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Discussion Starter · #1 ·
For an upcoming writing project, I've set up a machine that will saw lines back-and-forth over a variable abrading surface under variable pressure and deflection angle. While my operating range is limited, I'm pleased that I can at least produce frayed lines that resemble frayed lines I've replaced over the years, with no melting or cutting.

What lines should I be testing. I will certainly go to the common chandleries and get a few feet of everything. That much is obvious. But are there commercial or fishing lines that work well on recreational boats that are unknown to much of the boating public? Suggest a source and I'll give it a whirl.
 

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Contact R & W Ropes in New Bedford Ma.
Have been serving Commercial/fishing as well as recreational
mariners for many years. (climbers and safety/rescue as well)
Knowledgeable and helpful and might be able to sell/donate?
some bits and pieces as well.
Have been making some soft shackles out of Amsteel over the
winter (used some tubular webbing over some) will see over next
few seasons how they hold up...unless I read your article first.
 

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Discussion Starter · #3 ·
^^ Will contact.

I think most people find Amsteel soft-shackles to be rather wear resistant, and find a covering inconvenient. In my case, I simply go up a size if I'm concerned about wear. However, if there is an unavoidable rough spot, a cover will work better, since the cover floats.
 

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Don't forget to get the really cheap stuff from the boating section of your local WalMart or camping store. Not everyone goes to West Marine and I have seen quite a bit of crappy looking (likely colored polypro) line on MacGregors and the like.

Are you going to test docklines as well? I never seem to chafe through running rigging, but docklines get replaced due to chafe with regularity. 8-plat, 12-plat, double braid, 3 strand etc would all be useful to know about for docking and anchoring purposes.

MedSailor
 

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Discussion Starter · #6 ·
Go to ASTM.org and look up "abrasion testing - rope" etc.
No sense reinventing the wheel if there is already an established national/international standard test method already in effect.
Very true. I am aware of the method for yarn-on-yarn abrasion (D6611). Our method is related, but we are not testing the same thing. Did you have a specific method in mind?

I am a member. The challenge, of course, is that many ASTM rigs are too onerous for limited use. The second challenge is that they don't always measure what you want to test (there many not be an ASTM method for the characteristic of interest). In this case, for example, there are wear methods for ropes but not for chafing gear.

Some of my testing--I have some work on engine coolants coming up--follows ASTM procedure out the door. Other times the best that can be done is to copy the fundamental principles and practice good scientific method. Most often the challenge is to be certain you know what you are measuring. For example, in accelerated wear testing of rope you need to avoid heating problems, since that is a separate variable (certainly a very relevant variable in some high-load applications, but it is a separate variable).

Another factor is testing under widely varying conditions. Engine coolants, for example, are really tested only under engine operating conditions, which are relatively narrow and well understood. But rope chafe varies from high load on a sharp edge to light load against wood or something similarly benign. Clearly, there will be more than one set of tests. The reality is that cordage companies have their own methods, generally not ASTM; they each have specific interests, and so far as I have learned, no specific standard.

Fun stuff.
 

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Discussion Starter · #7 ·
Don't forget to get the really cheap stuff from the boating section of your local WalMart or camping store. Not everyone goes to West Marine and I have seen quite a bit of crappy looking (likely colored polypro) line on MacGregors and the like.

Are you going to test docklines as well? I never seem to chafe through running rigging, but docklines get replaced due to chafe with regularity. 8-plat, 12-plat, double braid, 3 strand etc would all be useful to know about for docking and anchoring purposes.

MedSailor
Absolutely. Of, course chafe guards and coatings (Maxijacket has been impressive) also make sense here.
 

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Discussion Starter · #10 ·
I would expect the presence of salt crystals in the lines would significantly affect wear and chafe, so will you be salting and soaking them to replicate the condition of real lines in a saltwater environment?
Internal wear, yes, but we're not testing that this time.

External wear on a smooth drum. Yes, and in fact when testing lines for mining it is normal to coat them with lime or other dust. But we will be using surfaces with sufficient roughness to overwhelm any salt crystal effect.

In fact, I'm willing to bet pre-soaking the lines in a standard lime slurry followed by surface cleaning and drying would be a more repeatable way of modeling this, since lime crystals are far more uniform and persistent. This seems to be the loose industry standard method, if there is such a thing.

A good thought.

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I will, pre-wash all of the lines several cycles to remove those spinning lubricants that would wash-off in the first year or so anyway. This is a standard part of testing lines for durability (a major manufacturer had me do this in a prior testing program).
 

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Discussion Starter · #12 ·
^^ I started the project focused on running rigging, and now I see much of the interest is on docklines. I guess I never give those much thought, since with good chafing gear they last forever, and without chafing gear they last no time at all, perhaps not one storm.

That will definitely be a focus. I also have the gear to break them after wearing a set time, so comparing brait to double braid to 3-strand won't be hard. the only challenge will be what I can find in the smaller sizes I will be working with (3/8" - 1/2").
 

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Three-strand nylons, double-braid nylons, 8-strand braits

I suppose those are the dockline choices, no?
All can be anchor line choices as well. Nylon lines of the above mentioned braids seem to be more popular in the US where as polyester anchor rode is popular in Europe from my understanding.

Resistance to chafe in anchor rode is a VERY desirable quality!

MedSailor
 

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Discussion Starter · #15 ·
* Do you test until they wear clear through, or only through the cover? Most lines are not designed to function with the core exposed, some are.

* How do you compare a single braid (Amsteel, brait) to double braid, when there is no cover as a wear indicator?

* Loss in weight is possible, but some fibers shed while others fray. No good.

* Cross section under light tension is possible. Measure both ways and calculate as an oval or a D. For most lines, cross section correlates rather well with breaking strength, though it does not consider internal damage.

*I can't break-test the samples because the high-mod lines will be too strong until nearly finished.
 

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* Do you test until they wear clear through, or only through the cover? Most lines are not designed to function with the core exposed, some are.

* How do you compare a single braid (Amsteel, brait) to double braid, when there is no cover as a wear indicator?

* Loss in weight is possible, but some fibers shed while others fray. No good.

* Cross section under light tension is possible. Measure both ways and calculate as an oval or a D. For most lines, cross section correlates rather well with breaking strength, though it does not consider internal damage.

*I can't break-test the samples because the high-mod lines will be too strong until nearly finished.
Are these questions for me?
 

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Discussion Starter · #17 ·
Are these questions for me?
This is a forum. They are open ended and for anyone interested. This figures to be a right good size project, so the more ideas I collect, the fewer false starts.
 

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Discussion Starter · #18 ·
^^ I guess my feeling is that while we can easily look-up strength and stretch data, there is no abrasion data available, even though it is the most common reason for retirment.

I'm not going to create anything definative--there are many abrasion senarios and I'm only going to pursue one case (light load), with a few abrading surfaces (wood, grind stone) and a few chafe guards. IF the results are interesting enough, if there is reason to believe higher loads will give different rank-ordering, and if there is enough interest, then comes phase 2 (higher loads).
 

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I think it would be good to see some real data like this on Amsteel Blue VS coated and un-coated steel life lines. Since there are a lot of people going synthetic on life lines now, even in the cruising world.
 

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Discussion Starter · #20 ·
^^ That is another part of the project. I will be using a stanchion as one of the abrading surfaces, fitted with several anti-chafe options.

Typically each test runs about 1 hour, so many permutations are possible.
 
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