Thursday, August 24, 2017

Big Purchases That Were Worth It

The big items that we can no longer do without:

Auto Pilot

Emulating Rory McDougal's "Harry" (the Belcher wind vane for his epic ocean voyages), I have "Frank" the Raymarine ST1000 for my harbor and coastal micro adventures. In terms of the value of having an auto pilot, there is life before Frank, and life after Frank. Frank has changed my life.

12 volt power and Everything That Goes With It

Making the autopilot work practically has been a philosophical journey into evolving complexity on a boat. You want one thing that is good and useful, but it doesn't work unless you have this, and this also.

A really simple boat without the complexity of wiring and batteries etc. etc. is a beautiful thing. But it is a beautiful thing without an autopilot. There is a book about this called Catch 22.

New Sails

If you like to sail, you need good sails. That means new sails from time to time. Some folks almost never get new sails. Old sails work really well most of the time - that is they work well sailing off the wind. Even your auntie's old bloomers will work off the wind. If you ever want to sail into the wind (however), you will need sails that have some shape - that means fresh sails.


The Tiki has a really short rig. That is really good when you get caught in open water with big winds. It is not so good when you are trying to make progress down wind in 5 knots of breeze. Tikis with just the white sails up are really slow off the wind in light air.

The funny thing is that you would think that a spin would be the sail that makes the Tiki go the fastest, but its not true (in my experience). Once the wind is in the 20 knot range, Little Cat will reach faster with the white sails up. BUT, the spin will make the boat go way faster in the mid-wind strengths - in 10-15 knots of true wind speed, Little Cat will sit on 8 - 10 knots or more, for ever, and that is a rate that will really eat up the miles, or power the boat at a good rate against an outgoing tide etc.

Extra Long Shaft

Want to go exploring 50 miles up the coast, but MUST get back within X amount of time?

Want to venture out into a dubious coastal environment with a reputation for permanently detaining the unwary and the unprepared?

Want to take the CEO and the kids for an afternoon on the harbor, and still be married at the end of the day?

YOU need an extra long shaft outboard.

Friday, August 18, 2017

Rudder Redo

The rudders on Little Cat were having a hard time. They had performed for eight years without a problem, but were looking beat up. They were also flexing a lot at the head of the rudders where they articulate with the tillers. Although built to plan (unglassed 5/8 plywood), clearly some additional stiffness was required. So, after the hull refit in Summer 2016, the rudders came off for an overhaul. The job required a substantial clean up of the unglassed wood, application of an all-over layer of 6oz glass, and a repaint with plenty of coats.

Encapsulation with 6 oz glass cloth.

The wood cleanup took time. First paint strippers were used to expose the wood. Some water had got under the original epoxy barrier coat in places and the damaged wood had to be gouged out and filled with thickened epoxy. After further sanding and prep, 6 oz glass was laid up with West 205 epoxy, and then followed by two further fill coats.

Reinforcing the rudder bottoms with layers of glass.

Because Little Cat sits on a drying mooring, I wanted extra protection for the bottoms of the rudders, so two extra layers of 6 oz glass were added, and I made sure that there was plenty of glass and epoxy around the vulnerable "front" corner below the bottom hinge.

Finished bottom corner. Filling behind the hinges with epoxy.

The rudders on Little Cat each have three sturdy handmade stainless hinges. These are a departure from the Wharram plans which specify lashings, but I like them as it is easy to remove the rudders to keep up with maintenance. Like any metal in wood, though, they are a PITA to maintain and are inclined to bleed rust stains. I should have removed them for the refit, but ended up treating them with West 650 epoxy coatings in place, and also filled the cavities between hinge and rudder with epoxy.

Another view. Lots of sanding and filling to go.

After all of the epoxy had set, I painted the rudders with two coats of Interlux undercoat, and a single coat of Interlux Brightsides topcoat and put them back on the boat. I went for the sail described above to Half Moon Bay to check if the single layer of 6 oz glass gave the rudders sufficient stiffness, or whether a second layer was required. The rudders seem just right with a single layer - there is a little bit of flex remaining, but the head is now plenty stiff. Adding a second layer would add little but weight. The last job was to get in the water and mark up the water line on the rudders for the antifouling.

Three coats of Interlux Brightsides top coat. Yes, I am proud of my roll and tip technique.

So, the rudders came off again for a further two coats of Interlux Brightsides topcoat.

Three coats of hard antifouling paint.

The last job was three coats of Interlux Fiberglass Bottomkote antifouling below the waterline. The final tally was a layer of 6 oz glass cloth, three coats of epoxy, two coats of primer, and three coats of topcoat (above the water line). It was a lot of work, but now the rudders are stiff, fully protected from water intrusion, and should be looking good for several seasons of sailing.

Saturday, July 1, 2017

Can Wharrams Go To Windward?

Of course I know that they can, but I keep coming across "informed" commentary stating as received wisdom that Wharram cats perform very poorly to windward.

This issue has interested me for a long time. When I was growing up sailing with my Dad, I was often told that multihulls, and Wharrams in particular, were death traps only good for off the wind sailing (also that fiberglass would never take on as a boat building material!).

After reading a new thread on this recurring topic on "Wharram Builders and Friends", I decided to record another gps track directly up wind the next time the opportunity presented itself.

Last October I was in the North Bay off San Quentin, and diverted from my journey for a run of several nautical miles directly into a NW breeze coming out of San Quentin Bay (see first image). The wind at the start of the run was about 10 knots true, and built to around 15 knots true by the end of the run next to the Corte Madera marsh (i.e. from right to left in the picture). The tide had just turned, and so we were heading directly into about a knot of outgoing tide, and there was a small chop.

Running the video of the run (above) recorded in GPSAR software there is a legend showing:

- V = speed in knots
- Angle = angle to the wind in real time
- Average Speed = average speed in knots measured over 1,000 meters (1 kilometer, or just over 1/2 of a nautical mile)
- Average VMG = average velocity made good in a direct line upwind over 1,000 meters
- Average Angle = average angle to windward measured over 1,000 meters

The streaming graph at the bottom of the window is a second measurement of average VMG, this time over the default GPSAR distance setting of 500m.

Over the run, speed ranges up to 8 knots and the angle to the wind in real time swings widely from the the mid 30s to high 60 degrees. The problem with using software for measurements like this is that it cannot account for windshifts in the real world - it records the numbers as if the wind was fixed at 290 degrees (in this case). So the boat is not really sailing at 35 degrees to the wind (or 69 degrees), instead the wind has veered in real time in the real world. To get around this problem I set the average angle and speed recordings over 1,000 meters - using a large distance will correct for the small swings in sailing angle caused by wind shifts.

This means that the last two numbers are the most useful: average angle to the wind and average VMG over 1,000 meters. The average angle of the (true) wind ranges from 48 to 58 degrees, and actual progress to windward (VMG) ranges from around 3 to over 4 knots.

Note that progress to windward is about a knot slower on the northerly tacks than it is on the westerly tacks. This reflects how much the boat is sailing into the outgoing tide - the northerly tacks are more directly into the tidal flow.

So what does it all mean? On this day, Little Cat was tacking through from a best of 96 degrees to a worst of 116 degrees, and maintaining an average 3 - 4 knots progress directly to windward. Is this any good or not?

Working in our favor was a breeze in the golden range of 10-15 knots true, and Little Cat had a freshly painted (smooth) bottom. Working against us was a one knot tidal current, a small short chop in San Quentin Bay, and a mainsail which no longer has such a great shape after a lot of use. In other words, conditions were a good approximation of real world conditions.

In my opinion, these tacking angles are pretty good, and compare favorably to most sailing company - even performance multis can be hard to tack though better than 50 degrees when conditions are less than ideal.

Ideal conditions for a Wharram cat are flat water, no tide, and wind in the golden range of 10-15 knots. In such conditions, I think a a Tiki should tack through 90 degrees. With all of the water movement in The Bay, such conditions don't occur often, so Little Cat doesn't get many opportunities to try. In fact, conditions in The Bay, are more often "anti-Wharram" with strong tide and currents, a shallow-water chop and very high winds, very light winds, or constantly changing between the extremes. In these more typical conditions, tacking performance on the Tiki can be disappointing - for example, on a recent trip to Drake's Bay we were tacking through 130 degrees.

However, most sailboats (except racing boats) find strong head currents, short chop, or very light winds, hard to tack through; so overall I think that the Tiki can hold its own to windward when conditions allow. One caveat is that the Tiki is not an easy boat to trim to windward, in my opinion. I have sailed other boats that sail as well or better to windward with a lot less attention to trim and tiller.

Monday, June 19, 2017

Electrical #2 Solar Panel

Now I have my nice & tidy double battery install under the middle cabin floor, I need a system for charging them. Little Cat is on a swing mooring so I cannot rely on shore power like most folks.

I use a Tohatsu 6hp outboard which has a 5 amp charging circuit. This is wired directly to the batteries (with a 10 amp fuse). The charging circuit seems to help, but doesn't provide as much juice as I had hoped. I think that the problem is that I mainly run the outboard at low revs (the Tiki does 5 knots at around quarter throttle), whereas the charger works best at high revs (as it would on a power boat).

So I figured that a solar panel could exploit all of the downtime that the boat is swinging on the mooring in the sun, and keep the batteries topped up.

Fabricating mounting frame from aluminum angle

I wanted something that would deliver at least 1 amp of rated charge and still be easy to handle. I bought a Coleman 20 watt solar panel that is rated at a bit more than 1 amp current in ideal conditions. The panel was not expensive (about $70) but once I started thinking about mounting it on the boat, I realized that buying the bits was the easy part.

The problems started with the wiring on the back of the panel. The terminal box that the cables come out of sticks out so far that that the panel won't sit flat. I wanted a robust setup so decided to fabricate a frame that would elevate the panel enough to give room for the cables underneath, and to provide a solid accessible mount for bolting to the deck

Finished frame.

I bought some lightweight aluminum angle stock from the hardware, chopped it up and attached it to the solar panel with stainless steel rivets. It doesn't take long to write that down, but all of that was quite a few hours of work (see pics above).

Now I had a solid and stiff mounting that would be rigid when bolted to deck or cabin and would protect the wiring underneath the panel.

The next step was the charge controller. I bought a Sunforce digital PWM (pulse width modulation) 10 amp controller for less than $30. This is not as fancy as a the more expensive MPPT (Maximum Power Point Tracking), but it is a multi-stage charger with a digital display of voltage and charging status.

Testing and adjusting the charge controller. The towel is to cover the panel. Note panel is without the frame/base.

I hooked up the panel to the controller and a spare battery to check that everything was working and found that the controller needed some setup as it was switching rapidly between float and charge modes. Thanks to the internet, I found a really useful post from someone who had already solved this problem by turning down the charge cut-in switch from a too-high factory setting (13.5 volts). With the help of a multimeter, I opened the case and made the adjustment down to about 12.8 volts (for the float charge cut-in) and have had no problems since.

OK. So now I could mount the components on the boat - but where? I had planned to permanently bolt the frame mount to the top of the cabin, but after mocking it up I could see that it was going to get in the way when under sail, as well as using up valuable deck space.

I finally decided to not bolt it down, but to further mod the frame for easy handling so that I could put it out on deck when moored, and stow it below when under way. Here the 20 watt panel turned out to be the ideal size, as it is small enough to fit in the cabin, flat on the floor when not in use.

Wired and sealed with heat shrink, cable is anchored to frame with zip ties, and the plastic cover/base is screwed on.

I used countersunk bolts to fix a 1/4" thick panel of lexan to the bottom of the frame. The idea is that this would protect both the panel frame and the boat from abrasion, and protect the wiring from too much moisture. Before bolting the lexan cover on, I sealed the cable connections with heatshrink and zip-tied a section of slack cable to the inside frame to act as a strain relief (see picture above).

Plastic base is fitted. Saddles for tie-downs are bolted to the frame corners and ready to go.

So, when the boat is on the mooring, the panel is out on the deck and has a couple of ties to saddles that are bolted to the frame/base. The cable runs to a connector fitting that screws into a waterproof socket on the cabin side. From the socket, the cable runs through the charge controller, which is mounted high up in the middle cabin (away from any water splashes), and then is wired direct to the battery.

The panel cable is wired to the plug (above) which can be quickly detached from the waterproof socket mounted on the cabin side. I needed a jeweler's screwdriver (from Harbor Freight) to tighten the very small screws in this fitting from West Marine.

I have had this system in place for about 5 months and am very pleased with how it works. It only takes a moment to put the panel out and plug it in, or to put it away. Using simple ties to keep it on the deck has worked fine in the high winds that frequent The Bay.

Charging and showing 13.2 volts. Controller is mounted next to the window in the middle cabin.

I had been initially concerned that a 1 amp charge rate would be too low to keep the batteries charged up, but I always find a healthy charge >13 volts when I get back on board for my weekly sail. All good so far.

Saturday, June 3, 2017

Electrical #1 Batteries

It was time to tidy up my makeshift 12v system that had evolved chaotically. I had added a battery to power the autopilot and it was all very untidy.

The first stage of my nice n' tidy electrical install is the battery choice, wiring and mounting. The Tiki is little and doesn't have much space for cluttering up with batteries. I already had one U1 35 amp hour AGM battery that I had chosen for its small size. Going on the convention of only running it down to 50% of charge, this only gave me 18-odd amp hours to work with. Although my power needs are low (autopilot 1 amp/hour; VHF 0.5 amp/hour, + phone and hand-held recharging), 18 amp hours is not enough for extended trips over several days. On the other hand there isn't room on the boat for a big 60 amp hour battery.

2 x 35 amp hour U1 AGMs getting a final charge.

So, I decided on two 35 amp hour batteries wired in parallel, which gives me the same as a big 70 amp hour battery, but in a size that is small enough to fit under the boat's floor boards. The batteries are sealed absorbed glass mat (AGM) so that I don't have to worry about topping up with water, or battery acid in the bilges. I used 8 AWG cable as it is more than large enough to handle the current for my setup (i.e. not required for starting the outboard), and can be assembled using a standard tool and the marine grade ANCOR crimp connections that I use with all my wiring projects (using the 4 AWG cable needed for electric engine starting requires special tools and fittings).

Marine grade heat shrink was used on all connections.

The battery circuit is protected by a MEGA fuse and holder. I was shocked by how much these were at West Marine, so shopped around and got them aftermarket (Del City Online). The fuses were ~$1 each instead of $10.50 at WM, and appear to be exactly the same product.

I knocked up two battery mounting bases from 5/8 marine plywood and gave them two coats of epoxy. The bases were then filleted into the bilges using thickened epoxy. The bases are mounted under the floor in the cabin in the middle of the boat to get the weight away from the stern where they would contribute to stern dragging. The battery hold down straps were pre-installed so that I didn't have to grovel around in the bilges after installing the mounts.

Out of the way under the floor boards and ready for the next step.

The batteries are placed in standard U1 marine boxes and strapped down onto the mounts. The floorboards fit over the boxes with plenty of clearance, and you don't even know they are there - apart from all of the wires emerging which will be dealt with later when I install a distribution panel.

Saturday, May 27, 2017

Just Reward

...after a lot of hard work was an overnighter to Pillar Point Harbor (Half Moon Bay) with ideal wind conditions both ways. I watched the weather and waited for two days with a north westerly on the first day to blow us down the coast, followed by a southerly the following day, to blow us back.

I hadn't been getting much sailing done because of a lot of backlogged maintenance. I have been holed up:

- stripping and painting the tillers and (re-glassing the) rudders
- installing a solar panel
- sanding the topsides for new paint
- making new nets (again)
- doing sail repairs, etc.

More on all of that later, but after getting the rudders and tillers back on it was time for a decent sail.

The Bay was blustery and cold and we seemed to be the only boat heading out on Saturday morning. As often happens, once clear of Pt Bonita, it was nicer outside of The Bay than inside, and a NW settled in at 10-15 knots giving us a nice reach all of the way to Pillar Point Harbor (the blue line).

Little Cat is looking a little rough on the topsides as she is sanded in prep for paint.

Just reaching under white sails, our times and speeds were good. We hit an indicated 12 knots, and averaged 9.1 knots over our best nautical mile run. Saw a whale a hundred yards ahead just before making the turn towards the harbor entrance bouy.

Sunset. Note the ripped front tramp waiting the new replacement.

Settled in for the night at Pillar Point Harbor. I took the time to set up the awning over the gaff+extension. It takes 15 minutes but is worth it as everything stays dry on deck for a comfortable breakfast and early start in the morning.

Sunday saw us heading out at dawn with almost no wind. We motored out for a few miles with the wind from the south at 5 knots or less, and I expected to motor all of the way back. But it was not to be as I noticed that the coolant stream was dribbling out of the outboard and I turned it off to prevent overheating. What followed was a true salty experience as I had to sail all of the remaining 35 nautical miles without the motor (a la Pardy purists). I hoisted the spinnaker and ended up having one of the best ever sails on a run/reach in 5 knots from the SW. The wind built to 10 knots, and we gybed back and forth all of the way home (red line on map). Even though winds were light, Little Cat had a best nautical mile averaging 7 knots, and a best hour averaging over 6 knots.

My "pure sailing experience" also included just missing the tide to enter our bay, and I had to sit off on the mud until the tide came in at 10 o'clock. I had gone to sleep and had to get up in the dark, with cold rain and a 20 knot wind to make the last 1/4 mile to the mooring.

It turned out that the motor was fine, and there was a bit of salt obstructing the "pee" hole.

This trip: 78 nautical miles.

Thursday, October 6, 2016

On the Hard Again (Part 2)

I rolled and tipped the undercoat to make it as smooth as possible for the topcoat, machine sanding between the coats with 220 grit. Some parts of the hull that were still not well faired got the treatment with West 207 filler and then sanded. The Berkerley Marine Center rents high-quality Fein sanders which helps the whole process considerably.

More undercoat

The first top coat was rolled and tipped on after wiping down with alcohol on paper wipes, and then wiped down again with Interlux 333 "Brushing liquid". The weather was pretty hot so thinned the Brightside polyurethane with the 333, and also followed the procedure of using a good brush damped with 333 for the tipping off.

To get a good finish with these expensive, hard, marine paints, it seems that you have to follow all of the procedures by-the-book, which is really hard work. For example, the weather has to be just right - not too hot and not too cold, meaning morningish. I started by painting a whole hull coat in one sitting, rolling on about 4 roller-widths, and then tipping off. But I soon found that the paint would start to thicken, and the brush would drag, so ended up painting each hull side separately. So, 4 hull sides X 4 coats = a long time. Factor in work in the real world, and it took me a month (!) to get the job finished.

First top coat.

The first topcoat was machine sanded with 320 grit, and then hand sanded all over with maroon 3M pads. This hurts because you have a nice shiny coat which you then destroy to get the matte surface required for the topcoat. The topcoats are nervy because you can't fix any foul-ups by sanding afterwards - what you roll on is what you get! Before final coating, the surface got the two-wipe-downs regimen followed up by a final wipe with a tack cloth. The two wipe downs (alcohol then 333) worked so well, that there was little or nothing on the tack cloth afterwards.

I found that the tipping went better with less 333 and some paint on the brush. Too much 333 seemed to contribute to brush lines in the finish (learned this on the first top coats).

Second top coat - looking good.

As well as the hulls, I also gave the 4-coat treatment to the underside of the center narcelle which had some flaking paint, and the glass seam repair.

After the hull paint had hardened for a few days, the next job was to tape up the waterline. I used the existing true waterline mark that I had left on, and then marked up 3-inch arcs using dividers. Three inches is a lot above the waterline, and means less shiny topside showing, but Little Cat is on an open mooring now and gets a lot of wave wash action that had put slime above the previous lower water line mark.

Taping up the water line. The blue tape is the true waterline.

Next, I rolled on the Bottomkote Aqua. Now the weather was real hot, so I thinned it a bit with water (water based paint). It went on OK, but had to work fast as it dried quickly in the heat. I did two coats over all, plus an extra coat on the waterline and edges (pretty much three coats).

Bottom paint goes on

Now it was time for Little Cat to get an actual name saying "Little Cat". I ordered the name and numbers from BoatUS and they were good quality and easy to put on.

She is now looking sharp and will no longer suffer from an identity crisis. My only regret is not getting a larger letter size. Because the hull sides are small compared to most boats, I went with 3" letters - in hind sight 4" would have looked better with this font.

OK, so now we are looking good and started the clean up to get back in the water. Some detail not mentioned here is the work that went into prepping and painting all of the steel work - what a PITA, but now all done with epoxy base coat, 3 or more coats of undercoat, and 2 topcoats. I really expect that the steel fittings will remain rust-streak free for the life of the paint. Another job I completed that I will show in a later post was bolting the center deck section to the cross beams to reduce vibration when the outboard is running.

Looking good

Then it was launch day, and she was lowered back into the water gentle as a baby. That was a lot of work and I'm expecting that she will still be looking good in two years when she comes out again for the next bottom job.

But the work is never over - right? I still have the rudders to re-glass and paint, and the entire deck and top of the boat are still waiting for the four-coat treatment - I should be done and ready for next summer. Because I took so long, the job was pretty expensive, but now everything underneath the boat is in great shape, and I can work away on the decks in my own time on the water.

Materials used:
2 quarts of  Interlux Pre-Kote primer
2 quarts of Interlux Brightside polyurethane top coat
0.75 gallon of Interlux Fiberglass Bottomkote Aqua hard bottom paint
0.5 gallon denatured alcohol (cleaner)
1 quart 333 Interlux Brushing Liquid
5 x 2" paint brushes
Too many roller covers, paint trays and containers, sanding disks, rags and paper towels to count.