Tech Talk #5 – Time for a Refit

May – July 2021


After a very pleasant time in far Nth Qld, we headed south to the Gold Coast. ‘Opal Lady’ was built in 2009 and was due for some maintenance work and we had always planned to do some upgrading and re-fit works on the East Coast. We had heard from several boating friends that the place to do it was at The Boatworks on the Gold Coast, so despite it being a fair way south we headed down as we knew that all the various trades we would require would be available and the service from the yard was supposed to be pretty good. More on that later.

One of the Sanctuary Cove neighbours

The initial plan was to spend around 2 weeks on the hard, to complete all below water works required, whilst other works would either be done at the same time or at Sanctuary Cove. The first reality check was that although we had arrived at Sanctuary Cove in early May, the first time slot where all the various trades were available was 24th May. Not to worry, Sanctuary Cove is a pretty nice marina, with the added benefit that we would be there for the Sanctuary Cove Boat Show, which is one of the best boat shows in Australia. We also had some other things going on in our lives which Suz will cover in her blog.

Initial Plan

The initial list of works is shown below, divided into below waterline works and above waterline works. One of the things we were acutely aware of is that when undertaking large works like this the “opportunity” for cost, time and scope to blow out is pretty high, so we would need to be very disciplined and work closely with our various trades. Having said that, we were also aware that the environment of the Coomera Boatworks area was extremely good, so no doubt opportunities would come up to complete work we would not have done otherwise.

Lastly, our good friends John and Tracey from ‘Mad Max’, whom we had first met in Darwin, were also at Sanctuary Cove. Their vast experience and large contact base was invaluable in sourcing high quality trades out of the myriad of options available at Coomera (the area of the Gold Coast where the marina and boat works are located).

Below waterline works

  • Anti-fouling including sandblasting hull back to base
  • Removing Main Shaft, inspecting, cleaning and reinstalling
  • Complete Stabiliser service
  • Replace Anodes
  • Replace main Engine Mounts
  • Replace engine Coolant and Coolant hoses

Above waterline works

  • Re-upholster salon and pilot house furniture
  • Replace carpet in salon
  • Repair steering gear leak
  • Replace Murphy Gauge
  • Replace Wrinkle Belly on exhaust stack
  • Replace Vibration Damper on main engine shaft
  • Replace Genset insulation (tip – xylene excellent for removing old glue)
  • Replace ‘Opal Lady’ lettering on transom and top sides

Works Description

I won’t describe every piece of work, as some are pretty straightforward, but appreciating how much I enjoy reading how others have done their maintenance, I have expanded on some projects with photos for those interested.


This was one of the more expensive elements of the work plan. During ‘Opal Lady’s time, since commissioning, she had had multiple layers of anti-foul applied. We knew at some point we would need to take all the old anti-foul off and start again and as we intend to go overseas in the next few years we decided to get it done now in a location where we were assured of the quality of the work.

The works were done by Affordable Antifoul and consisted of firstly sandblasting all the old anti-foul off. During this process the keel coolers were also sandblasted and cleaned up.

After initial sand blasting
First epoxy primer coat and fill applied

‘Opal Lady’ was then moved to another shed for the next stage which consisted of three coats of epoxy primer being applied, with the hull being filled, faired and sanded between coats. Next, two coats of anti-foul were applied. Lastly PropSpeed was applied to all the running gear. It was really pleasing to see how smooth and well she presented after the works were completed.

Hull completed

Points to note with this work program: Firstly, the careful need to manage interactions with the other trades working on the stabilisers and the main shaft to ensure all works could be completed in a timely manner. All trades were great to work with and made this exercise a lot easier than it could have been. Secondly, the original anti-foul height up the hull was definitely too low in the tropics with full fuel and water tanks.  So the anti-foul was raised by 50mm to prevent the large amount of growth we had experienced along the waterline.

Main shaft – inspecting, cleaning and reinstalling

I had become concerned with some minor pitting on the main shaft, having read about and heard some poor outcomes with other boats. I did not want to have an unexpected learning experience when we were out at sea as well, so wanted to have the shaft inspected (as well as giving an opportunity to change out the cutlass bearing).

Nearly ready to pull the shaft

Watson Marine Engineering had been recommended to us and they performed all the shaft works, as well as replacing the engine mounts at the same time. These guys were very professional and easy to work with. They quickly had the shaft removed and taken away for inspection and cleaning. They also identified that the cutlass bearing on the wing engine shaft as well as the main shaft needed replacing.

Cutlass bearing not quite where it should be

The guys also identified that the bump stops in the spur cutters were missing and that the spur anode was nearly gone, so replaced these as well.

Old engine mounts
New Isoflex engine mounts

I had purchased the appropriately sized Isoflex engine mounts for the main engine, which the guys fitted in a very short time. Using this particular mount meant that there was no need to jack the engine up, which we would have had to do with the old type. Lastly the guys also inspected the rudder shaft gland and bearing, but as these had been replaced 2 years ago, all was good.

Once the boat was back in the water the guys were there to adjust the shaft packing.  And 2 days later, after everything had a chance to settle in the water, they came back to do a final shaft alignment.

The difference when we are running is very noticeable. Previously at idle there was a very strong vibration, but with the new engine mounts and shaft alignment that has all gone. A great result.

Almost back together

Stabiliser service

Stabiliser with fin removed

Followers of our blog will remember we had an internal service done on our stabilisers at Shark Bay back in 2019, as part of repair work that was done. We now needed to complete the external part of this service and Stella Marine Group, who had organised help for us in 2019, came in to do the work which was pretty straight forward, no surprises and no fuss. Whilst doing the service they noticed the seal on the locking pin was leaking so these were also changed out. Finally, the hydraulic oil was changed out as well.

Replace engine coolant and coolant hoses

With the initial delay to hauling out ‘Opal Lady’, I proceeded with this job as I could do it while still in the water. It is a relatively simple task, but I thought it was worth describing the process along with some photos for others wanting to tackle this. Two important tools to make this task stress free is a wet/dry vacuum and a flexible funnel sheet. The key trick is to remove as much coolant as possible before undoing any hoses to minimise mess.

Step 1: Remove coolant tank cap and shape the flexible funnel sheet to capture coolant from the drain cock on the port side of the engine as shown below.

Step 2: If you have been patient and drained as much as possible from the previous step then you can disconnect one of the inlet hoses and remove the stainless u- tube without much mess and drain the small amount left down to that level.

Step 3: Now the fun part. Get your wet/dry vacuum set up. Take the suction hose and wrap it with gaffer tape until it forms a nice plug when inserted into the inlet hose (on the engine) as shown below. Turn your vac on and go for it. This is very quick and does an excellent job. From memory I had to do this process 3 times to fully empty the keel cooler.

Custom made plug

Step 4: Reattach the engine hoses and stainless u-tube and refill the cooling system with water and automatic dishwasher cleaner (liquid detergent). Reading from previous Nordhavn owners who have done this, use around 1 litre of detergent.   Fill the system completely, then run the engine until warmed up and coolant is circulating.  Leave the engine running for 20-30 minutes.  Next, repeat the process of draining the system completely. In my case when I drained the coolant initially it was still a blue colour, but as you can see from the photo below the washing liquid certainly cleans the system out.

Dregs after using detergent

Step 5: Fill the coolant system again with fresh water only and run the engine, and drain again. Repeat step 5 until the drained water is clear. We had to this twice before the water looked ok.

Step 6: Fill the coolant system with appropriate coolant (we used pre-mix). Job done! (Keep some spare coolant handy for topping up the system after it has run for a bit.

As the coolant hoses on ‘Opal Lady’ were 11 years old, I took the opportunity after Step 5 to remove all the coolant hoses and replace with new ones. This is a relatively easy process as long you make sure you check diameters on the various sections as they differ in diameter with reducers involved as well. Other than that, a relatively quick job to do.

Re-upholster salon and pilot house furniture

Although we have loved the original Ultra Leather used on all the furniture in the salon and pilot house, after 11 years it was very worn in high use areas and needed to be replaced. This was one of the more costly upgrades, but necessary. We discussed at length whether we should use Ultra Leather again, but we had found in the tropics with high humidity that it was not the greatest material when you are sweating heavily. In fact, we had taken to using towels everywhere to sit on to allow for this.

Old, worn out covers (with cat for scale)

We decided to go for a fabric (removable for laundering) and after being on board a Nordhavn 60 called ‘AraRoa’, we saw exactly what we needed. Our friend John put us onto a marine trimmer called Pacific Trim, located in the Gold Coast City Marina precinct. Jason and his team were brilliant and within 10 days we had brand new fabrics throughout the salon and pilothouse.

New covers (again with cat)

Repair steering gear leak

For the last 2 years we have had a very slow leak from the steering gear, which although annoying, did not affect performance but now was the time to have this fixed. Nick from Marine Control Systems took charge of this exercise, with the system being refurbished and returned within a few days. He also cleaned up the steering pumps and soft sealed them at the same time.

Steering ram showing oil leak prior to refurbishment

Replace Wrinkle Belly on exhaust stack

One of the after effects of the rocking and rolling we experienced at Cape Stewart last year was that it exacerbated some cracks in the wrinkle belly of the exhaust stack. Although not critical, this needed to be repaired for long term operation, so with the assistance of Geoff and his team from Choice Stainless we went through the process of repairing the stack. It could not be done insitu, as a new wrinkle belly needed to be welded in, so the first step was to remove the exhaust stack. This proved relatively simple for Suz and I to do, with the use of our bosuns chair and judicious use of ropes to lower the stack safely down.

Undoing the clamps on the stack
Safely lowering the stack down

As a side benefit it also gave us the opportunity to polish the entire stack prior to Geoff and his team taking the stack away to cut off the old wrinkle belly and weld in the new one.

New clamps ready for exhaust

From there it was the process in reverse, albeit with a bit more difficulty.

Once the stack arrived, Susan and I, along with young Anton from Choice Stainless, put the stack back in place. With everyone briefed on what we needed to do, and taking our time, we had this job completed in an hour despite the rain! I do love our bosuns chair which made the task relatively simple. In hindsight, I we should have tied the lifting rope 1/3 of the way down from the top of the stack, so that we could lift it above its fitting and drop it into place – learning, learning, learning.

Exhaust waiting to be lifted

We found that despite our best efforts positioning the stack, the new wrinkle belly had changed the orientation of the stack so we couldn’t get it to stay any distance away from the mast where one of the ropes comes through. Instead of forcing it into a slight twist (and risk encouraging a new stress crack in the stack), I cut another slot below where the stack crossed the mast, for the rope to come through.

The new slot before sanding the edges and rethreading the rope

While waiting for the stack to be repaired I thought I would investigate some rust flakes that had started appearing near the turbocharger. Once the insulation was taken off, we found that although the rust was only minor surface rust, the wrinkle belly located near the turbocharger also had cracks in it between the individual bellow rings. Geoff from Choice Stainless checked it out to see if it could be repaired, but this was not possible, so a complete new piece had to be built. This was organised by Bellis Australia in Coopers Plain, Brisbane. Although they originally quoted 4 weeks to complete this, we had the new one back after 2 weeks, which turned out to be about the same time as the repaired stack was returned. Of course the new delays meant our departure for the north was pushed back again. Not to worry, better to have this fixed now than have it fail catastrophically in some remote area (like our muffler!).

Just a bit of rust on the insulation wrap
Yup, there is a leak
Installing new bellows (before the yellow transport bars are cut off)
Ready to Rock and Roll

Replace Vibration Damper

One of the last tasks was to replace the vibration damper on our trusty Lugger 1066T main engine. The manual says to replace this once the engine reaches 4500 hours or 5 years, whichever comes first. As our engine is 11 years old and has done 4,800 hours, it was time to make the move. I have to say I was not looking forward to this, as everything I had read on doing this job by various other owners and engineers, emphasised how difficult it was to get the old damper off. For others that attempt this, I have catalogued the procedure as well as the troubles and pitfalls we encountered along the way. As part of the process, we also replaced all the belts to the 2 alternators.

Firstly remove all the guards. In our case, to do this we also had to remove a stainless-steel guard rail (which encloses the entire engine) which prevented one of the guards from being removed.

Removing the serpentine belt

Next undo the 4 cap screws that hold the bottom alternator pulley in place. Once that has been done you can get access to the main cap screw and large washer you can see in the photo below. This large bolt is easily removed by judicious use of an impact hammer drill.

The vibration damper (after removing the alternator pulley)

The next step is to remove the old damper and that is where the fun begins. The damper has a tapered fit onto the crankshaft, applied with Loctite 680 and the cap screw tightened to 375 ftlb (500NM), so it does not want to move. I first tried using an ordinary gear puller that screwed into 2 of the 4 cap screw holes as shown in the photo below.

Butane torch

I used a butane torch to heat up the tapered nose then attached the gear puller. All I did was bend the gear puller, so on to plan B.

Impact drill

I then went to a John Deere dealer who located the proper puller in Melbourne but it was $290 with a 4-6 week delivery, so that wasn’t going to work. They did not have one in their workshop either, so getting them out to do the job was also a no-go. With the help of John from ‘Mad Max’, he made up a custom-made puller which was similar to the JD one one but much beefier (being 20mm thick and a large 20mm bolt applying the pressure). We then drilled a concave receiving indent in the top of the old cap bolt for the puller bolt to push against. Unfortunately in my eagerness to get the damper off I thought I would use the impact hammer again. All this did was stuff up the concave hole in the old main bolt and the whole thing started turning. I consulted my friend John again who decided he would make up a revised bolt and washer arrangement for the puller to work against.

Custom made puller
New puller components (much beefier)

With the new puller fabricated, it was time to try again. This time we used a much larger propane torch. John was very careful to only apply the heat around the nose of the damper itself, as we did not want to put excessive heat into the oil seal. After heating, we started applying torque to the puller (no impact hammer drill, but there was some swinging of a sledge hammer to try to jolt it) but it still did not want to move.

Just a little sledge hammer

So, after removing the puller once again heat was applied somewhat more vigorously to the same area and suddenly, with a bang, the puller just fell off. We videoed the whole thing, which is really interesting, as it clearly shows a flash of what we think is the Loctite burning off. John immediately applied a cool rag to the nose of the crankshaft to cool it down.

John applying heat for the last time
The big bang
We have lift off
We have ignition
Lots of ignition
Clear below

The next problem was putting the new one on as it has to be done up to 500NM or 368 ftlb which is a hell of a lot. My torque wrench only goes up to 150NM. As a new one, capable of doing the job was $900, I really did not want to go that route. Fortunately, one of John’s mates runs a trucking company and was happy to lend us one. These are big items at about 1.1m long. This meant the only place it would fit was vertically between the 2 water tanks which meant we could only tighten 2 clicks with each 20o of movement. The recommended Loctite 680 has a working period of 4 mins, so we were careful to have everything prepared before starting (not forgetting to use a bolt to lock the flywheel from turning; and then to remove the bolt before starting the engine!). To get the required torque it took two of us pushing and pulling, but it all went smoothly and 2 mins later it was all finished. What a relief. The next day I put the pulley and belts on and ran the engine for 30 mins to check all was ok. A final retightening of the small alternator v-belts and then the covers were put back on. As an aside, with everything thing pulled off the front of the motor, Suz took the opportunity to clean the rust off and paint the affected areas.

Clean the crank shaft taper
Clean the damper
Apply the Mother of all Locktites
Screw in the washer and center bolt
Fit the Mother of all Torque Wrenches
It takes two to torque tango

Completed in less than four minutes – a cold beer was had by all.

Additional Projects

In terms of the work items we had scheduled, we were very happy with how they were executed both in time, quality and cost. With the extra time we were spending in the Gold Coast we took the opportunity to complete a number of “nice to have” projects we had on our list. The key ones we completed were:

  • Replaced current helm chair with a Stidd. Much more flexible, robust and comfortable. We spend a large amount of time in this chair so comfort is important.
  • Completed minor furniture upgrades including a new magazine rack in salon
  • Installed a shade canopy extending from rear upper deck. This will be brilliant when we head back up to the tropical north.
  • Installed a new stainless-steel rail at rear of swim platform, which allowed the bait board with rod holders to be moved from under the new canopy (Suz also loves that this gives her extra support for getting out of the tender).
  • Replaced the sound insulation on the gen set panels
  • Upgraded engine room ventilation. We found the engine rooms temperatures were still getting far too high on long multi-day runs in warmer climates. This is quite an interesting project and will be dealt with in more detail in a separate Tech Talk.


One of the important learnings we have had, both from our own previous experience and reading about others, is that costs can quickly blow out if not closely managed. With this significant set of works we were going to complete I was keen to manage both scope and time to prevent major blowouts. So how did we go? Firstly, on time, extremely well. Our fellow boaties at Sanctuary Cove were amazed we were back in the water just 10 days after being lifted, which was what we had allowed. The key to this was delaying the liftout until I had all trades confirm availability. From there it was developing the relationship with each of these, and ensuring they were aware of their time slots and what  other works would be also being completed simultaneously, especially between the antifoulers, the stabiliser guys and the shaft work. As usual things changed along the way as works proceeded, but by being present most of the time and ensuring continual communications between all the various groups, we kept on track.

In terms of cost, I was pretty pleased. My original estimate for the scope of works was $50k. The actual for all the original work envisaged was $47k with some ups and downs within the actual. The only significant overrun was on the Boatworks charge, as the height of ‘Opal Lady’ to the top of the mast was 11.2m, which meant that we needed to get a Superyacht shed at $250/day rather than the standard rate.  But having a shed was essential to getting a good result on the anti-foul. This was more than offset by savings on my estimates on other works. Where we did incur additional cost were the result of scope changes by taking on the additional projects. Altogether these cost a further $19k.  We were happy to spend this as it was for projects we wanted to do, but weren’t sure we could get done before we arrived at Sanctuary Cove and saw the facilities and trades available. By far the lions share of these costs were the ventilation project, with the furniture upgrade, the Stidd chair and the shade canopy all costing a good few boat units ($1000/BU) each.


Overall, we have been really happy with this refit. Some specific comments:

  • The Boatworks complex – although we had heard how good this place was, you have to experience it to really understand what it is about. The service is excellent, nothing is too much trouble. The ladies in the office are there at 7am ready to help and with the number of boats going in and out it feels like a marine version of air traffic control. The facilities available for live aboards while doing work on their boats is brilliant. I can now understand why people bring their boats up from down south for work and it certainly backs our decision to travel down from Cairns.
  • The Trades – with two major boating complexes being The Boatworks and Gold Coast City Marina, along with the presence of Maritimo and Riviera, there is a huge concentration of trades to support these companies. This is brilliant for all of us boaties, with the only issue we found being that everyone is extremely busy and without the advice of our friend John (who knows everyone down here), it would have been very daunting knowing who to choose to do the various works. As it was, all the companies that worked on ‘Opal Lady’ were very professional, the quality of work was high and all were on time. Can’t ask for any more!

As mentioned previously, project management is very important. From my previous time in mining this was not an issue for me, but if you were not used to doing this sort of thing, paying someone to do it for you would be worthwhile, as costs would quickly mount up if things started to go pear shaped.

This Post Has 6 Comments

  1. Holy Moly! What a comprehensive report Suz. But then I would expect nothing less from you 🙂 I am sure you will understand that I didn’t read every word. A bit of skim reading and a look at your very specky pics. Glad to see that your pussy is still hanging in there! I hope you are both well. Lisa xx

    1. Hellooo Lisa, Peter writes the Tech blogs for other boaties, so you did well to tackle it. Reading how others had done things was a great way for us to learn how to do things when we first started out (there is so much to learn). Peter will be happy to hear that he hasn’t lost any of his report writing skills – I have told him that people really just want to look at pictures (but I do suffer from excessive verbal footage myself). Neon says hello. Suz

  2. The main thing Dave wants to know. Does the beer fridge still work.

    1. Hi Jeni, you can assure Dave the beer fridge is classified as critical equipment, like the life raft, so is working fine based on the principal that high turnover of contents helps.

  3. Great report. We did similar refit to our sailboat in Fort Lauderdale about 10 years ago. Costs blew out by 100% because I was a totally hopeless project manager and I allowed the scope of work to creep. Your points about active project management is critical.

    Is Opal Lady still a 60 Hz/110V boat? If so, has this been a big problem not just at marinas but for spare parts?

    1. Hi Niels, It’s all a learning experience and probably my exposure to project management in my previous career helped me quite a bit. One of the key things is that I monitored costs almost daily and a golden rule is that when something starts going wrong, it does not get better and you have to try and get it back on course as soon as possible.

      Opal Lady is built for Australian standards so is a 240v 50hz system so there has been no issues in this regard. Peter

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