Another Dust Collection Question

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Forum topic by harriw posted 09-26-2012 03:37 AM 2459 views 0 times favorited 33 replies Add to Favorites Watch
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129 posts in 2380 days

09-26-2012 03:37 AM

Hi folks,

So which do you think is worse… no dust collection at all (other than a shop vac for a ROS), or a dust collector with poor final filtration that spits back out the tiny stuff?

I’m ready to start addressing dust collection after limping along with a shop vac for years. I’ve done a ton of reading on the subject already including reading through some of Bill Pentz’s site, looking at Wynn’s 35A canisters, looking into the various trash-can separators, etc., etc. I’m an electrical engineer so air flow isn’t exactly something I deal with on a daily basis, but I’ve got the background for it, and understand the general relationships between flow and pressure.

So I get Bill’s “ultimatum” about minimum 6” lines, 800CFM at the tool, 3HP blower required to generate that, etc., etc. But I’m not made of money. Also, 220V is not an option for me in the garage. That places limitations on the size unit I can actually run. (When I move to the basement in a year or two 220V does become an option, but I’ll need to re-evaluate dust collection then anyway since I’ll no longer have a giant garage door to open up).

Anyway, I think the Harbor Freight 2HP unit is more realistic for me at least at this point. I’d be adding a Wynn cartridge to it as soon as I can as well, but I’m wondering if until then adding a 5-micron “dust pump” to my garage would make things better, or worse? Right now my dust collection is almost non-existent. I hook up my shop vac to anything i can, but that’s not really doing much for my table saw, miter saw, or router. Most of the dust I create now winds up going wherever the saws spit it. Is this better or worse than sucking it all into a collector and spitting the sub-5-micron stuff back out into the air through the filter bag?

I’m wondering if I’d be better off getting a collector when I can, then getting a better filter when I can, or if I’d be better off waiting until I can afford the whole setup and getting them together?

By the way… The older posts talk about the HF unit going for $139. I understand it was re-designed a while back with what looks like a corresponding price increase. It seems to be permanently on sale at the HF website for $199, which comes down to $160 with a 20% coupon. Are there any better coupons out there anywhere that will still get you the $139 price, or do I just need to stop reading threads that are 5 years old and pay the $160?

Thanks very much in advance!

-- Bill - Western NY

33 replies so far

View Lifesaver2000's profile


556 posts in 3285 days

#1 posted 09-26-2012 03:46 AM

I just saw a post on another forum that the current issue of Wood Magazine has a coupon good for $149 on that DC unit. It was a Wood magazine coupon that got the price down to $139 in the past. They sell Wood Magazine at Home Depot, so you might check through it there and make sure it has it before you buy the magazine (I haven’t seen it myself, just read about it in another post).

It is up to you if it is worth the trouble and cost of a magazine to save that extra $11 (plus sales tax I suppose).

View Cole Tallerman's profile

Cole Tallerman

392 posts in 2357 days

#2 posted 09-26-2012 03:50 AM

Ask someone on here for the wood magazine $150 coupon code. Not much of a difference but oh well. The 5 micron is actually pretty good. I have the hf and although its not in my shop, no noticeable dust escapes. Some dust collectors come with 30 micron bags! with 5 micron, that means that some particles will escape. a 5 micron bag will also stop some .5 micron particles but they can only guarantee down to 5 micron. Buy it and when money allows, go for the canister.

View DIYaholic's profile


19659 posts in 2847 days

#3 posted 09-26-2012 04:00 AM

Buy the collector now:
1) Before the price goes up again.
2) The collector WILL be better than the Shop-Vac.
3) Ducting and connectors can be bought as needs arise.

Just my $0.02
BTW, I have the HF 2HP DC with the Wynn 35A NANO canister filter.

-- Randy-- I may not be good...but I am slow! If good things come to those who wait.... Why is procrastination a bad thing?

View harriw's profile


129 posts in 2380 days

#4 posted 09-26-2012 04:22 AM

Thanks guys – I’ll stop by Lowes and HD and see if they have Wood on the rack (I wouldn’t mind having another rag to flip through anyway).

My only other hold-up is that I AM wondering if the HF will be sufficient for me when I move to the basement, or if I should hold out for a true 2HP Grizzly (or something similar). I can get away with dirtier air in the garage since I can open up the big door to purge. Once I’m down in the basement though, I’ll be relying on my machines (I’m assuming the main work-horse dust collector, and a ceiling-mounted air cleaner) to keep the air clean for me. Both shops are right around the 400 sq-ft mark, but I won’t really have access to 220V until I’m in the basement. For $150, I’m thinking my best bet might be to go with the HF for now, and I can always sell it on craigslist and upgrade if necessary whenever I move downstairs (I’m guessing a Wynn 35A would probably fit on a Grizzly 2HP too, so I could re-use that as well).

Can anybody comment on using 6” ducts with the HF model? I’m worried about a.) overloading the motor, and b.) whether the corresponding drop in air velocity in the 6” duct will be enough to let dust fall out of suspension and pile in the ducts.

Thanks again everyone!

-- Bill - Western NY

View woodforge's profile


3 posts in 2282 days

#5 posted 09-26-2012 04:33 AM

Hi Bill, I see you are a fellow WNY-er :-)

I went through many of the same issues when I started buying tools. Most of the money seemed used up by the time dust collection was thought about. I am very careful with my money except when it comes to tools and my safety. With having a large door you can open, that helps unless it is 20 below and snowing. I had a Jet 650 and upgraded the bags, tried different lines, and finally gave up. Most of the time I didn’t use it because it was either full or the bags were dirty and basically it was a pain.

My recommendations;
- The cheapest option is buy a box of good quality dust masks and use them. I never got the formed masks that look like a boob to work right with my beard and found the newer fold-up 3M masks to work great.
- If you are using a shop vac, upgrade it with a $39 Dust Deputy cyclone and save up for a real system.
- Sell some more projects and ask Santa for cash. Then go visit Oneida Air over in Syracuse. If he has time, the owner Robert is great to talk too. He has a background in industrial hygiene and knows the effects of long term exposure to contaminants.

Hope this helps. If you do get to Syracuse, tell Robert I said “hi” :-)

- Ed

View Lifesaver2000's profile


556 posts in 3285 days

#6 posted 09-26-2012 04:39 AM

There are a lot of discussion threads about pipe sizing, the HF dust collector and separators over on the Thien forum:

View Fred Hargis's profile

Fred Hargis

5139 posts in 2666 days

#7 posted 09-26-2012 11:03 AM

I’ll offer this, having lived with a 5 micron nag for a year some time back. If your concern is health…I think the 5 micron filter on a DC is worse than nothing. What it does is put the most dangerous particles back into the air much more efficiently than any of the source tools. In my case the coating of dust that forms over those hidden areas over time changed to those much finer particles and got noticeably thicker than it did before the DC. Once I noticed that, I bought new bags that were much tighter. That said, in a garage with the door open it may dissipate to the outdoors, making it a manageable situation. But in a basement I would think it will eventually work it’s way into the house (never had a basement shop, no experience). So try it yourself in the garage, but be sure to tighten it up before moving to the basement.

-- Our village hasn't lost it's idiot, he was elected to congress.

View HorizontalMike's profile


7770 posts in 3086 days

#8 posted 09-26-2012 11:12 AM

”...So which do you think is worse… no dust collection at all (other than a shop vac for a ROS), or a dust collector with poor final filtration that spits back out the tiny stuff?...”

You know that even a “poor” filter gets better with use don’t you. As some of the dust cakes up on the inside of the bag/filter, the filtration increases. So bottom line is to buy the REAL DC unit. Also, I built Thien separators for both my main DC unit and my shopvac that I dedicated for my mitersaw. On the shopvac I also added a hepa filter. Very little dust makes it to the shopvac canister as most ends up in the 30gal separator can.

RE: the basement—Only my opinion here, but IMO using a basement for a shop is a major trade off and is much more limiting than in a garage environment. The basement is probably the most “convenient” use of space but not the most “efficient” use of space. I am thinking gas furnaces and flammable dust in the air. But this is just my opinion and I know that many others will say otherwise, but if you have the opportunity for working in a standalone shop environment like a converted garage then I don’t think you would regret it.

-- HorizontalMike -- "Woodpeckers understand..."

View harriw's profile


129 posts in 2380 days

#9 posted 09-26-2012 11:27 AM

Thanks again for all the input!

HorizontalMike – I hear what you’re saying, and would much prefer to be in the garage, all things being equal. But the garage also has to store my garden tractor, lawn mower, snow blower, ladders, various yard tools, kids sports equipment, bikes, etc., etc., etc. The garage also serves as the “autobody shop” when its time for oil changes, brake jobs, etc. It reaches the point that I have no wall space to park a took against because no matter where I go, I’m blocking something. And it’s COLD out there in the winter :)

My thought was that if I move the wood shop to the basement, I can dedicate that space 100% to wood working and not have to share it with all the other tasks mentioned above. As you point out though, it’s not exactly ideal mainly because of the dust issue. I do think I’d put up a wall to try to contain the dust to the shop area (and away from the boiler, hot water tank, and general storage). Can’t get dust all over the wife’s Christmas decorations…

My original plan was to build a large shed in the backyard for all the yard stuff, freeing up the garage. But I’m looking at around $4k to do that. The basement is already there, and I could setup a pretty nice shop down there for half of that.

Thanks again!

-- Bill - Western NY

View jmos's profile (online now)


890 posts in 2542 days

#10 posted 09-26-2012 12:23 PM

Bill, just a couple of thoughts for you. Any cyclone system will work better than a regular DC (per FWW article maybe a year ago), and this will become more of an issue in a basement. I’ve got a basement shop. I think once you move down there you’ll be wanting pretty good dust control, so spending money now might not give you equipment you’re happy with later.

While you’re in the garage, can you vent the dust outside? If so, that’s the way to go; use a DC and vent outdoors.

Overall I think a poor filtering DC is worse than nothing, as it constantly stirs up the air and puts the fine (most damaging) particles back in the air.

If I were you I think I would use a good dust mask in the garage (and keep the doors open with an exhaust fan whenever possible), skip the DC (unless you can vent outside), and save for some type of cyclone system for your move to the basement.

-- John

View crank49's profile


4032 posts in 3143 days

#11 posted 09-26-2012 12:30 PM

The HF coupon for the 2 hp DC for $149 is in virtually every issue of Wood Magazine, Popular Woodworking and several other magazines every month. There is no reason to pay more.

I find the HF DC just fine with its 5 micron bag. That’s collecting as much dust as your Shop Vac, unless you have the HEPA filter option on it. The Wynn cartridge is a worthwhile option for sure.

Another option, and better in my opinion, is a shop air filter, either homemade or purchased. These units make virtually no noise and can run all the time you are in the shop and the 1/6 to 1/3 hp fan will not break the bank. The Dust Collector would drive you nuts running all the time, Not to mention the boost to your electric bill.

View woodforge's profile


3 posts in 2282 days

#12 posted 09-26-2012 01:02 PM

There is this misconception that using an air filter in the shop is going to help with dust collection and protect your lungs. The bottom line is to capture the dust AND particulates as close to the source as possible. Anything in the sub-5 micron level could take hours to settle and “stirring up” the air with a cleaner doesn’t let those particles settle, rather will keep them in the air. Unless you are planning on keeping your head near the output of the air filter, you will not see the benefit. I made a filter with all the top of line filters and my old 4-speed furnace fan. It seemed to work for a short time but when the filters start to get full, air flow is significantly decreased. I am considering taking it out and filling the space with drawers which will keep the dust off my better tools better than any air cleaner.

Like I said before, use the mask for now and save for a cyclone when you move…

I don’t believe in using a DC and air filter and wouldn’t spend a dime on one. I think eventually, you will find the dam thing.

View crank49's profile


4032 posts in 3143 days

#13 posted 09-26-2012 01:13 PM

The key is correct design of a filter. Commercial wood processing shops very often incorporate filters to improve the air quality for the workers. True the fine dust will not settle if it is stirred up. That’s why the filter should have capacity to filter all the air in the space up to 6 times an hour.

I am an engineer and have designed pollution control equipment and systems for 40 years.
I gave you my opinion earlier so I will not repeat myself.

Cyclones, by the way, can be way less efficient than the 5 micron bag filters if they are not properly designed as well.

View HorizontalMike's profile


7770 posts in 3086 days

#14 posted 09-26-2012 01:13 PM

I have now seen the comment of something to the effect of “A poor DC filter is worse than none IMO” a number of times now. Please consider the following from a “good” filter company. Even a “good” filter company(Wynn in this case), fully admits that filters actually NEED a break-in time to develop better filtering. This is because all filters do accumulate/cake with use, and it is advantageous that this process occurs. What this means is that even a 5.0micron filter will filter better than 5.0microns after sufficient break-in. In other words, do not under rate that stock filter bag on your cheap HF DC unit, because it gets better and better at filtering over time.

And BTW, I use a Thien separator on mine as well.

”...We get occasional calls about our posted 99.99% efficiency, as it compares to the ASHRAE 52.2 test standard.
The chart below shows the Particle Size Efficiency of a filter made from our 80/20 blend, based on the ASHRAE 52.2 test standard. The numbers just below the chart (beginning with 0.35) are the particle size “geometric mean”, in microns.
As you can see, these filters test very well, but the results do not indicate the 99.99% at 0.5 micron rating that we have given to our 80/20 blend. This is because the ASHRAE 52.2 test standard is not designed for round pleated cartridge filters. More importantly, it is not designed for cleanable filters. It was actually designed to test flat disposable HVAC filters, so the resulting data needs to be taken with a grain of salt. The ASHRAE 52.2 test does not give a true indication of what a user should expect to see from their dust collection filter…it can only tell you what the filter will do when it is brand new.
Background info and further explanation:

-ASHRAE 52.2 requires a minimum face velocity of 118 fpm. This equates to over 1100 cfm on our Farr style filters! We never push these filters past about 750 cfm, and normally run them at about 500 cfm, so the 52.2 test pushes them way beyond their intended flow rating. ASHRAE 52.2 gives all cartridge filters (not just ours) an unfairly low indication of the true as-installed efficiency. ...”
More info here

-- HorizontalMike -- "Woodpeckers understand..."

View WoodWorkWarrior's profile


46 posts in 2245 days

#15 posted 09-26-2012 01:54 PM

I made the upgrade early this year from shop vac to a Grizzly 2HP DC. Definitely worth it. I have a garage shop that I usually use with the garage doors open. The DC certainly keeps the dust down (and my wife’s car a lot cleaner!) I have the 5 micron bag, and per the comments above I think it’s broken in now and does better than that. MDF cuts produce ultra fine particles and used to make a huge mess – much better now with a DC. Also have a trash can separator that helps with the cleanup because I don’t have to take the DC bag off.

One day I’ll step up to a 3HP cyclone or better, but until money is falling out of my pockets, I’ll keep what I have and it works well.

-- Jason

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