youre all overcomplicating this. Get a computer power supply. Can be very easily modfied, had for free, and easily spport enough aperage and voltage for this to work. Plus, use aftermaret UI’s and codexes to modulate the power.
Car battery jumperleads and some wire from the dollar store works for me. Bow is H shaped Bungy cord at one end. Wire at other cheap simple works. 
search function…it’s all there…if you live in Australia there’s plenty of surf supply companies…for you…so you do not need to make your own blank…buy a blank. stop wasting your time.
Stingray and several other people have posted several times …There’s so many threads on how to do this…making your own blank is easy…use the search function…
The Aircraft Spruce hot wire materials are on their site under composite materials. The doorbell/dimmer wiring diagram picture has changed so it may be correct now. There are other hot wire set ups and accessories offered also that are interesting.
IN PICTURE:
Laptop adaptor with rheostat to balance voltage for smaller hotwires using same wire and power pack as for 28".
12" hotwire.
Pink elastic.
while probably not overly difficult, the adventure into electricity and hotwires doesn’t seem that exciting to me. the wire saw does. thanks everysurfer.