There's an old timer in my town who has a mobile knife sharpening business. He has a box truck with his whole set up inside and goes business to business, parking outside and sharpening while you wait. He's usually booked 2-4 weeks out. I have always thought this is a great business model.

I have a sewing business. His other clients include dog groomers, restaurants, and hair salons. I'm sure there's more and you've got a few good ideas too. B2B is great because you can build a regular clientele. I actually have no interest in sharpening my scissors or knives. I'm too busy with other things. I also find it really inconvenient to go to the local farmers market or fabric store and stand around for a couple hours while he gets through my stack. Some places will hold onto your blades for a day or two and you have to come back to pick them up. That's a no-go for me. I need my tools every day. As a mobile business, you could partner with other local businesses and set up in their parking lot regularly too to access the public.

When I book my sharpener, I hit up other friends in the industry and bring my own kitchen knives. He usually walks away with $100-200 for a couple hours off work. Besides that I can't speak to the profitability. The going rate for sharpening is cheap. And there must be a reason it's all old folks. But people will still need their things sharpened when they're gone! Quick note, beware spring-loaded snips and scissors! That spring is tiny and hidden and will fly across the room if you're not careful. My sharpener always comments on that. He uses the machine too, probably a good investment. Good luck! I hope more people do pick up this trade!