Brion Toss

Does any rigger out there have any definitive spec's on the creep properties of Amsteel (Dyn. SK60)?
How much creep, how much load, over how much time?

I have read over and over again about how "SK60 creeps, so don't use it for halyards".

What I don't yet understand is if that is applicable to me. For example, you could also say that line XYZ stretches too much for jib sheets, but for a 4KSB, maybe that doesn't apply since the loads are lower than say, an IACC boat, or something.

So, what are the specs and figures on SK60 creep? Then I can decide for myself if I am willing to save a few bucks going with SK60 vs SK75 for a halyard.

As an example, here is a paper I found for SK75 creep properties:
http://www-lgm2b.iut...li/PE fibre.pdf

-M

Hi,
This is definitely a fuzzy topic for me, and a read of the above paper might indicate why. But some very patient engineers, the kind of people who would actually find that paper intelligible, have explained that creep is how polymers accommodate stress. They don't do it the way most materials do — fracturing, for instance — but by "relaxing", almost as if their little molecules just got tired of hanging on, and just slipped a bit. Accordingly, how those molecules are oriented will go a long way to reducing creep, but the nature of the materials is such that it doesn't seem possible to eliminate it.
Load over time appears to be the primary factor, and one source had it that you basically have about 100 hours at typical sailboat design loads before the rope creeps. Higher relative loads, and higher temperatures might shorten this time, but at the very least we can unrecommend Spectra for anybody's roller-jib halyard, or any boat on a passage.
As for details, I don't have a number, in terms of percentage of halyard length, for how much a rope might creep, relative to load and time. But before I stopped using it for halyards, it seems like the rope would stretch out at least a couple of inches when it crept. Annoying. And I understand that creep deformation is damaging to the rope, so it's not like you can relieve the load and start over.
Fair leads,
Brion Toss

Passivation is a process by which steel becomes "stainless" by immersion in a heated bath of phosphates.
In a salt water environment this protective film is often worn or corroded away.
Wichinox is a non-hazardous paste which contains a phosphoric acid that will re-passivate, seal and protect your stainless steel.

As I understand it, the grade of (high-strength) metal preferred for shackles these days is more susceptible to surface corrosion than other grades of stainless; long-term shininess has as much to do with how well the piece is finished as how well it is forged, or in what material. Tylaska is famously obsessive about finish, Wichard not so much. So follow-up polish and passivation should take care of things, assuming standards aren't slipping in other departments.

According to Brion Toss, "Making Your Own Eye Splices" video:

Brummel splices are for uncovered spectra-type lines. Burying isn't enough, because the tail will come out when the line isn't loaded (lines are low friction). He also states that lockstitching is a waste of time because these type lines tend to be heavily loaded and the stitching will just break. He suggests DOUBLING the usual tail length, even with the locked Brummel.

I think the ol' boy knows what he's about, so I'll take his word for it.

Ol'boy? Thanks, I think. Interesting discussion here, and I thought I'd chime in. First of all, someone asked why bother burying the tail, if the Brummel takes the strain. You can in fact do this with a single Brummel, which is why that (or, preferably, one-and-one-half Brummels) can be used to make one-piece Genoa sheets in braided Dacron.
In high-modulus rope, the load is too localized for ultimate strength, though we have found that multiple Brummels, proplerly spaced, will break in the high 70's of ultimate strength.
As noted above, we put a single Brummel, whenever possible, at the start of every uncovered HM splice, because it is more reliable than stitching for holding the preliminary load. Yes, I know that few people do this, but I've seen a few too many non-brummeled splices crawling apart. Even an "S" Brummel is preferable to stitching only. As for the Brummeled section weakening the splice, I can only point to the many destruction tests we've carried out, with numerous ropemakers, indicating that a combination of locked Brummels and good, long buries, with, as someone recommended, obsessively long tapers, will yield maximally strong splices.
Next, we do indeed stitch our uncovered HM splices, as well as Brummeling and burying. We do this, very lightly, at the point where the tail enters the standing part; the idea is to keep the tail from simply falling out of the rope when there is no load at all on the rope. If you don't Brummel, I urge you to stitch and stitch and stitch.
Someone else pointed out that there are no Brummels on a covered HM splice. True, but then you have a massive braided cover, run snugly up the entire length of the splice, compressing so tightly that it's hard to get the darn thing all the way home. And then you whip, or serve, or heat-shrink the cover nub down, which provides even more security. So you're accomplishing the same thing, by different means.
Finally, there's the matter of tail length. All splices work to the extent that they can generate friction, and different materials and constructions and uses have different requirements. This is true in stranded as well as braided rope. Most braided splicing instructions are based on multiples of 21x the diameter of the rope. We use 24x, partly because calculating tail length is thus infinitely easier, and partly because it allows us to work even longer, finer tapers into the rope. So a 1/2"d Dacron rope will have a 12" tail (24x1/2"), a 1/2" covered HM rope will have a 2ft tail (48x1/2") and an uncovered 1/2" HM rope will have a 3ft tail (72x1/2"). As the ropes get stronger and slicker, the tail length goes up, just as the number of tucks in stranded rope goes up when you mover from Manila to Nylon.
Fair leads,
Brion Toss