Thread: Want to setup my garage with Dust Extraction

150mm is the default size as 100mm will not flow enough air to pick up the fine dust that is sprayed everywhere during machining operations. When we say dust extraction we should mean just that, the fine dust that floats in the air. Chip extraction is easy, dust extraction to remove the fine dust is the problem as once it escapes from the machines it just floats in the air and enters our lungs and we are not aware of it happening. To condense it down to an answer you most probably do not want, yes it must be 150mm to be effective and you need an extractor that will flow the required air in the ducts. The exhaust or the machine must not return any air to the workshop unless it is filtered by proper micron filters not bags they simply do not do the job. The above is a brief summation to keep you healthy and your workshop clean, more can be found here Bill's Cyclone Dust Collection Research - Home Page

Be prepared to study this site over a period of time as it has a stupendous amount of information that at first glance is very confusing to say the least. Stick with it as it has all the information needed then when you are thoroughly confused as you will be come back here and we can try and simplify it for you.

The key parameters for collecting fine dust at source is according to Bill Pentz a system that can operate at 1000 cfm and 4000 fpm. The other key factor is to add very fine filters or (to get away from the noise as well) put the DC outside the work area so that it does not recycle the fine stuff back into the shed. By putting it outside I also don't mean putting it just outside the shed door. It needs to be placed outside the shed as far away from the door as possible, preferably on the opposite side of the shed from the door.

Originally Posted by Arry

Carba-Tec® 2hp Economy Extractor : CARBA-TEC

This is your first problem. I have a similar 2 HP unit at the milling yard. It's rated at 1200 cfm but with bags and a bit of 4" ducting and the most it can extract in practice is ~600 cfm. Adding 6" pipe doesn't improve matters UNLESS the impeller intake is modified to accept the full 6" of ducting direct onto the impeller. Even then it is border line and the most you can expect with short (<3 m) lengths of 6" ducting and clean bags is probably 900 cfm. Then as the bags clog up the performance will go down from there

I have it connected to my TS, Jointer, and Thicknesser.

That is a good start.

The other equipment has no dust extraction.

You can get around this by building cabinets or boxes around this equipment and adding ducting to these

I have been researching and the consensus seems to be that I need 6" or 150mm ducting.

Unfortunately yes. While a single 4" port or duct can draw >4000 fpm it simply cannot extract 1000 cfm using normal DCs.

Is this really necessary?

It is if you wish to meet the base specs for dust collection

I was planning on using 100mm as the 150mm is very pricey.

Well yes and no. Given your TS, jointer and thicknesser and DC are probably worth a couple of thousand so adding $500 worth of ducting and fittings and saving your lungs is cheap. The pipe is relatively cheap - I get mine for $50 for 6 m - it's the fittings that are expensive, especially at places like bunnings, but there are cheaper places.

I think the ports in my machines are probably 100mm or less anyway.

Almost certainly they will be 4" ports. If you have 2 or more ports on a machine using short lengths of 4" to connect the machine to 6" duct is a roundabout way of doing this. If the machines only have one 4" port then a cludge solution is to run 1 or 2 other 4" ducts to the close vicinity of a machine and just leave them open while you run the machine.

And remember, the DC needs to run for ~10 minutes after the last dust making activity. Machines directly connected to switch a DC or vacuum on and off only when they are in use is very poor design and will fill your shed up with fine dust.

Thanks very much for the lenghty explanations..

Only thing I am now confused on is the size of pipe going to the machines.

From my current Dust Extractor it has say 4 inch or 100mm outlets and so do all my machines.

So are you saying, have the main run of pipe at 150mm but then connect to the dust extractor and each machine with 100mm pipe?

Cheers

Originally Posted by Arry

Thanks very much for the lenghty explanations..

Only thing I am now confused on is the size of pipe going to the machines.

From my current Dust Extractor it has say 4 inch or 100mm outlets and so do all my machines.

So are you saying, have the main run of pipe at 150mm but then connect to the dust extractor and each machine with 100mm pipe?

The DE must have a 150 mm or bigger intake otherwise it is pointless using 150 mm ducting intake. Most DE have 100 mm intakes, either 1, 2, 3 or 4 intakes. These 100 mm intakes throttle the DCs. I will draw some diagrams and post them to show what I mean.

thanks, so I guess if my DE only has 100 mm intakes then I am stuck using 100 mm pipe for the entire setup?

Here are a few diagrams I started drawing a while ago and your question has spurred me to complete them as a picture is worth 1000 words.

Firstly, what's wrong with connecting a cheap DC/DE to my machines using 150 mm ducting


Now for ducting

The weakest link are the 100 mm intakes at the DC end of things. These MUST be enlarged for the 150 mm ducting to even have a chance of working properly.

Then:


And best of all

Originally Posted by Arry

thanks, so I guess if my DE only has 100 mm intakes then I am stuck using 100 mm pipe for the entire setup?

Yep - unless theses are enlarged it's a chip collector.

It is still really worthwhile to put your DE outside your shed. That way if you cannot get rid of the fine dust while it is being generated you can at least vent it out of your shed afterwards. If you leave your DE inside the shed you are just filling your shed up with fine dust.

Cheers Bob, as they say, pictures are worth a thousand words )

SO basically I have a chip collector.

One thing I started doing approx 12 months ago is wearing this when I am making dust, then I take it off approx 10 mins after using a machine.

[ame="http://www.amazon.com/gp/product/B000Z53WKU/ref=s9_simh_gw_p328_d1_g328_i1?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=center-2&pf_rd_r=146QJ7JHNFS15NKVMYBD&pf_rd_t=101&pf_rd_p=470938631&pf_rd_i=507846"]Amazon.com: 3M 7500 Series Reusable Half-Facepiece; Model 7503; Size: Large: Industrial &amp; Scientific[/ame]

It is very comfy and I guess in a sense negates the need to filter out the very fine dust as this does the job very well )

Originally Posted by Arry

. . . . It is very comfy and I guess in a sense negates the need to filter out the very fine dust as this does the job very well )

Unfortunately I know how ineffective most masks are although they are better than nothing at all. The gas mask style is the one dislike the most since these do nothing for the eyes and exposed skin. In the case of all masks the operators clothes get covered in dust which is then carried around till they get washed and every move pumps some dust from clothes into the air surrounding the operator. Then the human body also acts as a chimney so air wafts upwards from this continuous little fog of dust carrying it up to ones mouth and nose.

I lost my sense of smell for 6 weeks after working with MDF outside a few years ago which is one reason I got into investigating all these things and why I advocate Bill Pentz proposal of getting rid of as much as possible at source and then leaving the DE on afterwards. I do have a triton full face shield and dust mask which I wear mainly when milling timber with my chainsaw mill or ripping stuff on my TS.

Cheers for the advice Bob..

My garage is single brick with standard gyprock ceiling I think it is called.

What would be the best way to attach pvc to brick or to the ceiling?

I guess brackets of somekind but I presume the ceiling could not handle much weight.

If I use brackets where would I get them from as the idea I have in my head, I have never seen brackets like that....

Cheers

Possibly what you are thinking of is what's called a standoff bracket, these have a leg that can be attached to a wall then the top half of the bracket unbolted the pipe placed in lower half then top half bolted back together, any plumbing supplies will have them

Pete

As Pete says plumbing suppliers will have a range of stuff that you can use or adapt. For fixing to the ceiling it's probably not wise to afix to the gyproc but move the clamp so that it is attached thru the gyprock to a joist.

Take a look on this page and it will give you some ideas.
Flexistrut Engineering Catalogue

I find it easier to use clamps that are enable vertical adjustment and can be easily moved to different locations which is why I made my own. I used some 2.5 x 25 mm galvanised strap and bent them into shape with a vice and an anvil. 2.5 mm thick is overkill but it is what I already had, I reckon you could get away with even 1 mm thick.

Mine brackets hang from a 2 x 1 batten that holds up my under ceiling insulation.
They look like this.

There are 3 parts, a square hook that goes over the batten. A short piece of all thread, and a the lower half that wraps around the pipe.

Have a look here dust collection ducting for woodworking - Google Search

It might give you some idea for ducting, some of it is irrelevant and some is useful. As you rightly point out all machines have 4"/100mm adaptors and that is not effective at all. What I recommend is leaving the original dust port and adding another which is 150mm. On a table saw the gaps around the machine will make up the difference in air flow. The 150mm port is the extraction and the 100mm + housing gaps will supply make up air to ensure ensure the 150mm does not starve for air. Any cabinet with a DE port hooked up to it must have a method to supply the air needed by the DE. If it were hooked up to a cabinet that was air tight then no air could flow because there would be no air entering so you can understand now that it is important to provide an equal or greater amount of air into the cabinet. BTW two 100mm dusts will nearly but not quite equal one 150mm duct in air flow.

Cheers guys, that has given me some great ideas