In making spreaders for Loops I've found a great answer. Those Afro hair combs - you know with the long tines -about 8 of them with a flat handle. $2 shop stuff. Cut the tines (carefully) with pliers to about 1 inch. Screw the handle to your loop arm, wire it up and then hotmelt glue the wire to the spreader. Taught forever. The spacing of the tines makes the wire spacing about 3/8th of an inch - ideal I have read.
