I have about 2k sf of tile and thinset to remove from a concrete slab. Usually I use a shop vac with bags for such a job but last time I had trouble with my bags blowing out. So I have a few questions. Has anyone used their CT (I have the CT 36 AC) attached to a 7" grinder (with 2" hose) for grinding off thinset? My gut says it probably wont be able to keep up but if you did was the DC sufficient and did you have any issues with the festool bags popping? Or if you have any bag recommendations for a 16 gallon or so shop vac that doesnt blow apart Im all ears on that too. I usually buy the ridgid brand bags and never had an issue before so Im not sure if I got a bad batch or if I mistakenly bought the off brand ones last time.
CT & Thinset removal
- Thread starter afish
- Start date
luvmytoolz
Member
- Joined
- May 17, 2021
- Messages
- 1,795
I've used my really old (circa 1980) Festo SR5E with a 150mm grinder to level concrete without any issue, kept all the dust out of the air no problem. I used the original paper bags bought with the extractor at the time, so I reckon the CT36 and stock bag should be able to cope just fine.
Thanks, I just ordered a dust deputy too. I figured for 60 bucks its worth a shot if I can eliminate the bag altogether and just use the DD and a good filter would be nice. The last time the bag blew on me was a mess I had the vac around a corner in another room and between glasses, hearing protection and respirator I didnt notice it right away and it spewed ultra fine dust everywhere before I noticed. If I need to use bags again I will most likely extend the exhaust port outside so if the bag does blow its not a big deal.
luvmytoolz
Member
- Joined
- May 17, 2021
- Messages
- 1,795
The Dust Deputy is fantastic, worth it's weight in gold! I have a standard sized unit on top of a massive drum for my CNC machine, hooked up to a CT36 running no more than 50% suction, with a long life filter bag. In around 12 years of use I've emptied the bag once from memory, and it was just a small amount of quite fine dust.
I have another standard one on a 20L drum in the shed hooked up to my bandsaw, and again, barely anything makes it through to the extractor.
I did a lot of research at the time, and pretty much universally the DD came out on top of all the comparable products on the market.
I have another standard one on a 20L drum in the shed hooked up to my bandsaw, and again, barely anything makes it through to the extractor.
I did a lot of research at the time, and pretty much universally the DD came out on top of all the comparable products on the market.
Im looking forward to trying it. I have heard good things when used with wood dust. My concern was with the very fine dust produced from grinding concrete I was worried the cyclone might not capture much. I read some reviews and while people said that it doesnt work as good with concrete dust it still works very very good so that gave me enough hope to click the buy it now button. Now I need to find a good container for it. Im thinking a 15 gallon barrel Im thinking the taller the better to give more space between the intake and the dust the better. I also thought about getting the even bigger 4" DD and hooking 2 shop vacs to it in parallel to get more cfms for longer hose runs but that might be down the road I will test a single one for now hopefully that will be enough but I know that 7" grinder makes some serious dust clouds quick fast and in a hurry so CFM's are the name of the game here.
luvmytoolz
Member
- Joined
- May 17, 2021
- Messages
- 1,795
Given that the DD pretty much outperforms the competition, and concrete dust is possibly heavier or almost the same weight as fine wood dust, I'd expect it to be pretty good. You might need to shake the bag a little though as concrete dust does tend to spread itself over as a wide an area as possible being very fine.
For my CNC I cut the top off a gas cylinder to make a tank approx 450mm wide x 750mm high. To make emptying it as easy as possible, and also to flick off-cuts into it, I fitted a rubber strip around the top edge, and I mounted the DD on a sheet of melamine with a 15mm wide groove that fit over the rubber seal. Then I ran a bead of silicone around the groove leaving it very slightly proud to create a perfect seal on the rubber seal under vacuum load.
This way the lid is loose and easily moved but when the dusty is turned on it clamps right down. Hope this all makes sense?
It does in my head but that's definitely not an endorsement of any kind!
For my CNC I cut the top off a gas cylinder to make a tank approx 450mm wide x 750mm high. To make emptying it as easy as possible, and also to flick off-cuts into it, I fitted a rubber strip around the top edge, and I mounted the DD on a sheet of melamine with a 15mm wide groove that fit over the rubber seal. Then I ran a bead of silicone around the groove leaving it very slightly proud to create a perfect seal on the rubber seal under vacuum load.
This way the lid is loose and easily moved but when the dusty is turned on it clamps right down. Hope this all makes sense?
It does in my head but that's definitely not an endorsement of any kind!
Kodi Crescent
Member
- Joined
- Aug 6, 2010
- Messages
- 791
Make sure you wear a respirator when you do this. Although the concrete dust may be heavier, it may grind more finely creating a larger "respirable fraction" of dust. This respirable fraction, if it gets into your lungs is what contributes to health problems long-term.
luvmytoolz
Member
- Joined
- May 17, 2021
- Messages
- 1,795
Kodi Crescent said:
Dead right, good pickup! I should have mentioned that before myself, you can't rely just on the extractor when grinding stuff like that!
Yep get a dust shroud for the cup grinder and run the DD. One thing to consider is many times you can scrape most of the thin set off with an sds with a wide chipper blade. Better to take it in chunks than dust. 2000 sq ft is a lot to do with a hand grinder. They do have dedicated machines that you can easily rent
Thanks, I got the makinex trolley with 35# hammer but the dust control is my issue. There isnt a ton of thinset left after chipping but it doesn't take much grinding to make a mess either. Unfortunately this is in a occupied home so it will need to be done in stages so rental fees and multiple pick up/offs will be a turn off for rental. If it was just a straight tear out 1 or 2 day deal the rental would be fine but cant do it here. Its going to be a PITA shuffling furniture and temp walls. I already have everything but a industrial extractor and large grinder. The 7" grinder goes pretty fast as long as the chipper did a good job. Im going to add some dust collection to the trolley to help with dust too. I made a similar system and added it to my TE-75 and it worked really good but Im getting to old to be standing bent over all day over the TE-75 Trying not to go hog wild on a $4k dust extractor either. I have a dust shroud already on the grinder and that works really good unless the bag pops in the shop vac then all hell breaks loose. Just trying to work out the best DC setup without going crazy. I have high hopes for the dust deputy after the comments and reviews.
mino
Member
- Joined
- May 5, 2016
- Messages
- 1,984
Using a cyclone with CT 36 in auto-clean (AC) mode is pointless for concrete/grout/tiles work. I personally consider it detrimental even.
It makes sense for plaster/drywall where you have lots of fine@heavy dust which is optimal for a cyclone AND you do not care for the cyclone choking your vac a bit.
For concrete/tiles you will have most of the dust as bigger particles which means two things:
- cyclone choking your vac will negatively affect you, unlike with drywall work
- you are -not- really helping the filter, as the bigger dust will anyway fall down in the bin immediately and never reach the main filter, again, unlike with drywall
Due to the big particles, you need all the air volume you can get there. You do not really want a 2" hose combined with a cyclone choking the CT. The speed of air in such a setup would be too low in the hose and the heavy sand will tend to accumulate there.
I was grinding down a brick wall last weekend with my CTM 36 AC. it was crazy as the wall was like a concrete wall with brisks inserted - too much cement in the grout ... and ... it handled it absolutely fine. And that was a wet wall /basement, no insulation/ so I was really afraid the dust "sticking" in the main filter and re-forming concrete there. It DID create semi-concrete blocks in the hose start, but the filter was absolutely fine. I used the "middle" AC setting.
Just make sure you monitor your bin - you want to empty the bin when 1/2-2/3 full, not more. This is not like with bags where going 90%+ is absolutely fine. Bagless operation needs some space to allow the dust to settle in the bin and not "rotate in the wind" below the filter.
Also, even if you have M-class with the flow sensor, do not rely on it to tell you when to empty the bin.
It will sound the alarm too late with the "correct" hose setting and if you set it to a 50mm hose setting it will make false "alarms". The sensor is more a safety thing here. Works reasonably well for bag operation, no so much for bagless rough work.
[member=73094]afish[/member] Just noticed you mention bags: Forget them for this.
When you have AC vac, you do not use bags when using AC mode. Using bags is a band aid for this type of work when one does not have an AC vac. When you have AC, you use AC, not bags.
If you still have only one main filter, get a new paper/nonAC filter for bag use and dedicate your old PET filter for bagless use. That is the most economical. Trying to clean a main filter after bagless use is pointless. You need one dedicated for such use to get the best of the AC capability of your vac.
What I do is:
- remove a wood-dust bag from the bin (carefully) and the paper non-AC filter
- put in my AC HP PET filter
- do the work
- empty the bin, remove the HP PET filter (AC-capable)
- clean the bin, the filter holder and any hose end/etc. as applicable
- put back the bag (with dust in it) and the paper non-AC filter
- vacuum the PET HP filter a bit, so there is no dust falling from it and then store it, I do NOT attempt to force-clean the HP filter, as there is no point and it would only damage it
GL!
It makes sense for plaster/drywall where you have lots of fine@heavy dust which is optimal for a cyclone AND you do not care for the cyclone choking your vac a bit.
For concrete/tiles you will have most of the dust as bigger particles which means two things:
- cyclone choking your vac will negatively affect you, unlike with drywall work
- you are -not- really helping the filter, as the bigger dust will anyway fall down in the bin immediately and never reach the main filter, again, unlike with drywall
Due to the big particles, you need all the air volume you can get there. You do not really want a 2" hose combined with a cyclone choking the CT. The speed of air in such a setup would be too low in the hose and the heavy sand will tend to accumulate there.
I was grinding down a brick wall last weekend with my CTM 36 AC. it was crazy as the wall was like a concrete wall with brisks inserted - too much cement in the grout ... and ... it handled it absolutely fine. And that was a wet wall /basement, no insulation/ so I was really afraid the dust "sticking" in the main filter and re-forming concrete there. It DID create semi-concrete blocks in the hose start, but the filter was absolutely fine. I used the "middle" AC setting.
Just make sure you monitor your bin - you want to empty the bin when 1/2-2/3 full, not more. This is not like with bags where going 90%+ is absolutely fine. Bagless operation needs some space to allow the dust to settle in the bin and not "rotate in the wind" below the filter.
Also, even if you have M-class with the flow sensor, do not rely on it to tell you when to empty the bin.
It will sound the alarm too late with the "correct" hose setting and if you set it to a 50mm hose setting it will make false "alarms". The sensor is more a safety thing here. Works reasonably well for bag operation, no so much for bagless rough work.
[member=73094]afish[/member] Just noticed you mention bags: Forget them for this.
When you have AC vac, you do not use bags when using AC mode. Using bags is a band aid for this type of work when one does not have an AC vac. When you have AC, you use AC, not bags.
If you still have only one main filter, get a new paper/nonAC filter for bag use and dedicate your old PET filter for bagless use. That is the most economical. Trying to clean a main filter after bagless use is pointless. You need one dedicated for such use to get the best of the AC capability of your vac.
What I do is:
- remove a wood-dust bag from the bin (carefully) and the paper non-AC filter
- put in my AC HP PET filter
- do the work
- empty the bin, remove the HP PET filter (AC-capable)
- clean the bin, the filter holder and any hose end/etc. as applicable
- put back the bag (with dust in it) and the paper non-AC filter
- vacuum the PET HP filter a bit, so there is no dust falling from it and then store it, I do NOT attempt to force-clean the HP filter, as there is no point and it would only damage it
GL!
- Joined
- Feb 22, 2016
- Messages
- 3,014
I'm sure you don't want to invest in more tools for this job, but Hilti makes some excellent grinders and vacuums designed specifically for concrete surfacing that have been used on jobs I worked in the past (but not used by me directly, I was on the project management team not working with the tools).
They performed very well and did a good job of containing the dust. We had minimal cleanup which was important for the space we were working in as there were many large (up to 1000 HP) electric motors which they wanted to avoid any dust making it's way inside the motors which could not be shut down during the work.
They performed very well and did a good job of containing the dust. We had minimal cleanup which was important for the space we were working in as there were many large (up to 1000 HP) electric motors which they wanted to avoid any dust making it's way inside the motors which could not be shut down during the work.
Not sure I agree with the 2" being to big. My understanding is larger diameter = more cfm and smaller diameter = more lift. Maybe with the CT which has less CFM but with the shop vac that has higher CFM's the larger hose should help. The dust that comes off is very fine so I doubt I will have a problem with it collecting in the hose. Even when chipping it has enough lift to suck up decent sized chunks. After thinking about it more, Im thinking the combination of small hose and dust shroud might actually be causing the bag to burst by choking the vac too much and its building up pressure within the drum for extended period of time. I didn't seem to have any bag issues until I used the grinder with the smaller diameter hose. The shroud does allow some air in but not a lot plus the 27mm hose. When I had it hooked to the chipping hammer and everything was 2" and no restrictions I had no bag issue. Im actually leaning towards buying a new shroud that allows a 2" hose to plug on. The dust grabber looks like a nice unit and has a bunch of channels built into the outside rubber piece to allow good airflow in and prevent suction lock.
I still think you are far better off to rent a grinder. I rented a small Husqvarna 120v grinder for $75 per day including assortment of cutters to do some touch up leveling in my basement after I had gone through with a bigger edco. Thinset comes off easy so you could be done with the field in 2 hours and figure another 2 hours for edging with the hand grinder.
Your vac with cyclone would be fine. I had a Ridgid vac at the time.
Your vac with cyclone would be fine. I had a Ridgid vac at the time.
So, there are 2 parts to this question……dust collection/management and abrading the floor. I recently took the top off of a lumpy, painted workshop floor with a renofix rg130 and although I had a dust mask, it was 95%+ perfect at collecting the dust. I used the ‘hard disc’ which is silver and it sliced through everything including aggregate! Stunning bit of kit. It was attached to my ct26m via a 36mm hose. This was in full auto clean mode with a plastic bag inside and as suggested above, my older pleated filter. On top was the Oneida cyclone with systainer type collector. This took almost 2/3rds of the dust but plenty still found it’s way into the vac. The problem with any fabric bag is that it gets blocked by the fine dust and so reduces suction and so leaves the room in a mess. Don’t ask me how I know….And yes, empty the cyclone regularly as suggested above.
I would add eye protection was essential as the odd bit of aggregate did fly out as I moved across the floor.
I would add eye protection was essential as the odd bit of aggregate did fly out as I moved across the floor.
mino
Member
- Joined
- May 5, 2016
- Messages
- 1,984
I think you would be fine without the Oneida, but emptying it is sure easier than the vac bin ... the CT26 has a pretty small "bagless capacity" - about half the CT 36 in bagless mode.DeejayK said:
In addition, from what I have seen the Oneida is well-suited for high-air-volume use. The CT-VA, on the other hand, is a LOW-air-volume thing. The tubing is about 25mm inside the CT-VA cyclone and a D27 90-degree hose goes to the vac .. This reduces practical air volume to 1/2 as compared to a D36 hose direct.
The CT-VA is excellent (better than the Oneida) for wood and other fine/light dust as it achieves higher speed in the cyclone and thus better separation rates. But that also limits it. For high air volume I do not want it choking the vac.
For CT26 use, I may still consider the CT-VA though. The usable volume is pretty small in bagless mode, think like 10-12 liters. For CT36 it is 20-24 liters.
With the CT36 I got 2-3 hours netto of concrete/grout grinding work, before needing to empty the bin. That is absolutely fine with me. With CT26 I would have to check the bin for fullness 2x as often, which may start to bother me.
