Boat maintenance can feel like a never-ending task. But keeping your vessel ship-shape and dealing with problems before they arise is vital for ensuring a smooth sailing experience and avoiding expensive repairs. After all, the longer you ignore a problem, the worse it will get.


By staying up to date with your boat deck maintenance and repairs, not only will you be able to avoid leaks, but you’ll also be able to enjoy a much more attractive vessel that everyone will be envious of.


In this guide to boat deck maintenance, we’re going to look at three of the most commonly overlooked aspects of boat deck repair, including how to care for your teak decks, how to undertake a fibreglass boat deck repair, and how to keep your deck fittings in tip-top condition so that you can avoid much bigger, more expensive, and time-consuming work in the long run.


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A black and white cat sits on the deck of a fibreglass yacht that's been hauled out of the water for essential deck repairs while a man works on the bow. The deck paint has been scuffed up ready for repairs and repainting.

Keeping your decks ship-shape is the best way to avoid future problems and hefty boatyard bills. Photo by PS Copywriting


How to care for teak decks


When it comes to dressing the deck of your yacht or other vessel, few finishes are more attractive or popular than teak decking. Not only does it offer a beautiful appearance, but teak provides unbeatable grip, even when wet and with the boat well-heeled, and its durability makes it perfect for life in an often harsh marine environment.


A blue hull sailboat with teak decking is heeled over while sailing down a UK river.

Not only do teak decks look gorgeous on a boat, but they are also practical.


That said, while teak can be durable and grippy, it can quickly deteriorate if not properly cared for. And any owner of a teak deck boat won’t need me to tell them that teak decking can be very expensive – a new teak deck for a 40ft boat can cost upwards of £20,000: a bill that often comes as an unpleasant surprise to the unsuspecting owner.


The problem with teak decks


The biggest problem with teak decks tends to be a lack of understanding on how to care for them. While thoroughly scrubbed decks might look shiny in the pictures, this rigorous cleaning process literally wears the deck away – up to 1mm of thickness per year can easily be lost to scrubbing! This happens because, although the wood grain is very hard, the fibres between the grains are soft and can easily be scrubbed away. And while some teak decks are only 12mm thick (and even the best are usually only 15-18mm), it doesn’t take much ‘cleaning’ to inflict potentially terminal damage.


The second problem with teak decks is how they’re secured to the boat. Whilst improvements in adhesives over the past 15+ years have led to modern teak decks not needing to be fitted to the boat with screws, older vessels are much more likely to have been screwed in (if not now, then in the past). These screw holes leave a passageway for water to sneak through, leading to leaks and a weakened core.


However, even if you have a more modern vessel with a glued-on teak deck, this may offer other problems. Most commonly, these decks will be thinner than those of a more historic heritage, with some being as little as 7mm thick. Again, this can cause problems if you don’t clean your deck properly, as you’re likely to scrub away that precious and expensive covering.


 


How to clean your teak decks


So, how do you clean your teak decks to avoid having to invest in boat deck repair foam, soft spot repairs, or having to replace the entire teak deck?


The teak deck of a Bavaria 41 cruising yacht looks smart and clean with regular, gentle maintenance.

Getting the gorgeous scrubbed look - it is essential to use a soft brush and go against the grain.


The first (and most obvious) answer would be to avoid scrubbing the decks. For boats kept in sunny environments, all they need is a regular (ideally twice daily) wash with salt water.


In addition to being readily available for most boaters, salt water has the added advantage that it won’t strip the natural oils out of the timbre. After a few weeks, the decks will acquire a beautiful natural silver-grey patina – If you’re searching for a good-condition second-hand yacht, this is what you should hope to find.


But what if you’re not lucky enough to live in a sun-soaked climate?


Well, in more temperate climates, your teak deck may require a little more attention. But there are still ways to mitigate any loss of fibres when cleaning – by being as gentle as possible!


If you must wash your decks, use light pressure on a very soft-bristled brush, and always brush against the grain. This will minimise the removal of the soft timbre between the grain and significantly reduce the rate of wear. You should also let the teak cleaner – which contains oxalic acid to bleach the timbre – do as much of the work as possible. Patience is the key here: the less actual scrubbing you do, the better.


You should also avoid the temptation to use a pressure washer on teak decks, as the wood simply won’t be able to handle it over the long term. Stiff bristles and pressure washers might seem like quick routes to a clean deck, but they’re also quick routes to big boatyard bills and a significant reduction to the total value of the yacht!


Be sure to follow any teak deck cleaning with a generous application of teak oil to help maintain your ship’s appearance and the longevity of the wood.


How to spot if your teak decks need some extra TLC


Sometimes, cleaning isn’t the only thing to worry about. Loose caulking, movement of wooden plugs over screw heads, or splits or cracks in the timbre are all signs that your deck needs a bit more attention. And, as with most boat jobs, the earlier you spot the problem, the easier it will be to fix.


A white sailing yacht proudly shows off it's light-coloured teak decking and white cabintop.

Loose caulking, missing or loosed plugs over screws, or cracks in the timber are all signs that the deck needs repair.


Leaks through a teak deck can be particularly difficult to trace but are a clear indication that something needs repairing or replacing. Rectifying any leaks as soon as possible is essential to avoid the risk of water or frost damage lifting the timbre from the deck below, leading to the entire deck needing to be replaced.


Thankfully, over the last 10-15 years, teak decks have generally been glued in place. However, earlier versions relied on hundreds of screws to secure them to the vessel, with each screw representing a potential weak spot. As the teak ages, screws can become a significant source of leaks, which, in many cases, allows water directly into the foam or balsa core of a fibreglass sub-deck.


Again, by keeping an eye on your deck and spotting these problems early, it can be easy enough to remove and replace weakened screws or even fill the holes with epoxy and use an adhesive to glue the teak on instead.


What to do if you spot caulking or cracks in your teak deck


Caulking or cracks might feel like problems you can put off until your winter refit, but it’s always a mistake to ignore them! Cracks and caulking can escalate surprisingly quickly until the stage is reached when your only option is to replace the entire deck. But, thankfully, much boat deck repair work can be done relatively easily if spotted quickly.


If you spot a crack in the timbre, the first thing to do is to open it out with a small chisel or Dremel-type tool. Allow the wood to dry thoroughly, then fill the crack with an epoxy-based filler.


For loose caulking, you’ll want to pick out the affected area and clean it back to bare wood (ideally with a router), then replace it with new caulking.


Older teak deck repairs


If you have an older deck that’s been screwed down, you’ll need to keep an eye on the teak plugs above the screw heads: when these start to become thin, they tend to fall out. This looks unsightly at best, but it can also provide a route for water to enter the deck's structure, leading to soft spots and a weakened core. So, if you spot any missing teak plugs, you’ll need to remove the screw and drill out the hole to a level two or three millimetres lower. A new, thicker teak plug can then be glued in place above the screw head.


A neatly coiled line sits on the teak deck of the USCG tallship Eagle.

Keeping an eye on the teak deck plugs is a great way to spot potential problems before they occur. Photo by Rusty Watson on Unsplash


Teak deck caulking repairs


Assuming there’s no waterlogging underneath, in many cases, a deck that’s significantly worn and has damaged caulking can also be given a new lease of life in a few simple steps. Start by sanding the deck with a light sander until it’s smooth, then remove all the caulking using a router to make the groove between the planks two to three millimetres deeper than the original. This extra depth will allow the new caulking to adhere successfully. Once you’ve applied the new caulking, the deck will need to be sanded again to remove the excess caulking compound, and then the teak can be re-stuck.


By resolving any other problems at the same time, this procedure can help a carefully looked-after deck last a further five to ten years, yet costs a fraction of a new teak deck!


Caring for a fibreglass boat deck


Now that you know how to care for your teak decking, what happens if the problem is more severe and water enters the fibreglass? Or, what if you don’t have a teak cover on your deck and you’ve spotted signs of wear in the fibreglass or non-slip paint?


Whilst fibreglass is an incredibly strong and durable material for boat building, it can become structurally compromised if water reaches the foam or balsa core. And a boat deck soft spot repair can be incredibly time-consuming and expensive if it’s allowed to spread.


In theory, fibreglass boat builders would have removed core material from the location of any through-bolted fittings. But while more modern builders tend to be meticulous about this, you can’t assume this is true with older boats!


A neatly coiled line sits on the teak deck of the USCG tallship Eagle.

Properly bedded deck fittings should be capable of decades of use without developing leaks.


What can go wrong with a fibreglass boat deck?


Six major problems are likely to lead to needing a fibreglass boat deck repair:


1.Blisters


Blisters are small, horizontal cracks or lumps on the surface of fibreglass boats. They’re usually caused by collisions and other bumps, such as loading heavy items onto the boat’s deck or cabin. When these cracks fill with air, they let in water and will grow in size as trapped water droplets expand and contract. If left untreated, blisters can crack and tear the boat’s surface, leading to thorough repair work being required or, in some cases, having no option but to scrap the boat entirely.


To avoid blisters, try to avoid unnecessary collisions or being too heavy-handed when loading items onto the vessel.


Blisters can also be caused by marine fauna piercing through the top coating. By ensuring your antifouling is refreshed, and your hull is cleaned regularly, you can mitigate this common problem.


If you spot blisters in your fibreglass, you must act quickly to prevent permanent damage to the deck and hull. To repair the blister, you’ll first need to remove the fibreglass deck gelcoat and the fibreglass substrate. Use an epoxy resin to fill the blister and allow it to cure before applying a new gelcoat.


2. Delamination


Even if the core is dry, fibreglass decks can delaminate from the core over time. This can create a “bubble” effect, with bulges or waves visible in the outer layer.


This generally happens on boats with a wooden layer sandwiched between the inner and outer fibreglass (a balsa core) but can occur on any fibreglass boat, regardless of the core material. When the middle wood breaks down or pulls away from the surrounding fibreglass substrate, this causes delamination and potentially serious issues for the vessel. It can also happen if the core wasn’t properly wetted out (i.e., soaked in resin) at the point of construction, leading to an inferior adhesion as the core has absorbed too much of the resin, not leaving enough to stick to the fibreglass.


Because delamination is usually (but not exclusively) caused by water, ensuring your fibreglass deck is free from leaks is an essential part of avoiding this problem. If delamination occurs, you’ll generally require a qualified technician who will remove the fibreglass surface to access, remove, and replace any damaged core.


If your fibreglass is delaminating but it’s not wet, you’ll be able to identify it by a cracking sound when you step on the affected part. Thankfully, the repair is much more straightforward in this instance: all you’ll need to do is drill some holes in the fibreglass and use a syringe to inject epoxy resin into the holes.


3.Water damage


Water damage generally occurs in fibreglass yachts with a foam or balsa core. As with delamination, water damage is caused by water getting underneath the fibreglass through cracks or poorly sealed deck fittings (such as screws or deck hardware, which we’ll go into in more detail below).


Rot in wood is an obvious problem for fibreglass boats. However, although foam is a closed-cell material, water can still wreck the foam core, often leading to delamination, especially during cold weather.


The easiest way to check if your foam core is suffering from water damage is to look for soft spots on the deck. You may be able to notice these as you’re walking around the boat – part of the deck will feel spongy underfoot – or you can use a small plastic hammer to tap on the transom. If it rings, this indicates a healthy solid core, whereas a dull thud might indicate that you need to undertake a boat soft deck repair.


But don’t panic! Like many boat jobs, the key to an easy boat soft deck repair is early identification and treatment. If you find a soft spot on your foam core fibreglass boat, you can repair it by drilling a quarter-inch hole below the soft spot to drain any water (you can use a vacuum to speed this up), then dry out the foam with a dehumidifier. If you live in a sunny/warm climate, you might even be able to simply leave the foam exposed to sunlight until it’s completely dry.


Once you’ve successfully dried out the foam core, you must find the water entry point and ensure this has been repaired/sealed. Then, you can finish your boat deck soft spot repair by tapering the base layer of fibreglass, adding a new foam core (if required) and new layers of fibreglass to seal. Don’t forget to ensure you’ve used plenty of epoxy resin to create a good seal; otherwise, you may face issues with delamination later on.



4.Rot


Discovering a rotten balsa (wood) core is probably the worst thing that can happen to any boat owner. Especially if you’ve chosen a fibreglass boat to avoid the issue of rot that plagues beautiful yet expensive and challenging wooden vessels.


Like so many problems with boats, rot occurs when water manages to breach the fibreglass hull and soak into the wooden centre. You may be able to spot rot simply by looking at it: look for any discolouration, sagging, or giving. Dirty water seeping out when you remove bolts or screws can also be a good indicator that something isn’t right.


The second way of checking for rot is by smell. Rotten balsa smells a bit like sunbathed mushrooms or perhaps sweaty gym socks mixed with mothballs (delightful, I know).


If you see or smell either of those things, your next step will be to check the deck for soft spots, as outlined in the above boat deck repair: foam section. Then, finally, you can try the drill test: use a hand drill to make a small hole in the fibreglass where you’ve identified any soft spots. If the wood presses down easily or comes out damp, you may well have rot.


Again, Sailing Project Atticus has a good (short) video on identifying a rotten balsa core.



Repairing a rotten balsa core:


Depending on your skills and the extent of the rot, you may need a professional if you identify rot in your balsa core. But, as an overview, a boat deck soft spot repair will involve the following steps:


-         Drill holes through the fibreglass and the first layer of the balsa core.


-         Use an Allen key or bent steel to remove any affected wood (keep going until you hit hard wood).


-         Vacuum out any remaining soft wood and allow the surrounding wood to dry completely (you may want to use a dehumidifier, heat gun, or even hair dryer to speed this process along).


-         Fill the gaps with thickened epoxy (you may need some sort of frame to avoid drips).


-         Re-fibreglass over the holes, and be sure to create a tight seal.


-         Identify and address any leaks in the fibreglass or deck fittings to ensure no more water can breach the balsa.


5.Exposure to sunlight


Like most materials, fibreglass can become brittle and damaged if overexposed to UV rays. Unfortunately, getting a boat out of the sun is not always easy, and putting a cover on a vessel you’re using regularly will be cumbersome and impractical.


That said, it’s not impossible to reduce UV damage on fibreglass boats. Painting your boat with a UV-resistant clear coat, top coating, or varnish on your decks can help reduce the need for a yacht deck repair caused by sun damage. 


UV-resistant wax can also be applied every few months like a sun cream to keep your vessel looking its best for years to come, and a UV-resistant fibreglass deck gelcoat will also make a huge difference.


A man applies a white top coat to his fibreglass sailing yacht to help protect it from sun damage and keep it looking its best.

Using a UV-resistant paint or top coat on your fibreglass decks and hull can help protect your boat from sun damage. Regular waxing can also work like a sun cream to keep your vessel ship-shape. Photo by PS Copywriting.


6.Salt damage


It’s not just water that can creep into the fibreglass and cause damage to your deck and core: salt in the pores of your fibreglass can also cause damage to the fibreglass deck. This can lead to oxidisation in your fibreglass deck gelcoat, in addition to becoming a conductor when combined with water, leading to galvanic corrosion, which is especially damaging to metal components that get in its way!


Anodes and antifouling paints are excellent starting points to reduce the damage caused by salt water, as is repairing any scratches or paint chips immediately to ensure more salt can’t get into the deck or hull.


If you take your boat out in salt water, be sure to wash it with fresh water when you return to the harbour to remove salt build-up (and prevent stains and mould), and seal the hull with a marine wax.


How to fix fibreglass deck leaks


As you may have noticed, most issues with fibreglass decks occur when water (or salt) breaches the top layer of fibreglass and causes damage to the interior core. So, to keep your vessel ship-shaped, it’s essential to identify any leaks and repair them immediately before water can wreak havoc where it doesn’t belong.


The heart of the problem


Very often, the problem of fibreglass boat deck leaks is caused by well-intentioned owners bedding new deck fittings down with silicone sealant. The problem with this is that, to survive an often-harsh marine environment, excellent adhesion is essential. Unfortunately, silicones have a relatively low level of adhesion, which often leads to leaking once fittings move under load or when the boat around them distorts, for example, when sailing in a big sea.


This leaves two main options for effective sealants – a marine polyurethane adhesive sealant such as Sikaflex 291i or a polysulphide such as Life Caulk. Once cured, the former creates a permanent bond, ideal for fittings you never expect to remove. Polyurethane adhesives are available with different levels of adhesion – Sikaflex 291 and 3M 4200, for instance, have a lower level for use with general deck fittings. In comparison, Sikaflex 292i and 3M 5200 have a high level of adhesion for high-load items.


Polysulphides never fully set, so they are ideal for fittings that you know may need to be replaced or repositioned at a later date. Like polyurethane sealants, they stick tenaciously to almost any substrate. However, they are not suitable for use with some plastics as the solvents used may cause problems.


Four containers of Sikaflex 291i sit in the cockpit of a sailing yacht next to a glue gun, ready to be used to seal some gaps in the fibreglass.

Getting the right adhesive is vital when completing boat deck repairs to ensure a watertight seal. Photo by PS Copywriting.


Fixing fibreglass deck leaks


Whether you’re completing a boat deck soft spot repair, a fibreglass boat hatch repair, or a fibreglass sundeck repair, there are a few key steps you should take to ensure a thorough and tidy job.



  1. Surface preparation


Even the very best sealant is ineffective without proper surface preparation – this is the most crucial part of the job. 


Almost nothing will stick permanently to most silicones, so the first part of the preparation is to remove all traces of the previous sealant meticulously. This may involve a combination of scraping, sanding and applying solvents, including proprietary silicone removers. 


Once the deck is free of silicone, a coarse abrasive paper can be used to help provide a mechanical key (i.e., scruff up the area to allow for better adhesion), before thoroughly cleaning the area with acetone or white spirit.



  1. Keeping it tidy


One problem with any sealant is dealing with the excess – it's messy to work with but looks untidy if left in place. 


Since bolt holes are the only route for water ingress into the boat, a single bead of sealant running along the line of the holes and encircling each one is all that's required for a successful outcome. For a larger job, it’s possible to calculate the amount of sealant needed to produce a uniform layer 2mm thick, leaving a margin for excess.


To make tidying up easier, where possible, apply masking tape to both the deck and the fitting so that sealant squeezed out of the joint can be easily cut away with a sharp knife once it has mostly cured – typically after 4-10 hours for polyurethanes, depending on the ambient temperature.


A man in a red jumper carefully applies sealant around the bolt holes of one of his deck fittings. The holes have been outlined with masking tape to ensure a tidy job.

Applying sealant around the bolt holes, after masking the deck around each fitting.


The easiest way of doing this is by dry fitting the components first so that the deck around the new fittings can be masked accurately before applying the sealant. This technique works well and is a quick route to a professional-looking result, providing the sealant is removed at the right time – too early, and it gets really messy, too late, and it becomes awkward to remove.


A man pulls away the masking tape after re-attaching a deck fitting to neatly remove the excess sealant.

The sealant comes away neatly, although it would have been even better in this case to allow it to cure for a little longer.


How to care for and maintain your deck fittings


Deck fittings are a very important yet often neglected element on any yacht. As with many aspects of boat maintenance, a little frequent attention will help to prevent larger problems and failures.


Many deck gear failures can be traced to an ingress of salt and grit, so it makes sense to wash the boat thoroughly with fresh water whenever possible after sailing. While sailing, it’s also worth periodically examining all deck gear for correct and smooth operation.


Two sailors in the cockpit of a well-heeled elan 340.

It's worth periodically examining deck gear while sailing to ensure smooth and correct operation.


Lines and ropes


Modern low-stretch ropes can create new and unexpected problems, as peak loads that were previously absorbed when lines stretched are now transferred directly to deck gear, as well as to the boat’s structure. As a result, fixing points, blocks, and other gear may have become over-stressed. In extremis, this can destroy fittings that have previously worked for many years without any apparent problems.


Winches


Ideally, winches should be serviced at the start and end of the season at a minimum. However, many don't get anywhere near that much attention, even though frequent servicing is vital to their reliability, and failing to do so increases friction more dramatically than most boat owners realise.


The procedure is essentially similar for most models and takes only a few minutes once you’re accustomed to the procedure. The service instructions should always be consulted before starting work – these can typically be found on manufacturers’ websites. Similarly, all manufacturers sell spares kits covering different models and requirements. However, these aren’t essential as long as you have a suitable supply of circlips, pawl springs, light oil, and waterproof grease. It’s a good idea to take pictures of your winches as you disassemble them, as this will make reassembly a much more straightforward process.


A dismantled, cleaned, and serviced winch dries on some spare cardboard, ready for reassembly on the deck.

Servicing winches: always refer to manufacturers' instructions and take care not to drop any pieces of the winch over the side! Photo by PS Copywriting


Common mistakes when servicing winches include using too much grease or greasing the pawls instead of using a light oil. In both cases, friction will gradually increase as the grease ages and, in extreme cases, can lead to the pawls failing to engage properly. A helpful tip when servicing a winch for the first time is to drape a sheet over the guardrails to prevent components from being lost over the side or to use an old cardboard box to keep the disassembled parts together.


Reassembly is a straightforward reversal of removal, checking that each component operates properly as you go. Electric models should also have the switchgear replaced as per the manufacturer’s recommendations.


Finally, check the operation of the winch itself before subjecting it to use under load.


Windlasses


Windlasses share many of the same design characteristics as winches but are in a much more exposed location, prone to getting drenched in salty water and subjected to abrasive particles of mud and sand that come up with the anchor rode. As a result, they often have a shorter useable lifespan than winches, especially on boats where the anchor is rarely used and problems with the windlass therefore go unnoticed, often until the whole unit has seized solid.


Such neglect can be expensive and result in safety issues if the anchor needs to be used in an emergency, such as in the event of engine failure. 


However, if the unit is washed with fresh water after each trip and serviced at the same time as the winches, its lifespan will be maximised, and you can expect near-faultless reliability for many years.


An anchor locker is opened on the deck to reveal a clean and well serviced windlass.

The windlass is essentially the same as a winch but will generally be more exposed to the elements and mud from the anchor chain.


Blocks


In addition to washing regularly with fresh water to flush out salt and other debris, it’s worth examining each block regularly. Modern low-stretch ropes used with older sheaves tend to cause a higher incidence of sheave cage collapse, meaning the block will simply stop running. This often goes unnoticed until you look closely at the block and find the rope is wearing a groove into the sheave.


Clutches


Just as many blocks are now subjected to higher loads than in the past, the same is also true of clutches. The problem can also be compounded when a clutch is asked to hold a higher load but with a smaller diameter line that’s more difficult to grip. 


Many units have been re-engineered to reflect this, with various cams to suit different rope materials. The good news is that many can be retrofitted to replace an old and worn cam, making an older unit as good as new but at a significantly reduced cost.


Rigging


At the same time as dealing with deck hardware, it’s also worth checking the rig. 


At deck level, look closely at the sheaves at the base of the mast, the boom, and the kicking strap, including the sheaves for the reefing lines at each end of the boom. Also, pay attention to the area around fittings, including swages, spreader roots, and rigging terminals. Spreader ends should be checked to ensure they are smooth and, as always, keep an eye out for soft spots or discolouration, which can be symptoms of much deeper problems. 


See our article on rigging and basic rig checks for more advice on ensuring your rigging is in the best possible condition.


As part of a full deck repair, a man checks the mast and rigging of his sailing yacht and uses Sikaflex sealant to re-seal any cracks or unused through-holes.

Completing boat deck repairs and checks is a great opportunity to check your rigging is sound and that there are no additional cracks or unused holes in the deck that could lead to leaks. Photo by PS Copywriting


 


Windows, hatches, and port holes


If you’re anything like me, leaking windows are the bane of your boating life! Because these fittings require large holes in the fibreglass deck, they’re an apparent weak point and will often begin to leak over time.


If you’ve noticed leaking hatches, the first thing to do is to check the gaskets. If your gaskets are old or damaged, they won’t be able to compress and seal the hatch closed, which is a likely cause of leaks. Hatch dogs and hinges that go through the lens can also be potential weak spots, especially those with O-rings that allow the dog to rotate – these need regular lubrication with silicone grease to operate effectively.


If you’ve serviced the gaskets and O-rings and there is still water getting through, this is likely to result from aged caulking or bedding, and your hatch will probably need to be rebed.


A fibreglass boat hatch repair is relatively uncomplicated, albeit a bit time-consuming and frustrating. First, unbolt the entire frame and remove it from the deck. Next, scrape off the old caulking from the deck and frame and drill out the fastener holes with an oversized drill.


While the hatch is out, it’s a good time to check for other issues, such as a rotten balsa core or other water damage. If this occurs, you’ll need to scrape out all of the affected materials, completely dry out the cavity, and then refill the space with thickened epoxy, as discussed earlier in this fibreglass boat deck repair guide.


A hatch repair in-progress. The damp core has been removed and filled with Tetrosyl Ultrasmart 2K Multi Purpose Smooth Body Filler

If you find any damp materials in the core of your fibreglass deck, you’ll need to scrape this out until you reach dry material, then fill the cavity with thickened epoxy. Here, we used Tetrosyl Ultrasmart 2K Multi Purpose Smooth Body Filler as a cheap and quick solution to fill the cavity when replacing our hatches. Photo by PS Copywriting.


Even if there’s no apparent water damage, if you can see any unsealed core, you’ll still need to dig it out to at least 10mm, thoroughly dry the core, and then fill the space with thickened epoxy. You will also need to fill the empty bolt or screw holes with epoxy to avoid any new leaks.


Preparing the deck hole for a new hatch by filling with thickened epoxy

Because our new hatches are a little smaller than our old ones, we built a frame and used some thickened epoxy to thin the gap. This also gave us an opportunity to fill the old screw holes without worrying about drips inside the boat. Photo by PS Copywriting.


Once the epoxy has set, you can set the hatch/port/window in place and drill new holes for the fasteners. After that, it’s a case of caulking the hatch and deck with a generous amount of sealant, then bolting down the hatch without fully tightening the bolts. Once the caulking has set and formed a waterproof gasket, you can then fully tighten the bolts to secure your window in place.


 


Filling screw holes


It’s almost inevitable that, at some point, you will need to change some deck fittings, either to replace a worn-out item or upgrade it to one of a higher specification. However, in many cases, the holes for bolts or screws will not line up with the new fitting. If this is the case, never succumb to the temptation to leave open screw holes after removing old fittings or to fill them with a silicone sealant. Once water finds its way into the fibreglass mouldings and reaches the foam or balsa core, the structure will weaken.


A proper permanent solution is to dry the area thoroughly, drill a hole a little larger in diameter than the screw thread, and then fill this with epoxy resin thickened with glass bubbles or microballons.


An old hole on the deck of a fibreglass boat has been surrounded by masking tape and refilled with some thickened epoxy to ensure no water is able to get through the fibreglass to weaken the core or cause leaks inside the yacht.

Whether you’re replacing a deck fitting or have through-holes that are no longer in use, filling any gaps in the deck with thickened epoxy will ensure no water is able to get inside the boat. Photo by PS Copywriting.


On a boat with painted decks, the paint can easily be touched up, while a fibreglass deck will need the top surface to be finished with colour-matched fibreglass deck gelcoat.


Yacht deck repair: the bottom line


In my boating experience, I’ve known some boaters who insist that boats leak and you’ll never get ahead of the problem, so why worry? And I’ve known others who treat every single drip as a catastrophe that will cause the boat to sink at any moment.


In reality, it’s true that all boats will leak a little, and excess water where it doesn’t belong is a part of boating that you’ll simply have to get used to. However, that doesn’t mean that leaks should be ignored or neglected: merely that you don’t need to panic.


As with most aspects of boat maintenance, the sooner you can identify and fix a problem, the less likely it is to become a major issue that causes significant damage and expensive repairs (or worse, having to scrap the boat entirely).


But the good news is that, although a boat deck repair might sound frightening, more often than not, it’s a simple case of rebedding deck hardware or sealing holes. A lot of these can be done without invasive processes, and if you use the right adhesive, it will last for years to come. 


A man relaxes on the clean and well-maintained deck of his sailing yacht in a calm anchorage at sunset.

Regular deck maintenance is really the only way to keep your vessel beautiful, safe, and watertight for years to come. Photo by Alex Block on Unsplash


Next steps and related reading:


For more on maintaining and servicing the equipment on your boat, check out the following related reading:



You can also check out all boats for sale right here at boats.com.





Written by: Pippa Shaw
Pippa is a freelance copy and content writer living on her 28-ft sailing yacht with her partner and Opie the boat cat. As a full-time liveaboard and digital nomad since 2019, Pippa’s got plenty of nautical miles and boat renovations under her belt and is currently completing a UK circumnavigation for charity before setting her sights on warmer waters.