Does anyone know how to accurately calculate the line weight of a blank when it is unknown?
Thank you
Robert

Use the Common Cents System (info at top left) to test the power (ERN) of the blank. Then you will have a very good idea how your blank compares to other blanks and rods which will help you decide what line to use it with. The CCS database (also top left) has 100s of fly rods and blanks tested for you to compare your blank with. Hopefully, you'll see some blanks or rods in the database that you are familiar with and that will help you understand what you have there, in terms of power. If the blank is unknown, you'll never know what the manufacturer intended, but who cares? How you want to use it and how much power it has is what matters.

Also if you can measure the butt and the tip top of the blank and " maybe " know who made it, you can look around and find some thing similar to compare it to.

In case you would like an alternative to the Common Cents system, I have found the following to be helpful as well, Now I'm not suggesting this is better than the Common Cents system but just something else that is easy to perform and it holds up pretty well to what I have found personally. OK, now I'm running for cover. ha

[home.att.net]

Rob, any tool that works for you is a tool worth having and using. No need to run for cover. If the CCS catches on more, it's utility will increase because manufacturers, anglers, and builders will all be speaking the same language instead of multiple different languages.