Thread: Questions about a Hafco DC-45

Ignore my thread, I found all the answers except for the plastic bag one by reading 30 or 40 of the dust posts.

BobLs dust measurement thread is first class. I loved those graphs.

Shame I don't have more room and budget for a clearview! Maybe later.....

[QUOTE=Evanism;1748570] can one clean the pleated filter by blasting it with some compressed air from the outside in?[QUOTE]
Nope plus there is a danger you can put holes in it. Just a light beating with a paddle is about all you can do from the outside.

should I toss the filter and buy a new one? Essentially treating it as untrusted...

A new one will be more porous and need clogging up or conditioning (put a bucket of fine sawdust into the DC and running it in ordinary air for 3-5 hours) and let more dust through until it is conditioned. But without a particle detection you can't test it.
Having a spare is handy so you can change over and clean the other at your leisure (not that there's anything leisurely about it)

the clear plastic baggies that sit underneath are pretty to watch, but is there a logic to them? (other than to see if its full) Is there any reason I couldn't just use the thick black garbage bags?

Thick is important because plastic bags are a major source of leaks, a sharp wood chip rotating around and around inside the plastic bag may generate lots of pin holes from which fine dust will escape. If they bags are not the right size and are too thick the seal around the bag housing will be compromised and leak. Some of the worst leaks come from this source.

bobL might (!) know, but is 1 micron of filtration fine enough?*

"1 micron filtration" is a meaningless statement because no filter works by 100% filtration of the particles bigger than a certain size lets through everything smaller that the rated filtration number
Also as all filters clog their filtration improves (but their flow rates drop).
The missing piece of info is what % efficiency the filter is filtering at 1 micron.
A calico bag or cheap dust mask may have 1 micron written on them but only be filtering 10% of particles smaller than this. may only be filter.
The thick needle felt bags that say they are one micron rated are, once conditioned, typically 99% efficient below 1 micron the thinker needleflet bags are about 90% efficient.
(90% sounds good but it's actually not that good especially if you make a lot of sawdust.
Remember collecting 90% of 10,000,000 germs still leaves behind about 1,000,000 germs
A hospital operating theatre filter will be typically rated at 99.95% at 0.3 microns or greater.

I'll be building a cabinet to sit it outside at some stage.

Do it.

* I ask, as I've read a few of his posts and it seems that the very air we breathe contains a fairly significant count of particles bigger than this. It would seem that running the machine for a while would seem a good way to clean the air...assuming the filter is trustworthy.

Except for really cheap filters the filters themselves are not that much of a problem - the elephants in the corners are "leaks" - which is why DCs should be located or vent outside.

BobL, as always over and above.

I have a small group of woodwork friends here and we talk about these kinds of things all the time. Big clearviews, cyclones, outside extraction, etc.

There is always such a massive competition where money should be spent: food, school fees, tools, dust collection.

While I will moan about these things in humour, I think we all understand we should do as much as we can. We certainly don't want to be coughing up a kidney in 15 years and saying "I coulda/woulda/shoulda".

BobL, I still recon we should put together a 20 page summery of all your posts and wisdom and sell it on the forum for $10. Help raise money to make it a better place.

One day I'll get a whizz bang cyclone....but my crappy 1hp 600cfm 4" unit with a pleated bag will have to do...dreamin.....dreamin....

Originally Posted by Evanism

BobL, as always over and above.

Some folks call it anal retentive

I have a small group of woodwork friends here and we talk about these kinds of things all the time. Big clearviews, cyclones, outside extraction, etc.

Sharin' the luv eh? good stuff.

There is always such a massive competition where money should be spent: food, school fees, tools, dust collection.

There sure is - the practicalities are always there. The more well off folks are the further their horizons seem to expand so it appears than more money doesn't solve the problem either.

[QUOTE]While I will moan about these things in humour, I think we all understand we should do as much as we can. We certainly don't want to be coughing up a kidney in 15 years and saying "I coulda/woulda/shoulda".[QUOTE]
there are lots of little things that can all contribute; like, regular cleaning up, ventilating the shed with open doors and windows, using dust masks, avoiding stuff like MDF, using hand tools instead of machines. more careful use of machines. How many sanders are being used to clean up material cut to too rough a size by other methods. A small block plane generates far less dust than a sander does when tidying up edges.

BobL, I still recon we should put together a 20 page summery of all your posts and wisdom and sell it on the forum for $10. Help raise money to make it a better place.

Sure but then what I would post about?

I will write something sometime. I have a heap more testing I want to do (especially related to what happens over time) but I need to do some woodworking to generate a reasonable amount of dust and I'm just not in WW mode at the moment.

One day I'll get a whizz bang cyclone....but my crappy 1hp 600cfm 4" unit with a pleated bag will have to do...dreamin.....dreamin....

8 years ago I started out with the same thing, within 2 years I had a 2HP and then in 2011 I got a 3HP. I don't do enough WW to warrant a cyclone at the moment. I may build one some time to play around with it - so many potential projects - so little time.