Sounds like UV has got it. Get braid on braid or 16 plait. Throw away the old stuff as strength is severely compromised. On second thoughts, could be used as a washing line. /forums/images/graemlins/cool.gif
I would trundle off down to local rope shop .... check out some nice soft multi-braid platted stuff .... replace ...
Put old sheets away as "general" grab-a-rope stuff ...
Just because they have hardened - does not mean they have "UV'd" or that they are suspect ... It could be as simple that they are salt laden etc. UV damage usually causes breakdown and powdering in the rope ... as well as brittleness ...
Are you sure that it is <u>polypropylene</u> and not polyester?
I don't know where you're at but polyprop would not last 3 years in bright sunlight, certainly not here in the Med.
I guess I must be lucky then! I've been using a fabric softener in the washing machine for my warps/lines/sheets etc for as long as I can remember. I'm still using the same lines etc and they're in near perfect condition.
Done a hell of a lot of miles too!
Any idea what fabric softner(s) are supposed to be 'nasty'??