The Refit Part 1


Time passed quickly for Duet’s crew. We left her with Jeff’s team in mid November, and here it was the end of December and we were in Seattle again. Naturally it was raining.

But first a bit on what happened to Duet while we were gone. Our project list included some 29 projects, all neatly laid out in a spreadsheet, with parts suggestions, etc. Some of these projects were substantial, like upgrading the Naiads, others were small, like adding positive locks to the fridges and freezers.

The key to managing project scope, as Nancy knew, having learned at the knee of her project manager many years ago, is not to let new things get on the list. That way lies trouble. So Nancy managed the list and her and Ron’s tendency to add things to the list, while Jeff managed the team and the service providers. A good partnership. 

 The refit was completed in several parts, driven by yet another schedule, namely that of Delta Shipyard, which had been chosen to haul Duet and put her safely on land, where her Naiads could be upgraded, her bottom painted and other items addressed. Delta couldn’t take Duet until after Thanksgiving, so that gave Jeff and the guys some time to get other things going.

 Duet’s refit can be divided into three types of work. First, standard maintenance, like bottom paint. There was little of this, as her previous owner lavished attention on her. Second, older gear which needed to be updated. Third, and this is the most elastic category and one that Nancy and Ron talked about daily, things Ron and Nancy wanted, based on our previous experience with our 46. Of all the money spent during this refit, at least 60% was in the Ron and Nancy want, rather than the Duet needs, category. Since this was also true of our recent house renovation, this revelation didn’t surprise us too much.

 So Jeff et al set to work. First, the dishwasher, a project near and dear to Nancy’s heart. The initial idea was to emulate our solution on the 46, namely remove the stove, replace it with a gas cooktop and recoup the drawer space lost to the dishwasher by adding drawers where the stove used to be. Sounded great in theory. In practice, however, this was a little more complex, mainly due to the lack of a cook top which would fit where the old stove went.

 After the old stove was removed, but fortunately stowed in Jeff’s shop, and much time was spent on evaluating possible cook tops, we decided to put the old stove back and see how things went with less storage space. Duet’s galley is huge compared to the 46, and we figure worst case we will address this again in the future if we need more storage, or not.

 Thus our galley refit was reduced to a new Miele dishwasher. A beautiful new dishwasher, for sure, and Kevin and Michael, Jeff’s cabinetmakers, did a great job making an end grain veneer for the front of said unit. Nancy, having watched her entire kitchen be rebuilt at the Tahoe house, knows a lot more about cabinetmaking than she did before and she can say, without hesitation, that Kevin and Michael are craftsmen. The other plus is the dishwasher actually works, which is always a positive.


In addition to the dishwasher, the other big “house” upgrade was a complete replacement of the head (toilet) hoses. For the non boaters among our readers, toilets are always a topic of interest on a boat. Essentially, Duet has her own municipal sewage system, complete with toilets, tanks and the necessary hoses to transport results from one place to another, until they are either pumped into the land sewage system, or overboard when we are offshore.

Over time, the hoses, which work hard, tend to wear out, which results in smell. Duet, at 12, needed new hoses. This was not a job that Ron was anxious to undertake, so it immediately went onto the refit list.

The objective of this entire exercise was to eliminate the smell aboard, which meant that not only the hoses, but possibly some of the vacuum tanks , needed changing out. Duet has Vacuflush toilets (just like an airplane) and in that design there is a vacuum tank between each head and the holding tank.

The master head vacuum tank had a long and productive life, but it was time for it to move on. Unfortunately, moving it on meant removing it from under the stairs leading from the pilothouse to the staterooms. Fortunately, Jeff’s team had done this type of thing before, so Brent gloved up, put on a mask, fired up the skillsaw and, presto, well not exactly presto, but relatively presto, the job was done. A nice new PVC vacuum tank (sewage odor doesn’t permeate PVC like it does other types of plastics) was installed, along with all new hoses (over 100 feet in all) and Duet smelled sweet again. Actually, it took some time for the old odor to work its way out of the boat, but after a month or two she smelled just like a new boat.

Kudos must go to Brent Stabbert, who spent literally hours upside down under various parts of the boat replacing hoses. This is not an easy or pleasant job, and the tendency is to want do it as quickly as possible, but he hung in there and did it right. He also serviced both heads, replaced the manual overboard pump, and upgraded the automatic overboard pump.

Enough about sewage. On to the something more interesting, the diesel heater. Our 46 also had a diesel heater. Ron spent years doing battle with it, and eventually triumphed, but he is not a fan of these units. Jeff’s team, in the form of Erik, spends a lot of time working on diesel heaters so they knew a few tricks Ron hadn’t learned yet. These units are critical to cruising in the Pacific Northwest, without them life isn’t worth living.

Erik spent some time crawling around our diesel heater, tuning it up and sorting it out. It turns out that the key to any diesel heater is to get the installation right. A diesel heater is very much like hydronic heating in a house: there is a furnace (in Duet’s case installed in the lazarette) which heats up fluid which then travels throughout the boat via hoses.

At particular points, in Duet’s case 5 points (salon, galley, pilothouse, master stateroom, and guest stateroom) the warm fluid enters a heat exchanger with a fan, thereby allowing warm air to flow in to the living spaces. There is also a large expansion tank, rather like the overflow tank on a car radiator, which acts to balance the flow of fluid, which expands as it heats up and then contracts as it cools down.

There are lots of opportunities to get a diesel heater installation wrong. The expansion tank must be placed and sized properly, otherwise it doesn’t do its job well. Too small an expansion tank, for example, allows warmed fluids to expand and spill all over the place. Erik upsized Duet’s tank by quite a bit and relocated it. It had been installed under the pilothouse instrument panel, where there is plenty of room. Unfortunately, if it leaks, there is at least $75,000 of electronic bits for it to leak on. So it was moved to the starboard side of the panel, where there is nothing in harm’s way.

Second, Erik did a standard service on the heater, which it was due for anyway. He also showed Ron how to do this, thereby enabling us to proceed on our own in the future. As an aside, this kind of cooperation is great from a service provider, as, while Ron can read the manual, there is nothing like getting the hands on perspective.

Third, Erik and Ron checked the whole boat for leaks in the system, which are pretty common. Once the new expansion tank was in place, on our next visit, Ron spent much time crawling about looking for hose leaks. As the system pressurizes, the expansion tank gurgles a lot and then should quiet down. It took a number of cycles before the quiet down part was achieved, but now the system runs like a champ.

As an aside, having the diesel heater hoses running throughout the boat has a significant benefit, it keeps all the spaces warm. So, if the heater is set at 50, the engine room (which has no direct blower) stays at least at 50 and often warmer, because of the warm hoses passing through it. Nancy’s favorite though, is that the hoses pass under the master bed, and therefore under the clothing drawers. So all her clothing comes out warm. There’s nothing like a nice warm set of socks on a damp Seattle night.

It turns out that the diesel heater uses quite a bit of fuel, approximately 3 gallons per day, when running to maintain temps in 60’s. When the boat is alone, the heater is set for 45, so it uses far less.

Erik, in addition to his role as diesel heater guru, is also Jeff’s electrician. So he installed a galvanic isolator for us. Boats are their own little electrical world, with shore power when we are tied up and generator power when we are not, as well as power from the main engine when it’s running. To make matters more complicated, this Duet has both 12V and 24V systems. Nancy has learned, over a long period, that she will never understand electricity. Fortunately, Ron not only understands it, but enjoys it.

When we got Duet, she had some corrosion issues. This is not uncommon on an older boat. All boats have a bonding system, which is designed to protect the equipment on boat from the vagaries of electricity. Essentially, and this is Nancy’s explanation, those wanting a more detailed version will need to email Ron, the fact that the boat sits in water enhances the chances of her equipment being eaten up by electricity. So she has wires (the bonding system) which connect every major bit of metal gear (engines, stabilizers, shafts, thru hulls, etc) to a sacrificial piece of metal, known as a zinc. Over time, these zincs are eaten up by the endless appetite of the electricity, so they are replaced on a regular basis. In the meantime, the other pieces, namely expensive engines, etc., are protected.

As you can see from the picture below, Duet’s sacrificial zincs are pretty large, this one is the base for the main hull zinc, of which there are two, this one is just below the waterline on the stern, the other is under the hull.



In addition to reworking Duet’s bonding system, which had gotten a bit threadbare over the years, Ron wanted to add extra protection in the form of a galvanic isolator. This piece of equipment does what it sounds like, it isolates Duet from possible electrical gremlins when she is connected to power on the shore. If you want to know how it does that, apply to Ron.

While Erik was beavering away on the diesel heater and Brent was buried in the head system, a series of other small projects were carried out. Fire extinguishers were inspected (required every year), a small bit of lagging on the main engine exhaust was replaced, and, in between dishwasher work, Kevin and Michael installed fridge bolts, rejiggered a hanging closet into a linen closet in the master stateroom and began the process of “patterning” various things which would be built later. These will be discussed in the next log, but include the scupper covers and the storm plates. They make a pattern in plywood first, fit it, drill it and generally make sure it works, before actually making it in the real material. This saves a lot of time and money later on.

So after two busy weeks at Jeff’s dock at Salmon Bay, Duet was ready to go to Delta. Because of Ron’s schedule, we were not taking her, Jeff was, accompanied by Brent. Moving our boat for Jeff was a non event, he, Chris and the team move boats all the time. It was, however, a big event for us, as we aren’t used to her being moved by other people. The day dawned, and all went well, Duet did fine and so did we. She arrived, was immediately hauled out and carried off to a concrete pad that had been set up for her. Jeff sent plenty of pictures to reassure us that she had arrived safely and was being carefully tended.



A word about Delta Marine. Jeff works with them frequently, as he captains several Deltas for their owners, and has refit at least one (the beautiful Delta 70, Sea Lion). They build truly gorgeous boats, the 136 footer shown next to Duet in the picture of Salmon Bay is a classic example of the quality they produce. Normally, a boat of Duet’s size wouldn’t go to Delta for work, but, both because of Jeff’s confidence in them (and strong relationship) and because of Duet’s rather substantial heft (at 40 plus tons she is at the top end of what other boat yards in Seattle can lift), we made the decision to go to Delta, even though, at first glance, it was more expensive. The lift shown below is capable of lifting 300 tons, or nearly 8 times Duet’s weight. 



Figuring out yard pricing is rather like trying to price medical care. You have the yard itself (the hospital), the various workmen (the doctors), the helpers (the nurses) and the parts, procedures, etc. Everything is priced differently at every yard. Some yards, for example, charge for lay days, namely when the boat is just sitting there, not having work done. Some, like Delta, don’t. Some package bottom paint jobs with haul out fees. Others don’t. So Jeff presented Nancy with various yard choices in Seattle, and recommended two, we chose Delta and are glad we did, they did a very professional job.

Duet spent three weeks on the hard at Delta. Someone from Jeff’s team, usually Brent, was present whenever work was being done, usually participating, so we were confident that she was well taken care of. During her time there she had her bottom painted, which is a biannual boating job.

Jeff, the Delta team and the Seakhawk paint guru all felt that she will need a bottom job sometime in the next 3-4 years. A bottom job means that the outer layer of skin below her waterline needs refreshing. For the ladies in the audience this is rather like a facial skin peel. It is to be expected on a boat of Duet’s age, the new owners of our 46 had one done about two years after they bought her from us. So it is on the list for the next time we visit Delta.



In addition to bottom paint, we installed large intake screens over all Duet’s thru hulls. Thru hulls allow us to draw sea water into the boat. While this sounds counterintuitive (aren’t we supposed to be keeping the water out?) sea water plays a lot of roles in a boat. It is used extensively for cooling equipment, like the main engine. It is what we used for cooling the air for our air conditioning. We use it to wash off the anchor and chain. So we need thru hulls. 

The thru hull shown below is for the new salt water washdown pump, which Ron uses to keep the area around the anchoring platform clean.



For those interested in Nordhavn construction, Duet’s hull is solid fiberglass below the waterline. The balance of her hull, her house and her decks are cored, to reduce weight. Shown below is the hole the team cut for the new salt water washdown pump thru hull. Seeing the thickness of a Nordhavn hull close up like this always makes Nancy and Ron feel better, especially when they remember it just after they have bumped into something.



But, and this is based on a lot of hard won experience, thru hulls not only suck in water, they suck in anything else in the vicinity, such as plastic bags, jelly fish, etc. These items do not play well with Duet’s gear. So we installed large Groco screens, which prevent anything but water from coming in. The strainer in this picture is 7 inches long and over 3 inches wide, as compared to the thru hull it covers, which is 1 1/4 inches in diameter.


These screens also have an opening thru which a diver can service the thru hulls, which need greasing every now and again. For the curious reader, the device to the right of the thru hull strainer in this picture is a speed log. 



Here is a picture of a standard thru hull strainer, which was installed on most of this Duet’s thru hulls, as well as her predecessor’s. As part of this project, any thru hull with this kind of strainer was removed, the thru hull replaced and a new strainer installed. All previously uncovered thru hulls also recieved strainers. 


During her time out of the water, Duet’s Naiad stabilizers were upgraded by Naiad’s Jedi Master, Dick McGrew. Nordhavn 50’s of Duet’s age tended to have either big Naiads or smaller ones. Because we plan to do a lot of long distance cruising, we decided to upgrade to bigger ones. For our technically minded audience, we changed up from Naiad 201s and 6 foot square fins to 252s and 7.5 square foot fins. We also changed out all the hydraulic hoses, a prophylactic move given that many of them were original.

Fortunately Duet already has the latest Datum electronic head for her Naiad system, so with the new fins and related gear we are all set. In the picture below you can see the old fins laying to the left of the boat. The old fins later went to a new home in Nanaimo, Alaska, where we are sure their new owner will get many years of great service from them. 



Also as part of the yard visit, Duet’s main drive shaft was removed for evaluation. The surveyor was concerned about corrosion on the shaft that he could see from the engine room. Given Ron’s worries about her bonding system, pulling the shaft to take a look see was an easy decision. Fortunately a review indicated all was well, the shaft was polished and returned. When it was reinstalled, it was also rebalanced.

When the main shaft is pulled, the main propeller also comes off, so it was sent to be rebalanced and polished. The pictures below show the main prop before and after it’s trip to the beauty parlor. At the end of the shaft you can see the new propeller zinc. As might be obvious by now, Jeff’s team and Delta are giving Duet a good going over.




We also wanted the Spurs serviced. Spurs are cutters mounted on the main shaft and are designed to cut loose anything that might wrap around the shaft, like a fishing net. Unfortunately, when the Spurs were removed, they cracked, probably due to age, so a replacement set was obviously called for. In the picture of the new Spurs below you can also see the new zinc, which protects the spurs from random electrical damage. 





Also as part of this process, we evaluated and decided to replace the main cutlass bearing. The cutlass bearing is installed at the point of entry for the main shaft into the boat. The shaft runs from the transmission through the back of the engine room and into the water. The point where it enters the water is always a concern, because it is a substantial hole and if it leaks we are probably going to sink. The cutlass bearing serves to reduce friction between the shaft and the shaft log (the log is the fiberglass tube in the boat through which the shaft exits). The picture of the old cutlass bearing below shows clearly that a replacement is due.



Finally, we restuffed the stuffing box. The stuffing box is part of the shaft entry to the boat, and keeps the shaft cool while it’s turning. It is literally a brass box, stuffed with some form of wool like material with grease on it. Seawater enters the stuffing box via the cutlass bearing to act as a lubricant while the shaft turns. Stuffing boxes drip very slowly into the bilge.

So, finally all this was put back together. Actually it went extremely quickly and well, as Delta was primed for our arrival and knew what needed to be done. All other providers, like the propeller and shaft shop, also knew we were coming and had worked with Jeff before, so he had confidence they would get the job done right.

We also took advantage of the yard’s lifting gear, to hoist Duet’s new Rocna 70 anchor, at a svelte 154 pounds, aboard and to put her new chain on the boat. Jeff’s folks can do this kind of thing at their dock, but with a little planning we can spare everyone’s back and use a yard truck.



The paint came last, as did the replacement of all her zincs, and then, bingo, she was back in the water and on her way to Salmon Bay. She returned in fine style, the stuffing box remained cool to the touch (a key sign of a happy shaft) and all systems operated normally. She also ran much more smoothly, due to the newly balanced shaft and propeller.

Once she was back at Salmon Bay, Dick from Naiad, Jeff and Brent took her out in Lake Washington on a rough day to test the new Naiads. They performed to spec and Duet returned to her slip, ready for the next phase.

On her return, work on other projects began, to be covered in the next log. We visited for two weeks over Christmas and New Year, just after Duet returned to her slip. We took her out for a few days, to test the new systems, and all worked as advertised, except the new anchor and chain. We did manage to go back and forth through the lock without incident, the fact that we were the only boat in it both times may have helped.

As our prior readers know, we are big believers in installing the largest anchor and chain possible. Most Nordhavn 50’s have a Rocna 55 and 3/8 inch chain. We went a size up, to the Rocna 70 and ½ inch chain. This installation required some tweaking, to put it mildly. Ron is shown here testing the installation at the dock, prior to taking her out. 



First, the Rocna shank is so long that it pulls the chain up and off the windlass while being recovered. This doesn’t happen all the time, but it happens enough to need fixing. Second, the 400 feet of ½ inch chain was so bulky that it kept blocking the chain pipe (the chain pipe directs the chain from the windlass to the chain locker below deck) instead of piling neatly in it’s locker. Obviously, some changes would need to be made. Ron tends to think things through very carefully before doing anything. So does Jeff. After some discussion, the anchor and chain issue was left until our next visit, at the end of January.

Other than this small issue, everything else the team had done worked perfectly. The diesel heater kept us toasty, the toilets flushed beautifully, and the dishwasher rumbled along. The dishwasher does require the generator to be running when in use, as we have an older inverter which doesn’t produce “pure” electricity.

This is similar to our 46, where the use of an older inverter caused the demise of almost every rechargeable item on the boat, including cell phones, razors, and, probably most significantly, toothbrushes. On one memorable occasion in the Southern Bahamas, Ron had to reengineer an old Braun toothbrush charging base to fit a newer toothbrush, as the new base had given up the ghost. Otherwise we would have had to resort to cleaning our teeth with straws. So this issue was not unfamiliar.

We plan to upgrade Duet’s charging system and the inverter in the future, in the meantime, the dishwasher has a great 30 minute express cycle which can be run while the generator is doing something else at the same time, like charging batteries, doing laundry, etc.

So after a wonderful two weeks spent sitting at the dock and taking advantage of Seattle’s great dining, coupled with 4 days out on the hook near Poulsboro, we returned home to Lake Tahoe, leaving Duet in Jeff’s capable hands.

The balance of the refit will be discussed in the next log.



3 thoughts on “The Refit Part 1”

  1. Great post! I really enjoy reading about the technical stuff and I look forward to following your adventures. I live in Fairbanks AK, and as soon as I saw your N50 at SBM months ago, I called Don K at Nordhavn to get the rundown as to what type N, name etc.. Then months later I come across your blog and the info is all tied together.
    Thanks again, Jim Evans, Fairbanks, Alaska

  2. Having read this I believed it was very enlightening. I appreciate you taking the time and energy to put this information together. I once again find myself spending a lot of time both reading and commenting. But so what, it was still worthwhile!

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