I'll give you something to try that will give you a very rudimentary way to get a starting point. It is using some basic principals from the common cents system recently developed by Dr. Bill Hanneman. PLEASE keep in mind that this is not really using his system to anywhere near is fullest (and intended) potential, but I think it will get you a reasonably close starting point. First, find a way to securely support the rod horizontally by the grip/reel seat. Perhaps in a shop vice would do nicely. Then, using a small hanging powder scale tray or a small bag of some sort that is as light as possible, start adding pennies into the tray or bag on at a time. You are going to add pennies until the tip of your rod deflects 1/3 of the length of your rod (minus the reel seat and cork grip), in this case approximately 2 feet 8 inches. Now, count the number of pennies required to make this deflection, adding an equivalent amount in to account for the tray/bag if it weighs a significant amount. Here is a rough conversion for you.
14 = 1 wt
21 = 2 wt
27 = 3 wt
34 = 4 wt
41 = 5 wt
47 = 6 wt
55 = 7 wt
63 = 8 wt
If your number falls in between, I'd use the smaller line weight unless it is very close to the upper number. Not perfect, but it should get you reasonably close if you choose a line that follows the AFTMA standards for lines (which they all should). I'd suggest getting a basic line and nothing fancy (or too expensive). Hope this helps.
