I've been using a dust mask I got at Walmart for when I'm working with the wood for scales and it helps, but I still end up coughing and just feel plain bad when I get done. Can anyone recomend a respirator to use? Should it be powered or not? I don't want to pay through the roof for one and I don't want to make the same mistake I did when I first started out with straight razors and wasted money on an ebay special! Any assistance would be appreciated greatly! My price range is probably around $75. Thanks!