Dux all in a row

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Dynex Dux was the first mainstream heat set Dyneema to arrive in the yachting world, and  had a huge effect on rope selection on racing boats.  Using heat and tension, it gave us higher strengths and lower stretch in a smaller package, and quickly stole ground from not just regular Dyneema, but has replaced Vectran and Zylon as well.

These days, there are quite a few varieties available in heat set prestretched rope. Stopping by this week is the most recent version, and likely the strongest,  from New England Ropes.  I thought it might be interesting to compare the available options, so below are some notes.

On the left is Gleistein’s Dyne One HS.  This is by far the easiest heat set product to work with, as it has a pretty wide angle, and is soft compared to Dux.  It’s also the roundest option, and tends not to flatten out over sheaves.  The downside is the high angle between braids should theoretically make it stretchier.  The other drawback is that it doesn’t seem to be much stronger than regular Dyneema, at least in the small sizes.  Last summer when doing some break testing I found that the 4mm Dyna One HS broke at ~3800lbs, where as plain old New England STS75 breaks well over 4000lbs.  The 9mm shown is supposed to be approx 18000lbs, which is again in line with regular Dyneema.

Second from left is Maffioli Ultra 75, actually the core from 11mm double braid. This is probably the least stretched product, and rated at 17000lbs it’s the weakest as well. It’s kind of an odd duck(x) here as it’s not targeted or made like the others, and I believe it’s just a quick prestretch to take out some of the constructional stretch.

Middle line, in dark gray, is Marlow’s D12 Max 78 product. Rated at ~23000lbs, this is much stronger than the first 2.  It has quite a long angle, partly from construction and partly from stretching.  This is the only SK78 product here, but they also offer an SK90 heatset, for max (ha) tensile.  Marlow has the widest range of fiber choices, and more importantly sizes, going all the way down to 3mm which is unique for a heat set dyneema.  The downside to Marlow is the stretching process makes for a rope that isn’t very round,  as it’s flattened out over whatever bobbin they use to stretch the product.  The Dyneema is a bit fuzzy when new, due to the fibers that fail during prestretching.  This is the choice of high tech dinghy and small cats, as the range of sizes makes for lots of options.

At the far right (I’m skipping the second right for the moment) is a piece of Dynex Dux in 7mm, as I was out of the 9.  The original, and still very good, it has a rated break of ~26000lbs, and is quite round and very stiff with less popped strands than the Marlow. The amount of prestretch is very high, which makes it a good choice for running rigging where stretch is key, as well as some standing rigging and slings.  I really like this material for backstays as it’s so light and strong you can be quite aggressive in downsizing.  Most people call any prestretch Dux, but that can be troublesome as some of the other heatset products aren’t exactly interchangeable as far as strength and stretch.

Second from the right is the newest arrival, an as-yet-unnamed product from New England Ropes.  Pretty excited about it, as it seems to have taken all the best attributes from the other brands and improved on them.  The construction is very similar to Dynex Dux, but lacks the flyaway/popped strands. The roundness of the rope is closest to Gleisteins product, and the smoothness is better than any of them.  NER hasn’t released final break numbers, but the initial tests had it all comparing very favorably with Dynex Dux, which is really saying something.  This particular spool is destined for the VO70 Il Mostro, replacing the Gleistein rope is arrived with.  I’ve got more spools arriving soon and am going to have more info soon!

Gear Review: Harken Hyperseal Semi Dry Top

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Had my first chance to try out a new piece of sailing gear last Sunday, which turned out to be ideal foul weather gear testing conditions-strong emphasis on the “foul”

Needing a new top besides my discount rack Gill jacket, I decided to try Harken’s new Hyperseal Semi Dry Top.  It’s similar to a kayaking or sailing dry top, but with neoprene seals instead of latex.  This is a big deal if you can’t stand the pinch in your extremities that latex delivers.  I was still a bit nervous as I’ve always disliked tight fitting neck seals, and have done a lot of trimming of the gaskets over the years.  I ordered a large and gave it a try frostbiting on a Sonar for 1 generally uncomfortable race.

Good:  The seals are great!  I was nervous they’d be too tight in the neck (hence the large when I wear a medium) but it was perfectly comfortable all day.  Since it was blowing 12-20 with giant waves, I got the chance to experience a few different methods for getting hit with water, and all the seals held tight.  It was a day where you’d definitely notice leaking seals as the air temp on land was mid 20′s, with a water temp around 32.  The fit is nice as well, and it’s generally easy to get in and out of.

Bad: the pockets are kind of silly, as 2 are way up high on your chest, which makes them difficult to reach for a handwarmer (see temp report above) and the third pocket on the sleeve is similar to the 2 chest pockets in that it’s just a mesh lining, so the second you open the pocket a wave will naturally do whatever it takes to deliver an icy-cold insult to your totally permeable mesh pocket.

WTF: The left sleeve has a clear window, theoretically for your watch. I say theoretically as any watch that’s encased in your sleeve, behind this window which is the same material as a sail window, is going to be useful only for admiring your taste in timepieces as you’re just not going to be able to adjust the buttons effectively.  At least, you would be admiring it if it wasn’t for the fact that it’s a clear window that forms a layer between a warm body and a cold world, so naturally it fogged up completely.

Above: the neck seal is great; it’s neoprene lined with lycra or something, which makes it quite comfy. Looking at the wrist seals you’ll notice the smooth texture on the inside, and the rougher, presumably more-UV-safe outside. Also notice the handy window on the left sleeve, which you’ll be able to gaze into in order to ascertain just how much you’re sweating, before checking your watch where it belongs on the outside of your clothes.

In conclusion, this piece of gear is great.  Aside from the disappointment that a Hyperseal isn’t some kind of excited or sci-fi harbor seal, and the silly watch window it’s a really comfy top and great in cold weather.  CYR has a special price for $160 plus tax on these for the rest of frostbiting season, and you can stop by to try mine on if you like. Just leave your watch off!

New Tylaska Thimbles

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By now the aluminum ferrule or friction ring is pretty ubiquitous, but just a few short years ago when one was needed we’d have to get it custom made at one place, anodized at another and then figure out what to charge for it (usually a lot per ounce!)

These days every boatbuilder and hardware manufacturer seems to have an offering on the shelf, and thats good news for us as the options are broad, the prices low and the quality high.  Tylaska is joining the fray a bit late, but with the widest range of options, very nice finishes and good pricing.

Above is the spec sheet, since I couldn’t find it online, as well as a few samples. Up right is the FR7 ferrule, which has a working load of 1900, and it’s little friend below is the FR4, which has a 600 working load but is the size of a dime.  The FR4 is “cute” and makes me want to make a really complicated little RC boat so I could use it for runner blocks!

Also in the image, bottom left, are some of the other brands of thimbles we use.  Bottom left is the Antal 20.14, and the Schaefer 2012.  These are comparable in size to the Tylaska FR14, and one would expect similar working loads. The FR14 is 7000 SWL, and while the other 2 don’t list loads it’s safe to assume they’re similar (and that the line that fits and runs will probably be far weaker!)  For what it’s worth, the retail pricing is $40 for the Tylaska FR14, $20.40 for the Antal, and $22.70 for the Schaefer.  Quality wise, the Tylaska is the nicest, with the best machined radius’ and slickest anodizing, and the Schaefer is on the other end (although still very good!) with duller and slightly rougher finish.

CYR works with all the manufacturers, and can help you sort out which hardware best suits your project.

1/8″ Dyneema Break Test Bracket: Quarterfinal Rd 4 Soft Shackle vs Brummel Splice

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Here’s the last result from the quarter finals.  That’s an 1/8″ soft shackle with diamond knot on the left, and a pair of brummel splices with full buries on the right. They are in basket configuration to even things up with the soft shackle.

3718lbs break, and it was the soft shackle that failed.

 

1/8″ Dyneema Break Test Bracket: Quarterfinal Rd 3: Bowline vs Sliding Sling Splice

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For the bowline apologist/splice deniers out there and other YC bar curmudgeons: the bowline lost.

Here we have an ordinary bowline with nice long tail to prevent pull out, vs a sliding splice.  The sliding splice has quite a few names, some more hilarious then others like “whoopie sling” or “that thing that that one dinghy had on it’s hiking straps, you know, to make it adjustable”   It’s essentially a buried splice that exits the line again, and so the size of the eye (and thus the length of the sling) can be adjusted by bunching up the splice and sliding the tail.  Well, it lives to fight again another day, as it’s stronger than the bowline.

1/8″ Dyneema Break Test Bracket: Quarterfinal Rd 2: Loop vs Short Bury Splice

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This one was a bit trickier for the oddsmakers in Las Vegas.  We have a plain loop, formed by doing 72 diameter buries together, and the short bury splice.  This splice is pretty common;  it has a brummel to lock the throat, then a short (in this case 5″) bury.  It’s a common fault in 12 strand splicing to make the buries too short, either by not having enough room, or plain laziness.  Theres not much time saved, and I’m not sure that saving 4″ of rope is worth it!

The test has the loop in a single/vertical configuration, and the short splice in basket. This is to try and even the playing field, as the loop has 2 passes of rope and the short splice was obviously 2 single passes.

I was a bit surprised the loop broke first, although the result may have a bit of an * next to it, as the tope broke around the stainless steel quicklink, and not at the join or at the end of the splice.  Looking closer at the quicklink, there was a tiny steel burr there that may have given the rope a rough surface to bear on.  The 1/8″ Endura 12 has a rated strength of 2100lbs, so this isn’t out of line, but I’ve found NER Dyneema usually breaks well over the rated strength.

If the test was for anything other than fun value, I’d probably retest the loop after smoothing out the burr, but since this is just for kicks I let the result stand.  Please don’t tell the International Riggers Casual Break Testing Organization, the last thing I need is an IRCBTO cease and desist letter.

 

Winner: The Short Bury Splice*

 

1/8″ Dyneema Break Test Bracket: Quarterfinal Rd 1 Skiff Knot vs Bury Splice

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First blood was drawn in our March Mildness rope break test bracket, and the results were… (k)not surprising!

We tested the standard single braid bury splice, which is a tapered 72 diameter long tail buried into the rope, with no brummel or other lock, vs a skiff knot. The skiff knot is a stopper knot that cinches against an overhand knot, and is often used to secure dinghy halyards to headboards. It’s nice there because it’s a “no profile” knot as it sits next to the headboard as opposed to taking up space above it.

The skiff knot was a royal pain for this test, since it never really failed, but pulled out repeatedly. Not too surprising here, as Dyneema is slippery stuff, but it was a tough result to use in the test.

I tried a few versions of stopper knots, before getting best results with the barrel knot. I could have kept adding stopper knots behind stoppers, but figured this best simulated how the line would be tied “in the wild”

The load peaked at 1076 pounds, then dropped as the knot slipped out. This gives us a 51% of rated load failure. Great job, skiff knot!

Conclusion? The skiff knot releases way early, and is best used with covered rope, or in low load situations (such as a dinghy headboard…)

Winner: bury splice

Tylaska Dogbones

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Metal or carbon dogbones are incredibly useful, strong and simple ways to terminate a line or integrate soft attachments. In the past I’ve either had them custom made from aluminum or steel, or cut lengths of steel or carbon. While this works, the custom ones are expensive, and the cut rod versions need lashing to keep them secure.

Much like spool shackles, these make all the sense in the world… once you’ve seen how they attach!  A loop of line is passed through the grommet on the sail, then the dogbone is passed through the loop.  When pulled tight, the loop cinches onto the dogbone and stays fast. 

Continuing their tradition of high quality versions of existing tech, Tylaska has introduced their line of dogbones in aluminum and stainless steel. With working loads from 650 to 15000lbs, there a dogbone for every application here. CYR is stocking select sizes, and will be using these in a number of upcoming projects. Uses for Tylaska dogbones include termination of sheets, halyards and control lines like outhauls, custom loop shackles, bobstays and more. Also in stock are CYR’s range of custom stainless/aluminum dogbones for high loads.


Aw snap

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It just so happened that a friend out east emailed me regarding extracting stripped machine screws at the same time a pile of Sonar booms arrived on my desk.  After a quick look at the booms, I sent back “give me a minute…”

The booms had been used in saltwater, and the builder hadn’t used any barrier paste in seating the screws, so I figured the odds were good I could join my friend in having to extract a tricky fastener.

It usually starts like this…

This is what it looked like before any attempt was made to open up the boom.  Looking at the screw head, it seems pretty obvious that someone has tried-although thankfully not too hard-to remove the screw, and that the screw resisted.  At this point, I usually give a pretty half hearted turn with a manual screwdriver, and when that doesn’t work (usually) I turn to the tools: 

The above will work for 99% of the problem-child fasteners in an alloy mast.  Any cheapo propane torch can reach well over 1400F, so will be more than sufficient to heat and release most metals.  The dremel tool is typically the last resort before drilling, so keeping it handy makes sense.  An electric impact tool isn’t as powerful as the air powered equivalent, but is more than strong enough for most fasteners up to around 5/16″

I like to start with heat first.  Warm the area around the fastener, and behind if possible.  The goal is to heat the aluminum around the steel, so that it expands and cracks the corroded bond between the metals.   Keep the torch moving in a circle around the fastener, taking care not to heat any area too much.  The impact driver is next, and the impact action usually breaks most fasteners free.  If this doesn’t work after a couple applications of heat and impact, or you’ve accidentally turned the fastener head to mush, the next step would be the dremel with a metal cutting wheel. I like to cut a groove across the screw head, with a width great enough to accept a large flat head screw driver.  Here you can see the groove, which has helped to extract the screw.  Try heat before extracting, and this usually does the trick. Also visible on the threads is the powdery white corrosion, which you have to thank for the last couple minutes of life that were wasted on this project. Remember, when reassembling use new fasteners and plenty of duralac/TefGel/Loctite… anything but nothing!