We’ve all heard the horror stories about people blowing themselves up while painting their car on these spray booth fan threads, but I have never heard anyone actually saying it happened with an airbrush. I just can’t imagine the minuscule amount of fumes produced by an airbrush being able to produce a remotely dangerous explosion, at worst no more than a ruptured drier tube.
People usually recommend squirrel cage fans, but their CFMs are pretty low for their price, and I’m going to need a lot of CFM for my booth since the fumes have to go through 20 feet of hose. I have seen plenty of modellers (experiences ones too) using range hoods, box fans, and even $10 walmart fans to exhuast airbrush fumes without any problems and none with problems.
So, is there a serious risk of using a cheap exhuast fan? I was thinking of using an inline duct fan or a bilge blower. I’ve also heard of people using duct collectors, are those explosion proof?
You need 3 things to create a fire, heat, fuel, oxygen( normal air). All 3 are present in a fan however you also need the right fuel/ air mixture for fumes to ignite. Odds are pretty good if you can touch the fan motor bare handed and not suffer a burn you do not have enough heat. You are correct in thinking that there is a small amount of fumes that are expelled from an airbrush, by the time you build up enough consentration to ignite you probably will have passed out. One thing I would do is make sure the fan motor is clean and free of dust and lint, these materials can wick moisture from the air and create an arcing issue. I have painted both enamals and acrylics for years without an exhaust fan and HIGHLY RECOMMEND using one.
Some fans have commutators or brushes where sparking can occur. These are the kind to worry about, even if they do not feel hot to the touch. I always use the brushless AC muffin fan type.
As long as you move enough air that you don’t exceed the LEL (lower explosive limit) of the vapors, you don’t have to worry about sparks. If you do exceed LEL, you need to worry about all sources of sparks, including static electricity.
So will a brushless AC motor be good? I happen to have a blower used for an inflattable water slide lying around. I have no idea why they used a brushless motor but I’m 100% sure that it is indeed brushless. Moves a massive amount of air and provides great pressure, would be perfest for me since whatever I use will have to move air through 25 feet of flex duct.
That sounds perfect. As stated above the safer the better. IMHO if you achive the right mixture of air, fumes and somehow get a spark you would probably be overcome physically. THAT BEING SAID if you can safely exhaust fumes DO IT, lungs are hard to fix.
Just so you know: The motor you are using was never ment for continuous use.( it will probably burn out at a most “inopertune” moment.)
Unless you are talking about the kind that are used for those “bouncy house’s” … like you would rent for you’re kid’s birthday.
In any case, you will probably never pump enough paint through a fan to cause a “major” explosion. A small fire …maybe. (but not very likely) Only if the fan has a defect. But unless you’re airbrush has a 5 gal. cup i wouldnt worry about it. ( By all means keep a fire extinguisher handy… I have been wrong … from time to time.)
Exactly! How much could you really be saving instead of buying a unit made for it. Why risk it and woder all the time if it is safe. Way to go Black Sheep!
My diy uses a large cfm capacity bathroom exhaust fan, with a 1.2m long hose attached, it works OK.
I used a filter in a attempt to stop larger particles of paint, but it significantly reduces the fans limited ability to extract the fumes, so It will soon be removed.
From memory the fan can move about 250-270 cfm, the ducting was old ac ducting.
I don’t belive the cheap AB booth’s will have suficient ability to push the quantity over the required distance, from my reasearch they use 12v computer fans that are pretty useless apart from moving air inside an enclosed computer case.
I’ve used a Dayton blower in my booth for years and never had a problem, even when using aerosols. I don’t remember the proper term but it isn’t an explosion proof version. Not to say that nothing could ever happen but it hasn’t. Don’t remember the number either but it’s around 325cfm. There is a fellow named Klaus Raddatz that I knew from another message board that had instructions posted online for building your own booth but I can’t find the complete article now. He had a formula for figuring what size fan you would need. It took into account booth size, ducting diameter and length plus bends or elbows. If you have a small booth, vented directly to a window then no, it doesn’t take much to move air. But, if you have a larger booth with a longer run of ductwork it takes much more fan than you may think to be effective. If you have a long run to make then smooth tubing would be much better than flex hose. But, just my opinion.
This is the blower that I use in my spray booth. The motor is outside of the air stream so there is no chance of an explosion. I also use a filter in the spray booth. The filtered air is exhausted through an exterior wall .
