On Board with Mark Corke

A Guide to Boat Fiberglass Care: Cleaning, Oxidation Removal, and Polishing

My Grand Banks 32; not bad for 35-year-old gelcoat. It took me a whole day from start to finish to get the boat to this level of gloss.

Introduction

I know I have covered looking after gelcoat before, but this is the perfect time for a recap now that winter is just around the corner and many boats will be getting hauled.

Proper fiberglass care is essential to keep your vessel looking its best and ensure its longevity. This guide will walk you through the necessary steps, tools, and materials for cleaning removing oxidation through wet sanding, and compounding, polishing, and waxing your boat's fiberglass surfaces. Whether you're a seasoned sailor or a novice boat owner, this comprehensive guide will help you maintain your boat's pristine appearance.

Tools and Materials Required

Before you begin, gather the following tools and materials:

Pressure Washer: A high-quality pressure washer helps remove dirt and grime efficiently.

Soft Bristle Brush: Use a soft brush to scrub the fiberglass without scratching the surface.

Boat Soap: Choose a boat-specific soap that's gentle on fiberglass.

Bucket: For mixing and applying boat soap.

Hose: To rinse off soap and debris.

Microfiber Towels: For drying the boat and for later steps.

Wet/Dry Sandpaper: Choose various grits (e.g., 600, 800, 1000, 1500, and 2000) for wet sanding.

Water Sprayer Bottle: To keep the surface wet while sanding.

Dual Action Polisher/Buffer: A professional-grade buffer like the DeWalt 9-inch polisher is ideal.Manufacturer link here

Compounding Pad: Use foam or wool pads for compounding.

Polishing Pad: Foam or wool pads are suitable for polishing as well.

Marine Compound: Opt for a high-quality marine compound like 3M Super Duty Compound.

Marine Polish: A top-rated marine polish such as Meguiar's M4516 is a great choice.

Marine Wax: Select a marine wax like Collinite 925 for long-lasting protection.

Applicator Pads: Soft foam applicator pads are necessary for applying compound, polish, and wax.

Cleaning 

Before applying any compounds or polishes, it is essential that the boat is clean, or you'll just be rubbing dirt into the gelcoat.

Start by rinsing the boat with a pressure washer to remove loose dirt and debris.

Mix boat soap with water in a bucket and gently scrub the fiberglass surface with a soft bristle brush.

Rinse thoroughly to remove all soap residue.

Dry the boat using microfiber towels to prevent water spots.

Removing Oxidation by Wet Sanding: only needed if the boat is heavily oxidized.

Soak the sandpaper in water for a few minutes.

Begin with the highest grit sandpaper (e.g., 2000) and only use a coarser grade if absolutely necessary.

Sand the oxidized areas in a circular motion.

Keep the surface wet with a water sprayer bottle.

Rinse and dry the boat thoroughly.

Compounding, Polishing, and Waxing

Attach a compounding pad to your dual action polisher/buffer.

Apply a small amount of marine compound to the pad.

Work in small sections, applying moderate pressure and moving the buffer in a side-to-side and up-and-down motion.

Wipe off excess compound with a microfiber towel.

Switch to a polishing pad and apply marine polish in the same manner as compounding.

After polishing, apply marine wax using applicator pads in circular motions.

Allow the wax to haze, then buff it off with a clean microfiber towel for a brilliant shine.

Foam Pads vs. Wool Pads

Foam Pads: Foam pads are gentler on the surface and are ideal for light compounding, polishing, and waxing. They are less aggressive and are suitable for maintaining well-maintained fiberglass.

Wool Pads: Wool pads are more aggressive and are often used for heavy compounding to remove deep oxidation and scratches. They can be followed by foam pads for polishing and waxing.

In conclusion, maintaining your boat's fiberglass requires careful attention and the right tools and materials. Regular cleaning, wet sanding for oxidation removal, and compounding, polishing, and waxing will keep your boag stunning and protect it from the elements. With the right products and techniques, you can ensure your boat remains a source of pride for years to come.

How to Keep Your Boat Running Smoothly: A Guide to Changing Your Raw Water Pump Impeller

I know I have covered it before, but I recently changed the water pump impeller in my generator and thought it worth going over a few things.

When it comes to boat water pump impellers, there are a few key things you need to know. You don't need many tools, and any handy boat owner will likely have all that is needed. However, there is one tool that makes things more accessible, and that is the impeller puller. I have used a could of well-padded screwdrivers to lever the old impeller out. It works, but you need to be careful not to damage the pump housing, which is easy to do and will lead to leaks and, perhaps, a costly replacement pump.

I have two raw after pumps on Seaglass, one for the main propulsion engine and a second for the generator. Of the two, the generator is far and away the more difficult of the two to service. The generator engine is a three-cylinder Yanmar which will be familiar to many readers; they are used both as generator engines and the main motive power on smaller launches and sailboats. The best advice I can give you if you have one of these engines is to remove the pump for service. The cover plate faces away from the front of the engine and is almost impossible to service with removal. This may seem a bit drastic but believe me, it will be far faster in the end and will save your temper and most likely lose the tiny screws that hold the cover plate in place from ending up in the bilge, never being seen again.

THE PULLER IN USE.

 

One crucial aspect is the impeller puller, a tool specifically designed to remove the impeller from the water pump housing. This tool helps make changing an impeller much easier and more efficient.

Every engine and installation is different, so this is a general guide and refers to Yanmar engines in particular. You will need a few tools to change an impeller, including wrenches or socket sets, pliers, fallen wrenches, and the impeller puller. The first step is to locate the water pump housing on your boat's engine. Once located, you can remove any necessary parts or covers to access the impeller.

Carefully remove bolts or screws securing the water pump housing using your wrench or socket set. With the housing removed, use the correct size Allen wrench to remove the set screws that allow the cover plate to come off. Sometimes it is stuck in place, and the edge of a craft knife is a handy tool to break the seal between the gasket, plate, and pump housing.

 

With the impeller exposed, use the puller to withdraw the old impeller, then clean up the pump housing, removing any old gasket fragments. Some pumps have an O ring instead; if so, remove this and discard it.

Getting the new impeller in place can be challenging; my go-to method is to wrap a plastic cable tie around the blades, squashing them down so the impeller can be slid into place. Use dishwashing liquid or glycerin as a lubricant to help the impeller slide in. Once the impeller is half inserted, cut the cable tie off and push it in, ensuring the cut out on the boss or splines aligns with the spindle. When the impeller is well seated, the cover can be replaced using the new O ring or gasket that can with the kit.

AVAILABLE AT THE PHARMACY, GLYCERIN IS PERFECT AT HELPING SLIDE THE NEW IMPELLER INTO PLACE

Finally, reassemble any parts or covers that were removed earlier and secure them back into place using your wrench or socket set. Double-checking for proper installation before starting your boat's engine is always a good idea.

 

WITHOUT REMOVING THE PUMP, THOSE SETSCREWS ARE SO EASY TO LOSE IN THE BILGE! (note the black burn mark on the housing, likely the result of  overheating at some time in the past)

By understanding how an impeller puller works and having access to the necessary tools, changing a boat water pump impeller becomes a manageable task for any boat owner or enthusiast.

Best boat carpet

As part of the overall refurbishment of the interior of Seaglass, Rita and I wanted to make the interior more 'homey.' Although we love the abundance of teak in our Grand Banks, it can be a little overwhelming, plus taking care of it also takes considerable time to keep it looking fresh and new. This is especially true of parquet flooring, which gets a lot of wear during the year. Although we take our shoes off when we enter the salon, the cabin sole can take a bit of a beating. There can't be many GB owners out there that don't have some rug, mat, or runner to add a splash 0f color and make the cabin sole easier on bare feet.

Uncertain as to precisely what we should do to the boat's interior, we called in Kate Seremeth, who runs Tack Studios in Maine. She has extensive experience working on yacht interiors and was a delight to work with; and would heartily recommend her services if you are thinking of sprucing up your boat's interior or going for a complete do-over. 

Amongst the other thing,  Kate suggested the use of a fitted rug. She also suggested working with Colonial Mills,s who weave rugs out of Sunbrella material. Ubiquitous with yachts, there can't be many boat owners who have not used or at least come in contact with, Sunbrella at some time. Most known for fabrics for awnings, covers, and cushions, the Sunbrella material that the rugs are woven from is far softer and has a look, somewhat, of woven sisal but feels so much better underfoot. 

Rather than buy a rectangular rug that fit the space, the lovely folks at Colonial Mills offered to make a bespoke one that would fit the space perfectly -- all I had to do was make the templates. 

 

As you can see in the picture,s I made the template from stiff building paper,r and this was later transferred to Tyvek so that I knew that the template would not tear or distort, leaving me with the wrong size carpet or worse. If you look closely at the images above and below,w you will see a line drawn in black Sharpie a half inch from the edge. This is an important step and makes completing an accurate temple much easier. Basically,y the technique is this; you cut the template almost the right size but deliberately undersized by a small amount. This saves your time and your temper, as you are not trying to cut it accurately at this stage. With the paper pattern then taped in position,n you use a straight edge of known width and, as in this case with the spacer pressed against the woodwork at the floor's edge,e mark a line, which is the one you see above.

 

Here's a close-up shot of the technique in action. Then when I got home,e I laid out a large sheet of Tyvek, taped the brown paper template on it,p and once again lined my spacer along the black lines I made when I was on the boat, and voila, a perfect facsimile of the wooden sole. Even s,o as it was,s I spent several hours making the templates -- first the brown paper and then the Tyvek that I sent to Colonial Mills. Rita and I chose an aqua colo,r but there are almost a limitless amount of colors to choose from, so if you are not replacing the upholstery I was we were,e then you are sure to be able to get something to coordinate.

 

Overall I think the carpet looks great; it's hardwearing and has stood up well. Best of all,l it is somewhat unique,e and it draws admiring glances from jealous owners when we have attended Grand Bank's get-together. You will also notice the edges are whipped to prevent unraveling,g and this,s plus the overall weight of the carpet, keeps it lying flat on the floor. If I have one regret,t it is that I had some cutouts put in the carpet to allow the two table legs to make contact with the floor. If I did it again,n I think that I would have gotten four holes cut to allow the removable bolts that hold the table in place to pass through and allowed the table to sit on top of the carpet; the bolts would have helped hold the carpet in place and it may have looked a little neater. But then, I may be being overcritical of my choice. But judge for yourself and let me know what you think.

 

Top Boating Videos of 2021

I'm happy to report that a couple of my videos came top of the list of  BoatUS' most-watched in 2021 and are embedded below for your viewing pleasure. Repairing gelcoat is a common boat owner task, but it requires more than just filling in small spider cracks. “How to Spray Gelcoat on a Boat Using a Preval Sprayer,” which shows how to make professional gelcoat repairs over a larger area, was the most-watched new BoatUS video of 2021, from BoatUS Magazine. The second most-watched video on the list, “Bilge Pump Not Working? Here’s How To Troubleshoot the Problem” proves that even in this technological era, boaters continue to be vexed with the age-old issue of keeping water out of the boat.

 

 

 

 

Gelcoat repairs

Here's a video that I recently did for BoatUS on gelcoat repairs. Gelcoat repairs are often seen as something of a black art and something that's best left well alone, gelcoat repairs are really not that complicated given the right tools, techniques, materials and mindset. Enjoy the video, and as ever I'd love to hear your comments.

 

Installing an automatic fire extinguisher

 

Of all the things that scare boat owners the most, sinking is probably at the top of the list. But fire is no less of a threat. Indeed, a fire, even if you manage to put it out, can easily lead to a sinking. The first line of defense when it comes to preventing a fire on board is to make sure that all systems are correctly installed and that there is nothing that can turn a small problem into a large one. Normally a single factor alone will not cause a fire; they are most often started by a combination of factors.

Should the worst happen you need to slant the odds in your favor of putting a fire out. The best fire extinguisher is probably a frightened sailor with a bucket, but after that, it usually comes down to genuine fire extinguishers. Most boats have a few of these on board. There should be one in each cabin, visible and easily accessible so that it can be grabbed and used in a hurry; speed is of the essence here.

But what if the fire is in the engine space? You may not even realize you have a fire there until it is too late. Worse yet, opening the engine cover to see what’s going on is often a bad idea, as it feeds additional oxygen to the fire and may cause a flare-up. The ABYC recommends that engine fires be tackled without opening the engine cover or—in larger vessels—the door to the engine room. The cover or door maintains a physical barrier between you and the fire and restricts the amount of oxygen that can reach the flames. Often, sailboat builders thoughtfully install fire ports in the front of their engine boxes; a small plastic disc pops out, allowing you to deploy the nozzle of a fire extinguisher through the hole. This is very sensible, but is not necessarily the best solution.

Top of the tree is an automatic fire extinguisher system. In its simplest form, this senses the engine room temperature, and when it rises above a preset limit, deploys an inert gas to deprive the engine room of oxygen, thus putting out the fire. Halon used to be the gas of choice, but environmental concerns have resulted in it being outlawed. New systems use another gas called heptafluoropropane, although halon is still acceptable for existing systems. (If you do own a boat with a halon system, be aware that it cannot be refilled with halon when serviced; the same holds true for older refrigeration units that use halon as a refrigerant.)

Installing an automatic fire extinguisher in the engine room is well within the capabilities of a competent DIY owner, but it is necessary to do a little research first. I contacted Sea Fire, who supplied me with the necessary parts to complete the installation that you see here after sending me a worksheet that asked some questions about the boat, engine size, location and most important, the size of the space that the system would protect.

In theory, it is possible to install an automatic extinguisher that employs a vial on a sprinkler head at the top of the extinguisher cylinder, which bursts at a certain temperature and smothers the fire. The advantage to this approach is that you don’t have to make any extraneous connections to your engine room. Most owners, though, will opt for a slightly more sophisticated system, which is what I did. Connected to the top of the cylinder in my system is a cable release controlled by a handle next to the helm that can be pulled to deploy the extinguishing agent manually. Because the boat in which I was making the installation had a large electronically controlled engine, I also installed an automatic shut-down system. With this, if the extinguisher is deployed either manually or automatically a relay trips and shuts down the engine. Shutting down the engine if it is running ensures that the extinguishing agent will not be sucked into the engine and ejected out of the exhaust before it has the chance to do its job and put the fire out.

 

Here’s How I Did It

 

Tools required:

Drill, screwdrivers, pliers, tape measure, crimpers, wrenches

 

Skill level:

Advanced amateur

1 Decide where the extinguisher will go. In many cases the decision is made for you, as there is not much space in the average engine room. Bear in mind that you will have to make a connection to the top of the cylinder and that, depending on the type of system you have, the cylinder will either need to be mounted horizontally or vertically. This will be made clear in the installation instructions.

2 Measure carefully, then bolt the mounting bracket into position. I had a nice clear space on the aft bulkhead, which was just perfect. You may not be so lucky and may have to reroute wires or hoses if they are in the way.     

3 Mount the extinguisher as outlined in the instructions. The Sea Fire I’m mounting has stainless steel worm-drive clips that pass through the bracket and around the cylinder. Make sure they are tight.

 
 

Install the manual release cable. Bear in mind that it is stiff, like a throttle or gear shift cable, and will not bend in a tight radius. Cables are supplied in almost any length, so measure the run of the cable before ordering. An old piece of 6mm 1x19 rigging wire is handy for this, as it has the same bend characteristics as the release cable.

 

4A. After deciding where the cable will go, install the plate for the manual release, which should be near the helm. You will also need to drill a hole for the cable attachment; I was lucky to be able to use the plate to cover an unwanted hole where a gauge used to be mounted  

4B.Install the brass nut and washer before passing the end of the cable through the hole.

4C.Then install the other components on the other side: barrel nut, O ring, T handle, and safety clip.        Connect the other end of the cable to the cylinder, which is retained by a spring clip. It is also worth noting that the cylinder has a safety pin in place that has to be removed, but leave that until you have completed the installation to avoid a possible accidental discharge.    

 

5 Use a hole saw to drill a mounting hole for the monitor panel.

6 The panel is passed through the hole and secured by a straddle clip on the back.

 

7 Wiring is likely to be the most time-consuming part of the job, as it must be neat and well ordered. First mount the relay/control box. I put mine behind the breaker panel. Use cable of the correct gauge; Sea Fire recommends no smaller than 16 AWG.

1. The wiring is fairly easy to follow, but requires connections from the top of the cylinder, a power feed and connections to the electrical engine shut-down solenoid. When connecting a shut-down solenoid, be aware that the contacts will either be normally open or normally closed. You may need to refer to the engine wiring diagram to identify your specific application and which wire you need to splice into.
2. Install the CAT 5 Ethernet cable between the monitor panel and control box.
3. Make the power connections to the fuse box, which must be protected with the correct amperage fuse. Don’t forget to mark up the fuse for identification later.

Finally, clip back the cables for a neat and orderly appearance.

With thanks to Brewer South Freeport and Matt Durkin.

 

Do Fire Extinguishers On Boats Need To Be Inspected?

 

 

There is a lot of confusion surrounding the use, testing and inspection of fire fighting equipment on boats. The rules for commercial passenger carrying boats are different to those used in the recreational market and in summary these are that non-rechargeable extinguishers have a life expectancy of 12 years after which time they are replaced. There is normally a two number date stamped onto the bottom of the cylinder 16 for 2016, 98 for 1998 and so forth. After 12 years they need to be replaced. However they need not be inspected by anyone other than the boat owner to ensure that they are in correct and proper order. The full transcript is attached below in the PDF pulled from the USCG website. This standard and most of the others relating to fire are jointly drafted by the USCG and National Fire Protection Agency, often just called the NFPA.
However if your boat has an installed fixed system in the engine room then this can only be inspected by a certified person and must bear a tag showing the date, the inspectors initials and the certified company that he works for (these resemble old fashioned luggage tags).
Link to inspection requirements

As I mentioned the rules for commercial boats are more strict, and this includes skippers with a 6-pack license who occasionally charter their boats, these must be inspected by a certified person each year.

Replacing a boat fridge

 

Until now I’ve never owned a boat with a refrigerator, all my past boats have had an icebox. This was not necessarily by choice, my electrical system has been for the most part pretty minimal and I’ve not had sufficient electrical capacity to operate a fridge, but this changed when I got Seaglass my Grand banks 32. By comparison to my other boats, electricity is profligate, not only do I have a huge battery bank but additionally I have a generator, able to supply 120 volts AC at the push of a button.

Like many marine and RV refrigerators the unit fitted to Seaglass is able to operate from either AC or DC. When the boat is connected to shore power, or the generator is operating, the unit runs from this supply, but disconnect or interrupt the AC and the fridge defaults to 12 volts. Up until now I been manually selecting AC or DC on the breaker panel and it was only after I spoke to the good folks at Thetford that I found out you can leave both breakers turned on.

The fridge on the boat was, I think, original and although it had soldiered on for 25 years it was showing its age. The old fridge didn’t look too bad but after 25 years time was up.

The door seals were worn, the flap to the freezer compartment was missing, and it ran almost all the time in an effort to maintain its temperature – it had to go.

When the boat was built the buyer had two options, have a meat locker cold plate style fridge replete with solid teak door and stainless steel interior or a standalone marine fridge. Frankly I wished my boat had come with the former option and although I could have had one built, the cost, along with the siting and mounting of the separate compressor/evaporator was more than I was prepared to tackle. The simpler option then was to replace the fridge that was there with a complete new unit. I had assumed that this would be a fairly simple matter of unbolting and sliding out the old unit and replacing it with new fridge of identical dimensions. Sadly it was little more complicated than that, as a direct replacement is no longer available. So after looking at all the available options I decided on the Norcold 0788, the closest in size to the original.

Here’s how I did it.

1. The first step after turning off the power was to get the old unit out. To make this easier I first removed the door.

2. Screws through a flange around the fridge secured the fridge to the surrounding woodwork. With the screws removed the fridge could finally be pulled forward to reveal a quarter century of dirt and crud.

    3. After double-checking that the power was off I disconnected the power connections, both 12 volt DC and 120 volts AC were hard wired through separate terminal blocks.

4. With the old fridge off the boat I measured the opening, as I knew that I would have to make some adjustments to ensure a neat and tidy installation of the new unit. Because the new fridge was slightly smaller in both width and height compared to the old one it was necessary to make up a new teak surround to blend seamlessly with the existing teak joiner work.

5. To promote good air circulation and give the fridge a firm base on which to sit two half-inch marine plywood skids were screwed into the base of the cabinet.

        6.The new fridge came with a right hand hanging door so I had to swap the hinges to the other side – an easy job – so that it swung the other way to make it more convenient for the         cook.

7. Before I bolted the fridge in position I had to connect up the power cables. I’ve said it many times before but don’t be tempted to use wire nuts, which should never be used on a boat at any time. I used proper crimped connections and cable of the correct gauge to extend the wiring that was then reconnected to the terminal blocks.

8. One final check before turning the fridge on is to make sure the door seals correctly. The instructions that came with the unit explain how to do this but a dollar bill should just be pinched between the seal and door edge. If the bill slides out too easily, or not at all, then the hinges need adjustment.

9. The completed job after the fridge was bolted in place through its feet into the ply skids installed earlier. An added bonus was being able to repurpose the space above the slighter shorter new refrigerator with a new cutlery drawer, which is made of teak then varnished to match the existing joiner work.

Many thanks to the good folks at Thetford for help with this project.

Repairs and upgrades - Norcold and Simrad

This picture (above) was taken with taken with my iPhone at close range and as I could not get far enough back so you will have to excuse the parallax error, but it shows the fairly well, I think the progress to date on the new fridge installation. The old fridge was noisy, the seals were worn so it ran all the time, it used a ton of electricity, iced up with gay abandon and the small freezer compartment door did not properly close. With that said I am pretty impressed that it managed to soldier on for 26 years, but it had to go and is being replaced with another, which like the first is from Norcold. The fridge is a dual voltage 12/120 model which looks pretty slick, but installation has required some modifications to the cabinet work around the unit as the overall size is a little smaller. The old fridge had what can best be described as flange around the unit and this screwed into the wooden framework. This had two functions, it sealed the gap between the fridge and the cabinetry preventing dirt and debris from entering and secondly held the fridge in place preventing it from moving when the boat moved about at sea. The new fridge lacks the flange which I miss and I hope that at some time in the future Norcold sees the wisdom in reintroducing this feature to at least some of the models in their range. The 0788 model that I am installing is fixed in position with screws through the feet which are visible when the door is opened. This works well on my boat but I could see may be a problem where the fridge is located higher from the sole where a solid attachment point may not be available. Because the fridge is less tall than the original I also have room for cutlery drawer and you can see the drawer front temporarily taped into position for photography purposes.

After talking with the technical folks at Norcold I found out that I had been operating my fridge incorrectly in the past. I had always assumed that with a dual voltage fridge one had to turn off the DC breaker before turning on the AC breaker to power the fridge but it seems that I should have been keeping both the 12 volt and 120 fridge breakers on when I was aboard. Apparently there is an automatic relay in the back of the fridge which by default runs off AC voltage, if this is interrupted or unavailable then the appliance automatically switches to 12 volts DC until 120 volts AC is restored. They have been wired that way for years, it seems, but I never knew, and now you do too.

I've never liked the way that many radar and chart plotter displays just tend to get bolted down to any free bit of space with the cables sprouting out of the back. I think this messy and I wanted to do something better. Seaglass has surprisingly never had a multi function display installed at either helm and this is something that is being addressed during this winter and spring fit out season. The truth is that I have a bunch of equipment on long-term loan from the good folks at Simrad for a series of features that I have been working on about installing an NMEA 2000 network. At the heart of the system is a beautiful 16 inch NSS evo2 MFD. I've played about for ages trying to work out the best location for this with initial thoughts that it might go above the windscreen. This looked like a good bet and would have worked well with the general refit of the headliner and lighting upgrades but a mock-up showed that it was just too far forward of the helm seat to make controlling it as easy as it could be. So further head scratching and another mock up brought me to the point I am at now with what I can best describe as a teak nacelle which sits on the self and to port of the main  steering compass. The MFD can now be controlled with relative ease from the comfort of the helm seat and the large screen is easy to read from most anywhere in the salon making watching movies when swinging on a hook a distinct possibility. I am going to miss the flat surface on which I placed pilot books and charts when underway and so I have to find alternative placements for these, but I think the trade-off worth it. 

In the picture above the MFD has been temporarily dropped into place just to see how it will look when finished properly; there's to be a matt black surround between the teak 'eyebrow' and edge of the MFD but this will not be installed until after the nacelle has been varnished to match the rest of the boat interior. Also, you will notice that the teak is still somewhat of a rather odd color. The nacelle is made of 9 mm marine ply onto which I have glued teak veneer with the adjoining corners and eyebrow from solid teak. Teak when freshly cut has a definite green tinge but this soon fades and the color reverts to that familiar honey tone within a few days and the nacelle is still in that phase but by the time the varnishing starts the color will be somewhat different to what you see here. I should add that the color continues to mellow even through the varnish and so with time will blend in well with the 25-year-old teak interior.

 

Water tank anode

 

 

 

 

 

 

 

 

 

 

 

 

See that hot water connection at the top of the picture above well I bet you did not know that there is an anode in there that has to be replaced periodically. It's a fact that most water heaters corrode from the inside out, the first indication is that something is amiss is a sulphurous smell each time that the hot water faucet is opened. Often this is put down to bad water in the fresh water tank and there are lots of remedies on the internet forums of how to deal with this from sanitizing the tank with all sorts of chemicals to replacing the hot water  tank altogether. But often it is just the anode that needs replacing  as if this is completely wasted the water inside the hot water tank starts to eat up the very fabric of the tank. The insides of most water heaters are aluminum and they have a coil that comes off the closed loop on the engine fresh water cooling circuit which heats the water indirectly as the engine is running. They also have an electric coil which can be switched on when the boat is plugged into shore power which works in a similar way to the electric water heater that you may have in your home. The anode which is made of magnesium protects the insides of the tank and heating coils. There is some miss information on the internet which states that these should be zinc. This is incorrect as zinc is close to aluminum on the galvanic scale and as such will not protect the internal parts. Magnesium is less noble that aluminum and offers much better protection and in any event if a replacement anode is ordered for a hot water tank the manufacturer will supply the correct part.

If the anode is not replaced the first indication that something is amiss is the sulphur smell mentioned above, then if nothing is done to address the problem the electric hot water fails soon after as it is consumed by the galvanic action. This usually gets the attention of the boat owner who then has the difficult task of either replacing the element or most likely the whole water heater. 

Replacing the anode is fairly straight forward but the level of dificulty is directly proportional to how accesible the tank is. The first step is to isolate the water from the hot water tank. If you have a valve turn that off if not you may have to drain down the entire water system. Don't foregt too to turn off the electic element if this is on and watch for any water escaping from the water heater as it will be hot.

After turning off the water or draining it down lift the pressure release valve on the side of the heater to let built up pressure release.

Remove any hot water connections that are attached to the outlet on the tank. The boat I was working on had copper connections but alternatives may be flexible hoses or PEX type pipework. Irrespective of what you have they have to be disconnected.

With the pipes out of the way unscrew any nipples or elbows that are attached to the outlet. If they have been in place for a number of years you may need a fair bit of effort to remove these. With these removed the threaded part that actually goes into the tank will be visible. Push back white plastic trim cover to expose the non threaded part and get your pipe wrench on that and unscrew it. I guarantee that it will be tight. 

No prizes for guessing which is the new anode. The old one was completely wasted away. I was working on a 12 gallon tank and just to give you some idea that new anode is 16 inches long!

Re installation is a reverse of the procedure outlined above but use teflon tape or pipe dope as appropriate to sea threads. Once everthing is back together check carefully for leaks before turning on the water heater and Ta dah fresh hot water without the smell, no chemicals required.

Incidentally the Seward 6 gallon water heaters do not have an anode but for less than $20 you can add one. You have to removed the drain stop tap on the front of the heater and replace it with a pencil anode that you can buy from online retailers.  It's a modification that is well worth the effort as it will pro;ong the life of the heater by many years.