I need to add DC to my shop. MDF dust is coating everything to the point something has to change.
What are the advantages of cannister systems versus bags. Are they worth the extra cost?
I have looked at the Grizzley, Jet and Penn State Industries systems. I am leaning toward the Penn State 1 micron cannister or bagger.
Advice appreciated
Chuck
Replies
Chuck, I'm a wannabe canister owner, been holding out awhile to get the funds together. Technically, the advantages are increased filtration area and finer filtration ability (without paying extra for better bags). Ease of cleaning is a big bonus for me. I've never owned a DC, but it seems to me that having to take a clogged-up bag off the machine and outside to clean it, getting me and the surrounding area covered with the same dust I'm trying to avoid, is pretty counter-productive. Now that there's an alternative, I'm willing to pay more to have it.
If you're doing a lot of work, just imagine the difference: Your DC starts losing power, from being congested. You can either stop, spend what? 20 minutes maybe, taking the bag out to clean it and re-mount it, or 20 seconds twirling that paddle around on the canister.
forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)
Another proud member of the "I Rocked With ToolDoc Club" .... :>)
Thanks. I am easy to convince if there is less dust involved.
I appreciate all the advice. I know nothing about dust collectors except that my shop vac is indequate.
Also, I am not sure how the response occurs. I think this will go to everyone which is what I intended.
Chuck
In addition to the cannister vs. bag and cyclone (2 stage) vs. single stage (normal bag/cannister type) you'll also find out that neither of these make a hill of beans unless you have a very well designed hood. The better your ability to design a hood to get the dust immediately at its source (typically the fast spinning blade/bit) the less dust that will make it in the air.
I mention this only because you mentioned MDF dust issues. When MDF is cut is turns into such a fine dust that you need a really good hood design to capture the stuff. And most tools (there are exceptions) have horribly built in dust hoods and require modifications to make them effective.
Bill's site is a good place to start for learning about collecting dust.
--Rob
Yes, it went to "All."
There's some discussion in the other Dust Collection thread that the canisters require more maintenance that originally thought (e.g., they have to be "paddled" more often and blown out with compressed air from the outside). Just to let you know it's not universally agreed that they're the cat's meow.
I heard somewhere, can't remember where, that some canisters have more paddles inside than others. Seems like that would improve cleaning efficience. Also, to let you know, some of the cyclone DCs have a canister filter attached rather than a bag, so they're not mutually exclusive.
I was hoping to get my DC by the end of the year. It's starting to look iffy, but if I pull it off, I'll report here what it's like in real life.forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I still have one with your name on it...
If you can afford it go with the cyclone/ cannister type machines. It will take a lot longer to outgrow it.
Mike
Chuck,
I have had a couple of different setups and would definitely go with cyclone if you can. I currently have a drum mounted delta and its going to go when i can get the cyclone. The bags are a bit of a mess to clean.
The cyclones from Oneida have been rated better than most, so it might be good to check them out. Thats what i will get.
Steve
Hey Chuck,
Seems like you're asking "bags vs. cannister" questions. The thread has evolved into "Cyclone vs. regular D/C". Both are legitimate.
I own one of the big Jet D/Cs...three years ago, it came with the standard bags.....dusty when changing, not as fine filtration, etc.
About a year ago Jet came out with a Dust Dog retrofit cannister for the bag system. the cannister replaces the top bag and a thick mil plastic bag replaces the lower bag.
I've seen two tangible improvements in the cannister retrofit..and this is a legitimate "before and after" comparison..same shop, same D/C and same ducting, etc.
The D/C suction is much greater.
There is much less dust when the D/C runs..presumably due to the lower plastic bag and the finer filtration of the filter...
It is no harder to change bags out either.
In terms of the cyclone vs. standard D/C, I'd go with the cyclone only because it generally deposits the "big stuff"...chips and the like..into a easily-emptied cannister/drum and THEN passes the air through a filter that removes the fine dust.
Around a year ago I had Oneida draw up a D/C setup. They did the ductwork appropriate to my need and then put the Cyclone ahead of my D/C, using the Cyclone for the suction and the filtering of chips and shavings and using the D/C for fine dust and final filtering. I've not done that (yet) but it was an interesting juxtaposition.
Keeping your respiratory health is a worthwhile endeavor...regardless of how good your skills and how inspired your design, if you can't work because you've aquired Emphysema or the similar, it's worthless.
Good luck!
Larry Pile
All,
Thanks. You are very helpful. I am starting from zero knowledge and great advice is a big help.
Chuck
Hi Chuck,
This is a good site that contains some great info on cyclone dust collection and piping.
http://billpentz.com//woodworking/cyclone/Index.cfm
I hope to soon add a cyclone unit to my shop.
There are more old drunkards than old doctors. Ben Franklin
'been doing alot of research on this lately as well. I think this is the current state of knowledge:
Bags: Good for collecting chips and nusiance sawdust. However, the carcinegenic and otherwise unhealthy fine dust blows right through the bags. I see thison my Grizzly DC, where a coating of very fine, powdery dust gets on the exterior surface of the mounting ring for the bags (it is soon going to live outside the shop in its own shed).
If you're a smoker, this is really all you probably need, since you're already putting enough fine particulate matter deep in your lungs anyway. A little bit more from woodworking is unlikely to make a difference. For the rest of us:
One can get finer bags, but at the expense of serious decrease in CFM.
Cannister: the bottom bag turns into an impervious plastic bag. The top bag turns into a "cannister": similar material as the fine bags, but alot more surface area since the fabric is pleated; so CFM is supposed to be less seriously impacted. the cannisters have handles that can be turned that are connected to interior paddles, that are supposed to knock the accumulated dust off into the plastic bag for disposal.
This system can trap fine dust; the only concern is that it generate enough CFM at the tool to capture all the fine dust as it is created at the tool, rather than allow some of it to escape into the shop air (and maybe lodge deep in your lungs).
One downside is that the chips may get flung into the cannister materal by the blower, potentially damaging it.
Some power tools are supposed to require up to 800 actual CFM in order to get all the fine stuff. An example is a table saw: it needs 400 CFM collected at the bottom, and 400 CFM collected at the top.
The "CFM" posted by DC vendors are misleading, since they assume no resistance from ducting or filters. The ducting will be a big determinant of actual CFM. In general, 4" duct will only handle 400 CFM. You need 2 4" duct runs all the way back to the DC, or 1 6" duct run, in order to handle the airflow.
Cyclones: On its way to the blower, the airflow is forced through a cyclone, which causes the chips and nuisance sawdust to drop into a collection can. Only the fine dust makes it to the blower impeller. This allows the the impeller to be a high-efficiency air handler, which may generate higher static pressures, rather than a lower-efficiency material-handling impeller with thick, heavy duty steel blades that can take direct hit from solid material, as is used on the bag & cannister-type DC's. The output of the cyclone blower goes to a large, fine filter that traps the fine stuff with little static pressure hit.
The collection can is often of 55 gal drum, big enough to not require emptying very often.
The cyclone itself causes a static pressure hit on the system, but the big blower and multi-HP motor is intended to offset its affects. Good ducting is still a requirement.
Last year I bought a 2HP 220 V dust collector & put a Veritas trash can cyclone in-line with the dust collector, as others have done to pick up most of the chips. With the bulk of the waste going into the garbage can I replaced the plastic bag on the bottom of the dust collector with another bag to decrease back pressure. Finally, I framed up a corner of the shop with the dust collector inside this closet and put a bit of furnace ducting from this closet to a nearby sliding window, which had a small fan mounted in it even before I bought the dust collector.
Before the dust collector I also bought a filter box to give my lungs some competition for capturing all the fine dust floating in the shop.
This system pulls well, and I don't shake out or empty the main bags very often. Anything that flows through the bags is blown out the window. As others could attest the pinch point is the length of the flex hose you need to reach your furthest machine. There is a fair amount of pressure drop per foot of that flex hose. The closet makes the dust collector a bit quieter, I suppose insulation would help further.
When I do shake out the bags I put on a really good dust mask (for welding) before I take the bottom bag off and dump it outside. Same goes for taking out a full can of dust & shavings.
All I want now is to put the dust collector & filter on auto so that they fire up whenever any of the other machines are running and maybe run for a while afterwards and perhaps as mentioned in another thread, upgrade the dust collector to a more efficient impeller instead of the cast alumium block which was designed to survive whatever is now falling into the garbage bin. A better impeller might pull the top half of what's in a fullish garbage bin back into the dust collector, so it might not be a winning solution unless I find a way to make the garbage can the bottom piece of a taller assembly.
Probably the best thing about this system was that it was useful at every stage and I was able to gradually resolve issues as they came along, or I had a bit of cash to do the next thing. For example, there was an intermediate stage with a shop vac and the Veritas lid & can combo.
One funny bit along the way was how expensive permanent duct work was just when I thought "done". Hence I have one blast gate and a long hose I drag around to machines that are all on wheels in a small shop.
It would be nice to run some big ducting to a post in the middle of the shop and use a shorter piece of flex hose, only because it might be less fiddly. The plastic blast gates on the machines crack & don't really hold the hose well enough. If the machines were fixed in place w/permanent duct work it wouldn't be an issue. I might glue the fittings onto the ends of the flex hose because these work loose over time as well.
The health difference before and after is that before I would be coughing a fair bit or at least have some nasty stuff in a sneeze or on the hanky, now I am fine after hours in the shop, excepting using the table saw to rip a lot of 2" lumber because I don't have dust collection on top of the saw. I will need to learn how to sew to make some kind of bag to catch dust from the sliding compound mitre saw. Ditto for the back of my contractors saw.
No matter what, anysystem will only go so far. Try and find a way to get there in stages. Putting most things in quick-and-ready cabinets to keep dust off them helped too.
Best regards,
Ted
"I replaced the plastic bag on the bottom of the dust collector with another bag" What kind/size bag did you use as a replacement?forestgirl -- you can take the girl out of the forest, but you can't take the forest out of the girl ;-)Another proud member of the "I Rocked With ToolDoc Club" .... :>)
I bought a middle of the road filter bag that fit the collector I had (General).
At this point I had the collector in the closet, with any air coming through the bags being vented outside, so I wasn't concerned about getting the best possible bag. The guy in the store pointed out that when the bags are loaded up they filter smaller and smaller particles to some limit as dust builds up inside the bag clogging up the holes in the bag cloth. It was this argument that dissuaded me from buying a fancier bag.
BTW, the fan sitting in the window by the closet is not a very powerful one, just your standard caged fan to help reduce back pressure seen by the dust collector seen in the closet. The fan was already installed in this window before I bought a dust collector so it might not even be neccessary. One thing to note is that the bug screen on this window does pick up a fine coating of dust which is visual proof that the filter bags aren't catching everything. It is that super fine dust that causes respiratory problems so it is nice to see it sitting on the window screen. The air filter hanging from the ceiling is also helping in that department.
All of the CFM of the dust collector is going outside so I typically have the basement door open (shop is in the basement) whenever the collector is running which means my shop (in Abbotsford BC) is effectively not heated in the winter. The furnace is in a room off the shop and the door to the furnace needs to be closed when the tools are running so that dust from the shop doesn't get blown by the furnace throughout the house. There is a separate connection between the furnace room and the outside air so that the furnace doesn't get starved for air. It would be nice to spring load the furnace door so that it defaults to closed all the time.
Basically it's a bit of a continual battle, I have had to be philosophical as various measures were put in place. The health benefits are a good motive for tuning the dust handling up bit by bit. It isn't as though I was willing to stop all other work in the shop while the dust collection was *perfected*. It's a bit like building jigs and fixtures that way.
Glad to be of help,
Ted
One question - what is your level of woodworking? I am a weekend woodworker and I got a basic Delta DC that so far works fine. Perfect for my needs.
Jeff
I looked at the cannister systems and passed due to cost. I have the 1 1/2 hp 1200cfm Delta 50-850. It uses a 5 micron top bag and a plastic lower bag. Nothing to shake out. You can tap the top bag if necessary (it hasn't been yet) but to empty just remove the bottom plastic bag, tie it and toss it and put a new bag on (or if you're frugal like me empty it and reuse it). Delta does have 1 micron bags available but they revert to the non-disposable bottom bag. Been happy with it so far. The cannister version of the 50-850 is the 50-850A and is almost identical other than the canister and it's $499.99 price, $220 more than the all bag 50-850 version. The cannister version is somewhat more effective; 2 micron vs. 5 micron but to me it isn't worth the extra $220. I'd be looking at cyclone systems. Penn State has cyclone systems for about what a Jet or Delta canister system would cost and only about $75.00 more than their canister system costs. http://www.pennstateind.com/Merchant2/merchant.mv?Screen=CTGY&Category_Code=CY Spend more and get a Oneida and they'll even design your system for you. http://www.oneida-air.com/ I'm not convinced that any benefit a canister system may have outweighs the much higher initial cost. And when it comes time to replace that filter, you're in for a shock. Penn State's filter costs $185; a set of 1 micron bags only $75.
Edited 11/27/2004 6:18 pm ET by jc
Edited 11/27/2004 6:25 pm ET by jc
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