Okay, so what you need to do first, is discover Haley's Hardware in Point Lookout. Enter the house and talk to Haley. Go through all the dialog it gives you when you first talk to him. Then, tell him to repair something. Pay attention to his repair level on the top of the screen, it should be 16.
Now, make sure he still has his handyman jumpsuit on. If he has something else on, it won't work. Basically, since the jumpsuit gives him +5 repair, entering and re-entering will strangely permanently boost his repair up 5 each time.
Now, leave his house. Take a full circle around his house - just entering and going back in won't work. Once you have circled around (note: it's okay to take shortcuts to make it quicker, like jumping over the car to hop over the fence, though it makes a small difference), go inside his house. If his repair is 21, you've done it correctly!
Just repeat the above step until he gets to 100. You'll have an NPC even better than Wolfgang to repair all your stuff!
But, repairing everything to 100% DOES cost money. So I suggest you do the scrap metal glitch.
With this you can have hundreds of thousands of caps, so you'll never be low.
By the way, I still suggest you get 100 repair yourself. It's far cheaper, and it gets very repetitive to go to Haley every time you need to repair.
Hope this guide helps. But don't forget it DOES take some fun out of the game.