Thread: Dust Extraction / Control used by woodturners

Originally Posted by cornucopia

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

[QUOTE=QuarkVI;1711888]
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.

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.

Originally Posted by BobL

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></o>

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.

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.

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.

Originally Posted by jefferson

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.
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.

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.

Jeff. If you want to email the pics to me I will put them up for you.

, 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.

Originally Posted by jefferson

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

Originally Posted by jefferson

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.

Originally Posted by jefferson

, 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.

Originally Posted by jefferson

, 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.