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!

16 Replies to “Dickinson Pacific rebuild”

  1. THANK YOU! I have been searching and searching for other people who have refurbished their old Dickinson diesels. We currently live in the tropics, a climate not well suited to a diesel stove, but we will be resuming our trek up north and want to get it going again before the temperatures start dropping. Have you ever had issues keeping the fire ring lit? I’ve been having issues and I think it’s because the cement is old and flaking away and there isn’t a good seal. What cement did you use? Is it the cement recommended by Dickinson. She looks so beautiful! Enjoy that hot water!

    1. Thanks for visiting SV Serenity. I wish I was there instead of here. Anyways, the cement is called Hybond and is sold in a caulking tube. Chances are you can probably get the parts from Canada and then rebuild it whenever you have some spare time and close the the cooler latitudes. The only time I have issues with keeping the fire going is when the fan is no longer assisting the draft and the wind is up. It must be dead calm to run without a fan but otherwise unless the fuel regulator isn’t set properly it should burn without any issues. If you think you have a draft problem from leaks, I can tell you that my stove had draft issues and once I rebuilt with new cement sealer the stove seems to work much more efficiently and burn cleaner. Thanks for following my blog! Cheers from Seattle.

      1. Thanks for the response Tony! I am finally in a position to start the rebuild and have a couple more questions for you. Where did you get your Hybond cement from? I’m only seeing options in cans, nothing in a caulking tube (http://www.suremarineservice.com/05-040.aspx). When you mention that you didn’t end up redoing the cement, is this the cement that comes in a bag and needs to be mixed with water? I think I need to take the cooktop off to determine if it needs new cement. Did you replace the fire brick or use the broken one? When putting the cooktop back on, was the Hybond cement still wet? Or did you let it cure a little bit? Finally, how did you get your stainless looking so good! I made the mistake of using a scotchbrite pad on my stainless awhile back and I think I’m going to regret that decision. Thanks again!!! Say hello to Puget Sound for us!

        1. The Hybond cement came from Sure Marine. You can call them and ask for the caulking tubes. It was much easier to work with than an open container. Especially at the end when I cemented the top on. I did buy a bag of the cement (yes just add water) but returned it. I did buy and cut a new firebrick. If yours is broken I would suggest replacing it. That piece help regulate heat at the stove surface for cooking. When I put the top back on the cement was wet because once you screw the top on the cement will displace and seal the top. I also added a little bit more once the top was on and then wiped it clean, like you would with a silicon caulk in the bathroom. I would not risk curing because the stuff dries very fast. Just apply a good amount on the top seam and then check and add more once it’s screwed back on. The key is to prevent any air from leaking in, our exhaust from leaking out at the top. I think the stainless just came that way and I was lucky that it didn’t take much to bring it back to original polish. The superheater is the part that the flame comes into contact with inside of the firpot. It is removable and the kind that I had originally sat low inside of the pot, which worked but did not help raise the flame like the new one that is much taller. If you have the old style tripod legs that sits down low, replace it. The new style is better at evaporating the fuel. The biggest difference is that the new one will require some draft assist at all times. Not necessarily a bad thing, once I realized that the stove temperature did not change keeping the fan on all the time. It does help when you’re running the stove and the wind picks up. I’ve not yet had a back draft of smoke into the cabin since I rebuilt the stove.

          Good luck on the rebuild! Feel free to ping me directly with any more questions.

        1. The superheater is a metal insert that sits in the burner pot transferring the heat from the fire to the oil pooling in the pot to help the oil vaporize. This type of stove must have one to operate correctly.

  2. I’ve found your site, and find it extremely suited for what I want. I’ve fell in severe like of the Westsail 32’s and will be rebuilding one within the next year or two. I’m a belt and suspenders kind of guy and I like the way you do things.

    1. Thank you Mitchell. If there was ever a love affair it would be with the Westsail 32 and an eager owner attempting to make her sail the world once again. Good luck on your refit. Feel free to inquire about anything if you think I can assist. Otherwise, we have the Facebook community that has been as good advice as ever. Cheers.

  3. Hey there,

    Great to see some info about your Dickinson Pacific, I have one on my narrowboat, as yet unplumbed into the hot water system -any chance of some more photos/diagrams of your setup/parts used?

    Many thanks,

    James

    1. James,
      Michelle works for Dickinson and if you have any questions they are extremely helpful. Give them a call and touch bases on your project. I think I called them at least three times during my rebuild to ask questions and order the new parts. Their diagram gives you a pretty good example of how to plumb potable water through the coil.
      Dickinson potable water installation diagram

      I chose not to use potable water for two reasons:

      • When water is heated at boiling point it will leave calcium deposits inside of the pipe and also in the copper tubing, which will eventually build up and clog the plumbing.
      • The other reason is because water will hit boiling point much sooner than glycol.

      I also added a small alloy expansion tank at the high point of the loop to allow steam to boil off and to allow the glycol to expand in the reservoir. It’s also a way to add more fluid if the water evaporates for any reason. You will need a hot water heater that has an additional coil inside to use as the glycol loop. Some boats use the engine to heat the hot water, but there is a way to use both the stove and engine plumbed together. I also suggest a way to dump heat with a forced air heat exchanger. It can be either the potable water or the glycol that runs through the exchanger. I chose potable water instead of glycol because I have a loop that runs into the bathroom sink faucet forward, so I just installed the forced air heater in the v-berth and ran the hot water loop all the way forward and back to the hot water heater. Here is the blog post that covers that installation. The primary benefit purpose of the loop was to conserve water when getting hot water to the bathroom faucet. I have a switch that activates a pump that moves the hot water through the loop. I am planning on adding a thermal coupler that will automatically activate the pump and forced air heater when the hot water hits 180 degrees to prevent a meltdown, which is possible if you run the stove for days in a cold environment. They are very efficient stoves and it is possible to heat the water above 200 degrees if left on for days with the draft assist fan on and the fuel is flowing above minimum.

      I hope this helps and feel free to keep asking questions here. I think Michelle has subscribed to comments so she can also provide her own feedback.

  4. Hey Tony and Michelle,

    Thanks for getting back to me with all the info, it’s weird that I havent’ managed to find the same diagrams and info here in the uk as you’ve given me links to… It’s great to hear other people’s (detailed) experiences of using their Dickinson stove.

    I have a twin coil calorifier positioned next to the stove, one of which is plumbed into the Perkins D3, I’d be interested to hear of your suggestions for plumbing the stove and engine together but am concerned that it may affect cooling of the engine (it’s skin-tank cooled).

    Perhaps at a later date I may fit a solar water heater on the roof (lots of flat roof space on a narrowboat) and plumb that into the same loop that the Dickinson is on, using glycol, circulation pump, pipe stat and expansion tank for the whole shebang for hot water in summer – whadya think, a possibility?

    Thanks for the info and openess to questions – much appreciated!

    All the best,

    James

    1. James – No I never did add the thermal coupler, but I have the wiring in place to get it finished. Are you planning on doing something similar?

  5. Hi Tony!
    Still planning on sorting out the coil and stove!
    So, I understand that the thermal coupler idea was for the potable loop with the Radex but what of the glycol loop – did you have header and heat pump for that loop too?
    How have you found the noise of the pump, does it cycle continualy currently?
    Cheers for your time, hope it’s not too cold over there – Seasons Greetings from the UK!
    James

    1. James,

      The thermal coupler is for the glycol loop, which when the temperature hits 180 degrees, will turn on the radex heater and hot water circulation pump to dump heat. The way you will need to wire the circuit is to install a blocking diode to prevent the independent circuits of the heater fan and pump from turning each other on. You will understand once you draw the thermal coupler circuit on paper. So far I have not needed the coupler when running the stove as long as I have the pump circulating the hot water, even when the radex fan is not running.

      I leave the glycol pump running when the stove is running to help regulate the glycol temperature. Otherwise the glycol in the firepot loop will achieve boiling point and steam off in the expansion tank, which is not very good for the pex and copper tubing. To address the noise of the glycol pump, I bought a variable speed dial to turn down the glycol circulation pump so it’s flowing at about 10 percent of it’s normal rate. It’s barely audible even with nothing else drowning out the noise. Here is the one I am using.

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