Spinnaker-Sock

Hello,

Ok, I finally did it - the Laser 2 Spinnaker Sock How-To. The puprpose of this document is to bring the two worlds of the Laser 2 together. World one is the one where there are tons of really great fast spinnaker trap dinghys available around North America for next to nothing - like $1000-$1500. The other is the world where Laser 2's aren't just fast, but they're fairly easy to launch & douse spinnakers in too, thanks to them being one of the early boats to come with a spinnaker launching system, or "launch tube" as Vanguard calls it.

The catch is that launch tubes were only standard starting in 1992, and boats that new usually sell for $2500 and up. Still a great deal but a far cry from $1000. I wanted it to be possible for someone to take an older boat and have it be just as cool and easy to learn in as a new one. While many argue that this system isn't necessarily faster than the bag-launching system, I promise you, it is much easier to learn. You can get into, and take full advantage of the boat's power and performance, much easier and sooner this way. Three summers ago, I got rid of my bag boat, and traded up to a tube boat b/c in three years of owning the bag boat, I never got good enough at the spinnaker that I wasn't terrified of it. There were few harbors wide enough for me to do a set without running out of water. And single-handing with the kite? Not a chance.

My goal was to come up with a system that anybody could add to their boat, cheaply, and without risking damage due to installation errors. You can get a real launch-tube kit from Vanguard for over $500, and you (or somebody) has to cut holes in your boat to install it. The thing that pushed me over the edge, though, to make this dream a reality was going to order a lauching bag (aka "turtle bag") for my second boat, and finding that they are $75. I just knew I could do better.

So, without further ado, the deck-mounted spinnaker launching sock.

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The finished product. You can click on any of these images to get one that's so big it won't fit on your screen.

All together, I think this entire project cost under $40, including not only materiels, but the grommet tool and the PVC cement. That's ironic since a turtle bag costs $75.

I got the fabric from The Rain Shed. They don't have much online, so just call them. The material is called Phifertex (it's $15.50/yd and comes in light grey, black, or almond, as of July 07). I highly recommend using this rather than experimenting or guessing; it's critical that the material be very slick, not absorb water, and not prone to the wet spinnaker "sticking" to it. This material is a plastic coated mesh, so it doesn't absorb any water at all. The roll is 54" wide, so one yard should be enough.

The PVC pipe & parts came from a local hardware store. They were even nice enough to cut the pipe for me since I don't have a vice.



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This is one inch PVC pipe, right angle & 45º connectors, and a 180º connector at the top (aka a barrel or straight-line connector). I used PVC cleaner and cement on every joint (as advised bye the hardware store guy).

The blue line coming in from the top is the retrieval line (currently tied off to the halyard, aka it's other end).

Yes my watch is huge, leave it alone.



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The reason for the 45º angles is that I learned via experimentation, that corners & dousing do not mix well. Oringinally I didn't have a complete loop, just 3 sides like the top you see here, then lashed to the deck. The corner between that & the deck was sharp, just open pipe touching the deck, and the kite always bunched up & got pinched there, and stuck. A square *might* work, but this does a better job of approximated the deliberated curvature of the factory tubes.

Here you can see the tension line running all the way back to the mast. The hooks pull forward & outboard, and this pulls back. Together they make a triangle of force that keeps the loop in place. But there is a better way... read on...



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I bought a cheapo tie-down kit for roof racks, just to vulture it's clips - because the were the shape I wanted, and they had a hole in the middle for a line. Unfortunately, they are rusting. Get something plastic or stainless. Load isn't high, so a solid plastic should be fine. Actually, scratch that - don't be a wuss like I was, and instead just go ahead & screw eyestraps into your deck right at the rails. If you want to be reall cool, add one off the middle just outside the hoop so it's anchored straight down instead of off to the side at that funny angle. Then you won't need the mast-back tensioning line either.


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The height & width of the loop are the same.


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At the center of each of the top 3 sides, and at the bottom of each vertical side, I drilled a hole, and ran a short stainless screw through. I folded an inch of sock material over, and put a grommet at the first corner. Then I ran the sock around the bottom, and measured where the next screw was, to locate the 2nd grommet. I continued around for each screw, getting the 1st & 2nd screws *twice*. This way, there is a full side of overlap, so it's not really possible for it to blow open.

I bought a grommet kit with brass grommets at a local sewing/fabric store.



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Just a couple tie-offs, one around the mast, or to the center bag fairlead, the other to the port bag fairlead. If you don't have these, screw a couple eyestraps in.

It's a little hard to tell here, but... 1) Since the sock overlaps itself at the base of the hoop, it does here on the bottom too. This is so you don't have to bother stitching the length of the sock. Thus, the tie-line is going through three layers on one side here - top, bottom, and overlap (also bottom). The other side goes through two layers - I pinched the top & bottom together so there would be more material. I should have used grommets, but I wanted to go sailing. Also, I left an inch of slack in the material on the top here, to make a little more room for the buched-up kite to be in there.



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Ideally I needed the fabric to be a little longer, so I could have cut it to match the deck shape. With this system, the kite sticks out a little, but it's just cosmetic, it works. The tape measure's end is right at the front of the tube, so you need to add 1" to what you see here, so you can fold it over, & double up where you put the grommets in.


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My cockpit layout (bow is to the right). IMHO, all Laser 2's should be rigged this way - it took forever to get it right, but now that I have... use it! The eyestrap behind the lance cleat directs the line so it auto-cleats. Don't use a lance cleat, get a small becketed cam cleat - a little more expensive ($18 vs. $10), but runs much smoother, and less painful to step on. Easier to mount too. The eyestrap on the other side guarantees retreival will be pulled in the right direction - one less thing for you to worry about.


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The retrieval line just runs up over the corner of the bulkhead. It would be nice to put a fairlead here so it doesn't wear out the deck - but sometimes you want to pull the kite in a little farther, when it's not coming down clean.


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The aft end of the cockpit routing. This makes it so there's very little slack in the halyard lying around the cockpit to get tangled on other stuff. It looked silly to me when I first saw it, but it works great.

I have a swivel block back there - this is a bad idea - it allows the line to twist on itself. This is the one thing left to fix on this boat - just put a fresh vertical eyestrap on the aft bulkhead, a little to the right of the bailer. A block is unnecessary here, there is never load on this turning point, and blocks can fall over, and end up at funny angles, where the line won't run clean.



A note about one-design class legalilty; Currently if you are sailing in a measured regatta, you need a waiver from the measurer. We will be addressing this necessity at the world council meeting this summer. All US regattas automatically allow any spinnaker launching system which is deemed to be equivalent in function to either a turtle-bag or a factory launch tube, and which is not believed to give a performance advantage over both of those systems.