Building Your Own Downdraft Table

A few tips on building a downdraft table for sanding dust collection in your shop. June 15, 2014

Question (WOODWEB Member) :
I am wondering what you all would recommend for a downdraft table? I was wondering if there was a company that had just a bare table - I would supply the dust collection.

Forum Responses
(Dust Collection and Safety Equipment Forum)
From contributor U:
If you are supplying the dust collection, why not build your own table? I have seen a few plans around on the internet and in certain shop books. I don't do a huge amount of sanding, but after looking at the cost of tables, I built one and use my dust collector to pull the dust through. Mine is about 24" x 60", 2 x 4 frame box with plywood sandwiched top and bottom. The box stands on four legs at a comfortable working height. I drilled a series of holes into the top, and connected the 4" suction line to one end. I sealed the box with caulking. If my shop layout was different, it would pull better with the suction at the center of the table, instead of at one end. I get a strong pull on one end and weaker the farther away you get from the suction. I only drilled an area 18x32 in the middle of the table to get the strongest pull. Too many holes will cause a poor draft. Experiment and you can get pretty good results.

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From contributor D:
Build a box like Contributor U says, but put the input in the center of the bottom of the box. Also, more and bigger holes equal less velocity, but more total cfm. Fewer and smaller holes equal higher velocity at the hole opening, but lower total cfm for the table. If this does not make any sense, think of your house AC: if you shut all the vents but one, the one open vent might blow your hat off, but the cfm moving thru the AC unit itself will be greatly reduced.