HELP! How catch dust in vaccuum when drilling wall?

[Goedjn]

[Goedjn]

Clearly you need a short length of dryer-hose, a bread-bag, and a roll of tape.

[David Peters]

Hmm. that's a nice little project. But the drum (a.k.a. dustbin) is large. Maybe it needs to be so large for the centrifugal effect to work.

I'm starting to favour using a pre-filter. The only problem is that the motor seems to feel it is working against a blockage with very little air being drawn up the hose. And that may lead to too much load on the motor itself.

Now I did see a nifty little kit for only £1 for attaching to a domestic vaccuum cleaner which could then be used to clean a PC. It had a vented coupling attachment to limit the vacuum suction ann lower the load on the motor. Something like that might work well. In fact all that's really needed is to cut some air intake holes in the vaccuum cleaner extension or hose or whatever part is most appropriate.

Then maybe the trick is to work out the best filter material. Glass wool would be nice but particles are likely to pass into the vaccuum cleaner and out through its filter and into the exhaust air. But maybe a thick enough was of cotton wool or a section of a vaccuum cleaner filter bag (assuming they are made of a carefully chosen material to llow air flow but trap dust). Oddly enough I found that something as simple and unexpected as a few layers of a J-cloth did a respectable job. Dense fabric like Egyptian cotton or upholstery fabric might also work well enough. It would seem that most of these wouls let the sub-micorn stuff through but in practise they seems to trap quite a lot.

And this method is good for evacuating the drilled hole of debris while drilling so that a faster cut is achieved and it also prevents possible clogging when putting in a wallplug.

[John Rumm]

Smaller cyclones (and ones with more taper) will give more air acceleration and hence better fine dust removal. The one I built was more of a chip and sawdust separater - its purpose was to collect all the granulr stuff and stop the vac getting full in five mins. So in its current form would not suit what you want.

To get very effective collection of the finest stuff with a cyclone requires a fair bit of suction and air flow to overcome the resistance of the cyclone.

It is more of a cooling issue it you eliminate too much airflow. Again you need to design the prefilter to trade off collection ability against air resistance.

It does not solve the fine dust clogging the vac problem though does it?

along with the dust. Beware that blow fibre glass shards into the air is going to do you far more serious harm than the dust!

To catch fine stuff with filters you need a large surface area and a fairly dense material. Big dust extractors usualy use pleated canister filters (like lorry / truck air filters), or large felted polyester bags.

Drilling technique can solve those problems usually, see the masonry drilling section here:

[Goedjn]

Why don't you just duct the dust out a nearby window, instead of trying to trap it?

[The Medway Handyman]

Most vacuum cleaners design for dry use have a direct cooled motor. Any restriction in the airflow results in less cooling air for the motor and rapid burnout. A partially blocked filter or hose can 86 a motor in 20 minutes.