I had a friend give me some rods that belonged to his grandfather. some have old grips and guides but some others are just blanks. They seem to be glass material. Since I build primarily fly rods , How do you determine what size line each blank can throw? These are very old one piece blanks and rods which I'm going to refurbish. I don't even know who mfg. these.

Dave, The best way is to read and use the CCS Data Site. Read all the information, go through the process step by step, and do it carefully and slow until you understand the process. It will give you the best information you can get on the rods and blanks with out having any labels.
Do not try to reformulate the process or out think it, unless your a Math genius, just go with what it tells you about the rods. Sometimes you look at the rods and then look at what the data tells you and you say to your self " NO WAY ", but trust the data it does not lie.

Dave, Tim is right on the mark but would also add, it's a good
idea to do CCS on rods that are labeled. You might say,
"I don't believe this".
Its all in RODMAKER MAGIZINE, thats why I'm a subscriber.

Does anyone have a link to that website I would like to give it a try.

The CCS Site is at the top of the column on the left.

Ok , Thanks to everyone I'll go thru the process and see what my results are. I will take my time with it. I will keep an open mind!!