Wednesday, July 29, 2009

Carbon Boom Rigging - Complete

Here are is a short video I took up at the harbor today. Very glad that that project is behind us and also very happy with the result. I stated another album with a bunch of pictures of the COMPLETED BOOMS HERE. Many thanks to Samson and Harken, as always, for making this project affordable for those of us that have limited resources(recent college grads). Thanks also for everyone who checked out our site. I hope this is a resource that will help you if you plan on rigging a new boom. Feel free to email or call me with any questions, I will do my best to help you out.

Monday, July 20, 2009

Carbon Boom Rigging - Part 3

Installing more hardware, almost ready for line.

Detail showing aft mainsheet block installed. The hole in the bonded fitting had to be re-drilled and sanded smooth.

G10 mounting plate for the mainsheet block before bonding. The odd shape is to accommodate the Harken part so the block can pivot through the entire 180 degree range. A slight modification was also necessary to achieve this range.

The plates were sanded to the approximate profile of the boom. I masked the bonding areas and sanded the booms well for a good bond. They were bonded with West System 105/206 with 406 filler(colloidal silica) and a small bit of black polyester pigment.

This same epoxy/filler mixture was used to bond the outhaul cam cleat bases. Note that on these plates, I pre-drilled and tapped the holes. This way I could avoid adding holes to the underside of the boom near the vang fitting. I used some machine screws sprayed with Mclube to fill the tapped holes during bonding.

After I completed all the fillets on each G10 plate, I carefully removed the tape and wiped the surrounding area with acetone.

Outhaul cleat base on the underside of the boom near the front.

2 layers of 6 oz carbon were laid up over the top of the gooseneck fittings. Make sure you aggressively sand any bonding surfaces on the inside of the boom. There is likely still mold release/wax on the interior from when the boom was made.

The forward outhaul turning blocks were mounted and thru bolted using machine screws and nylon lock nuts.

The forward edge had to be sanded smooth after the layup had cured.

The G10 plates were re-masked sanded and spray painted black after they had cured. The hardware was then installed using Loctite blue.

For the mainsheet cleats, holes were drilled through the G10 plate and through the boom. Those holes were then tapped and fasteners were installed with Loctite. I talked with several people about putting these holes in the bottom of the boom. I wanted to avoid it if possible, but this ensures that the fitting will stay attached as it is not entirely relying on the bond. I used a hand drill to carefully drill these holes. In hindsight, I should have rigged up the drill press for this application to increase precision.

The vang strops were sewn using 1" tubular webbing sourced from APS. I also spliced a 1/8" spectra loop that was luggage tagged on the aft end of the strop to hook over the keeper fitting.

The keeper fitting was bonded on with a small loop (don't worry, those holes are not drilled in the bottom of the boom!). This loop is used for the mainsheet shockcord, which is inplace to keep things from hooking on the fitting.
The pole retraction thru deck sheaves were installed by drilling and tapping the boom. The fasteners were then installed using Loctite. I did not add any backing or reinforcement as these sheaves are very lightly loaded.


Next up is rigging the outhaul, pole retract, and the patented in-the-pole foreguy system.

Friday, July 17, 2009

Carbon Boom Rigging - Part 2

Gooseneck fittings, aft mainsheet lead, outhaul sheaves:

The boom came the proper length which meant there were no scrap pieces to use for molding backing plates or to use for reinforcing. I made a mold out of foam to help mold the gooseneck fittings. This was made by hot gluing sheets of foam insulation together to make a block and then sanding it using the outside of the boom and sandpaper.

The outhaul fittings provided from Windrush would have put the top of the boom below the boom band and required moving the gooseneck. I also did not like the idea of installing a goosneck fitting with fasteners. I first made a small riser pad using epoxy and 1/4" chopped glass and some colloidal silica. I also used some black pigment for cosmetic purposes.

The idea I came up with was to use the supplied part and incorporate it into a bonded gooseneck fitting as Larry Tuttle and others have done. I liked the idea of using the stainless fitting so that the mating surfaces would be a metal/metal interface and would not wear over time.

The mold was lined with packing tape and sprayed with McLube. I wetted out 3 layers of 6 oz carbon and layed them up in the mold. Next, I set in the pre-fabbed risers along with more epoxy/chopped glass/filler/pigment mixture. I set the stainless fittings on a fid(sprayed with Mclube) that perfectly matched the ID. This way I could align the fittings on the center line of the mold even when I burred them in the epoxy mixture. At this point I was not optimistic as the whole deal looked super ghetto-fied when it was all laid up.

The parts were un-molded the following day after 24 hours cure time.

Next I trimmed the parts with a hack saw.

I then began sanding the parts. This was more of an undertaking than it had to be due to my sloppy molding job. That said the parts tuned out far better than expected after they were sanded and fit to the inside of the tubes.

Gooseneck fitting inside the newly fabricated part. Note that this stainless liner will not "wollow out" as a composite receptacle will over time.

Fittings shown inside the boom sections. Note this is not super high end fit/finish, but they should be bomb-proof which is what I care about.

Fittings were then bonded in using the same mixture used to fabricate the parts. Tonight I will laminate a few layers of carbon cloth over the top of the fittings and onto the tube. I am very happy with how these turned out.

This fitting was also provided by Windrush. These will go on the aft end of the boom on the bottom to lead the aft mainsheet block. The block will be lashed around the top of the boom and then through this fitting to keep it from angling forward. Note that I am NOT tying the block directly through this fitting. It will be subject to shear and very minimal peel loading.

The areas were masked off and the bonding surfaces were then sanded.

Parts were bonded on with epoxy/silica/glass mix. Not that these parts were a hollow skin. the entire cavity was filled with the bonding mixture for strength and I will have to re-drill the hole after cure.

The first holes I put in the sections were the outhaul sheaves. Note that before I did anything I very carefully marked the top and bottom along the center line of the boom with masking tape. The booms have a thicker wall at the top and the bottom so it is important to get those types of details from the manufacturer before you cut anything. Also note the hole has no sharp corners which have a higher stress intensification factor than curved corners.

Outhaul sheaves fit. These will be through bolted with machine screws/washed/nylon lock nuts. Cutting holes like this is far easier than in an aluminum section. I used a Dremel and a cutoff wheel to make a box and then sanded it to size with a small fine-grit abrasive wheel.


Stay tuned, more to come...

Wednesday, July 15, 2009

Carbon Boom Rigging - Part 1

Last night I started rigging 2 new booms for 7346 and 7611. Both will be set up with the conventional single port-side pole. They will be rigged with the option to go to double pole after the worlds this summer. That way we can source the proper parts and see all the fancy double pole setups that others have been refining this year. For now we will be using what we are familiar with as worlds is only one month away!

Boom Sections - Windrush Yachts, AUS
Spinnaker Pole Sections - Unknown builder, sourced through Holger Jess

I was at a loss as to where to start, so I decided to work on the spinnaker poles first. My first step was to fit both end fittings to the tube. We got some really nice(although now may become obsolete) fork fittings from Holger. They are a really well made with a machined base and a heavy gage fork that can easily be pinched to fit all line sizes. These are far superior to the fittings made by Mark Angliss.

The forks were supposed to match the ID of the poles that Holger also provided but the metal sections that fit inside the tube needed to be ground slightly with a bench grinder/file.

The standard Spiro inboard end fitting is a smaller OD than the ID of the new carbon tubes. I sourced some delrin tube from McMaster with an ID that was the same as the OD of the ball end fitting.

The OD of the delrin tubing was oversized, but was easily machined down to the proper size on the lathe. This material is very easy to machine. Should be fun to make some custom end fittings for the double pole system later this year...

The result is a very snug tollerance fit for the inboard end.

Wednesday, July 8, 2009

505 East Coast Championships 2009 - Regatta Report

This year's ECC's happened to take place on Lake Ontario. I guess that is close enough. For us it was a similar driving distance to the Mid-Atlantic, a 12 hour drive. It was a bit of an operation for us; three people driving through the night in a small car with a boat on the roof and another in tow. We made it there and back, and didn't miss any work. The trip was well worth the effort, good breeze and great fun were waiting for us in Kingston.

The showing was light on superstars, but the top boats were solid and relatively close racing made things fun. We arrived Friday at 6 AM after driving all night. We rigged up the boats and went out for 4 races. Fleet 13 posted some alphabet soup with Loe/Thompson blowing out a kite in Race 2 and Turney/Turney getting the spin sheets around the bow and behind the centerboard in Race 3. The conditions were pretty straight forward although there was quite a range of velocity as the rain system that passed through.

Saturday was sunny and windy. A very good day for racing. Wind was more offshore causing it to be quite shifty and challenging at times. Both Turney/Turney and Loe/Thompson showed moments of brilliance and moments of mediocrity. The low-lights of the day were Turney/Turney pulling the old "Bubba Gump Shrimp Co.", and Loe/Thompson coughing up the lead in Race 8 to finish 5th. The day finished relatively early with one race left in the series left for Sunday.

Saturday night was a very fun time. Unlimited supply of pizza and beers were availible at Jeff Boyd's house, which was within walking distance of our housing. We then went to The Grizzly Grill, one of the finest Canadian drinking facilities I have been to. The 19 year-old legal drinking age lends itself to somewhat of a "high school dance" atmosphere. Even with the crowds in the bar it was easy to spot the 505 sailors as they were generally the oldest ones and weren't dressed up in their "going out costumes". One individual managed to get kicked out of the bar on two separate occasions, another managed to make it back to the housing alone and on foot. I think everyone except me stopped by the Burger King next to the bar which was conveniently open late.

Sunday was a rough day. We got up at 9:15 which we thought was plenty of time to make it out for the 11 AM start. Unfortunately the start was at 10 AM. The course was very close in proximity to the club so we were rushed but we made it to the start in time. Both Turney/Turney and Loe/Thompson gated early expecting the left side to be favored. The situation looked grim mid-way up the first beat but the left came in nicely toward the top of the course putting Turney/Turney in first and Loe/Thompson in second. Loe/Thompson were passed on the second-to-last leg of the race which shattered our hopes of finishing in a Fleet 13 1-2 for the last race. Turney/Turney hung on to win the last race although extremely dehydrated/hungover.

Thursday, July 2, 2009

Packed for 505 ECC's

Heading out of town tonight for Kingston, ON.

3 People, 2 boats, 1 Ford Ranger....should be a fun time.