My wife buys me antiquated tools at garage sales. I have no interested in them. What should I tell her?

Can't you just say, Honey, I love you, but..........

The best thing to say in this situation is "Honey, how did you know THAT'S exactly what I wanted/needed?"  Say thank you and give her a big hug for being so thoughtful.  End of story.  Saying anything else could prove to be unwise as well as sexually unfulfilling. 

You should say thank you Dear