General Boat Maintenance Part I: Hull
The hull is the part of your boat that keeps you floating and thus quite an important one. Keeping it in good shape is essential for a good sailing experience, and the effort to achieve this depends hugely on the type of boat you have. In this article, I outline the different basic maintenance tasks a neat hull requires.
In order to estimate the amount of care that will have to be dedicated to the hull, it is useful to think of the different materials it can be made of and the resulting specific maintenance needs. Many modern yachts and smaller dinghies are made of GRP (Glass-Reinforced Plastic), a mixed material of glassfiber and epoxy resins. It is not only a cheap and durable material, but also easy to maintain.
Hulls made of GRP generally come with a finish of a gel coat to protect the underlying structures and laminate. The gel coat gives the boats a shiny touch and needs to be cleaned and polished occasionally. It is sensitive to UV light, as essentially all plastics. Cracks can occur after a few years through exposure to sunlight; or they are caused by physical pressure (bumps, scratches and alike).
If the gel coat is damaged, water can get in between the coat and the laminate and will cause the coat to peel off. Therefore, damages in the coat need to be fixed as soon as you notice them. Once every ten years or so (depending on the type of coat, bur more so on where you live and how harsh the climate is to your boat), you will have to renew the finish. That’s about it for GRP hulls.
The second material to think about is the classic one: Wood has been used in boat building ever since people have built boats. It looks good, feels natural, but is generally heavy and requires a great deal more work than GRP. The wood itself is always protected by at least one layer of paint, epoxy resin or other finish.
If this finish is damaged under physical pressure and parts of it rub off, the damage needs to be fixed to prevent water from getting in between the protective layer and the wood. It might be necessary to sand the affected area; for large-scale repairs, you might have to strip off a larger part of the hull. Take care to roughen the surface in order to increase the adhesion of the paint.
The finish on wooden hulls normally needs to be polished once a year. Fall is a good season for that, in the course of winterizing the boat. Depending on the quality and type of paint that you use, your finish should last for 3 to 7 years.
Hulls of larger vessels and cruisers are often made of metals, most commonly steel or aluminum; the are durable and require less work than wooden ones, however, don’t meet some (traditionalist) sailor’s aesthetic preferences and are not the ideal material for small boats. Much like wood, steel hulls come with a finishing layer of paint. Maintenance work for steel and wooden hulls is very similar, too.
Aluminum hulls are a different story; the material is light and very easy in maintenance, but expensive. If you apply paint to an aluminum hull, than essentially for aesthetic reasons – if they are left untreated, you will save on work and the metal’s surface will oxidize over time to an elegant gray. If you choose to paint the hull, it requires similar maintenance as steel hulls.
General maintenance work for all types of hulls
General tasks that you will have to apply to any type of hull include a variety of minor things that you should do frequently. They might seem like common sense, but nevertheless, they are often neglected:
1.) Check the through-hull fittings: At least once a year you should check all “holes” in the hull. Are they really sealed? Open and close seacocks frequently to keep them in shape and grease them if necessary.
2.) Check for damages: Every time you lift your boat out of the water, check for scratches or cracks and fix them as soon as you discover them. Look at the propellers, keel and rudder and get potential damages repaired.
3.) Clean the hull once a season and apply anti-fouling paint to fight barnacles, woodworms and other unwanted visitors.
4.) Always carry a repair kit that includes duct tape for emergencies, epoxy resin, paint or gel finish matching with you boat. If you get into trouble with a damaged boat, don’t rely on your own skills but seek professional help.
5.) If there are bolts in you hull – for example in the rudder bearings – remove some as samples from different parts of the boat once a year. Check for corrosion and replace bolts as required.
6.) Keep the “hull-attachments” in good shape: Check if your keel-hull-joint is sealed properly; if openings in the hull are damaged by electrolysis (requires two different metals and seawater); if the rudder-bearings and the propeller are still flexible.