There are lots of ways to tie the knot. Everybody has a favorite method.
First the rubber must be made slippery, or it will tear when the knot is
pulled tight. Saliva is often used. I dilute lube, made from green soap and
glycerine, to 25% with water and use that. If straight lube is used, the knot
will slip open. The rubber should be washed first. A popular knot is tie a
simple overhand knot in the two strand ends together, pull it tight, then tie
another in the reverse direction right next to the first, pulling it up snug
against the first. Square knots are used. Some put CYA on the outside. I
don't because the CYA hardens and has sharp edges. I put an overhand knot in
both ends of the strip, overlap them and tie a clove hitch of thread around
the two, followed by a square knot. Lube well and pull the rubber knots
together against each other.
Of course you must lube the motor well before winding.
