Author Topic: When to change CT bags? (Read 3533 times)

aCircle · « **on:** December 17, 2022, 05:53 PM »

Alright, this seems like a silly question, but I can’t find clear answers.

When do you change the bag on your CT? How full can the bags get?

I’m running both a MIDI and a CT26 and I… make a game-time decision each time. Curious if there’s reliable guidance on when to change based on efficiency, dust capture, and maximizing bag life.

Curious for the takes and experience.

Crazyraceguy · « **Reply #1 on:** December 17, 2022, 06:30 PM »

I don't change them until they are "full". I don't mean to sound snobbish, but they will literally fill the entire cavity of the CT. I have never noticed a loss of suction as it gets nearly full, but you have to be careful. They will actually keep sucking until the hose it full too. It has happened to me twice. Then I have to get a stick and plunge it back out. There is nothing on-board to warn you that it is getting full.
I would imagine that most guys who are hauling them around notice it by the weight, but mine sits in the same place, never gets lifted. I usually notice it when swapping hoses from the normal tool-hose to the one on the router table. I'll get some extra dust dropping from the connection point at that time. When I have overfilled it was because I wasn't changing the hose around.

ChuckS · « **Reply #2 on:** December 17, 2022, 06:52 PM »

Quote from: Crazyraceguy on December 17, 2022, 06:30 PM

Snip.
I would imagine that most guys who are hauling them around notice it by the weight, but mine sits in the same place, never gets lifted.Snip.

Same here, but I do lift the CT15 to check how full the bag is. I'm too lazy to check the bag by opening up the extractor.

I use the CT15 for sanding and Domino Joiner mainly, so I have replaced its bag only once over the past 18 months. Let me correct that: I've only cleaned the bag once, and am re-using the bag. My plan is to use a bag twice before throwing it away, cutting the cost by 50%.

I know that there's one school of thought that says dust bags should never be reused. But if I reuse my HEPA dust collector's bag year after year (and not just once), I don't see why not. Anyone who doesn't feel that is safe should, of course, not reuse their bags.

I use this kind of self-clean bag, about $10 Cdn each: https://www.leevalley.com/en-ca/shop/tools/workshop/dust-collection/parts-and-accessories/110576-selfclean-filter-bags-for-mini-midi-and-ct-15-dust-extractors?item=ZA204308

aCircle · « **Reply #3 on:** December 17, 2022, 09:54 PM »

Thanks both!

That’s part of my question — is it safe and/or ok to use the bags until they’re packed full throughout the entire volume of the bag compartment?

If so, then I’ve got some more life I can get out of my bags and that’s great news!

ChuckS · « **Reply #4 on:** December 18, 2022, 12:13 AM »

Last time before I emptied my bag, it was pretty full. There's no reason not to fill it up before replacing it as long as the compartment allows it and the suction stays good.

luvmytoolz · « **Reply #5 on:** December 18, 2022, 01:55 AM »

I've got several CT's (and an SR5E) and I always pretty much leave them until I notice a drop off in suction. As others have pointed out, they will happily fill right to max capacity without issue.

Cheese · « **Reply #6 on:** December 18, 2022, 09:59 AM »

I try to change mine before it "bricks out". In a CT 22 when it bricks out, it cannot be removed from the vac without damaging the bag...that then becomes a mess.

I've also bricked out a Milwaukee 8925, that's a 15 gallon vac that's about 25% larger than a CT 48. Again...what a mess. In each case I needed a 2nd vac to clean up the mess inside the 1st vac.

I've always wondered why Festool doesn't include some type of full bag alert, something simple like Miele has used for the last 20 years. Those really do work well, you just have to glance at the gauge and you immediately know.

Michael Kellough · « **Reply #7 on:** December 18, 2022, 10:43 AM »

My 40 year old Miele has one.

mino · « **Reply #8 on:** December 18, 2022, 02:37 PM »

From the horse's mouth:

Basically, as long as there is about 5cm gap between the dust in bag and the top of the bag (the bottom of the microfilter), you are good.

Quote from: Cheese on December 18, 2022, 09:59 AM

...
I've always wondered why Festool doesn't include some type of full bag alert, something simple like Miele has used for the last 20 years. Those really do work well, you just have to glance at the gauge and you immediately know.

They do. It is called the CTM series of vacs. The flow sensor is there exactly for that purpose. But it costs $, so most folks do not want to pay for that even in Europe where it is available ...

The flow sensor is configurable, so when one wants it to "scream" earlier, one can set it to "higher hose value". That said, I found it difficult to explain to folks in our shop why the vac is beeping ... what is an air flow sensor etc. etc. So I rather leave it at a "safety" value, so can communicate a simple rule of "when it beeps, do not use it and let me know". With a cyclone it does not fill anyway.

ChuckS · « **Reply #9 on:** December 18, 2022, 02:48 PM »

Great info.

According to my understanding, that means even if the bag in my CT15 is almost full, the suction still registers at about half of its max. output, which is good enough for my sanding and Domino applications. Regardless of how full the bag was, I have never had an issue with the CT15's suction in the past.

WillB · « **Reply #10 on:** January 07, 2023, 10:59 PM »

Nice chart...
while I do have issues with Festool vacs (but I keep buying them anyway)
I am impressed how suction remains constant regardless of bag fullness....
goes against conventional wisdom

NiteWalkerGR · « **Reply #11 on:** January 07, 2023, 11:44 PM »

Quote from: WillB on January 07, 2023, 10:59 PM

Nice chart...
while I do have issues with Festool vacs (but I keep buying them anyway)
I am impressed how suction remains constant regardless of bag fullness....
goes against conventional wisdom

What issues do you have with the festool vacs?
I have 6 other vacs (shop vac, milwaukee, dewalt, vacmaster) and the midi I have is easily my favorite and most capable of them all.

zapdafish · « **Reply #12 on:** January 08, 2023, 01:58 AM »

When you think its full but get lazy and continue to use it. I literally had a brick when I opened it and the fillters were absolutely clogged. Wish I had thought to take a picture of it, lol.
Bags are so expensive I got the Festool CT Cyclone CT-VA-20 Dust Separator. Gotta watch not to get shavings or it might clog at the bends but overall, love it.

luvmytoolz · « **Reply #13 on:** January 08, 2023, 03:37 AM »

Quote from: zapdafish on January 08, 2023, 01:58 AM

"Snip"
Bags are so expensive I got the Festool CT Cyclone CT-VA-20 Dust Separator..

When I bought my SR5E in the very early 80's, I bought a box of 5 bags with it. I slit the end and made a simple clamp to hold the end closed so I could fill and empty them as needed, as cyclones just weren't around then, certainly not in non-industrial settings anyway.

I'm on my 3rd bag in 40 years, 2 still left in the carton!

I couldn't be happier with the value I've gotten out of my old Festo gear!

Steve1 · « **Reply #14 on:** January 08, 2023, 07:25 AM »

Quote from: luvmytoolz on January 08, 2023, 03:37 AM

I'm on my 3rd bag in 40 years, 2 still left in the carton!

The Dust Deputy on my CT-36 is so effective that I have not changed the bag in ages.
I was beginning to wonder if the very finest dust was getting through the cyclone and clogging the pores in the bag. And maybe its time to change the bag just for that reason.

So maybe I am overthinking this.

WillB · « **Reply #15 on:** January 08, 2023, 08:23 AM »

Too funny on the DD... I feel the same way... I even upgraded to the new DD 2.5", its even better, if that is possible. With the DD, I just vac up everything, even chips, large shavings, etc, (vs. quick sweep of the big stuff) as the DD bags are so cheap. Using the 50mm hose, I rarely ever get a clog in the hose.

> What issues do you have with the festool vacs?

I too have lots of other Vacs, and I still like the Festool the best, specially combined with the DD. I never tried Festools cyclone as the DD work so great. Only one major issue I have...it's the plastic they use is too frail over time. I had a few that had light use, in storage most of their life, granted it was in Vegas summer heat... The plastic self destructs, cracks everywhere. Recently opened a CT22 to check the bag, which has the clamshell design, open to 90 deg, and there is a stop, unlike the newer CT's, which you fully remove the top half (much safer, less that can fail). When in the up (90 deg) position, sitting un disturbed, the plastic just cracked all over, the top half crashed down. The plastic in other areas cracked as well...I think this one was 8-10 yrs old but was in great shape, prob. under a 150hrs run time. But I have RIGID and Bosch vacs that went through the same storage conditions, and their plastic has has zero cracks. There is lots of complaints about the plastic on the garage tops cracking. Mine all seem to crack in that areas within a few years. This is an easy design fix, make the plastic thicker. The rear wheels are large and nice for pushing around as they jump over most things in a shop. But the front wheel diameter are too small to travel over its own electrical cord. Slightly larger diameter front wheels... a simple fix, maybe just a pet peeve of mine. Hoses are very costly...I finally start buying the new Rocker 2.5" hoses, where you can cut them to size and add twist on the ends, impressive hoses for the price. I have no need now for the anti static feature of their hoses.

But to be fair, there is a LOT i like about Festool Vacs, which is why they are still my Go To Vac... great suction, even with longer hoses, and really impressive with the 50mm hoses, suction remains even when bags near full as discussed above, reasonably quiet, HEPA filter system is well designed, HEPA filters rarely need changing, love the stacking ability for Systainers or DD, or nothing atop and used in small size mode, under bench for Kapex, etc. Auto on for our sanders, TS55s and dominos is a nice and reliable built-in feature. They are reasonably reliable from my experience and from reading forums. While to some they may seem too costly, when you compare them to other big brand name HEPA options, they are on par if you consider the added benefits of the Festool. USA tech support, u can get a human on the phone, which today is unheard of

Michael Kellough · « **Reply #16 on:** January 08, 2023, 10:19 AM »

I’d change the bag at least once a year. Very fine stuff will gradually clog the pores of the bag material so you might so you might not notice the reduced air flow.

I agree that ABS plastic is not the best material for a work vac. Too brittle. And so many parts, at least on the previous generation. They move and rattle and break.

I still mourn the death of my old WAP Turbo from the mid eighties. The tub was made of thick roto-molded polyethylene and the motor housing was extremely robust. The toughest and quietest vac I’ve used.

ChuckS · « **Reply #17 on:** January 08, 2023, 10:27 AM »

Instead of using time, I change my CT15 bag based on how many times it has been reused. Twice? Then it will be replaced. And that is about $5 every two or three years or longer (because it is an extractor mostly for the router, DF500 and sanders). All others have a DD.

I wonder if I could use up all the bags (a pack of 5 when bought) by the time I retire from the hobby.

NiteWalkerGR · « **Reply #18 on:** January 08, 2023, 10:56 AM »

Quote from: WillB on January 08, 2023, 08:23 AM

Too funny on the DD... I feel the same way... I even upgraded to the new DD 2.5", its even better, if that is possible. With the DD, I just vac up everything, even chips, large shavings, etc, (vs. quick sweep of the big stuff) as the DD bags are so cheap. Using the 50mm hose, I rarely ever get a clog in the hose.

> What issues do you have with the festool vacs?

I too have lots of other Vacs, and I still like the Festool the best, specially combined with the DD. I never tried Festools cyclone as the DD work so great. Only one major issue I have...it's the plastic they use is too frail over time. I had a few that had light use, in storage most of their life, granted it was in Vegas summer heat... The plastic self destructs, cracks everywhere. Recently opened a CT22 to check the bag, which has the clamshell design, open to 90 deg, and there is a stop, unlike the newer CT's, which you fully remove the top half (much safer, less that can fail). When in the up (90 deg) position, sitting un disturbed, the plastic just cracked all over, the top half crashed down. The plastic in other areas cracked as well...I think this one was 8-10 yrs old but was in great shape, prob. under a 150hrs run time. But I have RIGID and Bosch vacs that went through the same storage conditions, and their plastic has has zero cracks. There is lots of complaints about the plastic on the garage tops cracking. Mine all seem to crack in that areas within a few years. This is an easy design fix, make the plastic thicker. The rear wheels are large and nice for pushing around as they jump over most things in a shop. But the front wheel diameter are too small to travel over its own electrical cord. Slightly larger diameter front wheels... a simple fix, maybe just a pet peeve of mine. Hoses are very costly...I finally start buying the new Rocker 2.5" hoses, where you can cut them to size and add twist on the ends, impressive hoses for the price. I have no need now for the anti static feature of their hoses.

But to be fair, there is a LOT i like about Festool Vacs, which is why they are still my Go To Vac... great suction, even with longer hoses, and really impressive with the 50mm hoses, suction remains even when bags near full as discussed above, reasonably quiet, HEPA filter system is well designed, HEPA filters rarely need changing, love the stacking ability for Systainers or DD, or nothing atop and used in small size mode, under bench for Kapex, etc. Auto on for our sanders, TS55s and dominos is a nice and reliable built-in feature. They are reasonably reliable from my experience and from reading forums. While to some they may seem too costly, when you compare them to other big brand name HEPA options, they are on par if you consider the added benefits of the Festool. USA tech support, u can get a human on the phone, which today is unheard of

Thanks for sharing your experience with the vacs. I'll have to be careful about pulling my midi around by the hose garage.
And yeah, I upgraded my workshop setup to a dd 2.5 from the original and it's amazing.

Crazyraceguy · « **Reply #19 on:** January 08, 2023, 11:05 AM »

I don't see the cost of bags as an issue. I have been using the Powertech bags for the last couple of years. They cost $21 for a 5 pack, so 4 bucks each. The genuine Festool ones are a little more than double that, still not excessive.
At a price of $419 the cyclone would have to replace 10 packs of bags (genuine) or 20 of the knock-offs.
That's up to 100 bags. The question comes down to "How many do you use?"
For me, it depends on what I am doing, but somewhere between 4 to 6 weeks. More router table work decreases that interval, but sanding, Dominos, and TS55 don't produce nearly as much.
My CTs don't have to deal with the miter saw or table saw, there is a large dust collector for that.
100 bags is quite a long time in that case, but if a guy goes through 1 or more a week? Sure, that cost would get paid back pretty quickly.

WillB · « **Reply #20 on:** January 08, 2023, 01:33 PM »

Agreed on bags... you also have the HEPA filters, but again, not major cost as they seem to last a long time and u can hit them with compressed air...
for me, it was not just the payback, I hate bending down to get to the bags

I was changing them 2-3x per month.
with the DD, its at chest level....of course, if you wanted a lot of Systainers in that space, then, just buy larger vac and fill the bags...its nice that Festool provides us size options...for me, the 26 is big enough, cause the DD does 99.9% of the work...no need for bigger vac., as the suction is the same... the cleanable bags and DD is quite the combo.

NiteWalkerGR · « **Reply #21 on:** January 08, 2023, 02:18 PM »

Quote from: Crazyraceguy on January 08, 2023, 11:05 AM

At a price of $419 the cyclone would have to replace 10 packs of bags (genuine) or 20 of the knock-offs.

That's assuming one buys the festool cyclone. You can have a very serviceable setup for around $100 using a dust deputy.

That said, I do agree bags are not really a cost issue. For my midi, I have around 35 bags because I found a seller on ebay clearing out boxes of festool bags for $25 each. I grabbed em all. And my midi is my mobile vac that doesn't see as much use as my workshop vac, where I have a dust deputy set up. So those 35 bags will last me years. Whereas in the workshop I'd be changing bags weekly if not for the dust deputy.

JINRO · « **Reply #22 on:** January 08, 2023, 02:37 PM »

Ordered Macam bag and arriving today. It is a replica of Festool long life bag. I wanted to try since it has opening slot is on side which will be much easier with emptying dust/chips.

mino · « **Reply #23 on:** January 08, 2023, 02:56 PM »

Quote from: WillB on January 08, 2023, 01:33 PM

Agreed on bags... you also have the HEPA filters, but again, not major cost as they seem to last a long time and u can hit them with compressed air...
for me, it was not just the payback, I hate bending down to get to the bags I was changing them 2-3x per month.
with the DD, its at chest level....of course, if you wanted a lot of Systainers in that space, then, just buy larger vac and fill the bags...its nice that Festool provides us size options...for me, the 26 is big enough, cause the DD does 99.9% of the work...no need for bigger vac., as the suction is the same... the cleanable bags and DD is quite the combo.

Not much point paying for HEPA microfilters if one plans on compromising their filtration ability with compressed air ... just saying. It is possible to de-dust the PET microfilters with compressed air. But one needs to be carefull to not get too close to the filter. The air stream will punch (invisible) holes in the filter structure in no time, effectively destroying it as a filter.

Re bags.
The reason bag are one use and cost as much is to do with protecting our lungs. That is why we pay for FT vacs after all. Right?

Using a bag with good cyclone, the bag will be damaged/used up (as in leaking more than desirable) usually well before it is full. This is also why CT36/48 non-AC make little sense when a pre-separator cyclone is to be involved.

The easiest way to detect the bag giving up is checking your microfilter once in a while. If the microfilter is getting dirty, it is time to change the bag.

The same goes for when re-using the bag (sans cyclone). If careful to not damage/stretch the microfibers, it will last several changes.

Last, as it was not mentioned in this thread - the "long life" bag is no universal cure for "expensive" bags. They are not designed for use with micro-dust from sanding. They are great for routing, planing or cutting where huge quantities of relatively big dust is being generated. But not as a universal replacement for the one-use bags.

YMMV

Crazyraceguy · « **Reply #24 on:** January 08, 2023, 03:54 PM »

Agreed totally. Why would someone use a separator with a big vac like a 36 or 48?
When the cyclone is involved, all you need is the suction and filtration, the size of the bag (which is not supposed to fill up anyway) is irrelevant.
I would also think that having to deal with the separator in a van/jobsite situation would get old, as would lugging a bigger unit.
There would be an exception for drywall sanders and the auto-clean of course.

ChuckS · « **Reply #25 on:** January 08, 2023, 05:12 PM »

Quote from: mino on January 08, 2023, 02:56 PM

Snip.
Not much point paying for HEPA microfilters if one plans on compromising their filtration ability with compressed air ... just saying. It is possible to de-dust the PET microfilters with compressed air. But one needs to be carefull to not get too close to the filter. The air stream will punch (invisible) holes in the filter structure in no time, effectively destroying it as a filter. Snip.
YMMV

I could be wrong, but some people might've got the wrong idea about using compressed air to clean the HEPA filters after seeing that done in one of the Festool videos. Maybe Fine Woodworking or some other magazine has advised against using compressed air on HEPA filters as the damage done is invisible to the naked eye, and users might have a false sense of protection while using the filters.

WillB · « **Reply #26 on:** January 08, 2023, 06:15 PM »

some good input here....
I always felt the HEPA filters are the last trap for dust... the HEPA determines what escapes the vac. I have used the DD with the same bag for a long time, and I do occasionally check the HEPA filters, but they are always super clean. Bags must be darn good, sometimes I just change them cause they are old. They rarely have anything in them, at least visible.
The only time I had dirty HEPA when one vac w out cyclone... changed bag, had spillage, and it was not cleaned up, (stupid, we all get side tracked) so it ended up in the HEPA, a bit of compressed air and it was back... and point well taken, u cant blast these delicate filters, I shoot from far away, that is all it takes. I rack my fingers over the filter to be sure the compressed air gets to most of the pleats. i also use compressed air for my large drum HEPA in my Laguna P Flux vacs..those things get plugged, Laguna recommends compressed air.... i only use it occasionally, instead, I take my SYSVAC and vac it out, works great.
Valid point about using these Festool Vac on n off job site, vs. those of us who only work in a shop and not in the field. Different requirements. If I was in the field, I would get a slightly bigger vac, no cyclone, way to cumbersome to deal with when transporting, at least the DD, prob. Festool Cyclone not as bad... But as others pointed out, they are not mandatory, the Vac n Bag system is impressive, did that for 15 yrs without issue. Nice to see these 3rd party bag makers like Powertec, will give them a try...

luvmytoolz · « **Reply #27 on:** January 08, 2023, 07:26 PM »

Quote from: Crazyraceguy on January 08, 2023, 03:54 PM

Agreed totally. Why would someone use a separator with a big vac like a 36 or 48?
When the cyclone is involved, all you need is the suction and filtration, the size of the bag (which is not supposed to fill up anyway) is irrelevant.
I would also think that having to deal with the separator in a van/jobsite situation would get old, as would lugging a bigger unit.
There would be an exception for drywall sanders and the auto-clean of course.

I do, I cut up a huge LPG tank and put a DD on top of it going to my CT36 for my bigger CNC machine. I have a long life bag in the CT that has only ever been emptied once (bought the L/L bag before realising just how effective the DD is), but the tank has been emptied numerous times. Granted the CT36 is overkill as I only run it around 1/2 power anyway, but it all fits nicely out of the way and just does the job.

Crazyraceguy · « **Reply #28 on:** January 09, 2023, 05:55 PM »

I noticed a bit of suction loss this morning....yep, brick. A lot of it was solid surface dust from flush-trimming that white wall from a couple of weeks ago. It was very heavy.