Wednesday, December 11, 2019

Not the Bahamas

You don't have to be in the Bahamas to get pretty extreme weather. Right here in San Francisco Bay we frequently get big winds. OK, I know its not hurricane weather, but we are used to very changeable weather in addition to the potent tides.



The Winter is often very calm (see above), but then punctuated by strong winds. Here in the Big Muddy Bay where Little Cat is anchored, we will see 50 knot gusts a couple of times a year, but we get 30 knots quite frequently.

The Northerlies are always the worst, and in Big Muddy they are onshore.


These pictures show Little Cat in the same spot in a Northerly blow. The wind is a steady 25 knots, gusting to 30 knots.


The anchor system is a bridle going to a heavy chain set between two anchors, and has always been reliable.

Friday, December 6, 2019

Ten Year Refit

Well! Finally got to go for a sail in November, nearly a year after I dropped the mast last December to put the boat up on the hard for painting.
 
Little Cat at Ano Nuevo in November 2019
 
The long time offline was because the boat was getting what turned out to be a pretty comprehensive refit after 10 years on the go since her launch. In the intervening 11 months, she has had:


- the repaint at Berkerley Marine Center that I have already posted on
- entirely new standing rigging
- a new mast and mast base
- refurbished gaff spar
- new windows (see previous post)
- a brand new mainsail from Rolly Tasker
- refurbished side decks(see previous posts)
- a redesigned anchor mount under the front beam
- a new rear net
- a new deck tent enclosure for cruising trips
- installation of new Lewmar deck hatches and refurbishing of the existing hatches and refitting with gas struts
- installation of fitted seats in both cockpit/cabins
- installation of Whale hand pumps in both hulls
- installation of grab handles inside and outside the cabins
- a new Fortress anchor to replace the one I broke at Muir Beach

In addition to that lot, I also did a great deal of wiring work, including fitting:

- wireless AIS
- a VHF/AIS antennae splitter for above
- a masthead LED tricolor
- internal switchable lights in the cockpits and cabins (including running power from the port to starboard hulls)
- water tight bulkhead fittings for the above
- internal 12v and USB outlets in both hulls
- a deck light
- two Blue Sea distribution panels
- a custom switch box

... and other stuff that I can't remember already, for sure.

Anyway, I will get around to making posts about some of these projects at some point in the future.

The Wireless AIS unit that I stalled and read using OpenCPN on my smart phone.

LED Tricolor from MarineBeam worked great for 2 weeks and then stopped working - more on that later.

Fitted a Whale Urchin bilge pump to each hull.

Tuesday, August 6, 2019

New Side Decks

One of the jobs that was just too big to complete during the Winter re-paint was the side decks - that is, the center side decks.

Red arrows show where the center side decks are

The side decks are a part of the boat that take a real beating. They are the most stood on part of the boat. When you get in or out of the cabins or move around the center deck area, you are mainly on the side decks. These side decks are 10 years old (as is the boat now), and were epoxied but unglassed 1/4" inch marine ply. The plans call for a second narrower strip of ply down the center of each side deck to reinforce them, but the original builder had built two stringers underneath instead of the extra layer on top, which I like because it leaves them flat and the same height as the rest of the center decks.

Nice new coat of 6oz fiberglass

Over 10 years of use the side decks were pretty well banged up and had some surface cracking and checking, and it was time to replace or renovate. Of course I chose renovate as I always seem to do; the decks were still basically sound and just needed a bit of extra help. I started by stripping all of the old paint off down to the original epoxy layer. The next step was a 6 oz layer of glass on BOTH sides, with two further epoxy fill coats.

Underside of topcoated deck

With glass on both sides the decks are now super stiff, and it makes me wonder why glass coating on both sides, effectively turning the plywood into a core material, is not used as  a construction method more often. They are heavier, although not unduly so.


Topside masking up for anti-skid

The paint was next, and what a grind it is to do it properly. Two undercoats with Interlux Primekote, and three top coats with Interlux Brightsides. The five coats were all sanded between layers - lots of time. But wait, there is still the anti-skid to do. I used two coats of Interlux Interdeck after careful masking, and found it really easy to roll on in one go compared to my old method of sprinkling sand onto wet paint.


I also made substantial mods to the decks to make them more usable for my purposes (see above pic). I put new dyneema loops in (see previous posts) through the stringers - I use these for close windward sheeting of the jib, and also as anchor points to clip in my harness when it is rough. I added mahogany foot braces screwed through into the stringers. I have found that when it is very rough, you need somewhere to brace your feet. I also added new raised cleats that I can reach handily while sitting in the cabin/cockpits. I added a line of holes (back filled with solid epoxy) along the center edges that I will screw to the deck center section. The center section is now bolted to the front and rear beams. This final mod will make the hole deck area relatively rigid.

OK, lots of work, but the center side decks are now pretty much indestructible and will not need work for a long time.

Sunday, June 30, 2019

New Rig #1 Starting From the Bridle

While the boat was on the hard over Winter, I took the first steps towards building a new rig, starting from the ground up as it were, with the forestay bridle and bridle u-bolts.



Bridle and u-bolt positions

My original bridle was 5/32 1x19 stainless steel wire with 1/4" u-bolts. They were still tight after 10 years, but there was polish and wear on the u-bolts where they take the load from the bridle wires. The plans say that the bridle wires should be 3/16, so they were undersized as built.

There has been much discussion on several internet forums about building reliable bridle anchors. Later Wharram designs were specified with cord lashings instead of u-bolts. However, I was reluctant to drill multiple holes through the stem and wanted to keep the u-bolts. In an internet posting Rory McDougall had recommended 5/16 "or even larger" u-bolts to be on the safe side. 


3/8 u-bolt bearing surface and 1/4 stainless wire

Word to the wise - use forged u-bolts. Wichard makes a range of them and even the 1/4 Wichard u-bolts are rated to 1400 lbs working load and 4,400 lbs breaking load (that is, around a 4X safety factor breaking to working load). Unfortunately, I was on the hard at the boatyard and could not wait for the 2-week delivery time for Wichard bolts. So I bought some West Marine 5/16 316 (non-forged) stainless bolts - big mistake. These were "rated" to "2,200 lbs working load" which is a strange number because the breaking strength of a rolled stainless 5/16 bolt is about 4,000 lbs, and working load is some multiple of breaking strength (2X, 3X, 4X etc.). So 2,200 lbs is not even a 2X safety factor from the breaking strength of the bolt. Further when I was installing these bolts, I torqued them to the rated 11 foot pounds for a 5/16 bolt and they galled (welded in place). This happened to both bolts, so I bought a third bolt thinking that I had over tightened them, and carefully torqued this third bolt, and it to galled before reaching the final torque of 11 foot pounds. Thanks West Marine! Most of the stuff I buy from WM seems good quality, but these u-bolts were so bad that they are dangerous.


5/16 threads and nylock nuts on shaped base

So, then I found these stepped Ronstan u-bolts that have a 5/16 thread and a 3/8 U section. This gives me a working load for the threaded bolts of around 1,000 lbs (based on the 4,000 lb breaking load of a stainless 5/16 bolt), and the much larger section of the stepped U to absorb the wear of the bridle. Note that with each u-bolt taking the load on two threaded ends, the true working load is going to be much higher than for a single bolt. Unlike the awful WM bolts, the Ronstan bolts could be torqued and un-torqued to the 11 foot pound rating with no problems whatsoever (that is, good quality steel).

OK, so I had my u-bolts.I then spent considerable time drilling the mounting points oversize, filling them with thickened epoxy and then re-drilling them to the correct clearance size so that the u-bolts could be torqued into place and then removed whenever I want to, rather then being glued into place as the previous ones were. I also made aluminum mounting wedge plates that allowed the u-bolts to mount fair and square from the stems (rather then pointing forward because of the angle of the hulls) and epoxied them in place.


Rated triangle link ready to go

The next decision was which wire to use for the bridle. The plans specify 5/32 6x7 stainless wire for the standing rigging and 3/16 for the bridle. That wire (6x7) is generally no longer available, so I used 7x7 which is ideal for self-made rigging as it is flexible enough to use Nicopress swages. Working load for 5/32 7x7 316 wire is 440 lbs and breaking load is 2,200 lbs (see image below which belongs to Suncor USA). This specification from Wharram is obviously usually fine because there are hundreds of Tiki 21s sailing around the world with standard spec standing rigging. However what are the actual loads that a Tiki 21 rig is exposed to? It turns out that there is no easy formula for this important question and expert sources invariably say that there are too many variables to easily quantify. One source is a small table in Brian Toss's Rigging Guide that suggests that loads on a 20 foot boat are around 500 lbs, which fits with the Wharram's original spec.

But what about peak loads? I had a Harken High Load (wire) Bullet Block deform and almost break on the mainsheet bridle (which takes the full rig load). I assume that this was with the rig powered up going to windward in the usual 20 knot summer breezes in San Francisco Bay. That block is rated at 500 lbs working load and 2,000 lbs breaking load. This unscientific study leads me to believe that rig shock loads can approach the breaking strain of the standard spec 5/32 wire or, at the very least, that the rig is exposed to loads way beyond the working load safety factor. So what to do? For my new standing rigging I am going up one size to 3/16 wire which rates at 620 lbs working load, and a hefty 3,100 lbs breaking load - well beyond the shock load that nearly broke my Harken block.



All well an good, but what about the loads on my new bridle? The reason why the standard spec for the bridle wires is larger than for the rest of the standing rigging, is that the angle from the forestay to the bridle wires subjects them to a higher load. The graphic below (from LifTechniques.com) shows that lifting slings need to be rated to match the loads of the angle of the sling. The Tiki 21 bridle angle is about 60 degrees from the vertical, and the chart below shows that this doubles the load on each sling (each arm of the bridle). This means we need a wire rating 2X what it is for the rest of our standing rigging, or, around a 1,200 lb working load.


Going back to the table from Suncor, the next size up is 1/4 wire with a working load of 1,040 lbs and a breaking load of 5,200 lbs. This doesn't quite make the 1,200 lb level but is a full size larger than that specified in the plans, and if the rig does endure shock loads approaching 2,000 lbs, that will be 4,000 lbs at the bridle which is still well below the breaking strain of the 1/4 wire. Also, the 1/4 wire is really hefty, and going to a larger size would look plain ridiculous and would require huge swage fittings.

So that is what I went with, and the bridle was assembled from 1/4 316 stainless 7x7 wire, using a hand Nicopress tool and stainless fittings. The 1/4 size was maximum for the hand press but was quite doable after a bit of practice.

That just left the fitting to join the bridle to the forestay. The Wharram spec is an oblong quick link fitting, but it always bothered me that the oblong shape left the bridle wires at an odd-looking angle. So I sourced the Maillon Rapide 3/8 316 Stainless Steel triangle delta link that you can see in the above picture. It took me a while to find and order this part, and I went to the trouble because it was the only brand that was available in 316 and that had a test rating.

The bridle is now finished and installed, and is now just waiting for me to finish the new mast and the rest of the rigging - more on that later.

Tuesday, May 21, 2019

New Portlights (windows)

What do you call a window on a boat? Porthole? I think of a porthole as an opening window, so not that. In our family we always called them portlights, so that is what I'm going to go with - new portlights.


New 3/16 tinted acrylic (still with the sticky paper on) over the old faded and crazed portlights


During the last haul out, I took on the faded and scratched portlights that had done a good job for 10 years. The original builder had committed the crime of sealing the portlights with silicon. It took a day of solid work to get the silicon off the cabin sides for four small windows. I knew it would be a tough job and was convinced by the interwebs to order and try an expensive product called Debond Marine Formula. I can't honestly say that it did anything. In the end the most effective method was a good ol' razor blade followed by sandpaper. You can never get silicon entirely off, but I got the hull sides dead smooth and clean, if still a little slippery. I then went ahead and prepped and painted the cabin sides with 5 coats.


Pre-applying the butyl tape and screws

I ordered new 3/16 tinted sheet acrylic, and cut out the new windows using the old ones as templates. This made the whole job really easy and starting from scratch without the templates would have been a much bigger job. I clamped the new acrylic windows to the old ones and drilled through the old screw holes to get perfect reproductions of the original portlights.


Leave the protective film on until the portlight is installed on the boat

Instead of using a permanent hi-tech bonding goop, I used an old fashioned product that has come back into vogue - butyl tape. This stuff is amazing - it has the consistency of plasticine and can be shaped to suit what ever you need to seal, in this case a bead around every window.


Back in place

I pre-applied the butyl tape in a bead around each portlight, and stuck each of the screws through the tape ready to re-fit on the boat. It is best to leave the protective film on the acrylic as long as possible to protect it during fitting.


Looking swish

Back on the boat, the fitting was very easy, with the screw holes lining up perfectly. I reused all of the original screws, but bought new nylock nuts and washers. As you tighten down the screws, the butyl tape squishes out and you can stop at the point that you are happy with the seal. The excess can be scraped off with little residue left behind. The best thing is that the butyl never goes hard, and the next time the portlights need to be replaced, they will pop right off. Now I just need to convince one the Little Helpers to come and hold the allen key outside while a do the final tighten down on 60 nuts inside the boat.

Sunday, May 19, 2019

Painting Time Again

I clearly haven't been posting much over the last few years as, looking back, it all seems to be about haul-outs and painting. In reality, it has been every 2 - 3  years which coincides with the life of the Brightsides top coat on the hulls.

So, out the boat came over Xmas and it was time again. The two coats of Brightsides from the last round were solid at the tops of the hulls, but were starting to pit all around the waterline; I guess that the constant wave action and floating debris have more affect than I would have thought.

Little Helper #2 sanding between coats (smiling or frowning?)

So, sanded the hulls down and filled the pits with Interlux Surfacing Putty. Spot primed with Interlux Prekote i.e all around the waterline. Sanded and more Prekote. Sanded and first coat of Brightsides. Sanded and second coat of Brightsides. Sanded and third coat of Brightsides (yes, managed three coats this time!). Then new numbers and name transfers.

Ready to go

But wait - that was just the easy stuff. Also removed the windows and got three coats of Brightsides on the cabin sides too (also replaced the lexan windows - more on that later). DONT EVER USE SILICON on windows or anything else!! It took a day's work just to scrape the silicon off those teeny tiny window edges.

I also pulled the center main beam, and refurbished the beam chocks. The chocks on the port side had small pockets of rot, so I cut them off and replaced them with solid G10 blocks - they will never give trouble again until the end of Creation (no pics - too busy). I then finished up with three coats of top coat (plus prep) under the beams.

Heading out. Good shot of the Trinidad bottom paint



I also removed all of the center decking, and found further cracks in the fillets of the center section (see, last haul out). So, I taped ALL of the fillets of the center section with 4" 10 oz glass tapes, and don't expect further issues (no pics, too busy). Also, found spots of soft, wet, wood in the rails along the cabin sides that support the decks. Dug those spots out and filled with thickened epoxy. Then all those projects had to be finished with two coats of primer, and three coats of top coat.

Still missing some decking

Last time I used Interlux Bottomkote Aqua for the bottom paint and it held up quite well over 2 and a half years. It had hard growth after one year, but it scraped off fairly easily. Being water based it was very easy to work with and paint on the boat, with easy wash up in water.

On the other hand, it did get heavy growth that needed cleaning off. The Wharram deep vee hull is very dependent on being clean to perform well, and I decided to bite-the-bullet this time and cough-up for the really expensive and super toxic Pettit Trinidad. I got it on special for $250, and put on two coats with extra on the edges. This stuff is toxic - it was impossible to be around without the vapor breathing mask and stunk out the car for weeks. It is supposed to last for two seasons, so I will let you know.

Ready to splash

I did other jobs too, but too much to describe here without getting boring. Just a note on ongoing maintenance - if I was a builder I would use G10 on all high-wear edges i.e. hatch sides, cockpit coamings, beam chocks, deck rails and net rails. These are the areas that have required repeated maintenance on Little Cat as they were made from unglassed plywood. If G10 were used in high wear parts of the boat, and it was painted in two-pack linear polyurethane, then one would have a relatively low maintenance boat.

Monday, December 31, 2018

Gunkholing the Marin Coastal Seashore

Many times I have driven the Highway One coastal road to Muir and Stinson Beaches, and enjoyed the views of the rugged rocky seashore and the big Pacific swells crashing into it.

 
This part of the coast is usually closed to exploration by Little Cat because of the rough onshore conditions driven by the prevailing North Westerly winds.

Heading out. Note the morning shadow.
Very occasionally and usually in Winter, a period of contrary Easterlies will calm this coast, giving a temporary opportunity for gunkholing.

Pt Bonita North. Still some smoke from the Camp Fire.


Such was this occasion in late Fall, although still not without issues as the Easterlies were blowing 20 knots with gusts to 30 knots, and the only shelter was close up against the shore.

Directly under the Muir Beach Punta Vista.

So ironic to find calm shelter where it is usually a cauldron of angry water. Had lunch in this spot (above), and for the second time on Little Cat, could not get the anchor up. On the previous occasion, I buoyed the anchor line and came back days later with my snorkeling gear. That was not an option here, as it might not be calm again for weeks or months, so gave it full power with the outboard until the anchor shaft bent and it came up. Totaled the anchor, but luckily I have two.

Looking South past Slide Ranch


After lunch, Little Cat and I, explored north past Slide Ranch and got a close up look at the dozens of rocks and largely never-seen little rocky beaches along the shore line.


Looking North to Gull Rock.

I had to pay close attention, as we were constantly buffeted by 25 knot gusts if we got too far away from the shore. Little Cat was doing 5 knots downwind with no sails up!


No escape from the 25 knot gusts off the shore.

We circled around Gull Rock to head back to catch the tide through the Gate. Gull Rock was alive with seabirds, and is in a grand setting overlooked by a rocky point rising 1,000 feet (bisected by HWY 1).


Gull Rock up close (with gulls).

Sailed back on the first reef for the main and jib, and tacked through the Golden Gate Channel. Under the bridge the wind had veered allowing a close reach behind Angel Island.

Close up of shoreline route.

We stopped at this great spot under Bluff Point (Tiburon) to take a break and tidy up on the way back. In so doing, I spilled a bottle of Boat Soap that went all over the deck, starboard cabin, and into the bilge. Expletives followed. Note to self: don't carry around bottles of spillables.