I don't know if a respirator is necessary or not but I always wear one anyway. I usually use a respirator instead of masks for all jobs. It was only $30 or so and I've been using it for 5 years or more. I can remove the filters and vacuum them out whenever they start getting dirty.
Same, I have two respirators, one for shop partners, and at least wear them when I am doing any sanding or cutting on old boats. I recognize that I have developed sensitivity to Vinylester sanding/cutting dust, and probably to polyester resin dust as well.
That developed sensitivity drove some long-time boat builders out of their shops; better to let the seasonal shop monkeys doing the layup work develop their own exposure limits. With vacuum bagging and exhaust filtering maybe that is less of an issue today.
I wear a respirator even when I am doing less odoriferous epoxy resin work; I
really don’t need to become sensitized to epoxy resin. If that is even a thing; don’t know, not taking any chances.
To be on the un-itchy end of sanding I gown up or wear an old lab coat, long sleeves, gloves (purple Nitrile), goggles - really don’t need that crap in my eyes - and shower/change clothes immediately after long sanding sessions, especially with Vinylester hulls. By then I am already getting itchy despite full wearing PPE.
I had a sealed bag bag of virgin fabric surgical face masks in the shop. The missus kinda laughed at me when I pulled them out as potential Covid-19 protection a couple months ago. She sang a different tune when masks became required grocery store attire, and we now have a couple in each vehicle.
BTW, if you have a full beard none of that stuff works as effectively. The fabric surgical masks especially; they will beard-ride up into your eyes. The solution is to tuck your neck beard up inside the mask when you first put it on.
Not a good look, but it works.
The more PPE you do now the less sensitized you will be in 10 or 20 years.
