Jamie - are you serious about using string for firepois? The safety issues concerning this are absolutely huge...there is any number of ways that the strings can be weakened, or catch fire or break with the end result being one of the poi heads suddenly flying through the air and hitting someone, or landing on a roof or whatever.
Only use metal cables or chains for fire poi, anything else is just too risky...
As for tying the strings on, this will force the strings to twist up as there is no swivel to account for the rotation of the poi when holding the handle in a frim grip. By some fishing swivels or something of a similar design to attach to the handles and preferably to the poi heads as well.
Please don't forget to mention that when you put the screws in they should be sunken below the level of the cloth, making it much harder to be burnt by the super-hot screws during an impact. These screws can burn on contact otherwise.
Also, keep a close eye on the material when burning as tends to flake off a lot. This isn't a danger in itself, but you will find when a large portion has burnt away your coat hanger and screws become a nasty type of mace which is hot and has sharp bits poking out of it.
You also forget to mention spinning off the excess fuel so that impacts won't leave a burning residue on skin and clothing...
Not meaning to sound harsh, but be very careful of giving advice to others if that advice is likely to hurt them or damage property (i.e. flying flaming poi heads).
Thanks guys...
------------------
Charles (AKA INFERNO)
newdolbel@hotmail.com
http://juggle.co.nz/fire/fire.html