View Full Version : blowing dust outside

aaron welton
02-23-2008, 5:01 PM
setting up drumsander with 4" opening in top, want a system to blow dust outside, live in the woods, have tractor to move someplace to compost. everything I look at is for dust collection, don't want to collect it, collect to much stuff now! thought with all the stuff I have around here I could build something myself, having second thoughts about that. would be very thankful for any advice! Aaron

Anthony Whitesell
02-23-2008, 5:12 PM
How about a collection system that would collect it into a trailer that you could haul down to the compost pile?

There is a gentlemen on the site that has a box setup outside his shop to collect it. I would think something similar with wheels would be a nice idea.

Don't forget that if you exhaust a dust system outside you also exhaust the heat. You'll need to think of a way to "recycle" the air back into the shop to keep from losing your heat along with the chips.

John Keeton
02-23-2008, 5:26 PM

You may want to check this thread that is still active. I am planning a blower to the outside for my DC system.


Tom Veatch
02-23-2008, 6:43 PM
My first thought is to buy a motor and material handling impeller. Building a housing for the impeller isn't very difficult. I've made one on three separate occasions now. Check the Bill Pentz site for more information on one homebilt design. Then the blower could be either located or ducted to the outside.

You might be able to get a single stage DC (Harbor Freight?) for less than the separate costs of a motor/impeller. Then, just scrap the DC filter bags and duct it to the outside.

If you wanted to contain the chips for easier gathering and transport to a composting location, you could build a simple drop box to trap the chips and let the fines blow in the wind. If you put wheels and a hitch on the drop box, you could tractor it and dump it wherever you wanted to do the composting.

If you wanted to really throw money at the problem, an outside mounted cyclone exhausting to free air with a motorized valve at the bottom of the cone could drop the chips into a dump trailer parked below the cyclone. Then when the trailer was full, tractor it and dump it at the compost heap.

Of course, as mentioned before, unless you do something to separate the chips and dust from the airflow and duct the clean air back into the shop, you'll be pulling conditioned air out of the shop that will be replaced by ambient air that has to be heated/cooled. Only you can say whether or not that would be unacceptable.

Keith Outten
02-23-2008, 8:38 PM

Go to Harbor Freight and buy their 2HP dust collector, scrap the bags and connect a 4" pvc pipe to the outlet and stick it through the wall. Connect your interior DC piping or hose and fire it up.

If you are in a rural location no need for a chip box just let it blow out back. Most of the dust from your sander will just disappear, it won't even make a pile. Large chips from a planner will collect in a pile and you can spread the chips or compost.

I did this for many years but I had to start using a chip box when I started using a lot of Corian which won't biodegrade.

aaron welton
02-24-2008, 6:43 AM
now everybody's got me thinking maybe I should build a compost drum and blow it right into that, did I mention, my oldest daughter says I have ADD, well off to another project :rolleyes: Aaron

Tom Veatch
02-24-2008, 3:35 PM
now everybody's got me thinking ...

And that is the beauty of brainstorming. Maybe nobody's suggestion is exactly what you want, but even the most off the wall idea could generate that thought that leads to your perfect solution.

Bruce Shiverdecker
02-25-2008, 10:20 PM
Dumb question! How are you to replace the air that you blow outside? It has to come from somewhere outside, or else the house/shop implodes. (In the winter, it is cold out there!)


Tom Veatch
02-25-2008, 11:44 PM
Dumb question! How are you to replace the air that you blow outside? It has to come from somewhere outside, or else the house/shop implodes. (In the winter, it is cold out there!)


Yep, outside is where it comes from. No room or building used for human occupancy is completely, hermetically sealed unless very specific and very expensive techniques and materials are used which is only done for specific purposes - biohazard laboratories for one example.

There is some leakage around all openings, doors, windows, kitchen/bathroom vents, chimneys, heater flues, etc, no matter how well insulated and weather stripped. When a blower forces air outside, the resulting negative pressure allows ambient atmospheric pressure to force outside air into the room or building through those leakage points.

John Keeton
02-26-2008, 7:54 AM
Looks like a lot of you are presently exhausting outside or are considering it. I have decided to go with PVC ductwork, having considered all the hype about static, etc. and especially considering the cost. But, what about the blower? Where are the sources, other than paying over $600 for a 3hp, 1700cfm, Oneida? Has to be some other options. I don't want to bifurcate a system and collect the debris and exhaust the dust. I want to exhaust it all outside. I will sacrifice the warm air as I agree most of the heat comes from thermal mass. I know I can open my doors for several minutes in the winter moving material, and it is warm again within a couple of minutes of closing them.

So what are you guys using or what are you considering using for the blower? I see Keith suggests the HF 2hp and remove the bags - any other thoughts?

Joel Schnedler
02-26-2008, 11:28 AM
I bought the HF a couple of weeks ago (on sale & with coupon for $153), and bought a chip separator (cyclone) off ebay for $170. I'm in the process of plumbing 4" S&D PVC to my shop tools. Then I'll set up the chip separator on top of a 30 gal trash can, and mount the blower/impeller from the HF on top of the separator. The blower exhaust will run straight through the wall to the outside. I don't expect much visable dust coming out the exhaust.

John Keeton
02-26-2008, 7:13 PM

Sounds like some good ideas. Can you post some pics when you get into the project and share some layout experiences? I think I am going with 6" PVC after talking to a friend that has 4" and does not feel he moves enough air. I realize that you get 4" at the machine, but the overall resistance along the trunk will cut the movement a lot. Look forward to hearing more about your project. Thanks!

Josiah Bartlett
02-26-2008, 7:35 PM
You can always double up since the HF blowers are so cheap. I see a couple of problems with the situation, though:
1.) The HF motors may not stand up so well to not having a bag on the output. Blowers place the most load on the motor when there is either no backpressure on the output or no restriction on the input.

2.) You may find that a lot of dust finds its way back into your shop, depending on the prevailing winds. Some of the dust is too fine to see and it may be just as bad as no dust collection at all, so watch out for that.

Bruce Pennell
02-26-2008, 9:15 PM
I'm using two HF 2hp blowers. One dedicated to my table saw with an auto start plug. The other I use on my Band saw, jointer, planner, drum sander, and have one hole left open for my router table I still need to build. Both are piped through 4" ABS pipe out to a large trash can with an exhaust flap on the top (keeps the big chips lets the fine stuff drift away). The one thing I did do was ground the system, strand grounding wire from Grizzly. I had a metal chip collector and would get shocked with seconds of turning the jointer on. Why take the chance, the wire is cheap...Hope my 2 cents helps Bruce

Joel Schnedler
02-27-2008, 9:08 AM
I know there's a lot of discussion about 4" pipe not being large enough. I currently have my shop in a stand-alone building that used to be a horse barn. I took out the stalls, poured a concrete floor and installed an insulated ceiling. The actual shop space is about 24' x 24' with 10' ceiling. The DC/cyclone will be located just outside the shop, in another part of the building (where I have lumber storage). I have been doing hobby woodworking for about 25 years, and have had a number of shops in the various places we've lived. The only dust control I've ever had is a shop vac. I've been wanting to set up a central DC for about a year now, and reading all the threads on DC on a number of the WW forums kind of scared me off from actually taking the plunge. I didn't want to invest a huge amount of $ in the system, so I finally decided that anything is better than nothing. Finding the HF DC for $153 made it easy to do something. The 4" pipe is substantially less $ than the 6", not to mention the cost of the fittings and blast gates. I've seen discussion about potential motor problems caused by exhausting straight outside, but found several people that put together systems virtually identical to what I'm doing that had no problems whatsoever.

Chris Parks
02-28-2008, 2:46 AM
If you want to return the air this might work. Build a room off the side of the workshop and dump all the dust and shavings straight into it, it's been done before as someone pointed out. Now if the room is big enough, when the air from the dust collector exhaust gets into it the air will slow down and a lot more dust will drop out while it moves around, but the big thing is it slows down to nothing. Now return the air through a filter wall made of a couple of layers of panel filter material or similar. If the panels are large enough the air will very slowly return to the workshop and as it is moving slowly will not support the dust it once held and what is still in the air will not get through the panel filters as the air is not moving fast enough. It is all about the air being slowed down so it does not support the huge dust load and then returning it as slowly as possible through the filters.

aaron welton
02-28-2008, 6:37 PM
ordered the hf 2hp and kit yesterday, now am going to build something outside to blow it in, am considering building a compost drum. going to look for info on that next. Thanks for all the help!!! Aaron