Select Page

If you have ever witnessed a boat colliding with a rock or other submerged obstacle you will know that there is an almighty thump and the whole boat shakes and judders. While such hard groundings seldom result in catastrophic keel failure, something has to give and even the sturdiest keels can easily be damaged by such an impact.

Following a hard grounding it is always recommended to contact your insurance company as you may be covered for this and they will advise you how to proceed. Either way, the boat should be hauled out and a surveyor needs to inspect the keel and hull for damage.

Fin-keelers – A hard grounding can cause the keel-to-hull joint of a fin keeled yacht to split open as the keel is forced away from the keel stub by the impact. Aside from any damage to the joint and keel bolts the impact can cause cracks in the gelcoat which need to be repaired. More seriously, it can also force the aft end of the keel upwards, damaging the hull laminate in the process. This is repaired as follows:

  • The areas of damage around the hull-to-keel join area are identified and marked.
  • Splits in the laminate tend to be on the outside of the hull forward of the keel and inside the hull aft of the keel.
  • The damaged areas are ground back and repaired with layers of glass fibre and epoxy resin, before being faired, primed and painted.

Encapsulated keels – Although encapsulated keels are generally thought to be more robust than exposed keels, damage can still occur after a hard grounding. A gash in the GRP keel coating needs to be treated as it can lead to bigger problems if water reaches the iron ballast, which will begin to rust and expand as a result, eventually splitting the encapsulated laminate. This should be dealt with as follows:

  • For superficial damage to the keel coating, wash and clean the damaged area. Then roughen the edges of the gouge with coarse 40 grit sandpaper.
  • Wipe clean with acetone and dry the area thoroughly.
  • Apply a clear coat of epoxy resin, followed by a second coat of epoxy resin mixed with micro-balloons.
  • Cover the patch with some waxed paper taped to the keel in order to hold the epoxy in place until it hardens.
  • Sand the patch when dry. Fill any voids with more epoxy if necessary and then sand smooth.
  • Apply a two part epoxy primer to the patch, building up several layers of primer to create a waterproof barrier coat. Lightly sand when fully cured.
  • The repair is now ready for priming and painting.

Bilge keels

A problem with bilge keel boats kept on drying moorings is that the keel bolts and hull-to-keel joints sometimes fail due to the constant flexing load caused by the continuous grounding that occurs at every tide.

This problem can be solved by strengthening the hull on the inside with epoxy resin and glass cloth. This is in addition to replacing the worn keel bolts and resealing the keels, see above: Keel bolt and hull-to-keel seal replacement.

Lifting and swing keel inspections

There are two main types of lifting keels fitted to sailing yachts, those that lift up vertically like dagger boards and those that pivot at an angle. Both forms have lifting tackle which needs to be inspected and maintained on a regular basis according to advice given in owner manuals. Manufacturers usually advise owners which maintenance work they can do themselves and the work that should be carried out by suitably experienced boatyards.

Most swing keel lifting mechanisms have four basic parts – a winch, a cable, a pivot bearing attached to the keel and turning blocks. On larger boats, keels are often lifted by electric motors and hydraulic systems.

Lifting keel maintenance

Most lifting keel maintenance needs to be done ashore with the keel lowered, in order to get access to the keel housing, but some systems can be checked and maintained with the keel raised. Annual checks and maintenance should be done in accordance with owner manuals and are likely to include:

  • Winch mechanism inspected for corrosion and smoothness of operation. Lubrication of winch mechanism.
  • Centre-board pivots to be inspected for wear.
  • If applicable, lifting tackle rope checked for chafe.
  • If applicable, wire cabling checked for condition. If any wires are broken the cable should be replaced. Inspect the condition of the eye bolt where the winch cable attaches to the keel.
  • Turning blocks to be inspected for wear and lubricated with marine grease. Worn blocks to be replaced.

For a complete refurbishment of a swing keel, all the equipment will need to be disconnected and removed, the keel shot-blasted for rust removal and then repainted. Bearings, seals and cables will also be replaced.

 

What boating skills should you have before you buy a yacht?

Many people dream of owning a yacht and sailing off into the blue yonder. What boating skills should you have before you buy...

Always have an emergency grab bag to hand when at sea…

  Grab bag: In the event of having to abandon ship, it is recommended to have a designated waterproof bag to carry...

Keel maintenance and Repair – Part 2

If you have ever witnessed a boat colliding with a rock or other submerged obstacle you will know that there is an almighty thump and the whole boat shakes and judders. While such hard groundings seldom result in catastrophic keel failure, something has to give and even the sturdiest keels can easily be damaged by such an impact.

Man Overboard Drill

How to respond to crew overboard under sail • Keep the MOB in sight • Tack into the heave-to position, do not adjust the...

How to predict wind direction and strength by reading a weather chart

Weather charts, also known as surface pressure or synoptic charts, contain a lot of information that helps weather...

How to tackle osmosis

Many owners of old GRP boats live in fear of osmosis, but what exactly is osmosis and what can be done about it? Osmosis comes about...

Rudders and steering systems – Part 2

One thing all rudders have in common is that they have three main parts that need to be checked: the rudder, or a steerable drive leg in the case of many power boats; the system that joins the rudder to the steering; the steering control itself.

Keel design – options to consider when choosing a yacht

Keel design is constantly evolving and nowhere is this more apparent than in modern racing yachts such as the Imoca Open 60...

Cleaning & polishing painted topsides

The gelcoat topsides of a GRP boat can be pampered and restored to their former glory relatively easily when it is ashore. Gelcoat is only a very thin outer layer of the hull, often less than 1mm thick, so you should avoid cleaning it with highly abrasive cleaners, or an-ything that could potentially damage its surface.

Rudders and steering systems – Part 3

In the third of our three blog articles on rudders and steering systems, we look at how to replace rudder bearings and repair a water-saturated core.

Learn ColRegs: Traffic Separation Schemes

Learn ColRegs Rule 10: Traffic Separation Schemes. (c) A vessel shall, so far as practicable, avoid crossing traffic lanes...

Boat engine basics

Boat engines come in all shapes and sizes and include inboards, outboards, petrol, diesel, electric and hybrid systems. Some engines are...

Points of Sailing

The course on which a boat is sailing can be described by its angle to the wind, not to be confused with its compass...

Weather forecasting tips

Most weather forecasts present a general picture of what to expect in your area over a given period of time. We rely on such...

Essential Knots: Round turn and two half hitches

Essential Knots: Round turn and two half hitches Use: Tying a rope to a pole or a ring. Step 1. Pass the end around the object. Step 2....

Rudders and steering systems – Part 1

Rudders and steering systems. A rudder is one of the most critical parts of a boat. Rudder failure is a common occurrence on neglected or overworked boats and a very unpleasant and potentially dangerous thing to happen when you are out at sea.

VHF DSC radio – how best to communicate at sea

There are many ways to communicate with others at sea. What makes the VHF DSC radio the best form of short range...

Understanding your boat’s compass

Article submitted by Mike Rossiter, Certificated Compass Adjuster. Since the magnetic compass was first used by the Chinese...

Boat engine fuel system

If engines are installed and serviced correctly then most marine engines are very reliable, but one of the most important parts of the engine to check and service is the fuel system.

First Aid Afloat – fish spine injury

First Aid Afloat - Here is what to do if somebody stands on a fish spine: • Check for dangers. Is it safe for you to enter...

ColRegs – avoiding collisions at sea

ColRegs - avoiding collisions at sea ColRegs Rule 8: Action to avoid collision (a) Any action taken to avoid collision shall...

How to operate a winch

Winches are drum shaped mechanical devices used to handle halyards, sheets and control lines. One of the important crew...

Tacking a sailing boat

Tacking is the sailing manoeuvre used to change a boat's direction through an oncoming wind. Tacking a sailing boat calls...

Diesel engine winterisation

An inactive boat engine needs to be protected from corrosion during the winter, caused by the rising humidity levels through the cold months and the salty coastal air. This applies whether the boat is left afloat or hauled out over the winter. Read here about the two important stages of winterisaton for a diesel boat engine.

The give-way hierarchy at sea – who gives way to whom?

Whatever their size or type, all skippers have a responsibility to avoid collisions with other boats at sea.  It is...