Anyone putting their boat into winter storage now should not wait until the first cold snap to take frost-protection measures. The following tips from readers relate to specific tasks concerning the fresh-water system and engine cooling. They complement the Preparing the sailing boat for winter storage, but they do not replace the instructions for the built-in appliances.
Antifreeze life hack 1: Adapter to prevent damage to the fresh water system
Every year, as part of winter storage, the water pipes and the boiler need to be drained. To protect against frost, depending on the system, either a complete draining or the use of a specifically suitable antifreeze agent may be required. The specifications provided by the manufacturers of the pump, boiler and pipes are crucial. It is advisable to extract the water using a wet vacuum. The wet vacuum is connected to a standard flexible siphon connection hose with a diameter of 32 millimetres. For the threaded end, we used a triangular file to cut a thread on the side of a 10-millimetre-thick, 40-millimetre-diameter plastic disc, with a pitch matching that of the union nut. The centre bore has been enlarged to approximately 20 millimetres to allow a 1/2-inch double nipple to be screwed in tightly and airtight at a later stage. This creates the adapter needed to connect the vacuum cleaner to the water pipe.
Christian Herzog, Friedeburg
Editor’s note: Engine antifreeze is not automatically suitable for drinking water systems. Our article explains the differences in composition and application Choosing the right antifreeze for your engine and boat.
Antifreeze life hack 2: Further protection against frost thanks to laboratory accessories in the water filter
To protect the main engine’s seawater cooling circuit from frost damage, antifreeze is poured into the seawater filter and the engine is left running until the antifreeze is visibly discharged from the exhaust. Collect any antifreeze mixture that escapes to ensure it does not enter the harbour water or end up on the ground. The fact that it is labelled ‘biodegradable’ is no reason to omit this step. To prevent the antifreeze from leaking out of the filter through the intake hose, the seawater valve must be closed. However, this is difficult to access on our boat, and furthermore, the antifreeze in the section of hose leading to the seawater valve is of no use and is therefore wasted. We therefore seal this opening directly in the filter quickly and easily when winterising the boat using a rubber stopper for test tubes. These are available cheaply online or from specialist retailers.
Carsten Dubois, Gundremmingen
Antifreeze life hack 3: Protect the engine’s cooling system from the cold
To make it easier to flush the cooling system of our engine, we have fitted a two-way valve in the supply line. With the arrangement shown, there is no need to lock the sea valve – simply connect the flushing hose and flip the lever on the two-way valve. This allows the antifreeze to flow through until it emerges again at the exhaust. A side effect of this is that the impeller does not run dry, as water is continuously drawn in.
Jürgen Kruse, by email
Antifreeze life hack 4: The vent valve makes the pipe winter-proof
Any residual water remaining in the pressurised water system can cause considerable damage in frosty conditions, resulting in high costs and a great deal of work. We have fitted a small vent valve, of the type used in heating systems, at the lowest point of the supply pipe. The appropriate square-ended spanner is secured on site, within easy reach. In autumn, we open the valve and allow any residual water from the hose and pump to drain into the bilge. It can then be mopped up with a cloth. This ensures a worry-free winter.
Edgar Wallenborn, Kerpen
Antifreeze life hack 5: A way to catch antifreeze from the exhaust
Antifreeze is important, but it mustn’t be allowed to enter the environment. That’s why we use the filler neck of a petrol can to catch the liquid at the exhaust. To ensure the plastic spout stays in place in the through-hull fitting and remains watertight, we’ve wrapped the end in adhesive tape and thickened it to the correct diameter. This allows the antifreeze to be collected without any mess and stored until it’s needed again next autumn.
Josef Gius, Traunwalchen
Editor’s note: Collect the mixture in a suitable, labelled container. Before re-use, check that it is suitable and that the antifreeze concentration is correct; otherwise, dispose of it in accordance with the product’s disposal instructions.
Antifreeze life hack 6: Engine flushing
When winterising the engine, we first flush the cooling system with fresh water and then top it up with antifreeze and corrosion inhibitor. To do this, the sight glass on the seawater filter is replaced with a Plexiglas panel of the same size, into which a brass hose connection has been glued using Sikaflex. With the engine running, fresh water is first drawn into the cooling system via the additional hose, followed by antifreeze.
Helmut Neumann, Bad Salzuflen
Antifreeze life hack 7: Drawing antifreeze from a small storage container
Before winter storage, the fresh water system must also be protected against frost in accordance with the manufacturer’s instructions. If an antifreeze agent is used for this purpose, it must be expressly suitable for this application; it does not automatically replace any cleaning that may be required. If frost protection measures are not taken, any water left standing in the pump, the filter, the taps or the pipework itself may freeze and cause the surrounding material to burst. Leaks are the direct result. However, it is not strictly necessary to fill the fresh water tank to a large extent for flushing – and then to clean it afterwards. If the service hatch is large enough to place a jam jar containing antifreeze into the tank, the pump can also draw the liquid from this container. The container must remain sufficiently full during the flushing process. Before putting the system back into operation, it must be flushed in accordance with the product and manufacturer’s specifications.
Sascha Labuda, Hamburg
Antifreeze life hack 8: Blow out with compressed air
A homemade compressed air adapter can make it easier to drain the water pipes. Whether the system can be completely drained in this way depends on the pipework layout and the components used. A Gardena connection point on the on-board system is required. It’s simple to make: a Gardena tap adapter is drilled out to an internal diameter of 10.5 millimetres. A standard car valve, such as those available from a tyre shop, is then fitted into the connection. When combined with a Gardena equipment adapter, which is screwed into the tap fitting, this creates a precisely fitting compressed air adapter for on-board use. Using a 12-volt compressor, the water pipes and pumps can now be blown through and drained completely, leaving no residue.
Hans Stark, Ostfildern
Editor’s note: Only use compressed air if the components in question and their manufacturers permit it. This does not guarantee that the pump, boiler and pipes will be completely drained in all cases.
Antifreeze life hack 9: Collect the antifreeze after flushing
When adding antifreeze to the engine, it is inevitable that some glycol will be expelled through the exhaust. The expensive liquid spreads across the ground and seeps away. To prevent this sort of contamination, we use a plastic tube from a roofer’s supply. In new-build houses, this is used as a replacement downpipe. We secure it to the exhaust pipe with a clamp or a piece of string and place the other end in a bucket. We do exactly the same before filling the tank with water. We also collect the glycol mixture so that we can reuse the antifreeze the following year.
Peter Hoeck, by email
Editor’s note: The product specifications apply when reusing the product; in particular, the antifreeze concentration must be checked.
Antifreeze life hack 10: Blow it out with a pump
To ensure that the seawater cooling circuit is completely drained down to the very last drop during winter storage, we use compressed air. To do this, we have fitted a car valve into the lid of the water filter. We simply connect a standard foot-operated air pump to this. The air pressure forces the water out through both the suction pipe and the exhaust.
Dieter Behrens, Hanover
Editor’s note: Readers’ suggestions are not universal winterisation guides. In particular, modifications to the coolant system and the use of compressed air to purge the system must be tailored to the specific installation. If the manufacturer’s instructions are unclear, a specialist firm should review the procedure.
Do you have any advice for other sailors?
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Submissions to: YACHT Editorial Team, Quartier O, Paul-Dessau-Straße 8, 22761 Hamburg; or: mail@yacht.de
Even more handy life hacks:
Book recommendations
Stress-free engine maintenance Duncan Wells is carrying out more detailed work on the boat’s engine, which also needs to be done before winter storage. The manual explains maintenance and troubleshooting, as well as how to manage the cooling system. The book includes explanatory videos in English, including ones on flushing the seawater system and checking the coolant. Photographs, diagrams and checklists complement the instructions.
333 new tips for sailors, compiled by Fridtjof Gunkel, brings together readers’ ideas from YACHT’s ‘Skippers Magazin’. The focus is on small modifications, technical aids and solutions for everyday life on board. Examples range from a homemade chart plotter mount to securing open cupboards. Available as an e-book, this volume complements the frost protection life hacks with further DIY ideas, without being limited to winterising.
What solution do you use to prepare your yacht’s water system and engine cooling system for winter storage?
Lars Bolle
Chief Editor Digital