Thread: 'Ad-hoc' dust extraction

Originally Posted by charlieart66

So an lots of open windows would work?

I googled HEPA and found that it features in some domestic vacuums as well as industrial ones, would something like this suffice?

Thank you,

Only if you don't mind stopping every 2 minutes to empty it and clean the filter

You need to build a mini cyclone

Originally Posted by Burnsy

Only if you don't mind stopping every 2 minutes to empty it and clean the filter

You need to build a mini cyclone

Bursny is spot on. Those weeny domestic HEP filters will clog up too quickly. Vacuum cleaners are really completely impractical for fine dust control in a workshop/shed. A cyclone won't help either as the very fine stuff just gets carried along with the air. Cyclones only work down to about 10 microns.To grab the very fine dust, the cyclone needs to be physically much larger so the air near the outside of the cylinder has to travel through a much greater distance than that close to the middle of the cylinder. The larger the cyclone the greater the air speed needed to push the finer particles to the outside. Cyclones are good for catching big and intermediate dust but only something like high capacity HEPAs can catch the really fine stuff.

Originally Posted by charlieart66

Let me get this straight, is the extra cannister used to allow more time in-between emptying?

Correct

In this photo it seems that the air is sucked from the white Hoover head to the paint cannister through the black pipe to the Hoover itself? Surely suction will be lost.

The extra distance of this air path didn't seem to make a material difference to the function of the cleaner. Some extra load must be placed on the motor, but I don't have the means to measure that. I imagine if you had something that showed current draw of the motor it would help tell if a system like this is going to burn out the motor more quickly.

This would mean that the Hoover would get filled up first, at which point it would lose suction meaning that it cannot fill the paint tin up as the Hoover is full and subsequently loses suction?

As can be seen in another photo the air goes all the way through, but the bigger chunks drop out in the paint tin. There are other commercially available devices that aim to do the same thing based on some sort of cyclonic or other action. As can be seen if you follow the link to Phil Thien's site there is no claim made that this system is anything other than a chip separator. It is not intended to solve the microfine dust problem as others have pointed out.

However, many of us don't actually build much, prefer to use mainly hand tools and real wood. We might not have a huge dust problem but do have a garbage collection problem that can be improved by using a device such as this.

With the extra length of vacuum hose it does at least give a bit more flexibility in perhaps placing the shop vac so it vents outside the garage when working. Since only really fine dust seems to be making its way to the canister, I suppose it would even be worth considering removing the pleated filter in the canister and letting all the bad stuff blow through the motor and out the blower port.

A nice feature of this particular shop vac is the blower port is threaded to take the hose connection. If we took the filter load off the motor perhaps a longer blower hose could also be added to vent further away. I have been trying to find a plastic cap which has the same thread to play with making other connector hoses, but without success so far.

Ok, heres what I'm going to do.

I'll buy a cheap cleaner hopefully with a blow function. If I have time this summer I'll make a cyclone, which I'll use it to separate the larger chips that I get from the planer from the finer ones I get from the bandsaw.

Any sanding, which I assume makes the finest dust will be done outside if possible. If this is not possible I will do it by the door and possibly use the blower function to disperse the dust outside.

I'll let you all know before I buy one however.

Thank you very much

May the wind always blow away from you Charlie
Jim

With all this messing around...why not but a proper dust extractor. It might set you back a couple of hundred...but it will do the job a lot better, for a lot longer, straight out of the box. See the following as examples...

http://www.carbatec.com.au/store/ind..._350_1390_1400

or

http://www.carbatec.com.au/store/ind..._350_1390_1410

Workshop dust extractors work on the principle of High Volume / Low Velocity air, which is ideal if you want to remove lighter air borne particles in and around machinery. They also work great for cleaning up!

Vaccuum cleaners (shop vacs etc etc) work on Low Volume / High Velocity air. Great for picking up bowling balls, or cleaning carpet (and other flooring) when you want to remove the particles that are stuck aroung fibres or in tight places. The high velocity air 'agitiates' and loosens the particals.

Trying to step UP a standard vaccuum hose, to the standard 4 inch connector, most real woodworking machinery has fitted is a waste of time. You end up with reduced velocity and very little volume. And the inverse is true also. By steping a 4" extractor DOWN to 1-1/4" or 1-1/2", you loose all your volume and have little velocity.

That said... cyclones work very well (even those powerd by a shop vac), as the system runs very efficiently, with the dust particles never actually reaching the vaccuum source. They are forced to the bottom of the collection bin, and held there by the air pressure. Large industrial cyclones work on the same princlpal as these home made ones, and run with less power, less air flow, and less filter changing.

Do yourself a favour, upgrade to a 4 inch duct collector now. Its designed for the job without mod's. The drive motor is seperate from the dust (where a vaccuum has the motor IN the dust, if the bag fails) and besides that, you have a much larger dust capacity.

Best of luck...

Dohboy

Originally Posted by dohboy

why not but a proper dust extractor.... the following as examples...

http://www.carbatec.com.au/store/ind..._350_1390_1400


Dohboy

I'd be hard pressed to call these styles proper dust extractors (see comments above). DONT buy an underbench model unless you are prepared to cobble together some sort of pre separator.

Agreed.... and its a pain dragging the full bag around on the floor, and an in line dust seperator will help.

http://www.carbatec.com.au/store/ind..._350_1660_1830

The free standing models (for pretty well the same price) are the much better option.

Dohboy

Can someone please summarize and clarify for folks like me who are becoming more confused?
Big dust particles don't hurt us as bad as the fine stuff.
For the big ones we can in a pinch use a shop vac ( if we can stand the horrible noise) hooked up to whatever piece of machinery we are using...

For the small dangerous dust we need a dust extractor.... even masks might not do the job?

What exactly is the difference between the different dust extractors offered? I know our club's spend 800 bucks to get a small bucket looking unit to do the job, but it is so noisy we keep turning it off and there is absolutely no way I could work with it on in my small room.... there has to be something better?
Some compromise? Good for health and not a killer to the pocketbook and/or ears?
Like most things in life... it has to be simple before people will use it, not everyone is an engineer.

Juvy

Originally Posted by keju

Big dust particles don't hurt us as bad as the fine stuff.

[/QUOTE]For the big ones we can in a pinch use a shop vac ( if we can stand the horrible noise) hooked up to whatever piece of machinery we are using... [/QUOTE]
Sure

For the small dangerous dust we need a dust extractor.... even masks might not do the job?

Standard Dust extractors (ie using calico collection bags) located inside your shed are no different to vacuum cleaners.
There are other bags and filters for Dust Collectors but they don't help all that much especially for activities like sanding hardwood.
Masks are about the only sure way of minimising the risk but
- They have to be able to extract 0.3 micron or smaller particles. This does not mean those simple white hoods that cover your nose and mouth but something that uses OHS rated cartridges.
- They have to be worn all the time including well after you have finished any dust making activities. Maybe even a day or two after you have finished any dust making activities.
- who wants to wear a mask all the time?

Air purifiers that use HEPA filters do work but because they are usually slow at cleaning the air the operator still ends up working in an atmosphere of very fine dust and they are relatively expensive.

There are simple solutions to reduce risk;
1) Work outside - still wear a mask if the activity is really dusty
2) Open up all your shed doors and windows when making dust
3) Use large bathroom type venting fans to push the dust outside and/or draw fresh air into your shed.
4) Locate your DC or vacuum cleaner outside your shed opposite you major shed air intake and get a longer hose to run around with inside your shed.
[/QUOTE]

Major problem here......
I do my scroll saw work in a spare bedroom IN the house!
I don't do major sanding , but I do quiet often sit at the kitchen table ( so I can watch tv) while handsanding some of my scrolled pieces.
I would love to have some set up that would prevent all that dust getting out of that room and spreading itself all over the house.... but like I said.. it just can't be too loud...... my ears start ringing when a neighbour plays his "music" loud.
And I also can't afford paying 800 bucks.... if I could I'd get a better saw! lol

Juvy

Safety and health does not come cheap and fine dust is a real issue particularly if the wood work generating this fine dust is done inside a house where children might also live. If a proper cyclone separator cannot be provided then how about just changing the air in your room more often. A couple of big exhaust fans will at least blow the dust outside and not into your lungs.

Cheers

Tim

Originally Posted by charlieart66

So an lots of open windows would work?

I googled HEPA and found that it features in some domestic vacuums as well as industrial ones, would something like this suffice?

Thank you,

I highly recommend a respirator, the sort that you can buy that you attach 2 filters to. I must admit I do own the triton respirator also and although it is good for certain jobs it is not practical to use continuously when working inside the shed.

I find one of those relatively simple respirators is a god send, they are light, the glasses dont fog up (useful for us four eyes) but more to the point your lungs and nasal passages are clean when you leave the shed.

The Aldi vac does come with a HEPA filter, but even so nothing is 100 percent. In addition there are a number of tools you will not be able to hook up to the vac and hence you should consider always wearing a respirator in the shed. If you dont believe me, have a look at the dust floating in mid air in broad daylight. Even before you start working in the shed, just walking around will disturb enough dust to make it airborne.

Vacs are good, air filters are good but I wouldn't gamble my lungs on any of them.

And whatever you do, do not work inside the house!

regards

Marios