Send them to Delaware Diamond Knives, ask for Joe Tabeling, and you will
be charged $200 to recondition them.  If you have a Shandon Knife 
sharpener, IT IS possible to resharpen them for a time, eventually
they will need a full recondition.  800 222-5143  DDK also makes
TC d profiles at a reasonable price (~$900) with high quality.

My experience with TC knives and clear GMA sections, is that you will not
ever achieve a perfectly clear section.  The glass knife is still 
sharper, with a molecular edge (use freshly broken knives in one day)
but the TC knife is certainly time and cost efficient for thin sections.
My GMA always had a slight cloudy look off the TC.

Gayle Callis