Dickinson Pacific rebuild

This project has been on my list since the day I discovered that Satori was setup to circulate hot water through the stove to heat up the hot water tank. I have pondered the way a new system would work and what components I would use to make sure it is working with as much efficiency and durability as possible. This is a way to harness the heat from the flame in the stove to move it using glycol into the hot water tank to heat up the freshwater. I’ve spoken with several experts on Dickinson stoves and spent countless hours on the internet trying to design a dependable system without spending money on a new stove. So instead of replacing the stove, I have elected to rebuild the existing one and add the coil myself. Along with rebuilding the stove, I have a chance to clean and rebuild other parts of the system so it works as best as I can make it. So a list of components was built:

  • Mixer valve for preventing hot water scalding
  • Sharkbite fittings for copper connections to hot water tank
  • Temperature gauge
  • Propylene glycol for hot liquid inside of loop to tank
  • Stainless steel compression fittings to fit the copper flare fittings
  • Various hose barbs with flare attachments
  • 2 gpm, high-temp water pump, wiring and switch
  • 1 gallon alloy expansion tank and radiator cap
  • Replacement stainless bolts and screws
  • Hybond Cement for sealing cracks and top of stove
  • Two-turn hot water coil
  • Fire brick
  • Stove top clip fittings
  • 1/4″ Trident fuel hose
  • 3/8″ hose for blow-off valve on expansion tank
  • Hose clamps
  • CLR for cleaning existing copper lines and fittings
  • Stove pot superheater
Satori's galley with the Dickinson Pacific stove
Satori’s galley with the Dickinson Pacific stove

Most of the parts were ordered via mail order or through Sure Marine, just a mile down the road. They specialize in closed heating systems, LPG stoves, heaters and are a parts dealer for Dickinson. A couple of the employees have rebuilt stoves and also has installed hydronic systems so they have been a great resource for this project. Most of the stove parts and compression fittings came from their store. The first part of the project was to drill out the existing screws from the top of the stove. Because the stove is alloy (an indifferent metal to the screws) and heats up quite a bit, the screws cannot handle the extremes so they rust and the screw heads are heavily corroded. It took about an hour and a half plus two drill batteries to get them out. At this point I think most people would give up.

Drilling the old screws to remove the top of the stove
Drilling the old screws to remove the top of the stove

Once the stove top was off I was able to begin scraping and cleaning out the firebox. The cement inside wasn’t entirely brittle so I decided to reuse much of the existing cement and then seal it with hybond cement. The fittings on the back of the stove took most of my physical strength and energy to pull them apart. Once I was able to get the individual fittings apart I could bathe them in a mild acid to remove the calcium deposits that come from fresh hot water getting super heated. I also wanted to replace all of the fuel lines so I bought hose barb fittings that fit the fuel regulator. I also disassembled it to clean any nasty fuel deposits and cleaned it up a little. Once I was able to remove all of the copper fittings, I built a drain at the lowest point using shark bite fittings. I cleaned out the lines by running CLR through them to help eliminate any calcium, lime and copper residue and it helped considerably to clear them and prep for the glycol liquid. A few flushes cleaned the lines up well enough for a good flow without restriction. There is still a small amount of calcium in the lines but it seems okay to leave since there is still sufficient flow. I was considering using pex if the lines were too clogged but I that presented several issues. Mainly I just wanted to be able to run the stove straight to the copper tubes so I didn’t have to run the pump just to use the stove. The old coil and copper pipe used thermosiphoning to circulate the water by heat convection so being able to do this was critical, but without the copper pipe would have been impossible without risking burning the pex tubing when the pump is not running.

Stove top removed showing the broken cement and fire brick
Stove top removed showing the broken cement and fire brick

Once I had the stove out of the way I could clean up the flashing and the stove itself. Decades worth of liquids oozing down the side of the stove cleaned away easily. The flashing and stove cleaned up nicely. I bought new cement thinking that I would just add new cement to replace the old stuff but the existing cement was in pretty good shape, minus some cracks. Once I cleaned up the cement, removed the fire brick and cleaned out the firepot I prepped the stove for sealing. Much of the old cement was put back into place and then the Hybond cement filled in any existing cracks and spaces, plus sealed the cement parts together. I also used a wire brush on the top of the stove to get rid of the old sealer and remove any buildup of soot or other materials. On the top of the stove I used a vibrating sander to remove the old surface material so I can season the top with something that will seal the alloy. I am planning on using flax seed oil since this is my seasoning for cast iron cooking pans. I also removed the stovepipe flange, cleaned it up, attached and sealed it back to the stove with Hybond.

Nasty flashing and hull space. Nice to clean things up a bit.
Nasty flashing and hull space. Nice to clean things up a bit.

The new hot water system uses a low flow pump to circulate hot water so I installed a toggle switch at the stove so I can turn the pump on when operating the draft assist fan. The fan motor was replaced a month ago after trying to troubleshoot the noise. It turned out to just be an imbalanced fan and once I figured it out the fan was considerably quieter. I also replaced the wiring back to the electrical panel so everything would last another thirty years. Once I added the hot water mixer I began to have issues with the existing water circulation and so I removed it and relocated it to the bathroom faucet. This way the water can be raised to above scalding temperature and circulated through the cabin but if I take a shower or use the sink water, there will be no risk of accidental burns. The first circulation pump was also defective so I ordered a new one and tested the circulation before connecting the stove to the copper fittings.

IMG_2647
Nice and shiny stove again

One tough engineering problem I had was with the compression fittings that came with the stove. They were ninety degree compression fittings on both ends. Not only was the angle incorrect but they did not connect directly to the copper flare female fittings. This could not be solved by anything that Sure Marine had in stock so I decided to give Motion and Flow Control Products a try. They not only solved the issue but also suggested that I switch to stainless steel compression fittings. This solved the link between compression and flared attachment but also provided a better material for the connection. Stainless pipe to stainless compression to copper flare is much better than stainless pipe to brass compression to copper. It’s a very unique issue and MFCP did an excellent job helping me solve it. They also provided excellent advice on the circulation pump and lines.

Stove top ready to attach with hybond cement sealer
Stove top ready to attach with hybond cement sealer

This project has been a great engineering challenge for me and the only other project of this scale was the new plumbing installation and the bathroom rebuild. Not only have I managed to unplug the water heater while operating the stove but I have also given new life to something that may be several decades old. The cabin has been uncomfortable while this project was underway and littered with debris from drilling and cleaning. The tools took every inch of space and the stove took some physical energy to get apart and back together again. Without the highly specialized people at my disposal the project might not have ever been completed the way I wanted it. This is one reason why I decided to take this project on now, while it is useful to have water heated as a byproduct of the stove heating the cabin. During the summer the solar panels can practically run everything but in the winter I become dependent on shore power for heat and to keep the batteries topped off. With a diesel stove running for twelve hours a day I can heat the water, the cabin, cook from the stovetop and almost completely eliminate the need for electricity, except to top off the batteries. Now that this project has been ticked off, I can now focus on the engine’s water pump, prevent any additional corrosion and prolong the life of the engine. Once I have used the hot water heating system enough to know it’s quirks, I will make sure to update the blog with any discoveries.

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Hot water coil and new superheater. Much better!
Hot water coil and new superheater. Much better!

Jabsco Diaphragm Pump

The Jabsco water pump is a workhorse. I don’t think that I needed to rebuild it but I figure if the kit is available then what’s the worse that can happen? I had a partial kit that a PE (previous owner) bought but only replaced the diaphragm and left the rest of the new parts. I looked online and found just a diaphragm for sale. I piggy-backed the purchase with a Whale 25 Gusher bilge pump kit so I can rebuild the manual bilge pump. I’ll post later about that rebuild project.

Tonight I finally installed the tiller pilot so I can test it out this weekend. I’m a little disappointed with the range it has. I suspect it’s only going to be capable of steering in mostly calm weather while the sails are balanced. I don’t think it can take much force, although it draws 12 amps. I did some testing to see how easily it can bottom out. Without moving the mount further aft I’m afraid that it might only have a range of 50 degrees. Not much considering the tiller has near double the range of the pilot.

Anyways, I took a few photos of the newly rebuilt pump.I already have the holes drilled into the platform for when this pump was mounted so I just need to make sure it’s easy to attach. The old plastic fittings will get replaced with new ones and I will install a check valve on the outflow side and attach sharkbite fittings to make replacement a snap.

 

Taking it for a test drive to check belt tension
Taking it for a test drive to check belt tension
The left hose barb has a built-in check valve. No problem, sharkbite makes a check valve.
The left hose barb has a built-in check valve. No problem, sharkbite makes a check valve.

Rebuilt Jabsco diaphragm pump

 

New Freshwater System

I’ve been drafting and researching the freshwater system for a few months when I have spare time and have come up with some solutions I would like to share. I’ve decided to install Sharkbite branded fittings so replacing a pipe or fitting is as easy as possible. Also the piping is blue from the holding tanks and red from the hot water tank. This will make tracing easy as well at no extra cost. Inside of the engine compartment on the hot water side I have enclosed the piping with foam pipe insulation to help prevent heat loss in the unheated portion of the boat.

Tank attachments

The plumbing from the deck fitting to the tank is 1 1/4″ sanitary hose and schedule 80 PVC with hose clamps. Removing the hose is simple as the barb tank fitting is not exactly 1 1/4″ which means removing the tanks for cleaning will be a little easier over time. I contemplated over going with 1 1/4″ pex but decided to make the deck plumbing more permanent. The main argument? It’s a pain in the ass to route the hose from the deck fitting to the tank. Hopefully I never have to replace the hose.

The tank vent is 1/2″ npt so I chose to join the vents with a ‘T’ fitting and pex tubing, then at the end opted for a brass breather vent to prevent debris from entering the supply line and also close the vent down as small as possible to prevent any water overflowing out of the tank from flowing at the same rate as the rest of the system. The idea being that the tanks will be full of water and start filling up to the deck fitting so you know when to turn off the water. The vent  only leaks a small amount of water out into the bilge until you can run water through the galley sink to drain out the deck fill hose to a level that prevents the vent from spewing water. The alternative would be to keep an eye on the vent and wait until you see it leaking water and then run up and turn off the water. At that point you’ll have likely gallons of water already in the bilge and then need to clean out the primary bilge after every filling. The photo below is only one example of a vent fitting and I accidentally opted for something different which is simply a screen inside the fitting with a tiny hole drilled into the side of the nut portion. It turned out to be the right amount of air for filling with a garden hose at full flow and displacing the water in the tanks while consuming the supply. The interesting thing about vent fittings is that there isn’t already a solution out there and everyone is left to their own accord on solving this problem.

Freshwater tank breather vent fitting allows air in and out but prevents debris from entering the system
Freshwater tank breather vent fitting allows air in and out but prevents debris from entering the system

A ball valve for each tank will allow me to isolate the tank output for any reason. The previous valves were sitting low enough to be in contact with water in the bilge. The new valves sit three inches above the bilge instead of one inch. The photo below shows the ‘T’ above the tanks but I decided to move it down so the second tank would fill once the first one was half filled.

The freshwater tank assembly using pex Sharkbite fittings. Fill hose barb not attached yet.
The freshwater tank assembly using pex Sharkbite fittings. Fill hose barb not attached yet.

Tank to the pump

A water meter tracks the total amount of water that has passed through the freshwater system. This way if I do end up filling the tanks I can know exactly how much water I have left without eyeballing it. I can also log usage for replacing the water filter or simply to keep track of my daily and weekly average water use. I thought about getting a digital display but felt analog would be just fine since I will be in the engine room often enough. The meter is quite massive and heavy at likely five pounds but looks like it will last for the duration of Satori’s life and provide dependable service without requiring any electricity and very little maintenance. It’s located in an inconvenient place for reading the meter but I remedy this by taking photos of the meter for logging using my iPhone, which seems to be better for keeping track. Also the mount had to be custom built as you can see below it is odd shaped.

Inline water meter
Inline water meter

A strainer eliminates any large particulates that make it into the tank or rust that may come from the tank itself. This will attach to the input port of the pump. A 4.5 gallon per minute, variable speed pump delivers water pressure (35 psi) and freshwater throughout the boat. Variable speed pumps eliminate cycling using a solid state pressure sensor to regulate flow. Simply turn the water to your choice of volume and the pump will maintain a constant pressure   flow without the need for an accumulator.

Jabsco Sensor Max   variable speed pump with strainer
Jabsco Sensor Max variable speed pump with strainer

Pump to manifold

A 3.5 gallon per minute freshwater whole system filter eliminates most contaminants and provides clean freshwater at a reasonable cost. The filter will not eliminate the need for potable water and I would never want to introduce water that has not been treated to eliminate hazardous organisms such as giardia or cryptosporidium, which would make anyone ill from drinking. It will filter water down to .2 microns which eliminates everything I’m concerned about from most potable water sources.

3M B3 Water Filter - 3.5 gpm, .2 microns and 6 month/15,000 gallon lifespan
3M B3 Water Filter – 3.5 gpm, .2 microns and 6 month/15,000 gallon lifespan

I debated on purchasing a manifold of solid copper with sharkbite attachments but the manifold presented a few problems I did not like. First off I was stuck with adding a 3/4″ to 1/2″ sharkbite reducer just to install the manifold into the system. Also the manifold seemed a bit excessive for simply distributing freshly filtered water so I opted for “T” fittings instead. The cost is about $36 for the manifold and $6 for the reducer but only $12 for three “T” fittings.  They can be fitted closely together and accomplish the same thing and I can just add another “T” if I want to tee into the line pretty much anywhere I want.

Filter to hot water tank

A check valve is placed inline between the filter and the hot water tank to prevent hot water from back-flowing into the cold water lines. Since I’m running a variable speed pump, no need for an accumulator.

Currently I’m plugging the pex tubing straight into the hot water tank and then to flexible hose with Sharkbite fittings on both ends. I plan to replace the pex with copper on the tank end for long-term use as it’s better suited for near tank plumbing.

Hot water tank to radiant heater

A temperature gauge at the heater outlet allows me to visually see what the current temperature of the hot water is at any moment. If the tank has been off for some time I can check to see if it’s ready. If the tank registers unsafe temperatures I can switch the tank off or possibly add a mixing valve if necessary. Either way it’s added peace of mind.

Sharkbite temperature gauge
Sharkbite temperature gauge

A pressure gauge at the heater outlet allows me to monitor hot water pressure for the same reason I am monitoring the temperature; peace of mind for just a little extra money.

Sharkbite temperature gauge
Sharkbite temperature gauge

After the gauges I have a 2.2 gallon per minute solar pump so hot water is circulated throughout the boat and allows for instant hot water for any of the faucets on the boat. This prevents wasted water while waiting for the hot water to warm up in the bathroom, which is common in regular households with hot water tanks. The pump is wired with a simple rocker switch that can be operated from the bathroom in case the hot water heater is on and I’m not running the forced air heater to supply instant hot water to the bathroom sink as needed. I debated over the switch location and this seems to be the most logical location as it also supplies the heater with power in the same circuit as the pumps.

Circulation pump
Circulation pump

A ‘T’ sends hot water to the cockpit and then out to the rest of the boat to begin a recirculation loop. The loop heads forward with another ‘T’ to the galley sink and down under the floor in the salon on the port side to provide a little extra heat to assist in heating the cabin from below the floor. The loop then heads up to the bathroom sink and another ‘T’ provides hot water for the bathroom sink. The loop then heads to the forward berth and supplies the Dickinson Radex forced air heater with hot water to blow warm air into the forward part of the boat.

Dickinson Radex forced air heater
Dickinson Radex forced air heater

Heater back to hot water tank

The loop then heads back to the salon under the floor on the starboard side to provide a little more heat and finally back up to the hot water tank, which completes the hot water circulation loop. This is  also known as an open hydronic system.

All of the plumbing fittings are ordered from PexSupply or at my local Home Depot, which carries most of the basic Sharkbite fittings. Home Depot does not have any manifolds, gauges or check valves so if you’re planning on building a similar setup, expect to buy some parts online and the basic fittings as you need them at your local Home Depot. I underestimated the amount of elbow fittings I would need and suggest that if you’re going to use Sharkbite that you buy plenty of these parts to make the routing much easier. Also, Sharkbite fittings are expensive but when I did the math for hose clamps plus the same barb fittings it seemed about a dollar more per fitting. The pipe is less expensive than quality marine water hose so it might only be a little more. I’m not entirely finished with this project yet as the plumbing and electrical needs to be secured and some rerouting would be nice to tidy the engine compartment but it’s nice to have water back on the boat once again.

Finishing this project, I plan on repairing my Dickinson Pacific diesel stove by replacing the water coil that provides hot water to the hot water tank without the need to run electricity. The hydronic system with the heater fan on and pump draws less than 4 amps of power so it should prove to be very nice while away from shore power. I’ll follow up later when the heating coil project is complete. There is also an option to plug in a calorifier that uses hot water from the engine to heat the hot water tank. It would be nice to have another source of heat for the tank and the hot water tank already has fittings so I may also plumb in another pump for this as it does not look too difficult. I’m still debating the need so I’ll reassess once my Dickinson coil is in place.

This weekend is the Seattle Boat Show, which puts me into another project of getting a new chart plotter and radar. I’m hoping for a discounted deal at the show. Wish me luck!