How can I identify nylon vs. non-nylon line?

SFS

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Aug 18, 2015
2,066
Currently Boatless Okinawa
Ok, I've had the boat two weeks now. Working through little things, but that isn't preventing us from taking her out. Here's my next issue:

Reading various threads and getting unsolicited advice from dock neighbors leads me to believe my docking lines need to be nylon, for the stretch factor. The boat (1983 Hunter 31) came with a lot of lines on it, and I've just used what I had, without knowing whether it is nylon or not. Is there any way to identify nylon line?
 

Joe

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Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
I would solicit your dock neighbors' help to sort the nylon from the Dacron/polyester.... On my boat, almost all the mooring lines in the rope locker have an eye splice on one end.... so that might help in the beginning. Another strategy would be to go to your local chandler and ask the experts there the same question... Once you look at and hold them the differences will be easier to discern.
 
Apr 5, 2015
50
Islander 26 Little Creek Navy Base
I have quite a few nylon dock lines, a few poly.....even a few hemp.

The nylon material feels much softer to the touch regardless of the strands or braid type.... and are easier to tie off? The poly material, braided, or 3 strand lines are a bit more rigid and slippery. I rarely use any poly around the boat except for wrapping my sail cover, or securing some odds and ends.

I use those rubber shock absorbers (snubbers?) on all my dock lines due to higher winds in my area during the fall and winter. I got them free from another boat owner that is helping me along.

I am a newbie to sail boating myself. Hopefully, some more experienced members could chime in.
 
Nov 8, 2007
1,523
Hunter 27_75-84 Sandusky Harbor Marina, Ohio
Stretch it!

Secure one end of the line to a cleat on the dock, grab it about 30 feet away, and lean into it. Nylon will stretch much more than the others!
 
Jan 19, 2010
12,362
Hobie 16 & Rhodes 22 Skeeter Charleston
Go to a store that sells it... and feel it. Nylon is smoother to the touch.
 

Zed

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Aug 19, 2015
96
West Wight Potter 19 Bar Harbor
Nylon tends to get hard after awhile, especially if exposed to the salt of salt water. I'm not sure how big a deal it is if its poly or nylon, unless you are battening down for a big blow.
 

SFS

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Aug 18, 2015
2,066
Currently Boatless Okinawa
Are all of these things (smoother to the touch, gets hard with exposure to salt water, obvious stretch over 30 feet when loaded) true whether the construction is 3 strand, or double braid, or other type? Said another way, can I eliminate the material based on the construction technique?

How do I begin to educate myself on these issues? I've been reading threads on various sites, but those threads seem to be application driven (which is appropriate), and I'd like a broad overview. Do the major cordage company (New England Rope, Samson, etc) websites have primers?
 

Ward H

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Nov 7, 2011
3,645
Catalina 30 Mk II Barnegat, NJ
Are all of these things (smoother to the touch, gets hard with exposure to salt water, obvious stretch over 30 feet when loaded) true whether the construction is 3 strand, or double braid, or other type? Said another way, can I eliminate the material based on the construction technique?
Despite material type, 3 strand will stretch more than double braid. I started off with nylon double braid. When I used spare 3 strand line to double up for a Noreaster, I made the 3 strand lines slightly shorter than the double braid lines. It was obvious that the 3 strand line stretched until the DB line was pulled taught and jerked the boat because it did not stretch. I then switched to all nylon 3 strand lines.

So your boat neighbors advice is good. You should use nylon line for dock lines and 3 strand nylon if your boat gets tossed around a lot.
Here is what I was taught about the three type line materials.
Nylon sinks and will become waterlogged. It has more stretch. Good for dock lines.
Polyester sinks but does not become waterlogged. Good for running rigging.
Polypropylene floats. Good for rescue ropes for floatation devices as it will not sink and foul a propeller.

Hope that helps.
 

Joe

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Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
I think there are some pretty cool responses to this very interesting question. I like rgranger's burn test table..... and Pateco's article with pictures. Nice work, all of you.
 

SFS

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Aug 18, 2015
2,066
Currently Boatless Okinawa
Agreed. All the responses are much appreciated. I'll get back to this after I get the boat in the yard to replace the broken strut. (And maybe have a bottom job done while it is hauled. B O A T!)