I would like to setup a pull-pull system which includes a steel wire with metal couplers( no eye hook) .
as i understand the steel wire should be inserted into the coupler hole and then soldered.
i have several questions regarding that technique :
a) will it be strong enough to use within a fun fly
b) what type of solder material shold i use
c) is a 20w iron solder will be good enough
d) should i just insert the wire normally into the coupler and then solder
e) should i clean the steel wire with alcohol or something before soldering
f) how can i test the solder strength/quality

sorry for all the questions but this is my first pull-pull setup and i really would like it to hold up

thanks