As life advice goes, this is an odd one, but unlike most of what I post here, it could actually be useful.
Most people change the blade in their safety razor or the cartridge in their cartridge razor every few weeks. I change mine every few months. That’s how long it takes mine to get dull. The reason is something I learned from my father. He was a mechanical engineer who once advised a friend of his, who was an engineer at Schick, about how Schick could apply a Teflon coating to the edge of their razor blades.
My father used an electric razor, but he explained to me, a safety razor user, that razor blades don’t become dull as a result of cutting through beard hair. They are dulled by the oxidization that occurs at the edge of the blade while they’re wet after they’re used. Once they dry out, there’s little oxidation and little additional dulling. So he suggested that I rinse my razor in very hot water as soon as I finish shaving and then shake it vigorously to get as much of the water off it as possible. I’ve been doing that ever since with the result that I go through only three or four blade cartridges a year.
As soon as I finish shaving, I turn the tap water up as hot as it goes. While it’s getting hot I dry my hands and the handle of the razor so that it won’t slip from my fingers when I shake it. I hold the blade under the hot water for about ten seconds, then I whip the razor a few times with a snap of my wrist — as if I were shaking a mercury thermometer — to get as much water off the blade as I can. The fact that the blade and the water are hot ensures that any remaining droplets on the blade evaporate quickly before much oxidation can occur.
If you’ve ever wondered how you could spend less money on razor blades, try this technique. I think you’ll be amazed at how much longer your blades last.