Dust collector confusion

[walks]

Ok, so I ordered my SIP 01929 dust collector which arrived next day and unusually for me I looked through the instruction manual!

Here's where the confusion arises. It says twice in separate places that the "dust" collector should only be used to collect chips and shavings and not dust! So it seems I've bought a dust collector that can't collect dust!

I've looked on various websites and they all describe it as a dust collector and none say that it can't be used to collect dust indeed they state that it can collect particles down to 0.5 microns! I'd say that wood chips / shavings of 0.5 microns count as dust!

Am I missing something or is it just SIP legal people being too over cautious?

 

[CHJ]

The filter, bag? can only trap a high percentage of debris down to as small as .5 micron. Anything smaller is just likely to pass straight through and most likely a percentage of .5 micron as well as filter factors are often based on meeting a minimum level of entrapment, not total entrapment.
These smaller particles are the most dangerous as they remain airborne longer and enter your lungs with ease.

So a statement that the unit is not suitable for dust collection is correct from a personal safety position as it will just re-distribute all the smaller stuff around the shop.

 

[jimi43]

Also make sure you put the bag back on properly....

I was turning some elm the other day and realised that something was falling on my head...

Looking round I noticed that a small section of bag had been mis-clamped and was acting like one of those giant snow movers with shavings being blown up into the air and all over the workshop!

Yes...you need a filter box or a dust mask to remove the finer particles.

Jim

 

[walks]

Thanks guys, makes some sense now, I'll still be using my p3 dust mask so it should be ok.

 

[beech1948]

The current best approach to DC is to use the bag type DC with a dust separator. The dust separator is placed between the DC and the machine.

You can buy these from Axminster who will deliver a plastic tub with an inlet and outlet.

You should have a look on Woodblokes blog to see a typical installation.

You could read the blog from the Thien Separator web site. This is separator which is home built and comes very highly recommended. I use one in front of my DC. In practice all of the chips and dust will be collected into the separator with only tiny amounts of dust reaching the DC. The DC becomes the engine for providing suck.

Hope this is useful
Al

PS. Have a read of recent Fine Woodworking mag there was a 5 page article comparing DC approaches including cyclones and dust separators. Cyclones are rated the highest, the bag DC and separator approach the nest highest and the bag DC on its own as the least effective.

regatrds
Alan

 

[Chems]

Here's where the confusion arises. It says twice in separate places that the "dust" collector should only be used to collect chips and shavings and not dust! So it seems I've bought a dust collector that can't collect dust!

I used to have a record unit like this, and it was excellent at catching fine dust. The real problem was that the bag would often need to be taken out and washed to remove all that fine dust as it all clogged up. Dust extraction is a process of a few machines not one, you want to couple your extractor with a fine filter to filter any dust that does escape, have a pre filter like a Cyclone or Thein to minimize the amount of dirty airflow that gets to your extractor and give it the minimum amount of dusty air to cope with. And finally tools with excellent extraction to catch it all at the source.

I have a Jet air filter, 3hp chip extractor and cyclone, and a festool vac and only have tools with good extraction systems in place and the air in my space is so very clean I never have to wear a mask anymore. But in years gone by I have always had to revert to the mask as the air has become so thick with dust due to poor extraction and collection.

 

[fobos8]

there is a simple solution to the problem of filters passing fine dust back into the air. Put the dust collector/chip collector outside. I have mine in a little plywood lean too shed next to my workshop.

 

[Chems]

Its the perfect solution, unless you car about the heat loss.

 

[Itellya]

Can anyone recommend a source for a dust / chip separator container? I saw this good video which explains the process but not sure where I could find a similar container in the UK - youtube - watch?v=qnMtcKfGt1g

My setup is a small chip collector APW (Axminster) 1000DE from 1996. I expect it is currently spreading the finer dust around the workshop which is why I want to improve the filtration. It is mainly used for a table saw. Does anyone know if I can add a filter (as well as the separator) to a model like this or if replacing the bags with a type that can collect very fine dust would be a good idea? I've attached a picture of the collector.

 

[beech1948]

Now an old post which has sliupped into oblivion.

Bagged DC is really a bit of a nightmare because the bag allows dust through and out into the workshop.

Manufacturers lie and prevaricate and often are just totally ignorant of the best approaches to DC. Their job is merely to sell more.

Bagged DC at less than 2hp is just a triumph of imagination over hope and most perform poorly. Dust upto 2-3 microns is allowed to escape. Air constantly moves dust against the bag and out into the workshop. Manufacturers relay on the bag wall being caked to create any dust suppression at all. Belowe 2hp it is unlikely that you will be getting enough suck to give a good airflow and thus dust/chip capture. You need about 2000m3.

You can buy bags for DC which will capture down tyo about 1.5 microns.

A 50 tyo 80 gallon receptical between the Dc and the machine using either the Thein approach or a plastic "mini cyclone" from ebay will provide the maximum separation for you. You may still need the face mask as well.

 

[graduate_owner]

I thought filtration to 0.5 micron was classed as fine dust collection, and the chip collectors would filter down to only 5 micron. Am I misinformed here?

K

 

[Itellya]

beech, is your opinion that I'd be better off with a canister type eg dx4000? Why is that, considering their flow rate is low / similar to the 1hp bag extractors that you say don't work? If I stick with a smaller machine I can keep the flexibility of my workshop and move the extractor to the machine / workstation with very short pipe runs (around 1.5m) as I do now with the aptc one pictured above.