Down Draft Table

Any one using a down draft table for sanding? After a bad reaction to MDF dust I'm interested in checking these out. If you have one :
1) Does it do a good job keeping most of the dust outta the air?
2) What brand/size are you using? Would you recommend it?

Any help appreciated!

Thanks,
Mark

YES! I have a brand X, and we just keep it on all day so it acts as a general air cleaner as well as downdraft table. Our is pretty big...two sanding stations face to face on it. 220 volt motor, must be at least 1 1/2 hp. I have another that I need to finish up, and it will go full time as well. My machine dust collection is woefully inadequate...for now.

Yes. It is one of my favorite tools in the shop, because it allows me to use the tools in my shop. I leave it running often as a general air filter. I built it, and can share details, and pics at another time. I used a CanFan Max 12" fan, which moves 1700cfm at free air, and still around 1000cfm at 3WCI. It is a serious fan, and very efficient at only around 5 amps, I think. I have not seen any commercial offerings that even come close. It works very well. I use this in conjunction with a festool HEPA vacuum extractor hooked up to a Hutchins pneumatic sander with vacuum dust extraction. A respirator is not necessary at all. I used some 1" speaker damping material with a layer of some sort of damping mat to make it quiet. The first layer of filtration is a removable 200 micron filter screen, under the work surface. The next layer is 2 large industrial 85% Ashrae V-bank filters. It is designed for a final layer of overhead HEPA filtration, I have the filter, but have not yet built it in. The thing runs probably 3/4 of the time when I am in the shop, definitely if power tools are running. I blow the pre-filter out about every 2-3 weeks, and then it is not plugged catastrophically. The V-bank filters are not even beginning to load after 6 or 7 months. The first couple of years I used lesser filters, and still really liked this thing. With the industrial filters, it is the 'bees knees'. 1200CFM of HEPA filtered air in the shop is quite welcome. I thought about this system off and on for several years before building it.

I think a budget of $1500 could duplicate it, assuming that the source I got my filters from still has some. They are surplus industrial filters I picked up for about $100 each. Otherwise they are about $350 each to have made. The fan is about $350.

Yes, one of my favorite tools...

Here is a pic of another filter unit that is to be my tablesaw outfeed table, works with similar concepts/ parts. You can see another one of the fans, and the filters, and the damping material on top of one of the filters.

The design of the cabinet for the downdraft table is kind of like a folded horn speaker cabinet.

I will shoot a pic of the downdraft table in the next day or so.

Not sure how true but I've heard MDF dust is carcinogenic. So are burnt sausages though..............

Rick & Chris,
Thanks for the info. It's time for me to do something in this regard. I have a more than adequate dust collection system for my big power tools but nothing for sanding/routing and it seems that downdraft is the way to go. Chris, if you could shoot a pic of your working unit I would appreciate it. Sounds like a serious system. I was also glad to learn that you both basically run it when you're in the shop whether you are sanding or not. It's a practice that I will replicate.
Thanks,
Mark

PS: Liam, I'll stay away from MDF but can't promise to lay off the burnt sausages. I like a little "char" on my meat...

Re. the Festool vacuum cleaner...aka dust extractor...get the Oneida Dust Deputy cyclone accessory for it! It drops a good 95% of what is sucked up into a plastic bag in a bin that mounts on top of the Festool thingie. And then lose the tiny Festool hose which just gets clogged all the time and use a regular shop vacuum hose into the cyclone.

http://www.oneida-air.com/inventoryD.asp?item_no=AXD000009&CatId={6EE79B16-EB63-43E7-8F30-1E06240A24A4}

I just got a dust deputy for father's day - can't wait to get it all hooked up.

I have seen a simple one built by George Von Driska at WWGOA (Wood Workers Guild of America). It is basically a box with a top of pegboard, a vacuum hose slot, and adequate supports to keep the top flat, but allow dust collection. He may have something up on the site.

Anne Flynn

I'm all for simple solutions. I made one a couple of years back, see it here

http://argapa.blogspot.se/2009/02/dust-e-whacker.html

I use a good half mask as well most of the time. The dust evacuation gizmos help me from getting the workshop banned from the apartment.

I like concepts like this, but haven't tried it:

http://www.leevalley.com/US/wood/page.aspx?cat=1,42401&p=65482

The Man who invented the "Vacuum Cleaner" started off with a fan and a pillow case

The most basic rule of dust collection is to catch it as close to the source as possible. If you have to clean the air, you haven't done it right.

Practice what I preach and don't visit my shop 'til next year, though...my dust collection is totally inadequate right now with the wide belt sander being the biggest problem. 3 hp with two double bag filters is not sufficient. I need to more than double that.

Mya moe uses one.

http://www.youtube.com/watch?v=N3VuJuMPhbc

Yes, and it is my favorite "tool" in the whole shop. We do all the router work here except for work down on the router tables. We also do all the body sanding and some polishing of plates during the thickness sanding step.

The top is off, guess it is not ready for cleaning.. The prefilter is made with 200 micron prefilter fabric from American Filter Fabric.

Here is with the prefilter removed. There are 2 85% ASHRAE filters rated at 2150cfm @ 1" each, plenty of room for loading without reduced airflow. These are the exact filters used in clean rooms to protect HEPA and ULPA filters.

Close-up

and back to work again... This is still a work in progress. I wish I had about 6 months to do nothing but dial in my shop, but... I do it as I can. The opening in the face of the unit is for a drawer to hold routers, other tools. There will be an air manifold above for sanders, polishers, and for the pencil grinder. The fan is built in under the drawer.

The air is sucked through the work surface, filtered, and exhausted through a flue in the back. The V-bank filters are accessed though panels in the sides. I have not needed to pull them out yet, the pre-filter works great.

Here is the ULPA filter that will go directly above the work area. ULPA is a step beyond HEPA in efficiency. Most woodworking filters get the nuisance dust, if that, but the really nasty stuff, most of them do not touch that size dust. It basically stays in suspension in the shop 24-7, especially with any agitation. Some of the nastiest of the small particles are fragments from fancy abrasives like Abralon, and Trizact. super micro, and sharp, and probably slow to break down in the lungs, if at all.


Still lots of work to do..

This table works great. Sanding dust does not escape. It is quiet, because of the amount of damping material in it, and because of the design of the air passages. It is like standing in a gentle, clean, wind. When it is complete, it will not work as well as a whole shop filter, which is the reason for the other unit that will be the table saw outfeed table. That one will be ducted on the ceiling above all the work stations, HEPA air curtains above all the tools, work spaces, with blast gates to be more specific with where the clean air goes. And yes, collecting dust at the source is the first step. In my experience though, I have never seen a straight up dust COLLECTION system that can manage all the dust created in a wood shop. I also have a large spray booth fan that can evacuate my entire shop, separate from my spray booth. When major milling operations are happening, that fan runs, as well as when I sweep the shop, or blow everything down.

Chris,
WOW! Thanks for the info and photos. That is a heck of a system. That combined w/your Festool system probably keeps your shop as dust free as possible when sanding. You've given me lots to think about. Thanks.
Mark

Rick, Chris, et al
Been pricing stuff today and it does add up, but is necessary. I already have a JET Air Filtration system having off the ceiling of my shop. I have done more research on the net and contacted different vendors/manufacturers. Based on your input and what other info I've picked up I am leaning towards getting the FESTOOL Dust Extractor w/Oneida Dust Deputy Accessory and using the FESTOOL Random Orbital Sander for my sanding needs. I can't afford this AND a Down Draft Table right now and am thinking I will get the best dust protection for my money this way. Do you concur or would you recommend getting the Down Draft Table first?
Your input if really appreciated. Thanks,
Mark

Mark, I think I'd go with the Festool dust extractor + the 5" RO sander first. It's that "capture it as close to the source as possible" thing, and you can't get closer than the holes in the sanding pad. Then you could get one of the really simple down draft accessory tables as per Woodworker's Supply or Rockler...they go on top of your bench and can be attached to a small dust collector.

the Festool dust extractor is a great place to start, and if you have enough compressed air, forget the electric sanders, go pneumatic. If you have to go electric, the Festool RO125 is decent, possibly the best electric sander (small random orbital) on the market.( I have not touched mine for about 4 years now since going pneumatic, and often think of selling it. The only reason I do not is in case I need to sand somewhere else.) Then a decent dust collection system for tools. The little downdraft tables are pretty much irrelevant if you have the Festool thingy, because the dust collector is just going to throw what it collects back into the air.

Just the festool setup will be a quantum leap for you.

The Dust Deputy works great also, I do not use one, but the shop next door does.

Agreed re. air sanders. We use 'em. They last forever, and they deliver a lot of power in a small package.

Also, if you're going to do a lot of sanding, get vibration damping gloves like serious bicycle riders use. They have gel inserts that keep your hands relatively vibration free, thus helping to prevent "white finger"...which is a precurser to permanent nerve damage.

Here are some: http://www.superiorglove.com/work-gloves/anti-vibration-gloves/half-finger-anti-vibration-gloves

or:

http://www.drugsupplystore.com/serv...T-dsh-Glove-Vibration-Dampening-Gloves/Detail