How do you tell someone that the razor they bought out of lack of experience is actually not a good razor?

I'm a first year in college and have been meeting a few guys who share my interests and hobbies. I've met one guy who shaves with a straight and I offered to hone it for him, but his razor has been sharpened more like a knife than a razor. This means giving him back an inferior edge, or a lot of work grinding the proper angle. How do you guys break it to people?