So far so good, but I only spray solvent based paints for weathering. I paid ~$17 for mine at Walmart (used their ship to store option since we shop there) and at that price, one every couple of years wouldn't be to hard to stomach.
I stand corrected. Today's axial blowers are spark proof. The model I looked at made by Shurflo did not specify duty cycle though. Bilge blowers are typically only run for a short period prior to starting the engine. I would ask the manufacturer if there is any duty cycle limitation.
I do wonder how solvents might affect these blowers. They are mostly plastic.
CG
I'm sure in some cases, you may be right. I called the manufacturer of the fan I bought and was told they were safe in the bilge compartment to exhaust.
Bad link sorry
danB
CentralGulf No! No! No! Marine bilge blowers blow fresh air into the bilge, they don't suck fumes out. They are only protected against external sparking.
OOPS, my (very) bad!!
"Ignorance is bliss". Apparently I'm in a state of bliss.
Sorry,
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
danno54A good squirrel cage fan with motor out of airstream is the only way to go. Any type of propeller blade fan cannot over come the resistance of a clean filter much less a paint laden filter and ductwork. The paint on the filter is probably shot there straight from the gun as opposed to drawn by air through the filter.
The tiny four-bladed propeller-type fan in the plenum of my spray booth moves enough air that there's a very noticeable draught coming through the 4"x10" replacement air intake vent. The filter is in the ceiling of the booth, and while overspray lands (and dries) of the back of the booth, the filter collects lots of dust, drawn up into it by the fan. The duct run, with one bend to the outdoors, is about 6'. I use a simple fibreglass filter, and there's not a great deal of paint build-up on the fan blades even after all those years of service. I do change the filter as needed. While the filter is 10"x11", the duct is only 4", so when the fan is running, the paint dust collects over the entire surface of the filter, but only the air and fumes are drawn into the fan/duct area.
Wayne
So what is a good cfm rating to use? Or is there a formula?
A pessimist sees a dark tunnel
An optimist sees the light at the end of the tunnel
A realist sees a frieght train
An engineer sees three idiots standing on the tracks stairing blankly in space
A good squirrel cage fan with motor out of airstream is the only way to go. Any type of propeller blade fan cannot over come the resistance of a clean filter much less a paint laden filter and ductwork. The paint on the filter is probably shot there straight from the gun as opposed to drawn by air through the filter.
Check the static pressure or water column of the fan you purchase. Graingers and McMaster-Carr are a good place to start. The key to a squirrel cage fan is a tight fit of the scroll wheel to the housing. A bathroom fan with a plastic squirrel cage wheel can be adjusted to create a tight fit and increase pressure. You want to capture overspray at least a foot away from the filter. And then you have to drive the air outside. At least i hope we are.
The cheap fans probably won't even list S.P. A clean filter starts you off at about .5" of static pressure with a dirty filter exceeding 1.5".
JAMES MOON Goosetown, are you using an old body shop booth?
Goosetown, are you using an old body shop booth?
Old. No. Bought it new a few years ago. Why would you assume it's old?
Go big or go home!
hon30critter I recall seeing a suggestion on a previous thread regarding DIY paintbooths about using a marine bilge blower to move the air. No possibility of sparks igniting fumes, lots of air volume, and fairly cheap. Amazon has lots of them listed. Dave
I recall seeing a suggestion on a previous thread regarding DIY paintbooths about using a marine bilge blower to move the air. No possibility of sparks igniting fumes, lots of air volume, and fairly cheap. Amazon has lots of them listed.
Bump
I built my own spray booth, using part of the top of an old end table for the base. The sides, rear, and top are 1/8" Masonite, pop-rivetted together using aluminum angle used for siding. The fan, from an old air hockey game, is in the metal plenum atop the unit. While the photo shows plastic dryer duct to the outdoors, the unit is now in my garage (in a room constructed only for airbrushing) and has all-metal duct. The room also has a fresh air intake, to replace air forced out by the fan. There's a filter holder in the top, below the plenum, which accepts one half of an 11"x20" fibreglass furnace filter. I installed a turntable in the base when it was built, but don't find it to be of use at all.
If your fan is running before you start painting, I doubt that there would be enough combustants present to cause any explosions, regardless of fan-motor type. Mine has been in use, including commercial painting, for 35 years, mostly using Floquil, Pollyscale, and Scale Coat.
James
JAMES MOONRick, where did you obtain the Dayton squirrel cage blower from?
Rick, where did you obtain the Dayton squirrel cage blower from? Was it fairly expensive?
My booth is 30'lx15'wx11'h. Not a typo.
This is a paint booth I built using a plan in Mainline Modeler Magazine, behind the furnace filter is a Dayton Squirrel Cage Fan which does not let the air flow get to the motor therby keeping any chance for explosion using solvent based paints from happening. Not shown is the vent top and metal conduit venting the fumes outside.
The size is base on the furnace filter and I used pressed board from a discarded entertainment center for the top, bottom and sides.
Rick Jesionowski
Rule 1: This is my railroad.
Rule 2: I make the rules.
Rule 3: Illuminating discussion of prototype history, equipment and operating practices is always welcome, but in the event of visitor-perceived anacronisms, detail descrepancies or operating errors, consult RULE 1!
Hi Isi3009:
Here is my version. It is based on a 16" x 16" three speed box fan. I use cheap furnace filters and they seem to do a great job of catching most of the overspray, but note that the paint clogs them up pretty quickly. Even though the filters may not seem to be clogged when I pull one out that is partially blocked the airflow increases dramatically.
The fancy design was a result of the size of the pieces of plywood that I had available. It was not some great experiment in aerodynamics.
Filter removed. You can see that not much paint has gotten through the filter to the fan:
I mounted a pressure control valve right on top of the booth so I don't have to go back to the compressor to adjust the pressure:
The light fixture is a cheap under cabinet fluorescent unit. It works great. I installed a power bar on top of the booth so I can plug the fan and light into it as well as any other tools like a Dremel that I might occasionally use in the booth. One thing I haven't purchased yet is an airbrush holder. For now, I hook the airbrush over the pressure valve when I need to put it down but it's not a very safe way of doing things.
The booth is not vented to the outside, although that wouldn't be difficult to do. I only spray acrylics so I'm not worried about the fumes.
One small piece of advice. If you haven't used the booth for a while, wipe the cobwebs out before starting to spray! I couldn't figure out what the fine lines were that showed up on a fleet of cabeese that I was spraying until it finally dawned on me that mother nature was doing her part to add her own details to my paint job!
Regards,
im in the process of building a paint booth , before I start I would like too see some photos of others booths and ideas and what works the best thanks