April 26, 2013

Regalvanizing-from A to Zinc

rusty chain--some links are in better shape than others
If you’re not a boater, a rusty anchor chain probably isn’t that exciting a thing to contemplate. But when those rusty links are the link between your boat and your anchor (a piece of equipment that is easily one of the most important items on a boat, or under a boat) the rust gets personal.

Chain is expensive stuff—and in recent years, because of increased costs, the protective zinc coating found on chain has become thinner. This means that unless you are diligent about washing down your chain, end for end it as it shows wear, and touch it up with a wire brush and zinc paint when the first spots of rust do show up, before you know it you’ll have a rusty ball of chain in your anchor locker.
take your chain for a drive
Or at least we did. Our chain is about 5 years old. Not that old in the boating world—but a few years of constant use, followed by a year in the anchor locker meant that our chain was rapidly approaching the cut-off point between salvageable and garbage. Although surface rust, even if it’s a bit flakey, isn’t the end of the world for chain-but you do need to remove heavy rust to have chain regalvanized.

As a guideline you should toss rusty chain if:
- Wear exceeds 10% of a link diameter (check where the links connect).
- The chain is cut, nicked, cracked, gouged, or pitted.
- It’s distorted, twisted, bent or stretched.
- You don’t know its history, including how many times it’s been regalvanized.

If you got around to regalvanizing before we did and the surface rust was fairly light (indicating you still have some zinc coating left) you can probably send it straight for regalvanizing without prep. If you have more rust then you’ll need to look at sandblasting, which is normally hugely expensive, unless you try a version of poor mans sand blasting.
bare metal after 10 km--we were still able to see the stamps on the links indicating we hadn't lost much material
We headed off out of Brisbane in search of a sandy road. When we found one we tied the chain the trailer hitch and set off down the empty road (the one car that passed us was pretty confused, or thought we were confused). By end-for-ending the chain a couple of times and driving through sweeping S turns the chain started to show bright metal after about 10k. Then it was off for galvanizing.

Because I ask about this stuff I learned the first step of the galvanizing process is a caustic soda solution to remove grease and oils from the steel. The chain is then immersed into a pickling solution of sulfuric acid. Then it’s ready for the molten zinc.

newly galvanized chain

The result is a thicker coating of zinc than what the chain had when it was manufactured—which means it should last longer. Especially because we’ll take better care of it this time round and not wait so long before regalvanizing it again.

Our cost at Industrial Galvanizers in Brisbane was $2.05 a kilo—and our chain came in at $166. Far less than new chain would have cost (we can’t get our chain here so would have needed a new gypsy as well).

April 21, 2013

First Friend

Now and then
Way back in the beginning, when our new-to-cruising kid asked Santa for a friend for Christmas, I wondered if cruising would ever be right for us. But not long after Maia made her lonely little request, a boat we recognized pulled into harbour. We had hopscotched down the US west coast with a boat called Orca. We were always a little out of sync, but usually one of us would delay a departure by a day or so, so our cruising kids (two only girls with more in common than we could have imagined given a 3-year age gap) could get their fill of little-girl chatter. This went on for months; starting in Neah Bay, then on to Coos Bay, Eureka and Morro Bay.

A few months into the trip, injury waylaid Orca and we lost touch. But then Maia’s Christmas dream was answered—Maia and Sirena, who were each other’s first (and, at that point, only) cruising friend, had a chance to catch-up in Newport Beach.
Brisbane breakfast brings back memories of a La Paz lunch

By the time we reached La Cruz, Mexico Maia’s social life was filled to overflowing, and those first lonely months were a memory. We still ran into Sirena and family, and the meetings were as sweet as ever, but the fear; that Maia would be lonely forever and cruising would never work, was gone.

“Will I make friends?” Is the question every cruising kid asks before they cruise or shortly after they begin. In most places (the ones where big packs of cruisers gather for months on end, or where groups of cruisers migrate with the seasons) the answer is ‘yes’. And most families tend to modify cruising plans a bit to go where the kids are.
Swimming in Brisbane, paddling in Morro Bay

But as the years have passed (has it really been almost 4 years?!) Maia’s question has shifted a bit. She now knows she’ll make friends, but now she wants to keep them too. She wants a group of buddiess she knows are hers and who know her, not just for a season but for years on end.

It had been a few years since Maia and Sirena last played together. But when the fates brought them together this weekend the years apart disappeared. Their conversation lasted for hours, went late into the night and continued on the next day. Plans were made for the next meeting, and the one after that. It’s not the same as being neighbours year in and year out. But I guess when you live a nomadic life, and half your friends are nomadic too, you accept the gifts of friendship the way they come.

April 14, 2013

Technical Post - Catamaran engine choices

Evan here.  I've got a quiet night so I'm going to write about something that is unusual for most sailors - Engine choices, specifically for cruising catamarans.  If you have a regular monohull sailboat your choice is usually pretty simple.  Outboards for boats up to about 27', an inboard diesel for boats over 27' (give or take a few feet). Catamarans offer a lot more choices.  Here are my thoughts on a bunch of the options.

1.  Single Outboard.  Usually used by smaller catamarans up to about 25' or so.  The 32' Gemini was an exception with some boats delivered with a 40 HP or so.  Unless you link the motor to steer when you turn the tillers, docking under power is pretty challenging.  You need to have some speed for water to flow over the rudders to turn the boat.  Even if you link the motor to turn, it's still like driving a bus inside a shopping mall at low speeds

- cheap
- light

- steering under power is interesting

2A. Single diesel + Silette external drive.  Prouts and Geminis are the only production boats that I know that have used this combination.  A single diesel engine located in the cockpit and a steerable external drive leg is attached to the engine.  Visualize a big outboard leg with big 16" 3 blade propeller. The drive legs aren't too heavy (50 kg) but quite costly; around $6500 or so.  Owner's report exciting times when they put it in reverse and the leg kicks up suddenly when the lock mechanism isn't working.

- only the weight of 1 engine
- no drag when you tilt the drive leg out of the water. if it tilts enough

- Silette drive leg is pretty agricultural in it's engineering.  Reverse lock can fail and so can bellows and steering yoke

- works best on smaller boats that don't need the thrust of twin engines.
- about the cost of 1.5x diesels

2B.  Single diesel in one hull. You have to be a good driver in tight quarters with this combination.  Only seen on the odd custom catamaran.  If the engine is in the port hull, it will turn pretty good to starboard but turns to port take several boat lengths in radius.  Advance planning is required or don't even try to dock in tight quarters.

- well it's cheaper and lighter than 2 diesels

- handling in tight quarters is VERY interesting.

3. Single diesel in one hull + small auxiliary thruster.  The auxiliary thruster helps offset the unbalanced thrust of the one diesel. It can take the form of a smaller outboard, an electric bow thruster, or even an electric outboard motor.

Ceilydh has this type of system; a 27 HP Yanmar diesel in one hull, and a 6 HP outboard on the back beam near the other hull.  Because I'm so familiar with it, I'll give a bit more detail.

The outboard used to be a Yamaha 9.9 high thrust which would push the boat along at 5 knots in calm seas.
That died recently and we replaced it with a Tohatsu "Sailpro" 6. It offers a 25" shaft, remote operating, and quite light weight at 65 lbs. But it won't push the boat faster than 4 knots in calm conditions. That's enough to get into most harbours if the diesel dies but it won't push it against 25 knots of headwinds and it will ventilate in choppy seas.  The diesel died in California's channel islands. We sailed back to the mainland and used the outboard to get us the last mile to the dock through the breakwater entrance.

Powering with 1 diesel in open seas is no drama and the rudder deflection to counter the offset thrust isn't really perceptible (it's probably about 2 degrees). It's very common for twin diesel cats to use just 1 engines in most conditions.

It's noticeably low in power compared to a twin diesel installation when you're heading into strong headwinds. But we tend to sail in those situations or at least motorsail if the surrounding land doesn't allow sailing.

We usually anchor with just the diesel.  We've learned to live with the boat wanting to turn to starboard in reverse and just snub the anchor and straighten out the boat and then back down hard in reverse.

Our Yamaha was so unreliable we learned to expect it to die coming into the very rare marina or fuel dock and just docked slowly with the diesel.  Now we have 2 working engines it's much easier again.  
- lighter than 2 diesels
- lots cheaper than 2 diesels

- outboard isn't much use in choppy seas
- less turning ability on really windy days compared to 2 big diesels

Digression: Bollard pull of a motor is the thrust produced at zero knots of boat speed. i.e. the thrust you measure when the boat is tied to a bollard on shore. Useful for comparing tugboat performance, it's also the best measure we have to compare thrust performance of a 'thruster' motor at low speeds. Thrust values below are all are in forward; reverse will be around 1/2 these figures.

Tohatsu 6 Sailpro = about 140-150 lbs (Evan's best estimate)

Yamaha 9.9 = 250 lbs (KatieKat measurements) 

Yachting Monthly results:
MinKota Riptide 55 lb trolling motor = 37 lbs (manufacturer lies a bit maybe)
Tohatsu 3.5 = 99 lbs (must have been a good one; seems high)
Torqueedo 2.0 = 119 lbs (manufacture claims only 115 lbs)

Yanmar 27 HP diesl = about 400-450 lbs with 3 blade feathering prop (Evan's best naval architecture guess)

An electric bow thruster type installation is useless as a 2nd means of propulsion, and adds a bit of drag. But it can help turn the boat fairly easily.  Bow thrusters are fairly costly for the power they produce and can only be used in short bursts.  But for docking that's all you usually need.

- lighter than 2 diesels
- lots cheaper than 2 diesels (but still more costly than an outboard for similar thrust)

- no backup propulsion

An electric trolling motor is pretty low thrust. I know of a PDQ 36 that had one as it's auxiliary thruster. It didn't do much and was replaced with a very costly Torqueedo electric outboard. 

- very low chance of backup propulsion unless flat calm
- not enough thrust for real turning unless flat calm.
- extra weight of batteries to get 24 or 36V required for 100 lb thrust motors.

Torqeedo Cruise 4.0R - when the Yamaha 9.9 died I considered this as a possible replacement.  (slightly lower thrust at 214 lbs).  But the high cost of the motor ($3800 US) + the required 4 batteries to get 48V put me off.  (both weight and cost)

4. Two outboards This has been successfully done on lots of smaller cats (Gemini, PDQ 32/36, Seawind 1000).  And some bigger cats as well, especially in Australia.  Most owners seem to like them.

- lighter than 2 diesels
- much cheaper than 2 diesels
- good steering in tight quarters
- redundancy

- shorter lifespan of outboards.  About 1500-2000 hours have been reported for Yamaha 9.9 by regular users.
- harsh environment and maybe lower reliability - it's a tough life for an outboard. You're controlled by electricity and you keep getting regular saltwater baths.
- not as good in choppy seas due to prop ventilation
- bigger than 9.9 HP size and props and gear reduction are optimized for fast speedboats not slower catamarans so efficiency diminishes

5 Two diesels  The default solution on larger catamarans. 

- better fuel economy than outboards
- reliable and longevity since they're inside the boat.  Diesels routinely get 5 - 10,000 hours of life
- redundancy

- cost
- weight

I've left out hydraulic (shudder) and electric hybrid systems (double shudder). With hydraulics you have noise, heat, leaks, low efficiency, With electric systems you have low efficiency under most conditions and lots of complexity.

Final thoughts:
Sometimes you just have to take what the builder supplies.  If I had the money I would have put a 2nd diesel into Ceildyh.  I would have liked to have 2 engines each capable of powering her in all sea conditions.  I would have also considered an unbalanced setup; the 27 HP in one hull and say a 15 HP size in the other hull for a bit less weight but still enough power to power her, even a bit slower, should the bigger motor die.  Engineers love symmetry but I think this would be an interesting solution.

- Evan

April 8, 2013

Yanmar 3GM30F Raw Water Pump - Rebuild

Just before we left to go sailing on Moreton Bay, I rebuilt the raw (sea) water pump with spare parts I had bought in San Francisco, some 2-1/2 years ago.  New bearings, a lip seal, a new impeller, etc.

If you take your old bearings and lip seal to a bearing supply house they can supply generic replacements for about 1/4 of the cost of Yanmar parts.  Just make sure your lip seal has a s.s. spring or an O-ring.  It's not hard work really to do the rebuild, once you realize the 2 bearings have a circlip between them and you have to seperate them to get them off the shaft.

And when you put the pump back togther - the pulley is not symmetric.  It's dished on one side. If you put the pulley on with the wrong face facing the pump, the V-belt won't line up.  At all. Though you can convince yourself that all is well if you're trying to go sailing for a long weekend.  And motor for many hours with the pump working with a V-belt that is totally off by about 1 cm or more.  When you put the pulley on the CORRECT way it looks much nicer.

April 5, 2013

Sailing the Barnacle Farm

The Sand Dunes on Moreton Island
For reasons I can’t quite fathom, setting off sailing on a fun sailing trip can seem a lot like work. Part of the problem is to actually get out on Moreton Bay means timing the currents, setting off at high slack, then making a nearly two hour journey to the sea. The return trip needs to be timed almost as precisely.
And then there’s all that packing, planning and organizing. Moving your house is hard.

Charlie helps navigate
What this means is it’s been a year since we’ve been anywhere. A year. We’ve planned to get out a few other times but always some thing has foiled the plan; a cyclone, or a broken engine, or waiting for some vital part. But this past weekend all the fates came together—the weather looked fine, the tides were cooperative and most importantly all the boat’s systems are functioning.

Despite the fact we live aboard, have crossed an ocean, and got very good at provisioning in stores that had very little by way of provisions, getting ready to head out felt like we were flexing a forgotten muscle. It was like when we went camping two weeks ago and I thought I bought everything we needed but still managed to forget the eggs for breakfast and the butter to fry in. Except luckily this time I was able to just go back to the grocery store and hardware store every time I realized I missed something from the list (got sandwich stuff, but forgot the bread). And I still forgot to visit the liquor store…

raftup sundowners
Easter Bilby helps celebrate

Casting off was drama free. Except for the huge amounts of black smoke coming from the engine and the fact that no amount of throttle seemed to give us any forward momentum. Fortunately we have a second engine—a new outboard we use to manoeuvre and dock. With the current in our favour it can push us at 4 knots. Unfortunately we only carry enough gas for manoeuvring and docking.

So we dropped the anchor (after it was clear that running the engine wasn’t going to magically make the smoking stop) and Evan dove into the murky water and discovered that rather than having a loving three bladed feathering prop, we had a ball of barnacles. It’s been a year, remember?

Merlin underway
Eventually we made it out on the bay. Maia dove in for a swim and we came up with a definitive answer on whether or not our bottom paint is still working (no—the boat’s bottom was supporting a barnacle farm). But the sailing was great. The weather was lovely (other than one squall). We saw sea turtles and pelicans, climbed dunes and swam in warm water. Ate dinners with friends and watched the moon rise and wondered why we didn’t get out more often.
Convivia at sunrise
 It was so lovely we think we should do it more often—or maybe even for longer.

home again

April 4, 2013

It Seems I Have a Book

I had a very good time writing this last summer-delving back into the basics of sailing and rediscovering why I love the sport so much. My editor and all the staff at Penguin were fantastic to work with and I was fortunate to have Jamie and Behan from Totem act as technical editors--catching the details that slipped past after too many hours staring at the screen...