Wednesday, February 13, 2008

Deck Paint Prep/Boom/Control Lines

Missed a couple of updates since the camera charger went AWOL. Have a new one now so I can get back to photo-heavy articles about sanding.

Deck Paint Prep:

The last paintjob on the deck was bad, really bad. I initially want to leave it crappy white and fix it next year, but a couple things intervened. 1) I had the toerails off, along with a lot of other deck gear 2) The bow had to be fixed, 3) The previous paint job was peeling off. So, on we go to another project!

I started sanding off the old paint, which is a pretty slow process. Our local glass/paint expert Mick (from Lakeshore Marine) happened by, and before I knew it he had scraped off a 1x1' area of deck using only a dull razor blade. He knows from experience that the upside of an old crappy paint job is that it comes off fairly easily! So I decided to scrape the old paint, then sand the gelcoat underneath.

About halfway done I'd say, as I've scraped up to the front of the cockpit. A good carbide scraper means this goes faster than sanding. It's still going to need some time with the DA sander, but only what's required to prep for primer (and take out a few scrapes). The photo below shows progress, the white on the deck is interlux brightsides, the tan is the original gelcoat.

In the meantime, I've started working on the holes in the deck. Some of these are from old hardware and will be filled/painted over, and some are going to be reused, but with a disc of thickened epoxy inside the deck surrounding the hole, to keep water from getting into the deck core. For both the process is similar, overdrill the top of the hole, scrape out the core around the hole, fill with epoxy and sand flush. For the ones I'll be reusing I'll redrill a new hole through the center of the epoxy disc.

Scrape Deck Paint: 8hrs (partial)


BOOM!

Our old boom was pretty lousy. It had poor control lines, heavy hardware and was generally ugly. I scrounged up an old Shields boom section (thanks Skip!) that was in better condition than ours, and added new and old hardware to it.

I originally planned to do away with the heavy end casting on the aft end of the boom. New shields booms have an exit block in the top, and the back edge is bias cut to match the angle of the deck. It looks cool, allows access to the outhaul internals, and if you drop the boom on the deck it _may_ do less damage.

Unfortunately our boom (and all old booms) was too short for that. If we put an exit block in, even at the very back edge of the boom, we wouldn't be able to pull the sail all the way aft. This made the use of the end casting neccesary, but aw well. Maybe next year I get a new boom section and get it right.

The old boom had a very outdated outhaul setup. It was totally external, and had a wire pennant leading to a harken 5:1 magic box for purchase. I decided to go with an all internal purchase and increase it to 8:1. At the same time I improved the outhaul cleating setup. This boom (and most) has a horn cleat, which is difficult to adjust and means you have to really lean in/get into the boat to do it. On all the boats I've sailed on, this means the outhaul tends to get adjusted exactly once per leg of the race course.

The other problem with the boom was that it was just barely long enough to fit the sail (when pulled to max tight), and the shackle on the outhaul pennant was pretty long. I went with the shortest profile shackle I could find, which turned out to be a Tylaska S5 spool shackle on a 4mm SK75 pennant. This will let us pull the sail all the way to the class legal limit. At the same time I filed out the inside of the end casting in order to install a Harken ball bearing sheave, which replaced a really nasty old fiberglass one which was starting to fracture.


Outhaul shackle, hooked to mainsheet block to keep it out of the way
wow look at that weight savings... worth at least 6 knots

The internal purchase is all dyneema and harken carbo blocks, cascaded to 8:1. The cleat is a pivoting exit block, which means that the added purchase can be easily controlled from the rail.
beats the heck out of a horn cleat


The stainless bail on the boom for attaching the vang was in bad condition, so I decided to replace it with a dyneema strop attached to the mainsheet bail throughbolt. Since I was upgrading the purchase to 8:1 anyway, I incorporated the bail right into the cascade block, using a Harken 57mm Ti-Lite. I love these blocks, they're light, strong and the soft attachment means you have lots of ways to secure them.

All the hardware was removed from the boom and reattached. A shocking amount of it was either the wrong fastener (head wrong, wrong size!, not actually threaded to anything) so I ended up drilling out and retapping most of the holes. Everything was put back in with blue loctite and/or lanocote unde the heads.

It's great to have a project done with and put away.

Rerig Boom: 8 hrs

Although this was pretty straightforward, the extremely cold temperature in the yard made this difficult. Although it was up to 28 outside, it was a chilly 12 degrees in the storage building 88's living in. Touching a an aluminum boom at this temp is actually quite painful, not to mention the cold really slows down your reflexes. I had to run the purchases a couple times when my clumsy hands kept messing things up. Wish I could do this in summer but thats when I make my money!

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Jib Halyard Control

One of the most important controls on the Shields is also one of the hardest to adjust. Class rules say the only legal method of changing jib halyard tension is the winch, which must be located belowdeck on the wooden kingpost. On every Shields I've been on, this means that the jib halyard is on the port side of the kingpost, down low by the floorboards. It's usually locked off using a cam or horn cleat.

This arrangement really sucks for racing. Anytime you want to change the jib depth, someone has to go below and crank it up. In a perfect world I'd put a deflection style adjuster with 6:1 purchase on there, but class rules say not. Next best thing to me was relocating the jib halyard, and giving it a cleat and line location that could be controlled while sitting on the highside.

The halyards in the mast will be switched so that the jib exits on the stbd side and goes to a winch which is higher up on the king post. This means that the winch can be controlled by leaning in from the stbd rail.

On Shields 90, we had a spinlock clutch mounted after the winch for locking the jib, which I found to be a lot better than the cam cleat on 150. The cam cleats can be knocked loose too easily, and sometimes it's tough to tail the halyard into the cleat.

Mounting the clutch this way is bizarre, as usually clutches are mounted between the winch and the mast, but for on 90 it worked pretty well having the clutch on the king post. You could tail the halyard better, and ease it with tension on the tail.

For 88 I decided to try and improve on that, and made an aluminum bracket to mount the clutch in a way that kept the halyard accessible. In this mounting the halyard exits at deck level, pointing up. The clutch is accessible from both rails for easing, and on stbd tack you can use the winch handle from above deck.

Jib Halyard Clutch and Mount: 6 hrs (had to make this twice as I messed up the lead from the winch on the first try)

Control Boxes

The current best way to rig the Shields backstay and traveler controls is to mount them remotely under the side decks. Then you can control and cleat then from the opposite windward rail.

I really agonized over how to do this, and wanted to make up a large custom control tray out of carbon fiber. This would be quite cool, and make for a better cleating location. However, that would take a whole lot of time, and I already had the standard pieces from Cape Cod. They're aluminum, but not terribly heavy.

I'm going to have all the traveler purchase below deck, with Endura 12 pennants running above deck. Both traveler and backstay will have ratchet blocks to make trimming easier, and I'm considering mounting the twing cleats on the side of the control boxes. This is what they look like now. The two carbos in the middle are ratchets, the double block is actually from our old traveller car. The cleats have the extreme angle fairlead so the lines can be controlled from the front or back of the boat. One the forward side of the control box I'm mounting Harken Micro Carbo Cams in Extreme Angle Fairleads, and 29mm Ti Lite Carbo Blocks. This is for controlling the twing lines, which are going to be led below deck. Most boats either have the twings above deck (which means big nasty wood blocks to sit on) or routed below deck (to cleats awkwardly located underneath, up by the shrouds). Having trimmed spin and driven lots of Shields, I know this doesn't work all that well, as its too crowded and theres too much going on for people to be messing with these. I'm leading it aft so that either the driver, the trimmer or the 3rd crew can work the twings. This seems smart to me now, but we'll have to see how it goes on the water!

Load Control Boxes: 4hrs

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