cleaning cyclone D/C pleated filters - ARGH!!!!!

[Scott Driemel]

Hello. I took a search and didn't see the info I needed so hopefully someone with a cyclone can offer the pearl of wisdom and bail a fellow woodworker out.
I recently (after years of looking) found a nice Grizzly 3hp cyclone to buy. After assurances it was "like new, and properly dismantled", I arrived with a pal to pick up my new (I was almost giddy with excitement) machine. Needless to say, there it was wall mounted in a shop. Dust container bin filled to the brim with a lot of MDF dust. (Man, I hate MDF dust). So two hrs later, several gouges, crushed knuckles and not nearly as "giddy", I get the behemouth off the wall. (It really should be a 3 man job ... funny how friends get busier when it's a big heavey move).
So the Grizzly filter canister is pretty large. Maybe 5' long or so. It has a contraption of pulleys that operate a cleaning brush which goes up and down the canister to keep it clean. This one was PACKED with dust. I couldn't even move it. The dust was packed an inch deep all along the inside of the canister. Obviously this guy, (mint cond, cleaned & ready for pickup) didn't empty the bin and that wretched MDF dust (along with other dust) had been sucked thru to the filter. I was able to scrape gallons of dust off the sides with my hands in my attempt to dislodge the dust. (I believe I inhaled 5 years worth of MDF dust)
The "scrub brush "still didn't move. I then used a block of wood to try to get the brush mechanism to move which it finally did, still dislodging a ton more dust. So I got it to move, but barely. Seems the dust is still caked onto the pleats of the filter to the degree that it causes too much friction for the brush to slide freely up and down it's center post. (Which is still straight and clean)
Now, here is the question. I want to really clean the filter before reassembling the D/C. (The filter assemply is about $500 to replace) The cartridge is more than half.(If avail)
How can I get this pleated canister filter really clean? I've heard people say to spray it with water from the outside to inside through the pleats, then bring it inside, let it dry. I've heard others say to just run a hose thru the inside. Others say to hose it thru the inside to outside. Others say no to water, only compressed air. Others say compressed air is too damaging to the pleats. inside to outside, outside to inside?
Is there a method to save the filter canister, get it nice and clean, and get it back functioning like the champ it should be?
PS: I know we all have read that allowing the bin (or bags) to get too full is not good. I got to see just what a mess it can do to your filters. So anyone out there thinking "I'm pretty full, maybe next week I'll dump it out", lemme tell ya, do yourself a huge favour, dump it now! Thanks everyone, I know there has to be a safe effective fix to getting a badly plugged pleated canister filter the TLC it needs to get back on it's feet.

[John Lanciani]

If it's been packed solid with MDF dust I doubt you'll ever get it clean. Try a leaf blower, unless you're sure it's spunbond poly I don't think you want to get it wet. Filters are expendable, I'd guess that yours is spent.


On a tangent, rule #1 to buying used is to never trust the seller. Rule #2 is to always be prepared to walk away, no matter how bad you want something...

[Doug Ladendorf]

Scott, I feel your pain. I absolutely HATE when people mislead what they are selling. It is simply dishonest. I drove 2 1/2 hours to pick up a "mint" table saw only to find it anything but, and damaged to boot. This sounds very similar. As John said we need to be prepared to walk away, but it isn't always black and white when to do so.

I would not use water. Compressed air should do most of the work. Be careful when brushing the pleats but that might help too. Good luck.

[Jim Andrew]

You can probably clean up the filter. Turn the pressure on your compressor down to no more than 80 psi, use a blower on your hose to blow through your filter, keep the tip about 6" away from the filter and blow away. Do it outside. When you get it all put together, just blow from the outside next time. There should be something to catch the dust in the bottom after you are finished, so you can empty the dust. I have committed the sin of tapping the end of a filter on a tire, the dust falls out pretty well that way too. Once you get it cleaned out, check your bin often so you don't over fill it.

[Larry Edgerton]

Back in the early 80's I represented a dust collector product line. Their parent company was a leader in cartridge filters for various applications, such as engine and vehicle exhaust. After several years of research and development, the filter cartridge dust collector was introduced for fine dust filtration. The principle was to have the dust exposed to the outer pleats of cartridge where the maximum amount of surface area was located. Air was drawn through the core of the cartridge. Compared to bag filters, the cartridge provided a substantial amount of filter area in a confined space. The units provided as much filter area as a bag house and required a substantially smaller foot print. They were primarily designed for fine, dry dust. A shaker mechanism or air pulse was used to knock off any cake build up. Used properly, the cartridge filter was a major innovation to the dust collection industry. Today, there are many types of filter material and outside wrappers that can prevent cling, cake build up, and even collect mist. I applied several units to toner dust, graphite dust, glass bead dust, and lead dust, just to name a few.

Then, a few years ago, I noticed an ad for a woodworking dust collector company promoting the cartridge filter as an after filter for a cyclone. My immediate thought was, this is a misapplication. A couple months later, I noticed more ads for single stage dust collectors promoting them as a viable replacement for the upper filter bag. To my dismay, it seemed everyone jumped on the band wagon, right or wrong. At first, they were sold without a method for cleaning. I received feedback from customers that had purchased these collectors. Most said the filters were quickly getting clogged due to cake and cling. Within a short period of time, they were sold with an internal brush for cleaning. Then, came the feedback about the brushes. It appeared the cake was forced into the core filter material and clogging the pores. The replacement cost for the cartridges averaged from $200 - $300 per piece.

Some only lasted weeks and the best case I heard of was six months. These were woodworkers that used the collectors on a daily basis. Some guys were using compressed air to blow out the inside in order to use them. In some cases, this was done every other day. Bag filter material offered today is substantially improved. There are 10 oz and 16 oz polyester felts with singe to avoid cling (1-5 micron range filtration), fabrics that control electrostatic build up, special surface treatments that improve performance, fabrics that extinguish sparks, and so on. The filter bag longevity with today's fabrics can be at least 5 years or more. If the air to cloth ratio and fabric is correct, I am convinced that the filter bag is substantially better than the reverse use of a filter cartridge. Certainly, those hundreds of dollars and hours of labor can be well spent elsewhere.

Curt Corum Sales Manager Air Handling Systems




This is a quote I found when I was looking for something else this morning. My own results confirm this. I went back to bags.

Larry

[Michael W. Clark]

This is a quote I found when I was looking for something else this morning. My own results confirm this. I went back to bags.

Larry

I agree. I generally design cartridge collectors for lower filter velocity than collectors with bags.

[Scott Driemel]

Thx gentlemen. I'm a bit of a loss to hear your perspectives. (ain't it the way when you don't hear what you want to hear?) I got rid of my 1 mic bag style filters to "Upgrade" to the Cyclone style canister type D/C. FW and all the other mags continuosly bombard me with the pro's of this versus the bag style. So I do hope there are some out there who like me, have the cyclone with the spun poly filter media stuff who've had to do a serious cleaning. I'm pretty committed time & money to this new D/C and would like to get it running. I can't see how running an outside hose at fairly low pressure could hurt, but I'm not sure which way to hose. Outside in? or inside out? I worry the "wrong" way will pack the dust in worse or am I mistaken?
Tomorrow is supposed to be dry but cloudy here in the Pacific NW so I'm going to give it a whirl. Man I wish there was a "just do this" fix for this.
Appreciated all the inputs guys so a big thank you. Hopefully a few guys with cyclones will chime in.

[Michael W. Clark]

If it were mine, I would take the filter outside and use a leaf blower to blow from the outside to inside of the element. Dirt is on the inside, correct? Keep the blower a safe distance away so you don't damage the media.

Put the filter on and try it. You need a pressure gauge (Magnehelic 0-4"?) to check back pressure if you think the flow is too low. If the filter was run for a period of time with that much dust on it, it may be blinded and need replacement.

Bag vs. Cartridge. Bags are easier to clean but you need more real estate to get the same surface area. It's all about air:cloth ratio which is filter face velocity. Take your CFM and divide by the FT2 of media to get the filter velocity. Problem is many hobby systems do not have enough filter area, especially with "high efficiency" cyclones and the flows claimed, IMO. That's another topic for another day though.

[David Kumm]

Both types have their place. I run Nano cartridges -4- on a cyclone but I don't do much sanding. The cyclone takes out much of the fine dust but not all. I clean periodically with compressed air carefully. Nano can't be washed or brushed. I run bags on the widebelt. If room was at a premium a shaker bag is pretty idiot proof- a good fit for me. Extra cartridges or bags are the key. Keep the air from pushing the dust well into the fibers. Dave

[Alan Schaffter]

To answer OP question simply- If the filter was completely clogged and "beater bar" immobile (who knows how many times he attempted to use it when the filter was severely caked and difficult to move), I wouldn't spend time attempting to clean it. Without even seeing it, I would say they are toast. Many of the air passages are likely completely and permanently clogged and any attempt to clean them with compressed air or water will likely worsen the problem and certainly has a excellent chance of damaging the filter media. Who knows what methods the previous owner used to clean it and how much damage it did to the media.

You have two choices- if at all possible, vent the cyclone outside with no filter which is the cheapest and best all around solution for dust collection performance, or buy new filters. Since you really don't know how well the cyclone separates, and it sounds like not very well, you might be throwing good money after bad by buying new filters.

I agree with the former sales rep from Air Handling Systems about improper use of cartridge filters- they were adapted home shop cyclones by many manufacturers with little or no engineering (surface area vs air speed, required CFM, etc.) to back up the selection of filter. It is a complete waste of money to put an expensive cartridge filter on a single stage DC. (By the way, the sales rep isn't an engineer either and is dead wrong about the surface area of a cartridge being greater on the outside than inside- it is the same inside as it is outside!! Imagine an accordion bent into a circle. You can prove it to yourself by making many folds in a sheet of paper then bending the ends so they meet. The space between pleats many be smaller but the total surface area is the same. Also, shakers and pulsed air cleaners are used primarily with bag houses and rarely if ever with pleated cartridge filters). Also, many filters, but not all filters are designed to flow in one direction.

[Sam Puhalovich]

I cleaned my 2-stack Wynn filters that are attached to the 3 hp Clearvue 3 days ago.
The 1st time I did it: sent note to Ed Wynn. Ed said "Use a blow gun @ 35 lbs, and/or, lightly beat w/ old tennis shoe".
I took the stack outside ... stuck a shop-vac hose in one end (in the exhaust mode) ... and started beating-away.
It was a non-ending and tiring task. Tried the air hose: it was a non-ending tiring task task.
Which-ever I did ... switching back-and-forth ... I was still getting 'stuff' out. After about 2 hours, I quit and put it back together.
There was a dramatic improvement to the 'suction'.
I read about trying a leaf blower. Bought some S&D to attach to the clean-out and ran the pipe out-the-door.
Turned the DC 'on' and 'applied' the blower: it didn't seem to work as-well as I hoped.
Decided to try the shop-vac in the exhaust (or blower) mode ... saw huge clouds of fines come from the same area.
That's what I've done for the last 3 cleanings.
It's a tiring non-ending chore that gets pretty good results in about 30 minutes time.
NOTE: a hose with a plastic end does not work well ... you need a plain rubber end.
Hold ... PRESS ... the hose-end to the filter ... and slowly advance. The-slower-the-better.
It's disappointing that one pass does not get-it-all, and it's tiring to fight the back-pressure.
I hope to innovate some kind belt holder/restraint for the next cleaning.
The 'suction' dramatically improved.

[Alan Schaffter]

If your filter isn't completely trashed and worth the effort to clean, AND if you have a spare filter or can temporarily vent outside, here is a cleaning method that is safer, cleaner and easier on you:

Remove the dirty filter from the DC and connect it to the inlet side of your system - use some flex hose and duct tape or other fitting, or build a little base like the one I built in the photo below, to make the connection (my filter has a foam rubber flange gasket). When you turn the DC on it will draw air through the filter in the opposite direction. While the DC is running, tap on it gently with a tennis shoe, racket, etc.

[glenn bradley]

Thx gentlemen. I'm a bit of a loss to hear your perspectives. (ain't it the way when you don't hear what you want to hear?) I got rid of my 1 mic bag style filters to "Upgrade" to the Cyclone style canister type D/C. FW and all the other mags continuosly bombard me with the pro's of this versus the bag style. So I do hope there are some out there who like me, have the cyclone with the spun poly filter media stuff who've had to do a serious cleaning. I'm pretty committed time & money to this new D/C and would like to get it running. I can't see how running an outside hose at fairly low pressure could hurt, but I'm not sure which way to hose. Outside in? or inside out? I worry the "wrong" way will pack the dust in worse or am I mistaken?
Tomorrow is supposed to be dry but cloudy here in the Pacific NW so I'm going to give it a whirl. Man I wish there was a "just do this" fix for this.
Appreciated all the inputs guys so a big thank you. Hopefully a few guys with cyclones will chime in.

I have the Grizzly G0440 2HP cyclone with the same filter setup as you describe (brush and cables). The brush does a great job if you just run it up and down, once or twice, about once a month. I did have the opportunity to overfill my bin. No, that's an understatement . . . I overfilled the bin, filled the cone and jammed the filter solid.

As you describe, trying to force the brush to help with the cleaning process after such blatant abuse is a waste of time and an invitation to damage. I mounted my cyclone with the inlet and outlet on the same side to save floor space.

Overarm-returns.jpg

This made removeing the filter a requirement. As you know the Grizzly filter bolts on in four places and you can't simply loosen things and rotate it.

I removed the filter and took it outside where (wearing respirator, safety glasses and earplugs [for dust, not noise]) it was pretty easy to gently bounce it on end on a piece of rug to jar most of the clumped up spoil loose. After that I reached inside and inspired the more stubborn spoil to move on out the bottom.

Once I had the filter in a state where it could be moved about without leaving a trail behind it, I set it up on the bench and chocked it so it would stay put. I then used my shop vac and extension wands to carefully run a brush attachment along the inside pleats. I restricted this movement to the inside 'top' and let gravity allow any loosened material that the vac missed to drop to the side of the filter that was resting on the bench. I would then quickly vac up all the droppings and rotate the filter about 10*. Rinse and repeat till I had gone around twice.

I then took the filter out back and ran the built-in brush up and down a few times as it was now functional again. I stuck the shop vac hose in the top, blocked it off with a couple pieces of cardboard (not perfect but, pretty well blocked). I fired up the vac and started shooting compressed air at the pleats from the outside. I went around several times. By now it had become a pretty clean job as there wasn't a lot of large spoil left to fly around and the vac was getting all the fines as I sprayed air in from the outside.

Once I noticed hardly any fines being produced from the compressed air, I remounted the filter and all was well. This little nightmare only took about 2 hours but, seemed much, much longer. The important lesson here is to take your time, be gentle so you don't damage the filter. If you're going to charge through like a bull and damage the filter, save your energy and just buy a new one right now .

To duplicate the surface area of my filter I would need a bag about 18 inches across and over 15 feet tall. I do have an oversized American Fabric Filter bag on a 1HP bagger that I use exclusively for the jointer and while huge compared to the factory bags, it performs well. It is easy to tell if your bags are properly sized; if they are, the bags will remain very softly inflated during operation. If they blow up like balloons they are restricting your airspeed.

I have since acquired a Bindicator for the cyclone but, have not wired it up yet. Its on the list ;-)

[Scott Driemel]

Update on the cleaning:
Well, after reading the responses, several which said I was probably doomed, the frugal side of me just couldn't "toss" the filter away without giving it some Yankee Doodle. So, I carted it off into my gravel driveway. Sunny day, about 60 degrees, thought maybe a 1/2hr of work and maybe, just maybe I'd save the girl. So, first I tried to beat the outer wire cage with an old running shoe. (which protects the actual filter, - probably from the exact beating I was trying to give her) After about 15 minutes of firm not hard pounding, I was pretty bushed. Looked inside, tons had come out, (maybe 3 1-lb coffee tins worth) but the filter both inside was caked between the pleats. The cleaning brush still didn't move. So, I grabbed my shop vac, put it on "exhale" and tried to blow from out to in. This was another 1/2 hr and extension cords up the driveway. Helped a tiny bit but not much. Next was to use the shop vac on suck and climb inside the filter, (arms and head),. This got a bit more out again, but hardly any. The pleats were caked. If I ran my finger between the pleats the dust just poured out.
So, with nothing to lose, I admired the garden hose nearby. I propped the filter up against some milk crates to create an angle and just using my thumb on the hose sprayed it from out to in. Not alot happend at 1st. The water would just run down the pleats on the inside but the dust didn't allow the water to permeate it thus not washing it out. So I soaked it. (I'm on a well so my water pressure is only about 35psi.) After 1 hr, I began to see progress. The water finally was soaking through the dust in the pleats and washing right out. Afetr 2 hrs, the outside of the filter which has been delightful MDF brown, was now pristine white and gleaming. After 3 hrs, not only was the inside spotless but I could now see every pore on the filter medium clearly as well. Tried the brushes and yes, they move. Let it sit in the sun for another few hrs then washed the whole thing again. Not hard pressure water, just steady streams. When done I used compressed air, (gently) and dried it off as best I could. I haven't hooked up the filter & tried it yet as I had just bought the unit disassembled and haven't put it into my shop yet.

I don't know if it will work, or if it is shot, but it is absolutely spotless, both the inside & the outside. I can actually see light through it now which of course was impossible before.

[Paul Wunder]

Scott... a lot of effort. Don't leave us like The Perils of Pauline (yes, I'm old) tied to the tracks waiting for the train to come.

Let us know how you made out. Us cyclone owners want to know,

We will either cheer you or console you.