Amsteel for Standing Rigging

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Jun 5, 2004
997
Macgregor 26D Boise
Have any Mac owners replaced their standing rigging with Amsteel (a Samson Rope Company form of Dyneema). I am in the process of fabbing up lifelines out of 3/8 grey Amsteel. I am next replacing the backstay with 3/16 Amsteel. I already have a foremost stay for my double headstay rig made out of Amsteel as well.

The strength factor is about 10:1, which means you can replace your SS wire with an Amsteel line 1/10 the diameter, making for a strange-looking standing rig. For instance, my lifeline replacement is wildly overkill, but I want the diameter to be nice on the hands. My backstay will be quite small, as it only bends the mast above the hounds in the normal, fractional rig. I will replace my sidestays with something like 3/16, reducing weight aloft greatly.

Amsteel is cheaper per foot than SSteel wire. It is way lighter, does not kink, and is easily formed into an eye by pulling its tail inside a particular length determined by the diameter. The Amsteel product is a class 2, 12 strand which makes it act like a Chinese fingercuff. If you "scrunch" it up, the hollow center opens up for easy passage of a loop. I handsew mine at the loop and tail to assure it stays in place, per the instructions online at Samson rope's website.

The blue color is stronger, the color comes off on your hands as you work it, and it costs a little more, so grey Amsteel is what I am buying. Pictures to come......
 
Jan 22, 2008
198
Montgomery 17, Venture of Newport, Mirror sailing dinghy, El Toro sailing dinghy Mound, MN -- Lake Minnetonka
I replaced my back stay and the running back stays/intermediate stays on my highly modified Venture 23 cutter with 3/16" Amsteel Blue. I'm on my second season with these and like them a lot. I did not want to replace the forestays because of the potential for chafe/wear as the headsail hanks slide up and down. I'm also a little leary of the spreader attachments for the upper shrouds. I might use the Amsteel to replace the lower shrouds, however, in the future.

One possible negative for the use of synthetic rigging was brought up in another forum: any kid up to mischief can bring down your mast with just a pocket knife.

I think you are mistaken about the strength factor. IIRC, the strength of Amsteel roughly matches or slightly exceeds that of the same diameter SS cable. It is the weight of the Amsteel that is 7 to 10 times less than the equivalent SS.
 
Jan 4, 2010
1,037
Farr 30 San Francisco
Colligo marine is pushing a synthetic rope (heat treated dynemma I think) as a SS wire replacement.

The issues seem to be
UV withstand
Creep a steady elongation with stress.

I doubt it is 10x Amsteel for SS wire on a diameter basis, maybe on a weight basis.
 
Jun 5, 2004
997
Macgregor 26D Boise
OK I get excited about something, and I overestimate strength.

I read that the dyneema products are pretty resistant to UV, at least until the 10 year replacement recommendation.

Knot creep is prevented by handsewing at both ends of the hidden tail.

I don't know about the kid with the knife.

Forestay chafe with hanked on sails: I will find out about this but I read that the dyneema is tougher than the bronze or brass in this application. It is amazing stuff.

This type of performance product may not be a good idea for everyone. Just adding an antenna and antenna wire to the masthead probably nullifies any weight advantage gained by this type of rigging. Any downsizing of diameter will definitely reduce drag.

Also any sailor with a knife can cut away a failed rig with no other tools, in an extreme case.
 
Jan 4, 2010
1,037
Farr 30 San Francisco
Not knot creep, actual creep. I am not an ME but as I understand it ropes have two specifications (the better to hide their deficiencies). Stretch is on spec this is the elongation with load and is recovered as the load goes away and the line returns to its original length. Creep is a steady non-recoverable elongation of the line with load. You could think of it as getting more line for free! Or you could curse and spend more time tuning your rigging than sailing.

What I do know is people use this Colligo Marine Dux, and others use PBO these are lines with low/no creep as well as low stretch. Diameter is about the same as existing steel wire to get creep to acceptable levels but the weight aloft and the weight of your wallet are reduced.
 
Jun 5, 2004
997
Macgregor 26D Boise
I started to build a quick disconnect bow sprite using the tangs on the bow rail for a pivot point. My last iteration was heavy and the sprite interfered with my camper shell. Along the way, I started to use Amsteel for the forestay and sidestays on the sprite. So far, I have not replaced any of the original SS wires.























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