Thread: Alternative Dust Extraction Solution

Bob
It would be a good test with the adding slates and testing, also the width of the slot could be tested as this would make a difference.

I made this one with the idea of a back draft add on. As under the slates I can flip up a baffle that pulls most of the air from the back 150mm and on top of the slates put a wall sloping from the 150mm to 0mm at the top of wire mesh with a poly wool on the mesh so that the air is pulled through this wall evenly creating a back draft eg mini spray both and still have some downdraft.
So far the down draft has worked well for any spray painting that I have done to date but I have the option.

R

I don't think DD tables work that well as the light dust is encouraged to rise very quickly and escapes due to the top surface being sanded (duh). As a rule they are too restrictive on air flow due to needing a work surface and the timber being worked blocks a large part of the vent. Placing extraction vents above the object in what I would call a sanding alcove/box is a far better way to do it as the dust rising can be captured more effectively. if the room is available a small sanding "room" will work very well, it could even be made out of large cardboard boxes and folded away if not needed. Done this way a lot of air is pulled into the sanding area from the are the operator is standing thus encouraging the dust to enter the vents and not drift towards the operator.

Originally Posted by Chris Parks

I don't think DD tables work that well as the light dust is encouraged to rise very quickly and escapes due to the top surface being sanded (duh). As a rule they are too restrictive on air flow due to needing a work surface and the timber being worked blocks a large part of the vent. Placing extraction vents above the object in what I would call a sanding alcove/box is a far better way to do it as the dust rising can be captured more effectively. if the room is available a small sanding "room" will work very well, it could even be made out of large cardboard boxes and folded away if not needed. Done this way a lot of air is pulled into the sanding area from the are the operator is standing thus encouraging the dust to enter the vents and not drift towards the operator.

That's more or less what I have done with my metal working fume hood.
It has removable bifoldable doors that can wrap all the way around the hood if required
The RHS image is with the small 600 CFM fan and the LHS is with the new 1200 CFM exhaust.
The vice is easily removable so I can quickly access the flat bench.
This I have to say works really well - I didn't think of using it for sanding but I will be doing that next time.

I may not have been active on this thread but my investigation has continued.

Yesterday I went and saw Rusel's CV setup (thanks for your time and great knowledge of many things). It was very impressive as he has a few more machines than me and has a great setup with his ducting and multiple blast gates. He also has a 'sneaky' inlet where he had a small frame built to allow sweeping 'stuff' into which is then sucked up into the system. He also has gone to quite a reasonable length to get the noise of the CV down such that we could still talk while it was running. From an invisible dust collection at source this is still by far my preferred solution, however there is a 'lot' of work to get it to this stage and it still is noisy.

Below is what I am currently thinking, primarily because:
- it will be alot easier to setup
- I have a separate 'wood shed' where I can put the DC
- it will be much quieter, especially having it in its own shed which I can insulate
- I am 'happy' to continue using my Paftec CleanSpace 2 powered respirator while actually working, although this is probably the biggest disadvantage

The three biggest machines with a cyclone that I can fit into my wood shed are in the links below. Unless it 'just won't work' I am very keen on doing a main separation (even a crappy cyclone) and just dumping the rest outside. I certainly do not want to play around with filters and cleaning
MWE-151AX Auto Cyclone - Major Woodworking Equipment
MWE-C1200T Cyclone - Major Woodworking Equipment
https://www.machineryhouse.com.au/W318

I went and checked them all out during the week. They all have a 6" inlet port underneath and have a motor rated at either 9.8 (major woodworking) or 10 amps (H&F). They seem to suck pretty good (with both cyclone and filters in place) but I have no way of measuring.

My plan would be to remove the filter and bags and vent outside after the cyclone running 6" ducting inside. The venting will be on a wall around 20metres from the house and shielded from the house by the shed so the fact that the cyclone is not nearly as efficient as a CV should only be a minor inconvenience as far as what is not captured.

What I think I know about doing the above:

- it will not capture all the invisible dust no matter how good a job I do with ports
- I should be able to make it very quiet inside the shed
- I will need to make use of my windows and garage doors to get rid of the invisible dust. I'll also look at an air filter for times when opening everything up is not as practical

What I am worried about:
- because this is far below the 'magic numbers' for fine dust collection I could get 'clogging' in my ducting. I have no real idea how much these non-optimal cyclones will cut down on the CFM
- that I won't be capturing any fine dust (or that much else) at source and I will have setup a fairly elaborate system that is fairly useless
- I have no way of measuring how good this will be
- there are still things I have not considered


As you may be able to guess, I am still after guidance.

I'd also be interested in anyone who has bought and is using one of the machines I have linked to.

And BobL, I will be more than happy (no matter how bad it is ) in having your expert opinion on this

Mick

Mick, PM me your phone no.

I pretty much agree with your summary.

I still think there are some ways to get around the height needed for a BP type cyclone.

Originally Posted by BobL

I pretty much agree with your summary.

I still think there are some ways to get around the height needed for a BP type cyclone.

Does that mean you think

I could get 'clogging' in my ducting. I have no real idea how much these non-optimal cyclones will cut down on the CFM .

or

- that I won't be capturing any fine dust (or that much else) at source and I will have setup a fairly elaborate system that is fairly useless .

thanks

Mick

Mick,

Another option you might like to consider, if height is a restriction, is to install a CV on an angle.

I've read that Bill Pentz has done testing on this. The cyclone is said to work fine in a horizontal position, but according to Bill, the problem comes when you have larger pieces of wood get into the cyclone; they need gravity to find their way to the bottom. According to the CV forum, the cone needs to be at least on a 35 deg angle; again according to Bill. That means that you could tilt the cyclone to 45 degrees and it should work fine.

If you wanted to pursue this further, a visit to the CV site and forum might be in order.

Good hunting!

As John said it does work on it side....When play around after unpacking it I ran it sitting on the bench horizontal and it run just as if it was vertical.
I see the problem if at shutdown with stuff lay inside the cyclone but at the correct angle so this would fall into the bin all would work.

R

Originally Posted by mick59wests

I could get 'clogging' in my ducting. I have no real idea how much these non-optimal cyclones will cut down on the CFM .

I haven't been able to get my hands on one to test any flows, but 2HP and 6" long ducting sounds like a potential clogging problem.
There are no hard and fast rules on this e.g. clogging is unlikely when used on a lathe because the chip generation usually not fast enough and it will be able to handle any finer dusts that it manages to capture.

But as you say . . .

- that I won't be capturing any fine dust (or that much else) at source . . . . .


These units will capture some fine dust but they will also leave fine dust behind in the shed. You can counteract that by running these units for longer after the last dust making activity but that won't grab it all before it settles. That settled out dust is a running sore because just moving or even walking past a fine duct covered surface (e.g. piece of timber) will continually waft it into the air.

[QUOTE] . . . . . and I will have setup a fairly elaborate system that is fairly useless .[/QUOTE]

I'd use the term "limited" rather than "useless"

Originally Posted by mick59wests

- it will not capture all the invisible dust no matter how good a job I do with ports
- I should be able to make it very quiet inside the shed
- I will need to make use of my windows and garage doors to get rid of the invisible dust. I'll also look at an air filter for times when opening everything up is not as practical

What I am worried about:
- because this is far below the 'magic numbers' for fine dust collection I could get 'clogging' in my ducting. I have no real idea how much these non-optimal cyclones will cut down on the CFM
- that I won't be capturing any fine dust (or that much else) at source and I will have setup a fairly elaborate system that is fairly useless
- I have no way of measuring how good this will be
- there are still things I have not considered

Mick,

Your message gave me a sense of déjà vu. You are going through what seems to be the same process as I did when selecting a DC system. Like you I looked at many options, visited suppliers and read a mountain of mages 'till my head swam.

My strongest recommendation is to re-examine your priority list, and remake it if necessary. Once this list is pretty settled, usually decisions are easier to make. As soon as I finalised my list, the decision was clear. Hope the approach helps you as much.

Good hunting.

Originally Posted by BobL

These units will capture some fine dust but they will also leave fine dust behind in the shed. You can counteract that by running these units for longer after the last dust making activity but that won't grab it all before it settles. That settled out dust is a running sore because just moving or even walking past a fine duct covered surface (e.g. piece of timber) will continually waft it into the air.

Bob,

I thought the fine dust was airborne so if I have good ventilation (double garage doors at one end plus windows opposite each other each a bit more than 1metre squared each) that most fine dust would get blown through or captured. Alternatively (or perhaps as well as ???) running a good air filtration system at least afterwards and possibly while I am working as well.

I fully appreciate capturing at source would be better but am thinking with my backup ventilation / air filtration I should be able to get rid of the fine dust from the shed.

The other thing about the 'cheapies' I am looking at. While I am setting up the ducting and fixing ports I can use it as a mobile DC. Not ideal with filters being inside but I expect a lot better than nothing. In my own mind as even doing the ducting will be completely new to me, I am expecting this to all take a fair amount of time but still want to do some woodwork.

Appreciate all of the help

Mick

Originally Posted by mick59wests

Bob,
I thought the fine dust was airborne so if I have good ventilation (double garage doors at one end plus windows opposite each other each a bit more than 1metre squared each) that most fine dust would get blown through

Double garage doors will be great, but like wind power that only works when there is a breeze. Still worth having and using.

Alternatively (or perhaps as well as ???) running a good air filtration system at least afterwards and possibly while I am working as well.

I haven't measured many air filtration units but I found they (especially the smaller ones) were slow at capturing fine dust from shed air which still enables fine dust to be deposited. Once it is deposited on surfaces, when you move around or move dusty objected this dust just fluffs up and decontaminates the shed. again into the air. I see these devices as backups to proper dust extraction, and to remove dust from air for special finishing work. My feeling about them is if you are going to be sinking $400 into one you might as well put it into a decent dust extractor.

The other thing about the 'cheapies' I am looking at. While I am setting up the ducting and fixing ports I can use it as a mobile DC. Not ideal with filters being inside but I expect a lot better than nothing. In my own mind as even doing the ducting will be completely new to me, I am expecting this to all take a fair amount of time but still want to do some woodwork.

DC filters are not usually a problem (the most efficient filter I have measured is on a 2HP cyclone unit), it's mainly leaks around the pressure side of the ducting and capture bags that cause problems. When they are new they are probably OK but as they get older and moved around they get beat up and all mobile units I have looked at leaked, some quite badly. It only takes a slightly rucked plastic collection bag to defeat the sealing arrangement on most DCs. This is the main reason for outside location of DCs.

I think we are going around in circles here. What was the problem with getting a 3HP DC and locating/venting it outside, Was it power requirements?

Originally Posted by BobL

Double garage doors will be great, but like wind power that only works when there is a breeze. Still worth having and using.


I haven't measured many air filtration units but I found they (especially the smaller ones) were slow at capturing fine dust from shed air which still enables fine dust to be deposited. Once it is deposited on surfaces, when you move around or move dusty objected this dust just fluffs up and decontaminates the shed. again into the air. I see these devices as backups to proper dust extraction, and to remove dust from air for special finishing work. My feeling about them is if you are going to be sinking $400 into one you might as well put it into a decent dust extractor.

I was planning on one like Microclene Australia Pty Ltd - MC 1210 but I will ask about this another day . Although money is always a consideration, it is not my main driver and if the CV would fit into my extra shed and it was more 'plug and play' I would jump at it.

Originally Posted by BobL

I think we are going around in circles here. What was the problem with getting a 3HP DC and locating/venting it outside, Was it power requirements?

The main reason for the 2hp ones in the links are they are the biggest cyclone ones I can find that will fit into my woodshed which is just outside my main shed. By getting the DC outside (and the fact there is a place to put one) I am confident I can keep the noise to a minimum and keep all of the available space in my main shed. If I could find a 3hp one that fitted then I would go for it. I am therefore trying to determine the limitations on what would be easiest (and lowest noise) for me. I still have not ruled out a CV but I know it will be a lot more work getting it up and running at an acceptable (to me) noise level.

thanks again

Mick