I use a double charcoal mask for most now. I don't think those cheap white paint masks do much. They don't fit right, too many gaps and I don't think they are worth much. Doesn't matter what a good one cost. It is worth it.

When it comes time to sand my full scale, I may just get a full suit that has a hose to a fresh air source. Seems extreme, but when I sand on that thing, I can put an eighth inch of glass and micro dust on the floor of the entire shop in short order. Its a big plane and I am taking off a lot of material.