Heath Robinson dust mod to my chip extractor

[flanajb]

After discovering my Axminster chip extractor bag was a 30 micron version I decided I needed to get something done to improve the filtration. I use HEPA bags in my Axminster vac extractor so it seemed pointless to then have such poor filtration on the large chip extractor. So here goes.

I replaced the top 30 micron bag with a cut down HEPA bag that I use for my vac extractor and replaced the bottom cloth bag with a rubble sack plastic one. So now, the only way the drawn air can escape from the extractor is through the HEPA bag. The suction seems ok.

If I have been a complete numpty here and overlooked something important, please feel free to comment.

 

[mindthatwhatouch]

Watching with interest as I have a chip collector which is missing both bag and filter!

 

[lurker]

Watching with interest as I have a chip collector which is missing both bag and filter![/quote


Me too!
I know I'm a nosey bu££er but what's the thing to the left?

 

[siggy_7]

The important things to consider with filters are the grade and surface area. Your setup should give you excellent filtration because the HEPA bag will be very fine. The problem is that with a finer filtration the resistance goes up, so to compensate for HVLP extractors the surface area of fine filtration cartridges is massive. If the performance to you is still acceptable then great, but I'd wager that with a relatively small surface area like that bag the flow rate is significantly reduced.

Sent from my SM-N9005 using Tapatalk

 

[Doug B]

You will loose some suction even Axminster used to say as much if changing from bag to filter, but if there is still enough "suck" to extract the waste from what you are using the extractor on then it seems a bloody good idea to me, better capturing the dust than breathing it in.

 

[flanajb]

Watching with interest as I have a chip collector which is missing both bag and filter![/quote


Me too!
I know I'm a nosey bu££er but what's the thing to the left?

It's a spray booth that I knocked up. I wheel it around into the entrance of my garage.

 

[flanajb]

I have also found that Metabo do a reasonably priced 0.2 micron fine filter which will probably fit a smaller extractor like the Axi one I have.

http://www.my-tool-shed.co.uk/p1090...916&gpla=pla&gclid=CI_6tMHI2MkCFUZAGwodGI0PbA

 

[Shrubby]

Be very wary of those numatic bags .They aren't HEPA but hepa-flo which is just marketing . They have a quoted filter spec of 84% at 0.5 micrometres and 78.4% at 0.3 micrometres (I use them in some vacuums and the outside of the bags shows dust can penetrate them)
As has been said the surface area is small, this will give an extremely high Surface Load Rate on the media
The Metabo cartridge is more suitable as it has an area of 5.2 Metres square
It isn't 0.2 micrometres though. that's a misunderstanding. The media they use meets a German test standard BIA-G which uses particulates with a median size between 0.2 and 2 micrometres - its quoted filtration is at least 99.5%
It's complicated and dull which is why most of the people selling it don't even understand
Matt

 

[flanajb]

Be very wary of those numatic bags .They aren't HEPA but hepa-flo which is just marketing . They have a quoted filter spec of 84% at 0.5 micrometres and 78.4% at 0.3 micrometres (I use them in some vacuums and the outside of the bags shows dust can penetrate them)
As has been said the surface area is small, this will give an extremely high Surface Load Rate on the media
The Metabo cartridge is more suitable as it has an area of 5.2 Metres square
It isn't 0.2 micrometres though. that's a misunderstanding. The media they use meets a German test standard BIA-G which uses particulates with a median size between 0.2 and 2 micrometres - its quoted filtration is at least 99.5%
It's complicated and dull which is why most of the people selling it don't even understand
Matt

Thanks Matt. It's rather sad that there isn't a proper standard for this stuff, especially, given the serious implications that not having correct filtration can have.