After ruining a blade and slightly nicking an edge or two using the dremel to sand and polish blades I've been trying out different ways to protect the edge. I've found electrical tape and such gets in the way to much to where you can't get close enough to the edge but I found a way that works great.
I don't know if it's been mentioned before but I cut a piece of a candle off and melt it in a pan on the stove, then dip the whole edge of the razor in it and take it out, when it dries you've got a edge coated in hard wax as thin or thick or as far up the blade as you want. Most polishing or sanding or grinding bits will just slide right over it if you slip and touch the edge, rather than nicking or chipping it. And if you get too close for a little longer the bit will get coated in wax and be pretty dull anyway. Also, you can tell your heating the blade too much once the wax starts to melt off.
Any other ideas for protecting the edge? I think working off a wooden slab with the magnets is great also.