Re: Remove 4" parallel section of tile for plate
The best way to collect this type of dust without clogging your vacuum filter, that a 5 gal. plastic bucket with top half filled with water, cut a hole on one side of the top insert a 2½" piece of PVC pipe down to about 1" from the bottom and seal around the pipe, on the other side of the top cut another hole and insert a piece of 2½" PVC pipe so it 's just below the inside of the top and seal around it. Hook a pick-up hose on the PVC that goes below the water and the vac to the other PVC. The air and refuse is drawn through the water which retains all the dust.
PS, I believe you over-reacted to havanagranite's post as he was pointing out that the supplier in question supplies industrial accounts and he knows that because of his back ground. I know many educated idiots with collage degrees and because you're 136 is less than mine that doesn't impress me either. I have learned far more from "the trades" than I ever did in collage. I also know that part of the NEC is influenced by the Mfg. Assoc. Members who push to have their patented inventions included in the NEC or who push for new standards to sell more products, whether it is a good idea or not. The same goes for most national standards, unfortunately.
Be sure you live your life, because you are a long time dead.-Scottish Proverb