 mg particle of sawdust in a cubic meter of air i.e. harmless.

A more sensible standard mentions the particle size range e.g. the European medical standard is "0.1 mg/m3 (PM10) "
The means 0.1 mg/m3 for particles of 10 microns or smaller. Still not brilliant but better than nothing

As they say "the devil is in the detail" so if Jeff wanted some peace of mind, moreso if he chose to not vent to outside for winter, some more details from Felder re the particle size/s of that 0.1mg/m3 is what he would be needeing.



Pete

BobL
14th November 2013, 12:27 AM
As they say "the devil is in the detail" so if Jeff wanted some peace of mind, moreso if he chose to not vent to outside for winter, some more details from Felder re the particle size/s of that 0.1mg/m3 is what he would be needing.

Sort of - what is needed is the efficiency of the filter for various particle sizes, like the graphs I post in the dust forum, but doubt Felder have measured this because all they worry about is the dust concentrations in mg/m3. There are several ways of measuring these dust loads and one is using particle size distributions which is what I do, but there are easier ways of doing this using external pumps and filters which is probably what they do.

I do have some data for a Felder filter but because it is only one filter I would prefer not to put this up in the forums and have folks make judgements based on one measurement. If people want to know the results off line they can PM me for details.

pjt
14th November 2013, 01:52 AM
Sort of - what is needed is the efficiency of the filter for various particle sizes, like the graphs I post in the dust forum, but doubt Felder have measured this because all they worry about is the dust concentrations in mg/m3. There are several ways of measuring these dust loads and one is using particle size distributions which is what I do, but there are easier ways of doing this using external pumps and filters which is probably what they do.

I do have some data for a Felder filter but because it is only one filter I would prefer not to put this up in the forums and have folks make judgements based on one measurement. If people want to know the results off line they can PM me for details.

I do seem to have a recollection of a thread/post on this subject, apologies for going back over old ground, so what we want to know is how good the filter is at stopping a range of particle sizes, viz. for every 100 particles of say 1um size if only one escaped the filter then is 99% eff. for that size, similliarly for 100 particles of say 5um if 2 escaped then the filter would be 98% eff. for that size, and so on.
Then all the escaped particles would add upto xmg/m3, in the Felder case they state less than 1mg/m3.
Then we want to know if any of the escaped particles sizes are harmful in those % concentrations.
Jeff can't quite breathe easy yet:;



Pete

BobL
14th November 2013, 11:10 AM
I do seem to have a recollection of a thread/post on this subject, apologies for going back over old ground, so what we want to know is how good the filter is at stopping a range of particle sizes, viz. for every 100 particles of say 1um size if only one escaped the filter then is 99% eff. for that size, similliarly for 100 particles of say 5um if 2 escaped then the filter would be 98% eff. for that size, and so on.
Then all the escaped particles would add upto xmg/m3, in the Felder case they state less than 1mg/m3.
Then we want to know if any of the escaped particles sizes are harmful in those % concentrations.

Correct.

Particles bigger than about 10 microns don't float all that well and settle quite quickly and only get inside airways if folks stick their nose or mouth in the sawdust stream. Those smaller than 10 microns and in particular those less than 5 microns tend to float around for a while allowing them to be scooped up. This is why dust particle size analysis focusses on particles of 5 microns or smaller.
Like this
http://www.woodworkforums.com/attachments/f200/234036-want-your-dc-checked-invisible-dust-dcandvca.jpg

The 5 - 10 micron size are the ones that get as far as the inside of the nose - these cause nasal allergies and maybe worse. Those between 5 microns and 0.3 microns get into the lungs and cause breathing issues.
The reason that we don't worry so much about those smaller than 0.3 microns is because these are not trapped inside us and are usually breathed back out again

jefferson
25th November 2013, 03:33 PM
I've bitten the bullet and have decided to order a ClearVue Maxi cyclone for the turning end of the shed. And I will have to vent outside, which doesn't matter much on 9 acres. Cold in the winter though.

Some of the guys on the Dust Extraction forum have been providing some good advice. I think I may have to get a sheet metal worker to make up some hoods. The one for the Stubby with its 750mm swing is going to give me problems. Any ideas on design? Maximum bell diameter?

I don't think positioning the hood with some adjustment will be easy either. I'll have to mount something to the floor probably.

Pat
25th November 2013, 05:33 PM
Jeff, just stand near the fire :q

NeilS
25th November 2013, 08:33 PM
. I think I may have to get a sheet metal worker to make up some hoods.


Suggest you begin by making some out of thick corrugated cardboard and testing out different designs and configurations as prototypes before having the hoods you finally settle on made up in metal. It is so easy to reconfigure cardboard prototypes with just a box cutting knife and a reel of tape.

Some of my cardboard prototypes lasted for years.

jefferson
26th November 2013, 08:24 AM
Good ideas Neil. I'll keep that in mind when I get down to the business end of things.