Mike,

The primary danger when building a stitch-and-glue boat like the NE Dory is dust. Wood dust. epoxy dust, glass fiber dust, primer dust, and paint dust. Stitch-and-glue construction involves a lot of sanding. None of these things are good for you to breathe. Here's a link to Testing Dust Masks.

If you are using materials supplied by CLC, the MAS resin and hardeners do not present much of a hazard in a reasonably well-ventilated space. In fact, they don't seem to have any odor at all. When we built my Peeler Skiff. we didn't worry about anythin but contact with our skin. We used disposable gloves and kept a gallon of white vinegar in the shop to immediatly cleanup accidental contact. Skin exposure to epoxy and hardeners can cause pretty nasty and permanent allergic reactions.

We used Interlux Brightsides (PreKote primer), with foam rollers and brushes, and did not use painting masks in our well-ventilated shop. If we had been spraying or using 2-part polyurethanes we would have. I do not have recent personal experience with clear coatings or varnishes and would suggest you check the manufacturer's recommendations.

As a side note, we used Festool sanders connected to a Festool HEPA MiniVac. There was no dust in the air. Unfortunately, when we hand sanded, we had to wear masks.

Regards,

Dick

   I bought a 3M respirator. Here is a link. I suspect most of the other 3M respirators are similar -- and I highly recommend them. The mask is comfortable enough that you can use it for hours, and you will use it -- even for ordinary household tasks like cleaning the oven. Save your lungs and wear a respirator!

To more directly answer your question, I recommend the paint mask. It has charcoal catridges that last a very long time to protect you from fumes (in varnish and some epoxies), and it also has the same dust air filters as the sanding mask. Those are cheap and need to be changed more often. Hope this helps.   

One thing to note is that some people are more susceptible to hardener fumes than others (I'm one of them). For us, the claim that epoxy/hardener has no odor is false. I can tell the difference between brands of hardener by the smell. More importantly, I have a non-allergenic reaction to hardener fumes. They can give me a massive headache if they're strong enough. The only protection is a respirator with VOC cartridges.

Even if you are lucky enough to not react with headaches, it's good to stop the vapors. If they enter your body through your eyes they can cause an eventual allergic reaction (bye-bye non-traditional boatbuilding). If they enter through the lungs, they can have carcinogenic and gender-bending effects (act as a pseudo female hormones). So be safe, wear eye and lung protection and have really good ventilation.

Laszlo