Thread: Choices, Choice, Which dust extractor?

I find that even with my Thien dust separator, some fine MDF and other dust goes through to the Dust Collector bags, so you cannot throw away the bags and filters. I would still use a cartridge

After reading this thread ,now I'm stressed I have a DC-40 from H&F and planned to connect it to my 36" radial arm saw, table router, 18" BS and Compound mitre saw. No, not all at once I'm not that crazy.
So I take it that I should get a bigger unit?

Originally Posted by JillB

I find that even with my Thien dust separator, some fine MDF and other dust goes through to the Dust Collector bags, so you cannot throw away the bags and filters. I would still use a cartridge

Of course it would and is the reason that bags are next to useless in the big scheme of things. The most important thing in dust collection to exhaust the dust collector to the outside of the shed and then you don't need to catch or filter it. In fact the dust collector will work far more efficiently used this way.

Originally Posted by Mini

Of course it would and is the reason that bags are next to useless in the big scheme of things. The most important thing in dust collection to exhaust the dust collector to the outside of the shed and then you don't need to catch or filter it. In fact the dust collector will work far more efficiently used this way.

It depends how close your neighbours are. Healthwise the visible stuff does not really matter but if you remove all the bags and your visible dust ends up on their washing or back veranda they will not be too happy about it. To stop that happening all you need is a coarse bag (even 30 microns is enough) and the invisible stuff that escapes and is diluted into the atmosphere is not seen by anyone.

They would have to be very close and you would have to be doing a huge amount of continuous work for it to be a problem. I doubt any average home woodworker on the average block of land would even approach the issue of deposition on a neighbour's washing. Forget bags they are a dead end, if you must, use filters out of a spray booth, far coarser and far better air flow and for the tiny amount coming out they will stop it. They can be hosed clean if need be but I doubt it would ever be necessary.

Originally Posted by Cured

After reading this thread ,now I'm stressed I have a DC-40 from H&F and planned to connect it to my 36" radial arm saw, table router, 18" BS and Compound mitre saw. No, not all at once I'm not that crazy.
So I take it that I should get a bigger unit?

Not unless it isn't doing its job. A good 1 HP unit connected directly to a machine with a minimal hose run should do the job fine. If it is clearing away all the waste, then why worry?.

BTW, fitting a cartridge element to the unit will improve its effeciency because the pleated filter has around 7 times the surface area compared to a bag, hence less resistance to the airflow.

Originally Posted by TP1

.... BTW, fitting a cartridge element to the unit will improve its effeciency ....

I thought of that and had a look at their web page, the FC-10 Filter Cartridge is listed to fit the DC-3, DC-5, DC-7, DC-80, DC-90 only..

Cheers Pete

Originally Posted by Cured

I thought of that and had a look at their web page, the FC-10 Filter Cartridge is listed to fit the DC-3, DC-5, DC-7, DC-80, DC-90 only..

Cheers Pete

The cartridge filters from Carbatec and Timbecon would probably fit. The most critical dimension is the diameter. Their cartridges are 370mm across and check to see if it will fit yours

I don't get it, why use something that from the get go is going to clog up and impede air flow even when it is brand new.

The cartridge filters come with internal paddles which are attached to a central shaft and turned by an external handle. By turning the handle, the fine dust is dislodged from the filter into the plastic bag below for disposal.

Apart from that, compressed air would also work wonders in cleaning the filters periodically. In practice, they don't seem to lose their efficiency as much as the cloth filters do because of their design, and just a few turns of the handle keeps everything under control.

Originally Posted by Mini

They would have to be very close and you would have to be doing a huge amount of continuous work for it to be a problem. I doubt any average home woodworker on the average block of land would even approach the issue of deposition on a neighbour's washing. Forget bags they are a dead end, if you must, use filters out of a spray booth, far coarser and far better air flow and for the tiny amount coming out they will stop it. They can be hosed clean if need be but I doubt it would ever be necessary.

I guess it depends on your definition of average? I'm living in 1/6th acre inner city block.
Prior to having an enclosure around my DC I accidently used it without refitting the bags and my small back yard was covered in a layer of fine visible crap after a couple of days doing some bandsaw work and using a 10" planer. SWMBO made me redo the large load of washing located about 6 m away from the open DC. Fortunately it was a reasonably calm day but it only needed the wind to be drifting in the wrong direction and it would have done the same to the neighbors washing located about another 5 m away on the other side of the fence.

Since then I have added an enclosure around the DC and that makes a big difference in terms of dust escaping from the DC if the bags are left off. I reckon I could run my DC without bags and just let the sawdust and chips fall into the enclosure but I don't like cleaning out the enclosure every couple of weeks - the sawdust and chips are just easier to handle in a bag. I have been thinking of making a top bag out of something called H-media from Email Industries - this stuff is even more free flowing that those from a spry booth and has a much higher capacity than just about any other filter material available.

Originally Posted by BobL

- this stuff is even more free flowing that those from a spry booth and has a much higher capacity than just about any other filter material available.

It sounds like a sieve. Doesn't that also mean that that it will stop far less dust getting onto the washing?

Originally Posted by TP1

It sounds like a sieve. Doesn't that also mean that that it will stop far less dust getting onto the washing?

Short answer is yes but it also has other advantages.

There are many factors to filtering media.
3 Significant ones to consider are;
a) size of the particle filtered
b) The amount of air that can flow through the filter even when it is clean - this is sometimes called the filter media impedance
c) The amount of dust that the filter can hold before it starts to affect 2) airflow- this is called the filter capacity.

Cartridge filters are
- for invisible dust; limited at a), good at b) but without paddles they are not so good at c).
- In addition, in terms of visible dust; they are very good at a)

30 micron (Normal) cloth bags are crap at all 3 factors for invisible dust, However for visible dust they will collect enough to prevent irritating neighbors and substantially reduce the amount of visible mess. They are very poor at b) from the moment they walk out the factory door. To keep c) at any sort of decent level the bags need to be emptied and cleaned well before they are full.

The H-media filter media I'm referring to is
- for invisible dust; crap at a) but good at b) & c) even without paddles like cartridge filters, although they would benefit even more from having a paddle system
- for visible dust this stuff is good for all 3 factors.

The best all round filters are properly constructed HEPA filters which are the ultimate for a) and b) for both visible and invisible dust. In really dusty environments they have to be prefiltered by either a cyclone or something like H media. They are also very expensive.

H-Media has longish particle capture path so it can hold a lot more dust before it clogs up. It's probably ~2" thick in its fluffiest state . It also has a kind of graded porosity. It has about 1" of very open and porous material (that catches the bigger chunks) and then slowly gets finer and finer as you go through the material - the final filtering ability is probably only around 30 microns. The big advantage over bags is significant improvements in b) and c). As far as I know it is only available in commercial rolls of about 1.2 m wide by 20 m long!

Have I confused you yet?

Cheers

Originally Posted by BobL

Have I confused you yet?

Cheers

No Bob you haven't, and thanks for your insight. But I have to say that it still doesn't seem like the best solution.

Surely even a rudimentary dust separator would be preferable to spreading dust everywhere. Perhaps then, the disadvantages of the coarser filter material wouldn't matter.

Also, does anyone know of any legal ramifications through Council by laws, Federal and State health and environmental regulations that may or may not permit venting dust and debris into the atmosphere?