Dust collection system
#11
I want to (finally) outfit my basement wood shop with proper dust collection.  I have a 1 1/2 HP Shop Fox that seems to be enough to do the system, which I plan to be one main pipe running down the middle of the basement, with 4 branches that branch off, two to each wall where my tools typically are running and in need of dust collection.  I was going to have the branches go about halfway down the wall, to blast gates, and then flexible hose (4") on the other side of the blast gate, to the respective machine.  All of my tools and my work bench are all on mobile stands so moving things around is not an issue. 

Questions are: what type of material should I use - PVC or metal?  I plan to get a cyclone separator of some sort between system and ShopFox.  I believe I can run my dust collector with one 6" inlet - comments on 6" vs 4" for main trunk of system?  I had planned (PVC or metal) to ground the system - necessary?  Also, I am seriously considering taking my Shop Fox apart and hanging it from the wall to save some floor space - it wouldn't gain much but I am still tempted to do it.  Also, I am not married to my ShopFox, but I do think it is still more than viable for my shop. While I don't want to spend a million dollars, I want this to be a very functional and very effective dust collection system, so I am ready to spend a little to make that happen.  

I will thank all in advance because this website is always so helpful.  

Also, if this post should be in another section, apologies to the moderators.  Thank you again...FPT.
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#12
I can only tell you what I have done in my shop. The dust collector seems to work well. I am sure it could be better. I have a Delta 1 1/2 hp dust collector hooked up to a 4" pvc main trunk with 4 gates. Each gate has 4" flex hose to the machines. I installed a pleated Winn filter to replace the cloth bag. Also installed a Oneida Super dust deputy, the steel version, on a 55 gallon steel drum and have 3 drums. I did not ground the ducting but I do notice dust does collect on the out side of the pvc, so there is some static build up. I have never received a shock from the static charge. The Super DD collect 95% of the shaving and dust. The only way I can tell when the drums get full is when the plastic bag under the DC starts to fill up. It is amazing how fast you can fill a 55 gal drum. I just finished a large kitchen upper and lower cabinets and filled 16 barrels of shavings. I can have 2 dust ports open and still get suction. I also have the Long Ranger remote with 2 transmitters. This is the second shop I have setup like this. I have a couple of machines that have to share the flex hose, but with the Rockler quick coupling it is not hard to change the hose to another machine.
Treat others as you want to be treated.

“You only live once, but if you do it right, once is enough.” — Mae West.
24- year cancer survivor
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#13
The choice of materials for the ducting often boil down to 2 considerations, one is cost, the other is availability. Should you choose to go with PVC, you might find it hard to find PVC. For some reason it's just not as available. Generally PVC can only be used with either a 4" size, or a 6" size (more on that in a moment), whereas metal (typically snap lock) is usually in 4, or 5, or 6" or larger sizes.  But it's very hard to get wyes in the metal without resorting to on line ordering, and the el s take a lot of sealing. If yo decide to stay with 4", PVC is almost certainly going to be the easier choice...and it should be less expensive. If you decide on 6", that might not be the case. But your DC might not handle a 6" line very well (speculation on my part). You do need a certain velocity to keep the dust/chips suspended, and that velocity will be less with 6" (versus 4").  On the other hand the 4" may not collect everything, especially the fine dust...that may not matter if the stock bags are 2.5 micron since they would allow the finest particles to escape.
So I suggest upgrading the filter (if yours has 2.5 micron) and using PVC ducting (maybe). I suspect you can deal with 6" ducting, and I would suggest doing so if cost and availability are not an issue. But don't choke it down at the tools...do everything you can to make the tool ports 6"; that's not always possible but it can be done on many of them. Also, use as little flex as possible, it has 3x the drag of smooth pipe. Otherwise, just use the 4" as still keep the flex as short as possible.

edit: forgot to add: the PVC you want is labeled ASTM D-2729, that's the thin wall stuff. In 6" you might run into 3034....which is usable but quite a bit heavier. Lastly, skip the grounding. It's not needed and it really makes future changes (and they will happen) a PITA.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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#14
In my last shop (a 2 car garage), I had a Jet 1.5hp collector with the canister filter on top. I used 6” PVC run for the main with 4” drops and flex to the machine, so similar to what you are considering. As noted, some dust sticks to it due to static, but no issues in the 5 - 6 years it was up - it was perfectly functional. If you go with PVC, I used 6” Sewer & Drain that I bought at a landscape supply house. It’s thinner walled than schedule 40, so lighter and cheaper, but never presented any issues in terms of functionality - just be sure your connectors are all S&D due to the difference in wall thickness with sch. 40. Some have strong feelings about metal vs PVC, and a few years ago there were some heated discussions, but my experience has been that both work just fine for a hobbyist.

While I now use metal on a larger system, I agree that if you upgrade the filter (if needed) and use PVC, you should be fine and will certainly save money over metal. If you use metal, have plenty of foil tape on hand to tape the joints, especially at the wyes, sweeps and gates - as noted above, there are a lot of joints on the sweeps. Silicone can be very useful at the gates to seal them (foil tape seems a little harder to use at the gate connections).

Just one persons experience.
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#15
I looked up the specs. on the Shop Fox 1.5 HP DC.  It says 1280 cfm at over 10" static pressure, which is very impressive and pretty hard to believe, actually.  But apparently others are having good performance with it.  Still, I suspect those ratings are with nothing connected to it and you will lose performance quickly once you start adding stuff like a cyclone and a more restrictive filter cartridge.  My own experience with a 2 HP unit, rated about the same as yours, showed that 10" of rated static can quickly get reduced to 2" or 3" when you add too much stuff and that's not enough to move dust and chips efficiently.  I ended up completely reconfiguring my system by increasing the inlet and outlet hole diameters, mounting the DC fan directly on top of the cyclone, and ducting the exhaust directly out a window.  That got me back up to enough static pressure drop (over 4") to pick up the sawdust coming off my large two port bandsaw.  

I have 6" metal ducting with 5" flex ducts to most machines, two 4" ones to the large bandsaw.  My advise is to go with 6" primary ducting.  If you end up having to upgrade the DC you won't have to replace the ducting, too.  Keep the runs as short and straight as possible and use sweep elbows.  Pay close attention to how you connect the cyclone to minimize static pressure losses.  Make a static pressure meter and use it to see what happens when you add things.  If you want to add pleated filters it would be better to add 2 in parallel rather than one.  


Or just start out with a 3 HP unit and be done with it.  Or go with Oneida's new DC/vacuum system that uses 4" ducting.  

John
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#16
It took me years to understand how a 1-1/2" collector is essentially a drag from machine to machine and have 10' or less of flex hose type of tool.... They arent really designed to hook to piping. 

Dust collection IMHO isnt about getting the big stuff....any dust collector thats decent will do that. Its getting the super fine stuff you cant really see at the point of origin. I didnt really understand that till I got my 3HP Oneida. Its night and day the difference between my 3 HP and my 1-1/2 HP onieda and I was basically just using a 10' hose with it. 

You dont notice a difference (other than the obvious suction difference) until you notice there is almost zero dust film weeks after cleaning.

Once Favre hangs it up though, it years of cellar dwelling for the Pack. (Geoff 12-18-07)  



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#17
FPT,
The cost of PVC ducting is MUCH less than spiral metal piping. The spiral stuff is really nice; but I couldn't justify the cost of it, and PVC works just as well. There are different kinds of PVC pipe. The common variety is called "Schedule 4". The kind I used and the kind most recommend for dust collection is called "S&D (stands for Sewer and Drain) piping. It's MUCH less expensive than Schedule 4 pipe. 6" Schedule 4 sells online for over $12.00/foot; 6" S&D pipe sells for a little over $3.00/foot. The difference in the price of fittings is even more dramatic. I had no trouble finding S&D pipe and fittings in my town. The best place with the cheapest prices is a contractors supply house near me, they have the stuff by the ton. I agree that you don't need to ground the ductwork. I've had my system for ten years. It isn't grounded and I haven't blown myself up or burned my house down yet. The only issue I have with not grounding it is with my drum sander. The static electricity builds up from the fine dust coming off the sander and it will bite you if you touch the duct. I found that Lee Valley has pretty good pricing for flexible ducting if you buy during their free shipping promotions - which is going on now.
My $.02.
Hank

P.S. I agree with packerguy, the real reason to have DC in your shop is to capture the fine dust. It's dangerous and is listed as a carcinogen. For years I would have bad sinus headaches after working with machines that filled the air in my shop with fine, invisible dust. I installed a serious dust collection set-up and the headaches stopped. Not only is my shop much cleaner with the DC, I feel much better working there, and I am not worried about my hobby killing me - at least not from cancer. I'm not sure the 1 1/2 hp unit you're planning will capture a lot of the fines, but it's a good start.
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#18
It's not the size of the DC that determines whether or not the fines get captured, it's the filtration system used.  Fines are the easiest to convey but the hardest to filter out.  Moving a lot of air does no good if the filtration system just returns them back into the shop.  That's one reason I got rid of the bags on my system and duct the fan outlet outside; however, the primary reason was to increase CFM.  Still, doing so was a win on both counts.  

John
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#19
I hate to rain on your parade, but there is no 1.5 hp DC that will rate 1280 cfm from 4” hose. A truer figure is probably around 350 cfm. The SDD will further lower the power. The SDD is a collector bin, and not a vacuum cleaner. Consider that a 5” hose will pull double a 4” hose, and a 6” hose double that. Concertina hoses pull half a smooth pipe.

All this translates to a collector for the >5 micron stuff, while the fine - dangerous - dust is floating around the shop.

Solution for a large shop: runs of 8”, branches of 6” (which involves ensuring all outlets from machines are 6” - 4” outlets will throttle the flow), lose the SDD, and up the hp to at least 3.

Solution for a small shop with 1.5 hp: very small run of 6" hose to one machine. Ensure the outlets are 6". Lose the SDD.

Regards from Perth

Derek
Articles on furniture building, shop made tools and tool reviews at www.inthewoodshop.com
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#20
My shop is a 2 car garage so space is precious, and I hung the DC and filters on the wall.   I built my meager DC about 20 years ago, based on plans from Wood Mag.   I use 6" ducts with 4" drops to the TS, Router table, and Miter/RAS bench.   I welded up the 15" impeller and use a 5 horse motor.   My filters are pleated 2 micron types.

Its been quite some time, but I seem to remember a velocity of about 60 feet per second as a minimum to keep saw dust suspended in the air stream.

To control the fines, I use A SEPARATE HVAC BLOWER incorporated into my DD sanding station/TS extension table.   The filters are two sub-micron Hepa filters.   Needless to say, with the whole house rated blower and dual filters, it can easily handle the air in the shop.
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