Peter, I wear the mask on the left when I am turning pens,
These dust masks are made for welding fumes, but the local hardware has just put them up to $19.90

I have a Trend Airshield Pro for bowls etc.
The mask on the right is what I use for spraying chemical, casting resin etc. But I find the uncomfortable and hot, after wearing it I can tip the sweat out of it.
