Frets in fretless

[Palle Clausen]

So, I have have done hundreds of refrets and several fretless conversions.

However, what I haven't done, is putting frets back in a fretless.

Now, I have a customer with a '77 Fender P-Bass that was made fretless many years ago. He want's it fretted again. It has plastic strips glued in where the frets were.

I guess it is sort of obvious how to do it, but would welcome any advise, experience, pittfalls, etc.. from those who have tried going from fretless to fretted?