Choice of workshop vac?

[weekend_woodworker]

Hi,

I currently have an Axminster chip extractor which is great for the large machines and a Wickes vacuum for hand held power tools. The Wickes machine seems to throw as much fine dust in the air as it sucks up and is really noisy. What would anybody recommend to replace it with that has good fine dust filtration?

Thanks

Mark

 

[LancsRick]

A screwfix titan vac and a plastic cyclone (dust commander is a popular brand but they're all much of a muchness).

 

[MikeJhn]

The latest larger Neumatic's and the Axminster versions have the facility to duct the exhaust where you want to, with the additional filters, mine has four, you do not get any dust into the workshop.

 

[weekend_woodworker]

Thanks for the recommendation. Which model of Numatic vacuum do you recommend? There seem to be lots of different sorts. Thanks

 

[weekend_woodworker]

Does anyone have any experience of the:

1) Makita VC3012M/2 240V M Class Dust Extractor 30L - FFX are selling at £385

2) Bosch GAS 35 M AFC+ Wet & Dry Extractor - Axminster are selling at £519.96

I was interested in an M Class Vac as it guarantees >0.1mg/m³ which is the HSE standard for workshops and I believe they have auto cleaning filters.

 

[MikeJhn]

Now think about that seriously, how does a filter self clean, back flushing per chance?

I can't recommend any modern Numatic as mine is a very old model that came out before they had names, but I would look at the Axminster NVD750 if I was looking again, twin motors like mine and I am very happy with it as a shop vac, facility for four filters and a Hepa module if you want finer filtration.

Link: https://www.axminster.co.uk/numatic-nvd ... r-ax782721

 

[SammyQ]

I saw two extractors - like the ones you posted photos of - recently, one older Bosch and a similarly constructed Hilti. The Bosch was being used for prepping a scabby internal wall to smooth for painting and the Hilti was attached to a wall tracker for Heli-bars.
BOTH HAD AUTO CLEANING AND WERE SUPERB!!!.
The auto-clean is a totally enclosed operation ' inside the box'. In both machines cases, the noise momentarily went up, then subsided, as the back-flush went down, but inbetween such phases, was quite acceptable, though I'd recommend Peltors for long use. There was bugger-all dust in the kitchen with the Bosch, a smidgeon - no more - with the Hilti as it was overdue a service.
I'd buy the Bosch in a heartbeat if I could find a decent second hand one near me, but I presently use a 'dust deputy' Chinese clone and a Record green/yellow somethingorother dustbin/dalek to power it. Between 95-99% cyclonic efficiency ( so the pundits say) and the Record paper filter, I can rout MDF indoors and not activate my asthma...kewl.

Sam.

 

[weekend_woodworker]

Now think about that seriously, how does a filter self clean, back flushing per chance?

I can't recommend any modern Numatic as mine is a very old model that came out before they had names, but I would look at the Axminster NVD750 if I was looking again, twin motors like mine and I am very happy with it as a shop vac, facility for four filters and a Hepa module if you want finer filtration.

Link: https://www.axminster.co.uk/numatic-nvd ... r-ax782721

The Axminster/ Numatic extractor looks like a robust bit of kit, but it you put the Hepa filter on to make give it M class filtration it comes to over £900, which seems like a lot. I guess you get what you pay for ultimately. Thanks.

 

[woodbloke66]

Thanks for the recommendation. Which model of Numatic vacuum do you recommend? There seem to be lots of different sorts. Thanks

I use the twin motor Numatic NVD 750; excellent - Rob

 

[MikeJhn]

Filters become more efficient once they become dusty, to self clean it back into the vac is defeating the object and only delaying the inevitable, bit of a marketing ploy IMO.

 

[Doug71]

Not sure about all makes of vac but I know with Festool the only difference between the L class and the M class is that if the suction rate drops (blocked hose, full bag etc) the M class will bleep to warn you, the filters and filtration level are the same on both. Unless you need an M class for site work the L class is fine, you know when the bag is full because it will stop sucking!

Have heard people moan about the M class because if you change the diameter or length of hose it can confuse the vac.

 

[large red]

Anyone tried Shop Vac? Huge in America, they sell over here through their Shop Vac UK website. They seam to be incredible value for the spec.

 

[SammyQ]

"Filters become more efficient once they become dusty"

No, no, and thrice no.

Interstices ("gaps" Nigel) in filter material fill up with particles too big to pass through their 'mesh'. True. That means that smaller particles than the 'mesh' size cannot penetrate the now utterly clogged filter material. In one way, yes, this is more efficient, but only as nowt is getting through? Hence, the urban myth quoted. But, in actual fact, the filter has now ceased to work...as a filter...passing clean air out. It's bunged. Also, the reverse or backward air 'pressure' of the slightly pressurised air in the ducting, created by the fan/impeller trying to push air through an effective solid wall is providing a resistance to the blades rotating, which is, Q.E.D., overheating the motor. How often do you want to buy an extractor?

The Auto-Clean function/ back-flush, I presume, acts in a similar fashion to the manual 'flapper' installed in some cylindrical filter mechanisms, dislodging particles bigger than the interstices of the filter material, thus permitting air passage again?? Siggy7 or someone equally knowledgeable please evaluate and correct this supposition!

Sam

 

[Eric]

Mark, I have a Fein Dustex which has excellent filtration, even on the brightest day I see nothing coming out. Not exactly cheap (£225 from Miles Tools), but still a lot less than a new pair of lungs. It is surprisingly quiet too, only 67 dB.

 

[craigs]

I bought the NVD750 recently and its awesome, superior to the Festool midi i had previously and I piped the exhaust outside so it's no big deal. I recently saw a video on YT of a guy that bought the same one, spent 300 on the hepa module and put it in an external shed to his workshop :/

 

[SammyQ]

The only problem with piping a dust exhaust outside, is the simultaneous extraction of heated air with the dust - in winter, particularly on a long 'run' of machining, you are just pumping your money 'out the wall'...
One solution might be to exhaust your filter into a labyrinth, like MikeG (I think) does. By vastly increasing his 'return pathway' through an enclosed maze inside a box, he induces even fine dust to fall out. Thus, returning air is clean(er?). His box, from memory, was about a metre square and 150mm wide, vertical orientation, so could be against a wall? MikeG please verify/correct.

Sam

 

[MikeJhn]

"Filters become more efficient once they become dusty"

No, no, and thrice no.

Interstices ("gaps" Nigel) in filter material fill up with particles too big to pass through their 'mesh'. True. That means that smaller particles than the 'mesh' size cannot penetrate the now utterly clogged filter material. In one way, yes, this is more efficient, but only as nowt is getting through? Hence, the urban myth quoted. But, in actual fact, the filter has now ceased to work...as a filter...passing clean air out. It's bunged. Also, the reverse or backward air 'pressure' of the slightly pressurised air in the ducting, created by the fan/impeller trying to push air through an effective solid wall is providing a resistance to the blades rotating, which is, Q.E.D., overheating the motor. How often do you want to buy an extractor?

The Auto-Clean function/ back-flush, I presume, acts in a similar fashion to the manual 'flapper' installed in some cylindrical filter mechanisms, dislodging particles bigger than the interstices of the filter material, thus permitting air passage again?? Siggy7 or someone equally knowledgeable please evaluate and correct this supposition!

Sam

Yes yes and four times yes.

Just give it a bit of lateral thought instead of a knee jerk reaction, the only time a filter stops working is when it is completely blocked, not when it is partially dirty, you will know when its blocked it stops sucking, anyone who has used these type of filter vacs will testify that during use after installing a new filter or cleaning an old filter lots of dust goes into the atmosphere from the vent, after a little use this dust reduce's considerably as the filter gets dust on it and becomes more efficient, obviously this can not go on indefinitely, supposition corrected.

 

[SammyQ]

Siggy7?

Adjudicate please?


Sam

 

[woodbloke66]

One solution might be to exhaust your filter into a labyrinth, like MikeG (I think) does. By vastly increasing his 'return pathway' through an enclosed maze inside a box, he induces even fine dust to fall out. Thus, returning air is clean(er?). His box, from memory, was about a metre square and 150mm wide, vertical orientation, so could be against a wall? MikeG please verify/correct.

Sam

I believe Mike does use this method Sam and a few years ago I once (under his online guidance) attempted to build such a labyrinth but for some bizarre reason I couldn't get mine to work. C'est la guerre - Rob

 

[craigs]

The only problem with piping a dust exhaust outside, is the simultaneous extraction of heated air with the dust - in winter, particularly on a long 'run' of machining, you are just pumping your money 'out the wall'...
One solution might be to exhaust your filter into a labyrinth, like MikeG (I think) does. By vastly increasing his 'return pathway' through an enclosed maze inside a box, he induces even fine dust to fall out. Thus, returning air is clean(er?). His box, from memory, was about a metre square and 150mm wide, vertical orientation, so could be against a wall? MikeG please verify/correct.

Sam

I completely get that, which is why I can just disconnect the external exhaust, cap it and let the exhaust internally, that being said its a 7'x7' resin shed.....soo its more a summer escape but every little helps in the winter.