Air Respirator

Do you have any good ideas for a mask? I have looked at some medical stuff, but didn't find anything that seemed very good. I have wondered about a mask from a fire department air pack. Ideas?

The problem I think you may run across is getting a sufficient quantity of air at the facepiece while contending with the necessary pressure drops through a fairly long hose between the air supply and the facepiece.

You will need to supply a minimum of about 4 scfm of air to your facepiece. You need this much to assure a positive pressure (with respect to the outside) inside the facepiece during inhalation. You also need to supply this quantity through a fairly long hose of reasonable diameter. Fifty feet would be about minimum since you must locate your air source where it will not suck in contaminants. This hose has to be a reasonable diameter to avoid becoming more of a problem than a solution in dragging it around with you (together with your gun air line) while you concentrate on the painting itself.

Fans are generally not designed or intended to provide the pressures necessary in supplying air over long distances through relatively small hoses. I personally think you would get a better functioning system by obtaining a dedicated non-lubricated compressor and using standard 3/8" ID air hose for distribution to your facepiece.

In any event, good luck with your project. You do need to have some type of fresh air supply to protect your health if spraying materials containing isocyanates.

Rod