Supplied air system on a budget..
Hi Walter:
A few years ago, Malcolm Zander published a tip in American Woodturner where he used a face mask and breathing tube from a commercial PAPR system to adapt it for a home made supplied-air system. If I recall correctly, he built his system using an exhaust fan (as in the type used to ventilate bathrooms) and an air filter mounted in a different room adjacent to (but not IN) his shop, and used HVAC ducting to bring-in the filtered air to a location above the operator's area of his lathe. He used a step-down adapter to reduce the duct diameter to that of a supply hose that was connected to the breathing tube of the 'face/mask' part of the PAPR system. He noted that this was a good use for the facemask/breathing tube part of the PAPR system that no longer worked, and that the clean, filtered, supplied air was sufficient to keep him happy and safe while sanding. An added benefit he mentioned was that he could readily tell when his wife was baking!
I use a belt-mounted, battery-powered 3M Air-Mate PAPR System with HEPA filters, and Racal Helmet & faceshield unit with breathing tube. My system was purchased on eBay from a hospital in Florida which was upgrading their emergency response equipment. All of the 3M components of the system (power unit, belt, breathing tube, NiCd Battery charger, additional dust hoods, etc.) were sold for just about $200, and were in essentially new condition (the belt pack/power unit did not have a scratch on it, and was in original packaging!). The helmet/face shield was purchased separately for under $100. I was not happy with the Trend Air Shield (original version) that I had purchased previously; for me, the belt-mounted, industrial PAPR system works far better, with more user comfort and for less money when purchased as a 'used' system.
You are asking the right questions, and if you intend to stay in woodturning for any length of time, protecting your lungs is as important as any other aspect of safety while woodturning. The nasty part of wood dust is that its negative effects on health are much slower to manifest than a blank flying off a lathe!
Spend the money NOW, and use the equipment, rather than spending much more money later to try to recover from your pain and suffering when respiratory problems will make you ask why I didn't protect myself "back then".
Rob Wallace