could i use insulation tape or should i go eith gaffer tape?
I wouldn't recommend either to be honest. I know some people use insulation/electrical, particularly for aesthetics, colouring etc, but i don't feel it does much extra protecting and gaffer just looks stupid on springs - always, cos it ends up a mess and even if it doesnt, its just wrong 4 the job.
A great stuff for it is hockey tape, its really nice, kinda tough, one roll should do a couple of springs if you do it right and you can still get it in a variety of colours. or a substitute is medical tape, but that only usually comes in white, but its a similar stuff