Every time I walk by a bin of MDF the availability/uniformity/price are tempting but: I have a dust shoe on the burly which does a reasonable job with wood chips but I doubt it adequate for cutting MDF. I’ve watched some videos of homemade shop air cleaners that were basically a window box fan pulling air thru one or two furnace air filters. I was wondering if anyone’s ever tried an enclosure with that set-up on one side and air entry holes on the other used in conjunction with a dust shoe and whether it makes cutting MDF tolerable indoors? Or if there’s a reason(s) that make the idea a non-starter?
The other way to make an air cleaner, which I plan to make is to use an old furnace blower motor, which makes more sense than a box fan.
Probably because I’ve never machine cut MDF I have no idea how bad the fine dust issue really is. I don’t believe I’ve seen an enclosure built that way and just wondering if there’s a downside I’m overlooking? If MDF dust is the issue it seems collecting it as close to the source might be a good thing but I’ve had what I thought good ideas in the past that had holes poked thru them. Just thought I’d invite comment from devil’s advocates.
I drilled holes for screws into my spoilboard. 48 holes. Sooooo much dust. Never again. -_-
Catching the dust at the source is always (in my experience) more effective then trying to clean it after it’s escaped, hoping to be caught by the air cleaner before it bothers to settle on every surface of your shop or your lungs.
I’m not getting why MDF dust would be harder to suck up in a shoe vac than chips.
Exactly what’s kept me from MDF. But from what I see the $$$/quality ratio of wood doesn’t seem headed towards the consumer’s favor.
What I meant was, in addition to the dust collection at the source, as some will always get through, having a furnace blower moving air through filters to do the last bit of air scrubbing will likely work better than a box fan.
I throw on a mask when I am making more than one or two cuts in mdf.
No experience yet but from what I read the dust is so fine it may be getting thrown beyond the range of the dust shoe to collect it.
Without some type of “second stage” (like a cyclone or thien baffle), the fine MDF dust very quickly fills and blocks shop vac filters, lowering suction, negatively impacting collection. From there it’s (@vicious1 - no disrepect intended) a vicious cycle.
Since I can’t justify a 5+ HP blower and super-tall cyclone, I’m planning a belt-and-suspenders approach, central dust collection (HF, Wynn filter, Thien baffle) with drops at major machines (table saw, CNC, sanding bench) plus a furnace blower air scrubber, (probably built into a cart that can double/triple as an assembly table and table saw outfeed) for the stuff that gets missed by the dust collector.
And a mask. Does that make it belt, suspender, and cummerbund?
I think it may make decent plywood my plan for a while.
Belt & suspenders on overalls… And there’s no need to bring Bandersnatch Cummerbund into the conversation.
My own dust collection journey FWIW:
- Buy a house with a garage after apartment living
- 0.2 seconds later buy a table saw to do all those projects you thought of in that apartment
- Cut some MDF
- “Ewww that’s gross” you think as you track a cloud of MDF dust into the new house
- Buy a Jet overhead air filter since that’s cheaper than a dust collector and takes less space
- Cut some MDF
- “Well that didn’t do much” you think as track MDF dust into the house
- Buy a dust collector with one of those overpriced pleated filters to catch that fine dust
- Connect the dust collector to saw and cut some MDF
- Think “Wow, that’s a lot nicer” as you track a lot less dust into the house
- Start using baltic birch instead of MDF
- Happiness (as you track some birch dust in the house)
Of course you spend a fair amount of money along the way there, more than a lowrider/mpcnc to begin with, but that’s where I’m at. Don’t need a full dust collector for a MPCNC though. Fair points about vacs quickly getting clogged, but I’d rather it clogging a vac than my shelves, etc. No regrets on the air filter, but I wouldn’t do that 1st.
Shop vac filter life will benefit from a second stage built from a couple of 5 gallon buckets and some pipe elbows or a “dust deputy” size cyclone. Lots of examples on the interwebs.
My burly’s in a back room that’s half TV room/half shop space. I haven’t done any multi-hour projects yet but with feeds/speeds producing chips rather than dust and a dust shoe, it’s quite tolerable. And I do like it being in an air-conditioned room rather than the un-air-conditioned garage. I think MDF use may be off the table for a while.
<dust collection rant!>
: Why no dust collector needed on the MPCNC?
My workspace is a room IN the house. I have (in order of effectiveness) a surprisingly similar setup to @Tuco with added goodness :
A P# respirator which I try to wear at all times when creating dust.
A 2HP dust extractor with 6" ducting to each machine. (The extractor and it’s filter are outside in a small lean-to built to house them. After years of having it inside, it’s a pleasure not to have to deal with the extremely dangerous and not to say messy superfine dust that lingers for hours.)
A shop vac with direct connection to smaller machines, sander etc.
Two 10" fans which extract air directly to the outside @abut 100cu ft/minute (leave them on for a couple of hours AFTER whatever dust creating operation).
A Jet filter which is also left on for a minimum of two hours after leaving the room.
A Damp cloth to wipe down all surfaces every so often because the above isn’t all that effective with the superfine (and dangerous) fine dust - the stuff you notice on horizontal surfaces the next morning.
There are many places on the web where you can get specific information (as usual be careful much of it is wrong) start here if you have nothing else to do for the next year or two: http://billpentz.com/woodworking/cyclone/index.php#index.php
So what have I achieved? - I have a reasonably clean space, and don’t track too much dust into the house.
The fine dust from MDF is VERY difficult to control and with my imperfect setup, I am going to say impossible to eliminate entirely (see 5). Apart from the mess, like many people I am hypersensitive to wood dust (Yes, I need another hobby).
If tracking dust through the house is not a problem for you, just wear a respirator and you’ll be fine.
If you want a really great mask that actually works and is light and comfortable to wear - here’s what I use:
</dust collection rant!>
Do you find fine dust settles on things overnight?
My workspace is used for seriously dusty stuff so it’s a bit different in that respect (the router is not terribly forgiving dust wise) - But I haven’t considered building the MPCNC without a full enclosure.
Do you have any issues with dust in the AirCon return air filters? I am a bit cautious about that (see above!)
Keep in mind I haven’t done any long, involved projects yet so this is with a grain of salt but, trying to make chips rather than dust seems to help and I wouldn’t say I’ve noticed more dust than the seemingly unavoidable from a forced air system and no issues with the return filters, some sawdust escapes the shoe and may end up on the floor but is easily vacuumed up. . Of course heavier use may change that but so far it’s not been too bad, even cutting foam seems easy for the dust shoe to control.
It also helps to not cut mdf in the house. They sell dust deputies at menards if you have one close. The home depot thing doesn’t work near as well. I change my shop vac filter once a year now.
I did build a big harbor freight modded two stage vac system, but still haven’t plumbed it into the shop…