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Looking for some advise please,

I am building a free standing spray booth, one end of a 7x 14 outdoor shed, about 40 sq ft. Have a 1500 CFM explosion proof fan and lights, and my questions are around mounting height for the fan, and make up air intake.

Mount the exhaust low to the floor and bring the makeup air from up high, the other way round, or does it matter much? If its too windy, can I regulate the make up air to slow it down, or will this overwork the fan motor?

Thanks for any suggestions!

Well, true air makeup cannot be done properly in any booth that small...
However, I always kept the fan above 4 feet just in case the floor was dirty.
Also - never mind regulating the intake, you'll never be able to fight Mother Nature (at least I can't here in Kansas where 20MPH winds are considered light breezes).

Where are you mounting your explosion proof lights?
And how many do you have?

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"Act your age, not your shoe size" - Prince

Two flourescent lights, with two bulbs in each. still have a blank slate, so can mount them above, behind, or on the side walls. Assume it's preferred to have the light coming from behind, rather than diffuse light from above

By "too windy", I meant excessive air flow in the booth from moving too much air, not outdoor wind. reducing make up air should cut down the flow, but dont want to labor the fan motor and overheat it

You'll want the lights behind, yes. On my last booth, I had 4 lights. Two were about 1 foot above my head, 6 feet part. The low ones were 1 foot off the floor, 8 feet apart. If there was a dry spot in my pattern, it was easily seen.

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"Act your age, not your shoe size" - Prince

1500 cfm is a pretty small fan. Ideally you want to move a curtain of air at around 100 lineal feet per minute through the spray area. Your fan will only accommodate a booth opening of about 4'x4' at that rate. If the opening is 7'x7' the airflow drops to 30 lfm which is almost not moving at all. I would say your best option is to place the fan and filter panel directly behind where you intend to spray otherwise I don't think it will be able to clear the stand off at all.

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

I'm in the process of putting in one if these:
http://www.grizzly.com/products/2-HP-Dry-Spray-Booth/G0532
Maybe the specs will provide some insights for you. I'm thinking if you made your intake hood smaller then the motor should be big enough.


Ken Jones
Mountain Song Guitars

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Mountain Song Guitars www.mountainsongguitars.com

Just finished my least favorite task - sanding back a failed finish. This is a hog/euro size 0. Tried the PolyWhey luthier blend and results were not what I wanted. Stuff does not seem to burn in at all. I'll give it one more try.

Edit: oops mis-posted.

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Steve Smith
"Music is what feelings sound like"

A Sherwin Williams Rep recommended mounting the exhaust fan near floor level. The thinking is the overspray is heavier than air and should be drawn down (below the work piece) and out as efficiently as possible. I would use a large filtered area for the makeup air to avoid having a defined "airstream" of high velocity air.

Pretty much I have my filters on a box with the explosion-proof fan inside then ducted to the roof. Not ideal but the building is brick and the boss vetoed the idea of cutting a hole through the wall. It does work; I can spray and a few minutes after I put the guitar parts in the drying box I can turn off the fan and not smell anything in the shop. I do wear a respirator when I spray.

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Steve Smith
"Music is what feelings sound like"