It is a tricky proposition to turn down a grip with the reel seat and guides mounted on the blank. I would be very careful. Not sure how you would go about it unless there is no guide on the but section. If that is the case, then put the blank thru the headstock with a few layers of masking tape to protect the section of the blank that will be in the chuck jaws. Then you just need a way to support the reel seat for concentric rotation and you will be in business. Just take it slowly and don't put too much pressure on things.