For installing ferrules, what is the easiest, preferred method for cutting a glass rod blank? Are there any problems with sp;intering?

Cutting? Last I knew, the ferrules lash to the surface of the rod - there's no cutting involved.

 

Course, last time I looked was back when I was considering making my own fly rod - 35 years ago.

I did a similar repair to a rod a few years back and I used the cut-off wheel to a Dremel tool.

Simply tape the section you want to cut with masking or blue painter's tape, mark where you want to cut and have at it. The reason for the tape is to keep the cut-off wheel from walking.

The important part of cutting any rod that has longitudinal fibers or cloth is to use very high speeds and very slow progression through the cut. Dremels with cut off wheels are ideal, as mentioned. I would tape on both sides of the kerf.

 

 

With the readily available travel blanks on the market I can’t imagine using the old metal ferrules.  

You probably know this but definitely wear a mask. A respirator is better. Breathing in glass dust is really isn’t good for you. 

You can also make a spigot ferrule using a cut piece from glass or graphite (better) rod.