All Replies on Dust Collection Woes!

It all depends on whether or not it’s Thursday and partly cloudy.

Seriously, if you put this much thought into your woodworking projects, it’s no wonder you don’t have any posted. (Okay, that wasn’t really seriously.)

My shop is the same size as yours, and my dust collection system is a Dust Deputy and a shop vac. Maybe that explains why I cough up projects rather than actually having to build them.

-- Charlie M. "Woodworking - patience = firewood"

In a one car garage shop, approximately 300 sq. ft., you’re not likely to have DC runs long enough to worry about static pressure drop. A dust collector must do only two basic things, have enough velocity (3500 ft/min) in the pipes to keep dust particles suspended in the turbulent airstream, and have enough capacity, cu ft/min, in order to take away the dust and chips from your machine as fast as it generates them. My planer is my test.

You’re not going to have two or three people working at the same time so you don’t need high HP, blast gates, and large diameter pipes taking up valuable space in your small shop. The magazines and their advertisers have almost convinced everyone that you gotta have 2 HP with 4” or 6” piping. For the 1000 sq ft or larger shop this may be true, but in only 300 sq. ft. this is overkill.

In my shops, both in Gainesville, and in the U.P. I have a small single stage dust collector with a 1 micron filter bag. I run 2 1/2” hoses to my tools and get along just fine. In fact I’m getting rather tired of people “chiding” me about my clean shop.

-- "Heaven is North of the Bridge"

Biowa, my jointer and my table saw have 4” dust ports, so I guess going with a 4” piping wouldn’t alter the over all by that much would it?

-- I started working with wood because of the biscuits.

Charlie,
I have a needy wife, a dog that thinks he is a princess and neighbors who can’t grasp the concept of righty tighty. Being the only “handy” man around has it’s advantages (food, drinks, etc…) but it does cut into projects being completed. I have a shop (the other side of my 3 car garage) full of 85% finished projects. I think I have ADD.

-- I started working with wood because of the biscuits.

2 1/2” to 4” adaptors are inexpensive and readily available. The trouble with a 4” hose is that on a smaller HP dust collector, the velocity may fall below 3500 fpm, letting dust accumulate in the hoses. The airstream velocity falls according to the square of the difference in diameter. Sorry for getting too technical here….........just keep in mind the fact that the air speed will decrease in a larger pipe or hose much faster than one would think.

Also in a very small shop, a 4” hose is clumsy & easy to trip over, and where can you put the thing to keep it out of the way when not in use.

Below is my dust collector, “tucked” neatly in the corner by the garage door. I actually have two eight foot hoses, which can be connected together if necessary. They stow nicely behing the dust collector. My shop here in Gainesville is in one half of the two car garage. My wife has her quilting machine in the other half. Obviously I need to keep the environment dust free. Thankfully, my dust collector has been keeping my wife happy.

-- "Heaven is North of the Bridge"

All that I am considering are 2 to 3 hp. Smallest has 2 4” ports and one has 3 4” ports. Also, if running 2.5” plastic how do I ground that?

-- I started working with wood because of the biscuits.

There’s never enough time to finish a project, but there’s always time to start another one.

-- Backer boards, stop blocks, build oversized, and never buy a hand plane--

I think it really depends on how much work you’re going to do in the shop. Before I bought my DC, I did a lot of research and was just as confused. I think that it is simpler than we make it out to be; unless woodworking is your profession and you are running really large machines that produce a huge volume of fine sawdust, you don’t need something huge and expensive. My DC is a 1 1/2 HP 1100 CFM General International with a 1 micron canister on top. I have it hooked up to my TS and my mitre saw. It does an adequate job for each, given the difficulties of capturing dust from a mitre saw. So far I’ve used my shop vac for my 2 1/2 port on my router, which works well. I have found no need for a separator; my understanding of a separator is that it captures the large chips well, so that you don’t have to empty the main dust collection bag as often. I don’t think it improves the fine dust collection, which is what we are concerned about for our health anyways.
The only improvement I plan for my DC system is an air purifier to catch the remaining small dust particles that my DC misses.
Basically, I think any DC over 800 CFM, coupled with an air purifier will be more than adequate for your DC needs.

-- Rob, Sault Ste. Marie, Ontario

6” for the main lines, 4” and 2 1/2” for the drops with blast gates at each drop, 2 to 2 1/2 hp unit, metal pipe, one or two drops can be open at the same time. Grizzly has some bag units on sale right now. I have a cyclone but my friend did the same thing with a 2 hp bag unit. I did a blog on dust collection in. It might give you some iedas on lay out.

-- Mc Bridge Cabinets, Iowa

Well i mysteriously received a link to a coupon for the 2hp unit from harbor freight. I read several threads about on here and bought it w/ the coupon came out for 150 with taxes. Tested on my router table and it moves some major air. It isn’t industrial but will suffice for my needs. What are blast gates?

-- I started working with wood because of the biscuits.

Blast gates are valves in your hard-piped ductwork system. You normally would have one at the end of each duct run where the ductwork attaches to the equipment. You use blast gates to control which equipment is being serviced by the suction of the DC system…

HTH

Be Careful!

Herb

-- Herb, Florida - Here's why I close most messages with "Be Careful!" http://lumberjocks.com/HerbC/blog/17090

welcome aboard

dust is your new friend

-- "Good artists borrow, great artists steal”…..Picasso

Good choice on the HF. Now you need a Wynn filter, and a Thein Baffle. The baffle is optional, but very handy, and inexpensive. The filter is NOT OPTIONAL, and you need the filter on any DC. You really need to get rid of the fine dust down to .5 micron.

There are two ways to connect a DC. One is a 10’ length of 4” flexible hose that you move around from machine to machine. If that works for you, it’s simple and cheap. The only thing you might want is the adapter that allows you to easily disconnect and connect the hose to the various ports on your machines. The downside is you have to maneuver the DC around the shop as you use your tools.

The other way is to install permanent ducts. Most LJs with DCs in this range use 4” S&D pipe. Run a main line with branches for your machines. Use 45 degree elbows, not 90 and Y’s not Ts. When you install duct permanently, you use blast gates right near where the pipe runs to the machine port to turn off all the ports on all the machines except the one you are running. That puts max suction where you need it. As a practical matter, it means you leave all the blast gates closed, and open the one for the machine you are using.

One nice addition to a permanent duct arrangement is a remote control for the DC.

The HF 2hp collector does a fine job and has plenty of capacity for most small wood shops. It’ll handle a 4” and a 2-1/2” duct being connected and open at the same time just fine. It has a “Y” with two 4” ports on the fan inlet, so I just used an adapter to reduce one side to 2-1/2”.

Adding the baffle on a trash can between the dust source and the fan has the advantage of droping the big chips, screws and chunks into the can and out of the airflow before they get to the fan. I hate the sound of a chunk of wood or a nail or screw going into the fan, and I think these things will eventually damage a fan. The baffle does add to the static pressure load on the system, but reducing the dust going into the bags can potentially reduce the load, so I think it’s a trade off.

You can run the 4” line in PVC, mounted to the ceiling or walls, with drops at multiple machines if you want. Just install a gate (shut-off) at each machine so you only have one open at a time. I have my jointer and table saw connected this way with a total of 20feet of pipe; works great.

My planer only has a 2-1/2” connection so I use the shop vac for this; it needs the extra static pressurs for high velocity flow. Most shop vacs generate over 60” of static, some go up to 120”, so they are the best choice for dust sources that need high pressure and use small pipes. Most portable power tools fall into this category, like routers, sanders, etc. In the case of the planer, I plan to add a “Dust Deputy” inline cyclone to the shop vac to handle the large volume of chips so I don’t have to enpty the vac so often.

I also plan to build or buy an air filter for the shop air instead of spending money on the cartridge for the dust collector. I want the air filtered all the time, and I don’t want to listen to the collector running that much. That’s just my preference, the independent air filter will cost about $200 where the cartridge would be about half that. But I just don’t want the DC running all the time; the filters are much quiter and clean more air more of the time.

-- Michael :-{| Diapers and politicians both need to be changed often; and for the same reason.

Crank,
I am also after an air filtration system that is a continous as well so let me know what you come up with. Noticed your avatar, so I’ll assume you ride. I now officially know two cyclists who puddle with firewood.

Br,
Sounds like a good Idea to add a remote and the gate explanation helps a lot.

-- I started working with wood because of the biscuits.

Crank

Let me get this straight. You want to get air with dust pulled in to the DC at the tool, drop off the big chunks in the bag, but then blow the fine dust into your shop.

Then you want to have an air cleaner pick up the air (again) and filter it down to .5 micron?

How much of that air exhausted into your shop will you breath before the air cleaner captures it again?

While appreciate the desire to save money on filters, and the DC isn’t going to get all the dust in it’s air stream, I do think you want to have a good filter on the DC. You then do probably want to have an air cleaner.

brtech,
Sorry I’m just getting back, been busy in the store and on the road.
You said,
“Let me get this straight. You want to get air with dust pulled in to the DC at the tool, drop off the big chunks in the bag, but then blow the fine dust into your shop.”
NOT
I was responding to a guy who asked for help cleaning up his shop dust problem.
The OP has no collection now and is considering adding a dust collector, but is getting bogged down with all the discussions about CFM and static pressure.

Adding any bag type dust collector will be many times better than what he has now; which is nothing.

Some people were telling him the bag collectors are no good unless you add a cartridge filter to it.
That is not exactly true. The DC performance, in terms of catching sawdust from a machine, will not be changed by removing the bag and replacing it with a cartridge filter.
- In theory the cartridge will have a larger surface area than the bag and thus could have lower resistance to air flow and allow for higher CFM.
- But the cartridge has smaller openings, 0.5 microns vs 5 microns, so it would have to be 10 times larger to allow the same resistance.

I was saying get a bag collector to get started. “has plenty of capacity for most small wood shops”
Then he could add a cyclone, or baffled trash can, between the dust source (ie. table saw) and the collector inlet to catch the big chunks and trash to keep this stuff from going through the fan blades.
The collected dust would still go through the collector and be captured by the filter bag the same as it was originally designed.

At this point I suggested he might be better served by a shop air filter than to go dinking with the collector by changing the bag out with a filter cartridge.

-- Michael :-{| Diapers and politicians both need to be changed often; and for the same reason.