Nylon vs Polyester

[cfarrar]

So does anyone know of a U.S. supplier for polyester multiplait?

[estarzinger]

[QUOTE=Kettlewell;636219]Back to the original question on this thread, for those of you who do use polyester anchor rodes, can you name which specific brand and type of polyester you're talking about? QUOTE]

Here is a polyester 8 brait:

Samson-The Strongest Name in Rope, PREMIUM POLYESTER-8

and here is a plyester 3 strand:

http://www.samsonrope.com/index.cfm?rope=22&inst=1

[Kettlewell]

Evans, thanks, those are available lines, but I was wondering what these polyester advocates are actually using. It would be nice to know what their specific experience has been with what specific type of product.

[Kettlewell]

By the way, that Samson 8 brait polyester you linked too doesn't come any smaller than about 1.625", so I'll have to wait until I retire to a tugboat to use it. The other rope listed is for arborists--tree climbing stuff. Interesting what lines are available for these specialized uses. It makes me wonder what else is out there that would be appropriate for marine use, and possibly much cheaper than when they slap the "marine" designation on it.

[boatman61]

LOL..... all this debate seems like much ado about little difference...
Me... different approach...
"DUHHH... Club get Meat.. Club get Woman... Club Good... no need Flower"

[estarzinger]

Originally Posted by Kettlewell

Samson 8 brait polyester . . . . no smaller than about 1.625", . . . . makes me wonder what else is out there that would be appropriate for marine use, and possibly much cheaper than when they slap the "marine" designation on it.

Yes, Samson makes some big lines for commercial ships. I can't seem to find any 'small yacht size' 8 plait polyester, but here there are some yacht size 12 plait polyester in polyester (here are two for example):

12 brait polyester
New England Ropes - Product Details

http://www.samsonrope.com/index.cfm?rope=70&inst=1

I believe Steve Dashew used normal sailing double braid rather than brait construction. So, I don't know anyone who is actually using a polyester brait for anchoring or mooring lines.

Lots and lots of other ropes outside the 'marine' labels. Just for example, I am using a yale spectra single braid that is primarily sold into the logging industry for my mainsail reef lines.

[Kettlewell]

Thanks for looking into those lines--still interested to hear from anyone who is actually using polyester for anchor lines and what specific product they use and what their experiences have been.

Myself, I am still highly skeptical of this idea. It seems to me that you are preventing one problem--too much elasticity leading to overheating--by creating a worse problem--too little elasticity creating unacceptable loads on your anchor and/or your deck fittings. I suppose you'll solve the overheating problem by jerking your anchor right out of the ground and letting it drag, but I don't think we want that.

Looking back at Dashew's article about this he repeats several times that one can increase the energy absorption of the polyester line by simply letting out more scope, but that is often not possible. As I said previously, if this overheating is caused by too much cycling at a high-percentage of the line's breaking strength than why not just go up a size or two in nylon?

In any case, I'm sticking to nylon until I hear some convincing arguments and real-life examples otherwise. Plus, I don't see any manufacturer's of rope recommending polyester for anchor rodes.

[estarzinger]

Originally Posted by Kettlewell

until I hear some convincing arguments and real-life examples

Steve D uses an all chain anchor rode and he uses a spectra single braid rode for his series drogue. He does have a para anchor with a dacron double braid rode but he has not used it in anger and never intends to use it (As of the last time we talked about it). If I remember correctly he is using spectra cored double braid lines for his mooring lines (with really strong welded on cleats). So you will likely not get any 'real life' feedback from him on polyester rodes.

[Kettlewell]

Steve D's current boat and even his previous boat are so far out of the mainstream that I don't consider many of his ideas to be "real life."

[boatman61]

Originally Posted by Kettlewell

Steve D's current boat and even his previous boat are so far out of the mainstream that I don't consider many of his ideas to be "real life."

Apart from all chain rode which is Spot On.....
Snub if and when you need too...... I do for the quiet...
but I'm sorry guys I've not heard one good reason here for changing a system thats served me well in the N Sea/Med/AtlanticCaribbean and US of A... in boats from 21 to 37ft (mine)... OP's delivery boats its use wot they've got... and worry...
To quote Fleetwood Mac... "You can go your Own Way..."

[Kettlewell]

Steve D's current boat and even his previous boat are so far out of the mainstream that I don't consider many of his ideas to be "real life."

Yeah, that sounds kind of harsh after rereading it. Actually, I admire folks like Steve D. who are willing to think out of the box and carry out their ideas. What I meant was that a lot of things he talks about are in relation to his unique type of boats that most of us do not have. That doesn't make his ideas bad or uninteresting, just not applicable to many of us. And then some of his ideas I just disagree with! Makes the world more interesting to have different opinions and different ideas.

[barnakiel]

Originally Posted by Kettlewell

Thanks for looking into those lines--still interested to hear from anyone who is actually using polyester for anchor lines and what specific product they use and what their experiences have been.

Myself, I am still highly skeptical of this idea. It seems to me that you are preventing one problem--too much elasticity leading to overheating--by creating a worse problem--too little elasticity creating unacceptable loads on your anchor and/or your deck fittings.

(...)

You have missed my post where I give the link to the brand we have been using.

What you say about too little stretch I think may apply to snubbers (we use nylon snubbers) but not to anchor rope. And before you get the Polyester stretch (and it does stretch quite a lot) you have the catenary effect of the chain come into play.

IMHO if deck fittings of a boat can suffer damage from anchoring loads then maybe the problem is with the fittings much more than with the Polyester rope.

I, for one, will always use Polyester for our anchor ropes. And if I cannot get Polyester I will then use Nylon. I did use Nylon and do not think it suffers from any issues if properly applied and used according to its limitations (and this applies to any material to the same extent).

b.

[Kettlewell]

Barnakiel, that is a product that is not readily available in the USA. Please reiterate (I may have missed it) why you use polyester instead of nylon. Thanks!

[s/v Jedi]

New England ropes (west marine etc) sells 3-strand polyester, like this: New England Ropes - Product Details

The Sundeer 64's came with 1,000' of 1.25" 8-plait nylon (from Yale cordage) and I'm still using it. While splicing it I found a marker inside that states it's manufactured in Colombia

The negatives stated about nylon are big and I agree that polyester is better while providing enough stretch (compare the numbers but also look at absolute stretch figure for polyester).

ciao!
Nick.

[s/v Jedi]

Hmm, while reading this thread a bit more I get the feeling that the disadvantages of Nylon may not be so clear as I thought. Here's the 4 reasons:

1. Water. Nylon absorbs water, loosing strength (15%) and gaining weight. Polyester does not absorb water and does not loose strength when wet.

2. Internal chafing. This is caused by heat build-up inside the rope. The 12-plait versions might do much better but you still have the water absorption (the more stretch, the more heat build-up inside).

3. External chafing. Polyester is more durable. Sure you can oversize Nylon which you also need to because of reason #1. But that doesn't mean Nylon is better suited for use on a boat.

4. UV damage. They say Nylon is as UV resistant as Polyester, which is BS. We wouldn't need polyester sails (Dacron = polyester) if that were true. They dare to state this because of a UV resistant coating on the rope. However, that coating will quickly disappear when you use the rope as anchor rode, loosing the UV protection at the same time.

-> New England Ropes 3-strand Nylon stretches 11% at 20% of breaking load. (http://www.neropes.com/Datasheets/MAR_3S_nylon.pdf)

-> New England Ropes plaited (12-strand) Nylon stretches 2% at 20% of breaking load. (http://www.neropes.com/Datasheets/MAR_MBII.pdf)

-> compare the previous numbers with the rule of thumb figures of Nylon stretches 22-24% and Polyester stretches 15%. Things don't compute.

Anyway, the stretch of Polyester as an anchoring rode is good enough or, if you really want more stretch, use a Nylon snubber on your Polyester anchor rode. Chafing resistance is the BIG reason that more and more select Polyester (but all chain is even better of course).

cheers,
Nick.