Where are the seacocks on a Rasmus 35, and how do I service them?

On a Hallberg-Rassy Rasmus 35, look beneath the galley sink, around the forward toilet compartment and low in the engine space, tracing each hose to its hull fitting. Positions and numbers vary with refits, so find every underwater opening before deciding which valves need servicing and which need replacement.

Where to find the valves

Find the engine cooling-water inlet first. If a cooling hose fails, you need to shut it immediately. Trace the hose back from the raw-water pump, through any strainer, to the valve at the hull. The strainer itself is not the seacock.

• Galley: look inside the cupboard beneath the sink and behind removable panels, following the drain hose downwards.
• Forward toilet compartment: look beneath the basin and behind or below the toilet for the flushing-water inlet and toilet-discharge valves. A holding-tank conversion may have changed the discharge route or added another valve.
• Engine space: follow the cooling-water supply through the access panels down to the hull. Check adjoining low lockers if necessary.
• Additional equipment: trace any seawater deckwash, refrigeration or other seawater supply separately. Check cockpit drains too; their arrangements may differ from the domestic plumbing.

At haul-out, walk around the hull and match every opening to its internal fitting. A transducer or exhaust outlet may have no seacock. Photograph and label each valve, recording its purpose and open position.

Inspect before turning the handle

A seacock assembly comprises the through-hull fitting, valve and hose tail. Inspect each part, along with the backing support, hose and clips. A new-looking handle tells you little about the metal underneath.

Before working afloat, keep a correctly sized softwood bung beside the fitting. Remove hoses, dismantle valves and replace underwater fittings only with the boat ashore.

• Look for leaks, salt deposits, cracks, loose mounting nuts and movement between the fitting and hull.
• On copper-alloy fittings, a pink colour, crumbling or porous metal suggests deterioration and warrants replacement. Green surface staining alone does not prove failure.
• Check hoses for splitting, hardening and chafe, particularly beneath clips.
• Inspect stainless clips underneath as well as on top. Use two marine-grade clips where the hose tail is long enough for both to sit fully on it.

Operate a valve that appears sound gently, watching the whole assembly. Stop if the body or through-hull moves. Do not use an extension bar on a seized handle: the extra force can break an ageing fitting.

Service each valve type

Quarter-turn ball valves: the handle normally lies parallel to the flow when open and across it when closed. Ashore, inspect the bore from both ends. Remove accessible marine growth without scratching the ball or seats, then operate the valve through its full travel. Many ordinary ball valves are not designed for internal servicing. Replace any that remain stiff, leak at the spindle or fail to close properly.