Steering Linkage

     I took a picture of the steering linkage as soon as I pulled it from the boat:

     As you can see, it was quite corroded and rusted. The factory connects the tiller arms to the tie bar with short, 1/2" hex head cap screws. This system works well enough, at first, and allows for a quick assembly at the factory. However, over time, the threads of the bolt slowly wear into the bronze forks, and play develops in the steering linkage. In order to eliminate any clearance, I bored both tiller arms, and both forks, to 9/16". Next, I fabricated two new pivot pins from stainless steel bar stock, as shown below:

     These new pins are .001" smaller in diameter than the bored holes in the tiller arms and forks, resulting in a freely rotating joint with no play, and just enough clearance around the pins for lubricant. Close-ups of the finished fork, and the finished steering linkage, are below:

     The tie bar was sandblasted, primed, and painted gray. The tiller arms and forks were blasted, then clear coated.
     I have quite a few new pictures, so there should be a couple more updates later this week.

Hot Water Plumbing Complete!

     It's done - finally. The heater is secured to the hull, the plumbing is done, and the electrical and pressure relief systems are complete too:

     I had to enlarge the pressure relief line from 1/2" to 3/4", to accommodate the larger water heater. Of course, the through hull fitting had to be enlarged as well. It is very important to make sure that the pressure relief line is not restricted in any way, and does not reduce in diameter from the tank outlet. You can also see a thermostatic mixing valve (tempering valve) in the picture, mounted directly to the hot water heater discharge. It is very important that any hot water heater that will be connected to the engine, and that will utilize the engine coolant to heat water, be outfitted with a tempering valve. Engine coolant temperature can exceed 180 F, so the hot water will also approach this temperature. Imagine a child, or even an unaware adult, turning on the hot water to wash something or take a shower. Severe burns could result. The tempering valve reduces the temperature of the outgoing water to a safe level, by mixing a controlled amount of cold water with the hot water. The outgoing temperature is easily adjustable between 120 F - 160 F. An added benefit is that, once the tank is up to full temperature, the hot water volume is further extended.

     Example: If we assume the hot water is 180 F (82 C), and the cold water is 68 F (20 C), then how much hot water is available at 140 F (60 C)?
     Since Q = mc(Delta T), from this follows: (3785 g/gallon)(12 gallons)(4.18 J/cg)(82-60) = X(4.18 J/cg)(60-20), where X equals the number of gallons of cold water, at 68 F, needed to reduce 12 gallons at 180 F to 140 F. The result is 6.6 gallons. So, in effect, the hot water capacity of this boat has been increased from 6 gallons (since the factory did not use engine coolant through the heat exchanger, there was no tempering valve, and the water was only heated electrically to 140 F maximum) to approximately 18.6 gallons.
     A side benefit is that the area adjacent to the exhaust manifolds, and the spark plugs, is now completely opened up, and the hot water heater has been moved forward, which is a better location, in terms of weight balance. If you look at the following pictures, you can see that a person can now easily stand next to the engine (once it goes in). With the old layout, there was no room for engine service at this location.

     Other features of the install include a back-flow preventer in the cold water feed to the water heater, a shut off valve, for servicing, and a drain valve, for winterizing and flushing. I also added a hot water line up to the wet bar, so I can have both hot and cold water there. I will be detailing the wet bar modifications in a future post. For now, it is on to the bilge pumps and discharge lines....

More Sanitation and Plumbing

     OK, the holidays are over - time to get back to work! For some reason, I seem to be about 5 pounds heavier this month than last month. Working on a boat is just the thing to solve that problem...
     The first problem is clearing the necessary space for the new hot water heater. The factory ran the 1 1/2" sanitation hose from the head to the vacuum generator right through the area I need for the water heater. They used a black rubber sanitation hose, and simply bent it around the fuel tank, and up to the vacuum generator. I have replaced that old hose with Sealand's OdorSafe Plus hose, which is considered to be one of the finest sanitation hoses available. Unfortunately, it is also extremely stiff and difficult to work with. In order to achieve the hose routing I need, I made up a short section of 1 1/2" schedule 80 PVC piping with the appropriate bends, and mounted it behind the water heater, as shown below:

     Each end of this pipe run is mounted with some Delrin mounts I made. Each mount is lined with self adhesive silicone rubber, to allow for a bit of freedom in the mounting. Rigid PVC has the potential to crack when improperly mounted, and the rubber isolation will allow a degree of deflection, while style providing for a robust mounting. If you look closely in the picture, you can see the orange silicone rubber at lower right, inside the pipe hanger. The pipe hangers themselves are detailed below:

     The lower block has two countersunk mounting holes, just visible in the lower picture, that secure the hanger to the hull. The rubber was then applied to both halves, and the upper block was secured to the lower with counter-bored socket head cap screws. A close-up is here:

     Once the sanitation line was neatly tucked up against the hull, the hot water heater fit into place easily. I took a pic during the mock-up phase:

     Here, the hot water heater is resting on the new mounting feet, and the holding tank installation has been completed. I will be mounting the water heater, and finishing the plumbing, today. The space below the vacuum generator may be an ideal location for the generator starting battery, but I have not made the final decision yet. I may place it right next to the generator, on the starboard side, but I need to take some additional measurements. The generator weighs over 300 pounds, so locating the battery on the other side of the boat, under the vacuum generator, would seem to be a better location, in terms of weight balance (assuming the holding tank is normally kept discharged). I will post the finished water system install within the next few days....