I don't have a garage or a good place to do it, but it does seem possible. I could see setting up a mobile sharpening trailer.

I'm not sure it's what I really want to do, but I think the idea has legs. If one of my kids wanted to get into it, I could see working with them to get it going.

Knives, mower blades, tillers, chainsaws, etc. Handsaws are pretty easy to learn, although hardly anyone uses them.

It might be a business two people could share part-time.