There is nowhere to buy a string, or materials in my small town.  I need to make a string for my Oak Pyramid bow, and a friend showed me how to make an endless loop, if that is the right term.  
My question is about materials.  I have some spectra power pro fishing line, 50# test, round vs flat shape.  I also have nylon sewing thread my wife uses in her krafts.  Can the fishing line work for a string, and the nylon work for serving?  If it can work, how many strands for a 40-50# bow?
I plan to get some materials online, but I wanted to get something to shoot with this weekend.  
I am asking for problems?
thanks
Scott