RE: BALSA USA 1/3 SOPWITH PUP?????
I used the JB we'd on my DR1, attaching the music wire into the aluminum struts.
The cotton is used to provide a stop for the JB weld so it does not run down inside of the aluminum tube. This allows the JB weld to remain in place so there is a complete bond with no airspaces. Notching the wire prior too, also allows for a solid joint and something for the JB weld to adhere too.
Seems to have worked pretty good, no issues that I know of.
Craig