Tip: Paint Respirator
 

I maintain I would rather work night shift at a convienience store than paint airplanes for a living. But out need recently, I learned a few things, even if I went into it kicking and screaming. The lower cowl on my C-150 needed to be stripped and repainted so a friend introduced me to the finer points of aircraft painting. The first thing he did was take me to the local auto paint supply store where I got an appropriate respirator. This is the disposable respirator with non-replaceable cartridges I bought that is said to be good for 40 hours of use. Believe me, the odor of Jet Glow Matterhorn white is every bit as obnoxious and dangerous as the Akzo epoxy primer I used on my RV-6A. With this respirator on, breathing was unlabored and you couldn't detect the paint fumes. I was pleasantly surprised as to its cost. Relatively cheap lung protection for only $13.50. I will still have my RV professionally painted though.



Rick Galati RV-6A "Darla" flying
RV-8 empennage

Those charcoal repirators work great for most solvents, but do zilch for isocyanates that are in urethane paints. The molecules are small enough to go right through and don't have a smell, and are very bad for you. FYI.

Steve Zicree

I talked to a 3M technical representative (1-800-243-4630) about the issue and was told it is very difficult to know exactly what performance the average homeowner can expect from this respirator (model number 07192) recommended for paint spray applications because levels of exposure would have to be monitored with the proper equipment and will naturally vary from one situation to the next depending upon ventilation efficiency, levels of concentration, and the length of time of exposure. Generally speaking the respirator should last through 10 painting cycles. They did say, however, that the carbon filters WILL absorb isocyanates up to a point but the moment odor is detected or breathing becomes more labored, the respirator should be discarded. I would recommend any person considering the use of this respirator contact 3M at the above number and discuss the painting variables anticipated by the user.

Rick

I find that troubling, since all of the literature I've seen says that the odor from isocyanates present in catalyzed urethane is below the level of human detection. So if you're smelling something it's likely other things and not a good indication of isocyanate exposure.

Steve Zicree

Steve is right on the money here. If you're spraying most urethane paints, a simple respirator does not really do a whole lot of good. The stuff that's really bad (isocyanates) isn't normally detectable with the human nose, and isn't entirely filtered with the passive respirators. Forced air breathing systems are a must when using Urethane paints.

Cheers,
Stein.

some additional info.
 

anyone interested in what the manufacturer says can read it here. in short there is no way to tell when the filter is saturated with isocyanates but they are good for a while. approx 40 hrs.
"if a painter smells the sweet, fruity pungent odor, of an isocyanate, you have probally already been over exposed."
a friend of mine at a high production shop was overexposed once and ended up in the emergency-room for the night. he will not use one for more than a week.
http://multimedia.mmm.com/mws/mediaw...66Sld7COrrrrQ-
http://solutions.3m.com/wps/portal/3...G.x=5&btnG.y=9

Forced air breather
 

I made one of these. Bought a full face mask on Ebay and 25' of sump pump hose. Worked great.

http://www.sonerai.net/CMS/index.php...id=56&Itemid=1

wow thats so simple it hurts. i've seen some similar but more permanent, but man thats way better than just a half mak purifier.

Dishwasher fan
 

I did the same thing, but used the fan from a dishwasher (motor is external to airflow). Fan is in basement, and sump pump tubing goes to garage via a central vac wall attachmet (sump pump hose fits in beautifully on either end).

don't forget
 

Don't forget that you can also absorb chemicals through your skin and eyes, so protecting your lungs alone isn't sufficient.

For my priming I constructed a simple downdraft spray booth that is basically an 8 foot cube. I have a set of bilge blowers for inboard boats on one end to create suction and a set of furnace filters on the other end to filter the incoming air. Airflow is from high to low and the fumes/particles are carried away from me while spraying. There is never mist in the air while I am spraying thanks to this setup. Finally I filter the outgoing air as well through a furnace filter and set of charcoal filters.