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Sawdust and sanding dust have always been a problem for me but lately they really aggravate my allergies. I had been looking for ways to minimize the dust in the shop including an overhead shop air cleaner but after giving it some thought I realized that a downdraft sanding table can offer a solution for at least three applications; sanding, shop air filtration and as a base for a spraying setup.

I was fortunate to find a 1200 CFM furnace fan w/ 1/3 HP motor for sale on the local Craig's list for a very reasonable price and the pieces began to fall into place. I did some homework looking at the various systems on the woodworking forums and also at the professional setup that Joe White has in his shop.

I really wanted the top of the table to be open grating to accommodate as much airflow as possible and sturdy enough to take some weight. I didn't feel like drilling hundreds of holes in masonite or plywood and started looking for some fiberglass grating that would fit the bill. As luck would have it I was walking down the aisle at the local borg when I saw that they had a special on storage shelving. The shelf sections were 24 x 36 with about 1 1/2" depth that was rated at 150 lbs. load.... Ah-hah!! This was exactly what I was looking for and would do well for the open grated top for the table. Besides, the unit was 5 shelves and I would end up with 4 spares...

I increased the pulley sizes to bring the CFM up to 1500 and made the table over the last few days. I wired it up yesterday and WOW... works great.... excellent air flow and I get an air change in the shop (my insulated/drywalled garage) every 4 minutes. The cost was very reasonable and I'm really pleased with the outcome.

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Peter

Very nice, Peter! What filters are you using?

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JJ
Napa, CA
http://www.DonohueGuitars.com

Those of you thinking about a similar unit should keep your lookout for a Delta made downdraft table. Made of reinforced plastics and topped with vented anti-slip coating, it is about 4 feet by a bit over 2 feet wide. It is around 8 inches deep and has a 4 inch DC flange on a long side. I am in the process of building a roll about frame for it and adding a 4 inch flange to the bottom of the "tub." I bought mine used from a Craig's list in the Midwest for around $90. If I come across a safe and suitable fan like that used by our OP, I will likely convert to self contained airflow and add the furnace filters to the side. I should have noted earlier that I hook it up to my 2 bag Delta DC. I have that odd little snail single bag Delta -it is set up with a "Big Gulp" hood behind my wood lathe which is mainly used for deluxe acrylic and celluloid pens- the odors are surprisingly "evident" when the friction and cutting are in process until I get to wet micro-mesh.

I am mulling over converting it to the table since it has the safe purpose built fan motor. As of now, I do not have a whole shop aircleaner and I believe I need such. I am in an older house basement around 35 by 30. The furnace is a very new High Efficiency with strong air filtration at intake and I do many more than typical homeowner filter changes(THOSE OF YOU IN SIMILAR WORK ENVIRONMENTS DO CHECK THE FURNACE FILTER[mine are HEPA] MORE OFTEN, I HOPE!!!!!!) My Shop down there is populated by 2 Shopsmiths(Plus additional add-on Shopsmith "Special Purpose Tools" = 6 x 48 belt sander, 1 x 40 stripsander, 11 inch bandsaw, 4" jointer, scroll/jigsaw-standard as delivered Shopsmith is tablesaw, lathe,horizontal boring, disc sanders[including a unique cone sanding dish which can joint]and drillpress), 3 various belt sanders, three router tables and the usual radius sanding and binding jigs, several ROS(one dedicated to polishing only-darn I love velcro and micro-mesh and double insulated power tools) and a Jet=Performax 10-20. Lots of ambient dust because Shopsmiths were not DC conscious products when conceived. In DP mode it sports a vertical sanding drum much of the time.

Thanks for reminding me to finish the unit. With "assembling" guitars as my only backup to Social Security, I need to be more serious about the abuse on my lungs which I am sorry to say includes smoking. Mike T.

JJ, the filters that you see in the unit when I took the photos are some MERV 10's that I had in the shop. I had been using them on the inlet side of a box fan. I should probably upgrade to a rating greater than that to take full advantage of the system. If you have any suggestions please let me know.

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Peter

Oh man....I suddenly feel I need one of those

I wonder if you could add a rubber sheet and use it as a vaccuum clamp system

Steve Wheeler built one last month. Its killer and sucks like a hoover. Makes me want to build one too. Maybe Steve will chime in this week.

J

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Joe