downdraft sanding box

[Helen Gee]

Hi guys,

I'm trying to put together a downdraft sanding box so I can continue with some projects that require hand sanding. The problem is that I don't have a real dust collection system yet, I have the festool 22 vac and a shopvac.

Currently I have built the box carcass, it's 6x24X36. I was thinking of making the inside part of the box with angled sides for the funnel effect through the hole? But with the vacs I have, it seems I don't have enough cfm to get a good uniform suction going if I place the dust port on the long side of the box. I was thinking of attaching the hose directly to the circle opening?


Is that the best way to do this? I'll make something with a better design in the future, but just want to get moving on some of my projects . Thanks for your help!

[tod evans]

helen, in my opinion a downdraft table powered by a shop-vac is a waste of time. are you trying to keep the mess down, or are you working with some type of exotic that is causing you to have a allergic reaction? can you work outdoors to solve either problem? if not a simple box fan blowing fresh air on you would help with allergies......just some thoughts....02 tod

[Helen Gee]

hey tod! yeah, i kinda had that feeling after we were doing some tests with the peg board on top . I'm trying to keep the dust down because the fine dust is causing all sorts of bad allergies for me. Hmm...didn't think of the box fan, but that's a great idea :-D, we have a few lying around too.

[Frank Chaffee]

Helen,
I’m with tod in thinking that a downdraft table won’t work until you have your full blown (?), cyclone system in.

Re: the box fan idea, I have rigged that many times when welding. What I found most effective was to have the fan pulling air away from me, especially 90° to the side. That way air (dust), does not wrap around one and blow right in one’s face.

Could you set a sanding table with box fan blowing air out the entrance door of your garage/shop, and open the overhead door a few inches for fresh air supply? The doorway above and below the fan could be blocked temporarily with cardboard. You would stand to one side of the table to work.

[tim rowledge]

Helen, I have a downdraft sanding area built into my bench, covering a slightly smaller area than you're aiming for. Even with a 3hp Oneida DC pulling through 7" pipe it doesn't get all the dust on typical sanding jobs. A shopvac is almost certainly not going to do anything actually useful for you.

What *might* be a workable temporary solution is to use it as a very local suction source. Make a funnel - say 8-10" sq at the mouth - to attach to the shopvac hose. Find a way to prop it up right where you are sanding and it should get most of the nasties. I use something like that when sanding away from my bench.

[Helen Gee]

thanks Frank and Tim.

Tim, I've been doing that right now Clamping the shopvac hose to the source, I thought it'd be fun to build the sanding table as a project too but it's really probably time for us to upgrade to a real dust collection system

[Joe Chritz]

This is about that size. http://www.sawmillcreek.org/showthread.php?t=29795

About half way down the thread. It is hooked up to a 3 HP Dust Gorilla and it works pretty good. Not sure if the angled sides help at all but I figured they can't hurt.

Joe