Thursday, November 16, 2017

Refurbishing the Tillers

In addition to the rudder redo, I refurbished and lightened the tillers and tiller bar. The tillers on the Tiki 21 are HEAVY as designed. If you take a look at the tillers on a Tiki 26 or 30, it looks like the same scantlings are used for all three, which is overkill for the little Tiki 21 IMHO.

The weight of the tillers has always bothered me, particularly as they hang off the tops of the rudders, and the rudder hinge points are carrying the weight of the cantilevered tiller arms.

I weighed my tillers and they were around 5.5 lbs each. They needed to be stripped and repainted, so I decided to also judiciously attack them with power tools to take off some of the non-essential bulk.

After paint stripping a sanding

After stripping them of hardware and the reinforcing bindings, I rounded off all of the edges, and cut off anything that wasn't doing much - like several inches of extension at the stern end of the rudders (see top picture). This was a lot of man-hours of work.

Had to work really hard to get all of the old paint and epoxy out of the webs. Also to sand between new coats. This was my method.

I also stripped off the old Brightsides paint using paint strippers, and sanded down to clean wood (this was also many hours of work).

First, three coats of West 207 epoxy (for clear coating)

Against my better judgment, I decided that they would look nice varnished - a ridiculous amount of work commitment, including having to re-coat them every year henceforth. l looked up the Gougeon Brother's Bible and followed their advice that three coats of 207 epoxy, followed by three coats of varnish was the go for a clear varnished finish.

With three coats of 207, and three coats of Epifanes varnish - nice!

That is six coats, allowing each coat to harden, then sanding before the next coat goes on. That is six days - even if you lived in a magic world where you don't have to go to work! In reality, it represents a couple of weeks. Still, they look really nice after the three coats of Epifanes traditional gloss varnish. I used foam brushes for the first time to tip the varnish on, and they worked really well.

Autopilot line attachment point

I included a few custom tweaks during the refurbish. The picture above shows a saddle to attach the auto pilot steering lines to (instead of just tying them around the tiller). The screws for the saddle go right through into a G10 web that was glued into the space behind. I did this so that the loads from the steering lines would be spread to both sides of the tiller arms. It is totally overkill because the loads are low, but I will never have to worry about them coming out.

Tiller bar reinforced holes for articulating with the tillers

Any articulating holes were drilled oversize and filled with hardened epoxy. they were then re-drilled to form a bearing surface and to prevent water from penetrating the surface of the tiller and crossbar.

Rather than wind on all of the binding reinforcements as in the plans, I made an epoxy-sealed hole at the stern-end of the tillers and fitted a through-bolt. In the highly unlikely case of a glue join failure in a tiller, the through bolt will stop the tiller from "unzipping" in half. Thus, I can do without all of the bindings, and it will be much easier to maintain the tillers in the future.

The above picture shows a reinforced hole through the front end of the tillers to accommodate some bungy cord. I use this cord in a loop around the tiller bar to stop it coming apart in a sea way.

Steering gear back on the boat. Still haven't properly reattached the steering lines to their new fittings.

So, after a great deal of work, the steering gear is back on the boat and looks really nice. I am surprised by how a bit of varnish work makes the boat look more attractive. By the time I was finished, the weight of each tiller had been reduced by around 40% (from 5.5 lbs, down to 3.5lbs). The effect seems much more as the tillers "feel" much lighter and don't seem to weigh on the rudders so much. I am really pleased with how this project turned out.

Saturday, November 4, 2017

In The Weeds

Literally in this case, on the edge of the marsh north of Buckeye Pt, China Camp, and looking along the coast towards Jakes Island, Gallinas. Little Cat is among the reeds, but there is still a foot or two of water under the keel at high tide.

Looking North to Jakes Island

This is one of the things that I love about Wharram cats: that you can push into shallow water that excludes most other craft other than dinghies. It is so much fun to gunk hole in shallow water that it would be hard to give up. I am sometimes tempted by the comforts of a displacement monohull (especially pretty and old wooden keel boats), but I would really miss being able to pull up to the shore and and enjoy a coffee with the local wild life.

Towards Buckeye Pt, China Camp State Park.

I usually avoid running the outboard as much as possible, but this was one of those days when the wind was right on the nose heading out with the tide, and right on the nost heading back with the tide. So it was a rare trip where we motor-sailed both ways for some hours (15 nautical miles this trip).

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.