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My first dust collector

2K views 20 replies 13 participants last post by  Holbs 
#1 · (Edited by Moderator)
I have been reading many articles on dust collection in the workshop lately and think it is time to purchase my first dust collector or extractor. I should mention my workshop is also my garage or my garage is my workshop however you want to look at it so space is always a premium.

Right now my only form of cleanup is a Ridgid shop vac.
I am wondering if I should purchase at dust extractor such as the Bosch or festool CT36, or is a dust collector such as this a better buy
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I am also wondering if a dust extractor such as the Festool can be used in place of a shop vac for say cleaning the floor and not simply hooked up to
portable tools such as a sander?

The topic of dust collection in the work shop seems to be beaten to death in other forum topics yet I am more confused than informed.
 

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#5 ·
An "extractor" is simply a shop vac that's very expensive so they call it something else. That's not to say I don't favor them because they are real reasons they are so expensive….so yes, it can clean the floor. But you can put a good filter on your Rigid and it will work very well (such as a Gore Clean Stream) albeit much noisier. Some of the higher price models use a bag as a prefilter to keep the main filter form clogging so quickly, and you could also do that with your Rigid. Anyway, regardless of what you do for a vac, it's not a substitute for a DC, and both are needed in a woodshop (my opinion). The opinions you get here (or any forum) vary widely because we all measure against a different scale. Some want to capture/contain every possible spec of dust, others want to avoid sweeping the floor. If you lean toward the first part of that check out the Pentz site in the FAQ section. If you lean toward the other end most anything you do will work.
 
#6 ·
What type of woodworking are you going to do and what tools will you have. A dust collector is great for larger tools and a vacuum like a dust extractor great for smaller ones like Sanders.

Dust Collectors move large volumes of air at lower suction ( 5-10 inches water).

Shop vac move less air but higher suction (50-100 inches water).

Either way get good filters rated as HEPA.
 
#7 ·
Tools I have to date are a table saw, 6 inch jointer, lunch box planer and miter saw. Lately been working mostly with composite materials (plywood, melamine and mdf). One consideration I have is that my dust collection needs to be mobile. Currently all my tools are on mobile bases. I generally pull the tools out into the middle of the garage when working on a project then slide them off to the side when done so I can still park in the garage.
 
#8 ·
Hargis, you are right about the shop vac being noisy. My shop vac is on the smaller side. Only 70CFM so anything would be a major step up. I noticed on the link you posted the author recommends at least 800 CFM for table saw. The dust collector picture I posted, is on a mobile base but is only 700CFM. Price wise its about the same as the Festool CT33 or Bosch (actually maybe slightly cheaper). I am wondering now if 700 CFM is adequate.

Ugh this is a complex subject.
 
#9 ·
If you want to collect sawdust or shavings from a table saw, jointer or planer, then a real dust collector with a 4 inch or larger hose is your only choice. Even a very powerful shop vacuum doesn't generate the air flow necessary to do a good job. I own the most powerful shop vacuum Ridgid makes and it is not even close to adequate collecting the shavings from my lunchbox planer or jointer.

Depending on your budget, you may want to consider one of the cyclone dust collectors.
 
#10 ·
Spitfire,
FWIW, my workshop is also in my garage, so I had to take space and funds into consideration. I currently run a Ridgid 12gal shop vac with a HEPA filter, bag pre-filter, and dust deputy for spot-cleaning (nice mobile solution). For larger collection, I have a HF 2hp dust collector (wall mounted, but the base isn't bad and will be re-purposed) running through a $25 trash can lid cyclonic first stage, then venting outside. I also have a Grizzly air filter than I run anytime I'm making dust.
I think all said and done, fittings and ducting outside, I'm in it for about $700, and the setup seems to do the job pretty well.

But do keep in mind that if you want a mobile dust collector and will just puch it up to the tool you're using, the filter may be more important than the CFM, since you won't be running it much distance (though 700 still seems very low).
 
#11 · (Edited by Moderator)
I use both a dust collector and dust extractor. If I could only have one, it would be a dust collector because I think they are more versatile.

The DC unit you have pictured has some positives and some negatives. A pleated HEPA filter is certainly a good thing, and the filter cleaning handle is a plus. The filter is a little small, but if you keep it clean it would probably work fine.
The lower bag will be a pain to change compared to larger bins on cyclone units.

With units less than 1-1/2 h.p. users typically complain of inadequate power.
 
#13 ·
Most of the time the factory CFM numbers on DCs are about as accurate as the 6.5 HP painted on your shop vac. By the time you hook it up to anything, that number will be cut roughly in 1/2. The Pentz number of 800 CFM is very ahad to achieve, usually taking a much larger DC and 6" ducting (minimum), to say nothing about the changes needed to most factory tool ports. If you intend to just use 4" flex for your mobile setup, i think the unit you show would do just fine. So would the HF unit unit (with some mods). the extractors have other advantages besides quiet, they are made to a much higher standard than the cheaper vacs and typically have a very long life. But to the hobbyist woodworker I'm not convinced they are always worth it.
 
#14 ·
Great advice. I'm loving this site more all the time.

Sounds like a dust collector is a better buy then an extractor. The one I pictured is currently on sale for $479. There is one very similar listed for $589 with a larger HEPA filter. I am in Canada so Harbour Freight isn't much if of an option. I have ordered from Grizzly before but brokerage and shipping across the border is a bit of a pain with added brokerage fees and the poor exchange rate. Although I am intrigued since they have a 1hp DC rated at 800 CFM.
 
#15 ·
Beware of CFM ratings that don't also include a static pressure value to go with it.
One means absolutely nothing without the other.

For example, a high pressure rating without a CFM is probably the maximum pressure with the inlet completely blocked. A high CFM rating without a corresponding pressure rating is probably the maximum theoritical flow without any restrictions; like with no duct work or hoses, not very useful information.

An honest rating would be like: 600CFM @ 14" WC. That means the machine can move that volume of air with 14 inches of pressure to create the needed velocity in the duct. There are charts and calculations that can be used to know what that system will actually do. Without both numbers not so much.
 
#17 · (Edited by Moderator)
I'll try to explain with two examples.
1. Propeller fans move a large volume of air with very low pressure.If you hooked a propeller fan to the end of a vertical tube of the same diameter as the fan it would move a large volume of air. Probably about 10,000 CFM with a 16" fan. Reduce the diameter of that tube to 2" and the flow of air will almost be non existant. Thats because the propeller fan only generates a fraction of an inch of pressure. The smaller the pipe gets, the faster the air tries to move but velocity requires pressure.
2. A shop vacuum fan generates a lot of pressure with low volume of air being moved. Hook the vac fan to the same 2" tube and it'll generate enough pressure to pick up a bowling ball. But, enlarge the tube back to 16" diameter and the air flow will be so tiny it wouldnt blow out a candle.

See, all dust collecting efforts require the right balance of flow and pressure. Google "velocity pressure chart". Velocity is how fast air moves. The corresponding velocity pressure is the pressure required to make air move at a given speed. If you have a 4" duct and you want to force 400 CFM of air to pass through it, figure the cross sectional area of the duct in square feet. you should come up with about .087 sq.ft. Now take your 400 CFM and divide it by that area. 400/.087= 4597. That is 4597 FPM (feet per minute) the air will have to flow to get 400 CFM through that 4" duct. Find the velocity pressure in the chart you Googled for 4597 FPM and that is the pressure required to generate that flow.
 
#18 ·
For a reasonable solution, I would suggest the Harbor Freight dust collection (~$230). You can swap out the lower bag for cyclonic trashcan to get the get the bulk and upgrade the filer to a .5 Micron. Should run about ~$300 all said and done.

Nez

- Nezzerscape
Can you help with more specs on this setup you have…? I'm especially curious about how to find the 0.5 micron filter upgrade. Thanks!
 
#19 ·
I would say read the Pentz page but it is very poorly written.

It seems like he has determined the answer to every question is 5hp cyclonic system with a large blower rotor and expensive HEPA filters.

He would probably say the 0.5um filter only captures particles that small when the pores are nearly clogged and airflow is severely choked.

I believe the guy but his universal solution doesn't work for me because I just plain don't have the electrical service for it.

It would seem that a less expensive dust collector with a Thein separator would work if the exhaust carrying the fine dust is exhausted to the outside where it can disperse but that might still allow a fine dust buildup in the shop if your dust collection can't get 100% of the fine dust at the tool (which Pentz claims takes a very high air flow rating and excellent dust collection ducting at the tool).

Since I don't have shop space and have to work outside, I plan to get a small dust collector or big shop vac with a cyclonic dust separator to get as much visible dust collection as possible for easy cleanup and a respirator that effectively filters fine dust so I only have to filter what I breathe instead of hundreds of CFM.

To me that seems like a good solution for my outdoor use case but Pentz ignores that or just hasn't thought about it.
 
#20 · (Edited by Moderator)
I've gotta be honest: dust collection has been the most complicated thing that I've yet encountered in woodworking. I've posted separately about my planning to build out a very small shop in a home I'm building, but I still feel as clueless as ever about dust collection. To make matters more complicated, in the extremely small space I'm working in now, I have no idea what to do for dust collection over the next year (until my new home is built).

I'm thinking hard about getting the little 3/4 hp "wall mount" unit from Rockler, adding a Dust Deputy (or similar) inline and building a little cart for the rig, with the thought that I might be able to get by with that mounted permanently and exhausting to the outside in my future shop. What I'm stuck with is wondering if I could get by with some sort of shop vac type solution for the short term instead without the whole thing being too unwieldy to move around as needed.
 
#21 · (Edited by Moderator)
You have another option instead of purchasing new and getting shipped: local equivalent to Craigslist and local auctions. I see single bag Jet & Grizzly & clones for $100 or $150 all the time. For reference, I bought my 3HP double bag Grizzly for $200 on Craigslist. I would go with single bag (or single canister if you get the Wynn nano filters) which most wood workers have in their shops. It's not "unwieldly" to move around. The problem would come in if you installed 4" ducting around your current shop and then have to move or upgrade to a larger 3 horsepower double bag dust collector or large cyclone which would require 6" ducting. Safe to say, most go 1.5 HP single bag dust collector and use 4" hose or short easy to remove 4" pvc/hvac duct. A 3/4 HP "wall mount", I think, would be a mistake for that would be too low for wood working and collecting small dust. Better than a shop vac though :)
 
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