vacuum prefilter

I've done several of these as dust & chip collectors when woodworking. They're easy to make, effective, and well worth it. If the listed thing is solidly made, I'd pay =A320 for it, otherwise make your own.

You have two technical problems: making dust come out of suspension in the air, then keeping the dust in the can and not being picked up afterwards. The second is often harder, especially in a small can. I wouldn't try making one out of a bucket - find something taller.

The designs come in three flavours: the "drop box" (search the web for US woodworkers), the parallel cyclone and the conical cyclone (web again, there are a couple of really good sites out there).

IMHE, rubble and plaster dust can be filtered with a drop box (sharp rightangle turn and expansion of the airflow as the hose enters the box). Lightweight sawdust needs a cyclone. Conical cyclones aren't worth the trouble except as big fixed units, but simple parallel cyclones certainly are.

One useful rubble & chimney sweeeping pre-filter I use a lot is made from the old case of a dead workshop vacuum. The original side entry is blocked and new entry & exit, with a central cyclone tube, are fitted to the old lid.

When I vacuum my old, non-condensing, cast-iron boiler, what comes out is mostly rust and dead wildlife. Nothing that I'd call ash or soot. I use an ordinary vac and floss it with thick cord.

Cheers,

Colin.

Mind if we put that on the wiki Andy? I'm sure some folk could use it.

NT

Hows the memory these days? ;-)

You added that and others last time it came up:

thats just a link rather than the content, unless I'm misunderstanding

NT

Sorry I thought you were proposing to use the link... my misunderstanding.

A dust collection wiki would seem like a good idea though... perhaps sections on coping with problematic tools (i.e. Wall chasers, sanders, planers etc) as well.

Sounds good.

NT