I'm in the middle of a project where I need to do a lot of working with plastic. Which when cut or sanded produces Large Amounts of fine, choking sawdust. I got a couple of nosefuls (and the Dremel throws it RIGHT in your face) and decided that Something Had To Be Done.

(When I was a kid, my best friend's father had a shop in his basement, and one time I went down there and he was sandblasting something. He had rigged up a fishtank with holes in the sides and rubber gloves stuck in them to hold the item being worked. I have no recollection of what he was making, but I remember the tank. I always kind of wanted one...)

Materials:

one plastic box with attached lid, available at houseware stores
one pair long rubber gloves
some duct tape

Step 1: Arm Holes

Open the lid and pretend to work on something in the box, to get a sense of where your arms want to be. Draw a rough guide with a sharpie. With a cutting wheel, or a hot knife, or whatever you like to use to cut plastic, cut out the holes. Tidy the edges up some so they don't scrape you.

The box is now usable; dust won't fly directly into your face now. But it will still come out of the armholes, and your hands will still be all covered in it. An improvement can be made!

Step 2: Attach Gloves

Put the gloves on and stick your hands through the holes to get a sense of the angle to attach the gloves at. Tape them in place.

Step 3: Cord Hole and Another Version

Now that the arm holes are covered in glove, you will need another hole to put the cord of your power tool through. Dust can escape through here but I haven't bothered to cover it. A temporary application of tape is probably the route I'll go if I decide it's necessary.

Check out the last pic for the Super Size box my boyfriend made. He did not add gloves but attempted to block the arm holes with fabric. It didn't work very well and I'm encouraging him to add gloves for the sake of our lungs.

NOTE: it is just barely possible, if you're working with something like wood that's flammable, and using an electric tool, that a very high concentration of dust might possibly explode. So Be Careful.