Show me your DownDraft tables

[kartracer63]

Hi Shopbotters,

The cedar sawdust in my shop has become a problem. It's now creating health problems and I need to take some steps to greatly reduce the airborn particles.

I believe the largest source of my problem is the sawdust created while sanding my signs with my random orbital sander. There's so much dust created that it plugs up the filter in the ceiling mounted air filtration system in just a few minutes of sanding.

I do wear a respirator while sanding and for a while after sanding. It's still a huge problem.

I'm thinking that I need to build a downdraft sanding table. My thoughts are to buy a 1½hp Jet Dust Collector (1100cfm) with the canister filter (for easy clean-out) and hook it up to the downdraft table. I think this would greatly reduce the amount of sawdust in the air.

I'd like to see your downdraft tables for design inspiration, and hear any thoughts you might have that could help my situation.

Thanks!

[dlcw]

Hi Eric,

I use cedar all the time in my shop. The way I get around the dust issue is to hook a good strong shopvac (Fein) to the sander itself. Make sure your ROS is set up for good dust collection also.

I also have a three air cleaners going but 95%+ of the dust goes right in to the shopvac. I've used downdraft tables and they work pretty good. My big problem is floor space. I'm out of that commodity in my shop. They are pricey too.

If I'm doing a bunch of hand sanding (doesn't matter the type of wood), I will set up a simple fan (with a stand on it) near one end of my bench and a portable air cleaner, on a stand, at the other. Dust is blown away from me by the fan and air cleaner sucks it up. Works great.

[adrianm]

I used to use a commercial downdraft table but in the end I found I got better results by attaching a workshop vac to the outlet of the sander and putting one of these (http://www.poolewood.co.uk/acatalog/Dust_Air_Cleaner_Microclene_MC100.html) on the bench behind the piece.

In conjunction with the ceiling mounted air cleaner that setup does the job for me.

[srwtlc]

I haven't made anything yet, but plan to when I get moved into a new shop. I've got a couple of 220v furnace squirrel cage blowers and my thought is to make a large table with a several furnace filters under the surface or some dust bag material of sorts on frames. I've also seen some tower type setups with furnace filters around the sides.

[michael_schwartz]

Your going to need to find a blower, that will work well with your choice of filters.

Box fans for example might work with an economy grade furnace filter, but my guess is that you want something better than that. If you use a high quality filter, you may burn up the fans. Don't ask me how I know this.

If your going to build a downdraft table that gets connected to a central dust collector, I would not use anything less than a 6" port, and that would be for a small table. I tried, building one with a 4" port, and it didn't work.

[knight_toolworks]

As others have said the best way is getting it while it is coming from the sander. Investing in a festool sander would make a huge difference in catching the dust and it will sand better too. they can be pretty much dustless when doing face work. of course you need a vacuum for it.

[dana_swift]

I thought about building a downdraft table, then thought.. why not come up with something out of stuff lying around?

So.. I rigged up my hanging "side drafter". Works just as well as a downdraft and I can hang things up while I sand them, or put them on a table and lay my pvc assembly down next to what I am sanding. Turn on the DC and walla.. dust starts singing "I'll fly away"..

http://www.talkshopbot.com/forum/attachment.php?attachmentid=15405&d=1337632143

Putting a hose directly on the sander is also a good idea, but it makes moving the sander around a real nuisance. So I just use my PVC approach, and add a dust mask to be on the safe side.


D

[jim_vv]

Greetings, Eric

I agree with Don. Connecting a Shop Vac to your sander will do the trick. I placed a mini cyclone in line which keeps the vacuum's filter from plugging up. I hang my hose from above the bench so it is never in the way. A nice feature I enjoy is that my Fein vacuum is turned on an off by the sander. I also have an air filter hanging overhead in the shop.

Kind regards,

JIM

[Ajcoholic]

For years, I too was against using a sander with a dust shroud, and holes in the pad. Every sander I bought, I'd replace the pad with a solid one, and live with the dust.

The past few years, I have begun to think more about the amounts of dust inhaled, and what it will do long term.

Once I started using a sander with a dust collection, started buying the right perforated paper, and actually used it - the small inconvenience of having the vacuum hose became second nature (I use small velcro ties to bundle the vac hose and power cord) and in no way in my way.

Sanding got better, faster and I can sand without a mask (a plus when its hot and humid).

A down draft table would be nice, but with the right sander, and a good quality vac (that's not too loud) you are good to go.

AJC

[dlcw]

I've been at this woodworking gig now for over 40 years. I know I've inhaled enough sawdust and finish fumes to cause me some decreased lung capacity.

I decided about 12 years ago to start working smarter and not harder at this gig. I have dust collection set up on every machine including hand power tools that will take dust collection (sanders, biscuit jointers, etc.). If a hand power tool will take DC I won't buy a version that won't take the DC hookup.

I figure I have at least reduced my lung deterioration to an acceptable level more in line with the expected life I have left. At least when I go to feed the worms and the daisy's I will do it breathing under my own power. Don't want COPD if I can avoid it.

[kartracer63]

This is all very good information guys... thanks!

So, it sounds like the downdraft table could be part of a solution, but not on it's own. Dust collection hooked to the sander sounds like the most popular answer.

I've got a couple more questions while we're at it.

@ Michael Schwartz, Why do you think the 4" ports didn't work on your downdraft table?

@ Dana, Do you think a 1100cfm Dust Collector would support more than one of your PVC set-ups. Say for instance, one on the back side and one off the end on the work bench I'm currently using to do my sanding? Do you think I would need a downdraft table if I had your set-up?

@ Don and AJ, Much of the sanding I do on my signs is done on the edges before I apply my paint. From your experience, with a dust collector attached to your sander, will the dust collector still collect the dust particles while only using the outer portion of the sanding disc? (similar to attached photo)

For everybody, If I purchased a quality sander with dust collection (say... Festool for example), do you feel the downdraft table would still be helpful used in conjuction with the sander/dust collector? Or, does the dust collection hooked to the sanders work so good, I would be wasting my time with the downdraft table?

Thanks again guys... you're the best!

[michael_schwartz]

@ Michael Schwartz, Why do you think the 4" ports didn't work on your downdraft table?



I had a single 4" port. I had drilled a grid of holes measuring approximately 24x36, and it just wasn't enough CFM. I ended up sizing the holes so that they were rather small so that I could enlarge the grid, and I am sure that introduced a ton of friction loss. A 4" port could work, if a table were appropriately sized. I think at this point, a universal shroud, or miter saw dust hood would be more effective. It would be small enough to be work, and you wouldn't end up covering it up with the work piece. Better yet, setup a shroud with a 6" port, and it might work pretty well.

In a best case scenario 4" pipe, not hose will allow about 300-400 CFM Max, depending on the velocity. Step that up to 6", and that increases, to 600-900 CFM, doubling the airflow. Hose, and any 90 degree bends add allot of friction loss. Charts that show more exact numbers can be found from most suppliers of duct collection systems, and fittings.

[jTr]

Upon connecting your sander to a pro vac such as festool, seems like 95+ percent of the wood flour is pulled away when sanding conventionally with pad fully engaging the work piece. No more cloud or haze in the air. Once you do it, you'll never go without - it really is a dramatic difference. If you are sanding irregular shapes, it's kind of like your bot - you're stepping outside optimal zone.
Also worth noting: Sander stays cool, which may extend tool life.

jeff

[Bob Eustace]

As others have said the best way is getting it while it is coming from the sander. Investing in a festool sander would make a huge difference in catching the dust and it will sand better too. they can be pretty much dustless when doing face work. of course you need a vacuum for it.

The Festool rotary/orbital is simply the best money can buy when hooked up to Festools vac with HEPA filter. Tried the torch test at night which revealed just about zero dust escapes. Festool uses a unique airflow system. It easily replaces your belt sander, orbital and disk. Only drawback is its the dearest thing money can buy. An unbelievably fantastic product!


http://www.youtube.com/watch?v=JrQ_X42_9i8&feature=youtube_gdata_player

[dlcw]

My ROS setup is a 5" Rigid with vacuum hookup and a 6" Ryobi with vacuum hookup. I opted to not pay a huge sum of money for a Festool with the same results. I can buy 3 or 4 Rigid or Ryobi's for the price of 1 Festool.

To answer your questions about edge sanding, I do the inexpensive fan on a stand at one end of the bench and air cleaner at the other end. Works great and I inhale no dust at all.

[Ajcoholic]

ERic,
I find sanding edges also catches a lot of the dust. MAybe not all of it, but I always sand over a piece of dark brown or gray carpet. I can see how much dust falls on the carpet and it is negligable.

The nice thing about Festool is the 30 day (full return, no questions asked) trial period. If it doesnt do what you need it to do, you can always return it.

Also, down draft tables need a lot of airflow at a low velocity. That means large diameter duct work.

AJC

[dana_swift]

@ Dana, Do you think a 1100cfm Dust Collector would support more than one of your PVC set-ups. Say for instance, one on the back side and one off the end on the work bench I'm currently using to do my sanding? Do you think I would need a downdraft table if I had your set-up?


Regarding your question: My CFM is only supposedly slightly higher that that, so you will probably get results you will also like. For certain its trivial to rig up and just try it. You could make 2 and set one on each side of what your sanding and I suspect it would still work nicely. Nothing says you cant do the PVC rig and use a downdraft table also. It isn't going to eliminate any options!

I came up with my rig when I was thinking about building a downdraft table on the bot. It works well enough I have never bothered. Im not saying its perfect, but its very flexible. Who knows- someday I may still make myself a downdraft table also.

I like all the festool recommendations, I can see that would be a good tool to add. This forum has lots of "what works" ideas in it. So festool will make at least one more sale.. :)

D

[CNYDWW]

Eric, Have you considered investing in an oscillating spindle sander? Even the cheap ones from harbor freight come with built in DC for a shop vac or small collector. I've got one of the HF ones and i use it constantly. Goes down to 1/2" radius and all dust is sucked under the spindle and out the back. Use that as an initial sanding then finish with the hand sander. Should be faster as well. I end up doing a lot of what i've attached. It requires a great deal of edge sanding.

Regards
Randy

[dlcw]

Great idea Randy. Rigid also has an inexpensive oscillating edge sander/spindle sander combo. This also has DC built in. I use it A LOT. It is a great little tool.

[kartracer63]

I've already got the Rigid Drum Sander. It really won't work for my signs because even the 1/2" drum is too big for many parts. Plus, I put a champher on the edge all the way around the sign that needs to be sanded.

But, it works great for sanding the edges of my cribbage boards.

Thanks,

[steve_g]

http://supergrit.com/products/products_metalworking-flapwheels.asp

A 10" X 4" flap wheel makes quick work of irregular edges for me...

SG

[Brady Watson]

Have you considered a Trend or Triton respirator helmet?

-B

[kartracer63]

I haven't looked at those yet Brady. I like the Trend helmet better than the Triton.

Thanks for the idea!

[steve_g]

OH BOY! I've been wanting to do a review of the Triton respirator helmet for some time now... I'll make it short. Don't waste your money! It delivers enough air to sit and watch your CNC operate... just don't try to do anything else. you'll find yourself panting for more air and flipping up the face shield... defeating the purpose of the unit.

SG

[myxpykalix]

"you'll find yourself panting for more air and flipping up the face shield..."

Steve I hope this wasn't a "gift" from your wife? Maybe she is telling you something!! lol:rolleyes:

One of the issues i've had with faceshields is that if you exert yourself too much your face gets hot and the facesheild tends to fog up. How do these sheilds keep the temp the same inside as out to keep that from happening?:confused:

[steve_g]

Jack
The Triton unit goes on like a divers helmet, air is piped in from a fanny pack battery/fan unit. The theory is that a constant supply of air will never let the humidity develop. I don't remember if the shield fogged... I didn't use it long enough to remember. By the way... I have a slightly used unit for sale cheap. HA!

SG

[ssflyer]

If you want to get really fancy, how about a Survivair fresh air system? :)

A painting contractor friend traded me his twice used system he paid ~$1400 for. Here's a quick synopsis:

Survivair supplied air fresh air system with one full face respirator. Complete system, includes: 1/3hp oilless air pump (most have 1/4hp), blue silicon double seal full facemask, 50' lightweight air hose, belt, strap for mask hose, and mask hose. Fully filtered air for painting, sandblasting, etc. - wherever you need fresh air to breath!

I don't know if anyone here would be interested, but I just posted it on craigslist for $500.

[steve_g]

1/3hp oilless air pump

Ron... did you not like the system?
It actually sounds like it has a chance of working...
I've attached an image of the little squirrel cage fan in the Triton. It has to pull air in through a filter push it through a HEPA filter, up a 3' hose and into the hood...Never had a chance!

SG

[ssflyer]

Hi Steve,

Actually, the system works great. I traded for it when I thought I was going to build a spray booth - never did... :rolleyes:

I've used it a few times, and it works very well. In particular, when surfacing my MDF spoilboard! I simply don't use it enough to justify keeping it vs buying new toys! :D

It definitely supplies enough air, and since it is a continuous supply, little to no fogging!

Here's a few pictures of it.

[bob_s]

take a quick look at the google search "fine woodworking power tool workbench plans" they designed a bench to be used with an inexpensive shopvac and mini cyclone built in - looks very interesting as they even thought about keeping the vac house supported while you work.

[mikek]

I built a simple box (2' x 4' x 4" to 6" high) and put some pegboard on top with a 4" connection for a dust collector and it sucks pretty good. If you have a bag or vac on your sander and a good dust mask it gets a good amount of the created dust. You can see the 4" connection in the top of the picture. The box sits on most any table. I use the rubber drawer liner material with holes in it to isolate the pegboard from finished parts. It also keeps things from sliding around while sanding.

[michael_schwartz]

I was digging around woodweb and I found this. It also doubles as a spray booth for non flammable finishes. Credit goes to Kerry Fullington.

http://www.woodweb.com/cgi-bin/forums/shopbuilt.pl?read=702170