Dynemma Chafe Guards

Jun 21, 2004
2,532
Beneteau 343 Slidell, LA
Have any of you tried NE Ropes, Dynemma Chafe Sleeves for chafe guards on dock lines, etc.
Didn't know that the product existed until I saw it advertised in an online site. Curious if anyone has experience with effectiveness, durability, etc.
Thanks.
 

Joe

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Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
No.... but short lengths of old garden hose work well and it's cheap.
 
Jan 11, 2014
11,321
Sabre 362 113 Fair Haven, NY
When it comes to chafe protection, heat not abrasion is the enemy. When under stress, as in a storm, heat builds up from the internal friction in the rope. Heat weakens the fibers and can begin to melt them. This is not usually visible from the outside. The inner fibers weaken and begin to break reducing the strength of the line.

Some traditional chafe protection has good abrasion resistance, but they allow excessive amounts of heat to build up. Garden hose, vinyl tubing, and fire hose allow this. Chafe protection made of fabric allows for better heat dispersion and allows water reach the rope and cool it.

I've used Dacron chafe protection with good results. However, now I am of the mind that chafe protection is not necessary and may be a liability because of heat retention, provide a nice clean run from cleat to cleat can be made without sharp bends, or contact with dock edges and other sharp corners.
 
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Mar 26, 2011
3,400
Corsair F-24 MK I Deale, MD
I have used and tested the NER sleeves for standing and running rigging, sliced in. Very nice. But overkill for this.

Tubular climbing webbing is the real deal, cheap and very similar to Chafepro. Very durable. Any climbing store or on-line (nylon tubular climbing webbing, 1" or 2"). I've been using this approach for 30 years.

Heat retention due to stretch...
  • Is only a factor 3/4" and up. You can do the math.
  • Most heating is due to friction. It has become internet legend that this is internal heating, because that is more mysterious. Use chafe guards that let the rope slide (tubular webbing) and minimize the distance from the rope to the chock (less motion). Again, you (an engnieer) can do the math on this. Or just rub your hands together and feel the heat.
If you think about the engergy balance, the only stretch energy that turns into heat is the hysteresis portion (the rope is not a perfect spring). The rest is simply returned to mechanical energy on the rebound.

Yes, broken lines some times seem melted:
  • If there was enough stress to cause heating, the rope was operating above the WLL and would fail anyway. The boat is tied incorrectly and/or insuficiently, or perhaps the marina is simple too exposed and there is no good solution. The US Navy has done studies on internal line heating, and below about 1-inch you just don't see it. On large ship tow lines, yes. We're not ships.
  • External friction, of course. Reduce motion.
  • ANY nylon rope will melt if pulled to failure ONE CYCLE. I do rope testing, and the ends are always slightly fused. This does NOT mean the rope heated due to cycling, this means there was a large energy release.
 
Last edited:
Mar 20, 2011
623
Hunter 31_83-87 New Orleans
Practical sailor just released an article on heating in dock lines