I am strictly a hobbyist but in the past 40 years I have sandblasted using silica sand and have cleaned petroleum tanks (big tanks) while wearing Scott breathing air supplied full face masks. So I am somewhat familiar with respirators. For sand blasting all I ever used was a MSA Comfo Fit half mask with filters. I am in the process of restoring a 1965 Cub Cadet garden tractor which at some point I will be painting. I have joined several Cub Cadet forums and have been doing my homework on the painting process. My main question was whose paint do you use? No shortage of answers there but what I am learning is that many of these folks are using a hardener in their paint, which of course generates more questions from me specifically safety related questions. From what I gather if you are using a hardener you need to use it in conjunction with a positive pressure respirator. Is this indeed the case? Out of curiosity I have posted the question about the use of respirators when painting with a hardener. Who uses one and what type do you use. I am 65 years old and not interested in harming myself in order to have a shinier and quicker drying paint job on my lawn tractor. Years ago I painted 3 different antique JD tractors and was more than pleased with my final results. I do not recall the subject of hardener ever coming up back then. If I stay away from using a hardener am I fine with just a half mask with the appropriate filters?