Why does Polypropylene rope get such a bad press ?

[Guest]

Pick up any book on knotting and it will tell you that this rope wears badly and has poor resistance to UV

Does anyone have proof of this ?

We see the blue stuff everywhere. I have seen it solely holding trawlers on mooring buoys.

A friend of mine had it as a painter for three years and exposed to the elements for all this time. As an experiment, at around 10mm this same rope held a 23 ton boat on a spring ebb with no problems. The damn stuff seems indestructible. There are many other types which have the hugeadvantage of floating and at a very good price. I would be interested in other people's opinion of this useful material.

I do have experience of that yellow type one often sees on lifebuoy lines and dingy painters. It snapped after only 6 months under very little strain and I was lucky to get my tender back. Stuff should be banned from sale.

 

[Guest]

You may have answered your own question - I suspect that your dinghy painter snapped after deteriorating due to exposure to UV. (Worth noting that lots of mountaineers, whose lifes depends on their ropes, are fanatical about storing them in the dark - not that they use polypropylene, though!)

Polypropylene doesn't strech much, so it won't absorb kinetic energy. This means that it'll possibly snap under dynamic loads.

What it is good for, as you've identified, is applications where you need it to float (like towing the dinghy-won't sink under the prop.) or for when it'll be abraded (towing trailer up the slip) or for static loads (like tying the boat to the trailer). Not good for warps or springs(dynamic load, and exposed to sun).

Of course at 15p a metre for 12mm it's almost disposable as well.

regards,
Rich.