Vac/cyclone filters clogging with super-fine dust

[BillK]

In short, my cyclone/vac is caking the first two vac filters with fine dust from plaster & filler sanding with a ROS.
But it's perfect with wood and misc work.

The setup is ash vac plus steel drum, dust commander type cyclone on top. Had this about 7 years, used every single weekday at least and been perfect with wood & paint from routers and sanders, and general workshop cleaning. Barely anything's ever made it past the cyclone & drum to the main vac drum. Never had to clean or replace the vac filters.
There's a coarse mesh filter, then a fibreglass/fabric main filter, and a HEPA filter.

I have a ton of new plaster and filler to be feathered in from where old plaster coving was hacked out, and making some ropey walls good, some filler etc. Basically the entire house to do. I'm using a sander (Deros II).
Yesterday the vac's first two filters got well clogged up, the HEPA's clean & clear. Most dust does end up in the cyclone drum, but enough zips past to choke the two filters.

I'm not sure what if anything can be done, any ideas very welcome.. I guess either there's so much suction that some fine lightweight plaster/filler dust zips past the cyclone straight to the vac, or there's some inefficiency in it - but as above it's perfect for wood dust and suchlike.

I've ordered a second bag so at least I can wash and swap and keep going longer. Tried reading the Pentz page but couldn't really digest it.
One thing I did see was extending the cyclone inlet to inside the cone, I'll see if I can give that a shot. I did wonder about reducing the suction slightly, maybe strategic pluggable hole/s at the cyclone half of the system. That'd be a right game of chance though.
Wondered about buying a Henry but no idea it that'd be any better. At least I could swap machines and keep at it for a time.

(Hope this is OK in here being not strictly woody)

 

[Sideways]

I cleaned out the loft of an old lath and plaster house in prep for woodworm treatment.
Hoovered my bodyweight of plaster dust using a vac with a cyclone.
The cyclone was 95% efficient, better maybe, at collecting the weight, but the few grams of super fine dust clogged the paper filter bags of the vacuum regularly.
I must have used near to 10 paper bags in all and they were all effectively empty, but blocked when I tossed them.
So the only suggestion I can offer is to use a vac that takes those disposable paper bags and to toss them when they block, even if they seem empty.

 

[Bingy man]

You said new plaster - new plaster does not fully dry for weeks possibly months depending on thickness and humidity in the house . This and the fact that plaster dust is usually very fine is probably adding to your woes . You could also consider a drywall sanding kit ( expensive) for a one off use but I think you can hire one .. good luck

 

[BillK]

Thanks chaps. The plaster being sanded is thin skim and had a couple of weeks, I've been doing cycles of warming & venting rooms and running a fan to help it along. There's deeper stuff as well but I'm leaving that be for now.

Does seem that most hits the cyclone can but a small amount gets by, after a time it's enough to coat and block the filter. I got through the day by whipping out the filter bag now & then and brushing it off outdoors. I did think about another vac but think I'll get another couple or three filters instead and to do quick swaps. Brush & wash at the end of the day. Should get me by and cheap enough at £11 a pop.

 

[Sachakins]

It's so much finer than wood, it's no surprise it's clogging up your filters.
No way round it, just keep cleaning filters often.