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I'm building a booth in my shop for spraying, mostly waterborne "lacquer" (acrylic, I guess) but it will be built explosion proof so that I can do touchups on nitro. Anyhow, the guy who's building it has automotive paint booth experience, and the configuration we're looking at is a rectangular booth with a door on the side. As you go in, to the left will be a small holding area for work in process, and to the right will be the exhaust fan and the painting area.

His feeling is that I should keep airflow going over the curing finishes, so he feels the intake filters should be directly behind the "holding" area, so anytime the fan's going there's airflow over the finish. My feeling is that I don't want airflow over the finish because the last thing I want to have happen is for the outer surface to cure too quickly and trap solvents. I'm more of the mind that the intake should either be directly overhead or in the door, and that airflow over the holding area should be incidental.

What do you guys think?

Thanks.

The first thing that popped into my head about the airflow going directly across the guitars was humidity. Even if the humidty in the room is good, it may be too dry with alot of airflow directly across the guitars. In my booth I turn off my big fan when I'm finished spraying and cleaning my gun, but I leave a small (bathroom) exhaust fan on for curing. My main (big) fan is explosion proof, but the bathroom fan isn't. I don't think (hope?) the explosive vapors are gone before I switch fans.

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I hang my stuff up, out of the area of best airflow. The theory is to avoid excessive cooling & any small dust particles that are floating around. My inlet filter & fan are on adjoining walls, so there are two relatively "dead" areas in the room. Seems to work nicely.

Back when I was doing a lot of finishing, I had a small Binks booth with the exhaust fan on top, exiting out the buildings vent. I built a room around it, with the compressor outside, and the intake filters were in the door, approximately 90 degrees from the booth. I hung any guitars outside the booth after finishing, and the fan shut off - I never worried about drying times because Kansas had pretty high humidity most of the time, and air makeup systems cost more than the Federal budget. I used a lot of reducer when I sprayed to avoid blushing.

My explosion proof lights were behind me when I sprayed (above and below), and I ended up using cheap central air filters in the door and the booth because they worked as well as the high dollar paper filters from Binks.

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On a similar note, where are you guys getting all of your explosion proof stuff?

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Explosion proof ?

ummmmmmmmmmmmmmmmmmmmmmm shhhhhhhhhhhhhh dont tell !

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Explosion proof fan is pretty easy to get. Explosion proof lights cost a fortune. Current plan is to use a plexiglass ceiling with the lights just sitting on top. Apparently, that's perfectly OK as the lights are out of the booth entirely.

Explosion proof lights are cheap and easy!
Made a bunch of them in junior high shop class.

Get an old mason or mayo jar with the lid.
Screw the lid to a block of wood, and then mount the light fixture in the lid - running the wire out a hole in the bottom or the side.
Install your bulb, and screw the jar into the lid.
Viola! An explosion proof light for your spray booth.

Put a switch in the wire and you won't have to unplug your lights, or run switches to your outlets on the outside of the booth. Easy peasy.

You mentioned putting them in the ceiling - you'll want two of them below and behind you on each side and two above and behind you on each side. This gives you plenty of light (25 watt bulbs are fine) to see reflected light. You see every dry spot, run, orange peel, etc. It's great!

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

I built some sealed plywood boxes for my movable fluorescent lights. You can get inexpensive faceted acrylic covers for fluorescent fixtures & screw them on the front of the box with caulking or weatherstripping tape, to keep the fumes out.
Any unsealed switch can cause a spark. If you're nervous about explosion hazard, its probably best to avoid them. (Pulling a plug for a light or heater under load can cause a BIG spark!)
In my booth, I put the light & fan switches on an outside wall, next to the entry door.

I am right in the middle of doing the same thing. It sounds like
I have a little less space, so my make up filters will be in the door.
I am currently shooting EM6000 but wanted to be set up to be reasonably
safe spraying varnish or others. I have correctly matched the fan & filter
area size, but was a little worried about gassing off, so thought it would
be good to have the fan variable or on a timer (or both).

I had quite a time sourcing a fan I wanted but finally went with this.
The first link I included to show the web price $475
http://cgi.ebay.com/12-Dia-Tube-Axial-E ... 1372wt_907
This is their company web site with contact info...speak to Jack real nice guy,good service.
http://www.mannixllc.com/
They also sell small spray booths and bench style models,filters etc.
I also purchased my customized duct work,filter frames and grids and filters here.

I wanted to be able to vary the speed of the fan, but preliminary research showed this was not possible
with a single phase motor. Eventually I found it was possible if you use a 3 phase motor and this device
(or similar) http://dealerselectric.com/item.asp?cID=28&PID=428
The input on this is 115V 1PH and the output 220V 3PH, so it's essentially a converter with
the added bonus of providing variable control.
$131 from Dealers Electric

Also available in Canada from http://www.wesco.com/branchlocator/index.htm .......many locations.
It's $209, but by the time you add shipping and the shippers pound of flesh brokerage fee, I decided
to pick it up locally.
http://www.wesco.com/branchlocator/index.htm

Cheers
Bob Hames

Bob (and everyone else) off gassing from varnish isn't really a big deal. It does smell a little, but it cures by cross linking, not by evaporation.

Disclaimer, this is just what I do. Everyone is responsible for their own safety

For varnish finishes after 24 to 36 hours I bring the bodies and necks in my house, and let them cure in an un used bathroom. The allows me to turn the HVAC off in my finishing room, and save on utilities.


Also, nice fan. Do you need variable speed, or just the right speed? I suspect you could change the speed with a pulley change. (My fan is a direct drive Jenny, but it features variable speed)


Here's a body and neck hanging in my spare bathroom.

_________________
I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

True, but the variable speed allows for other eventualities.

Bob

The current plan is to use a variable speed fan. The thinking is I can keep it on low for drying and delicate work (touch up airbrushing and the like), and then crank it up when I'm shooting clear coats. He didn't seem to think it would cost all that much more in the grand scheme of things.

By the way, I wanted to thank everyone for all the input. I think you guys have confirmed my initial gut reaction to what the proper configuration should be. Thanks!

Really? Didn't seem to me that your question about airflow over the guitar was addressed.

I hang the guitar directly in front of the fan and have never had a problem with that.