The original safety razors used a thick blade that was meant to be honed and stropped. Modern DE blades are designed to be disposable. They are so inexpensive that I cannot see any reason to try and extend their useful life. The goal of a modern DE blade is up to 3 (yes, some can go longer then that for some shavers) good shaves. Instead of trying to resharpen them, you get a consistent edge by replacing them. If you want to maintain the blade edge, I have some straights you might be interested in. ;)