Seacock’s jammed… should I replace anything else while I’m at it?

QI have a Moody 31 built in 1989 and one of the inlet seacocks has failed in the shut position.

This doesn’t unduly concern me for the present as I’ll replace it before long with a new Maestrini DZR Ball Valve when the boat comes out of the water at the end of the season.

My question is should I be replacing the skin fitting as well as the ball valve? I don’t know if or when they have ever been replaced before I owned the boat. MR Daniels Colchester COLIN BROWN REPLIES: The answer is short and simple. Yes! You should definitely replace the skin fitting – and hose tail – at the same time as the seacock.

If you’re fitting a DZR valve then you should also fit a DZR skin fitting and hose tail. All of these fittings on your boat may well be original – in which case they’ve done very well lasting this long.

Taking the valve off a skin fitting without dislodging the fitting can be a challenge in the first place, and removing the collar to reseal the old skin fitting if it has moved in the process can also be a big challenge.

The extra labour involved in trying to save the old skin fitting may cost more (in terms of time, money and knuckle skin) than a new fitting which costs around £15.

To get rid of the old skin fitting you can carefully cut off the flange from outside using an angle grinder and cold chisels then simply pull the whole assembly through into the boat.

You should also consider fitting a new hose to your new seacock. Unless you’ve changed them yourself and know better, the hoses on your boat may also be original and they tend to stiffen and become brittle with age, making them vulnerable to breakage as they move when you try to get them off the old seacock. Our main photo shows a broken skin fitting from a Moody 33. The valve was still working but the skin fitting had suffered dezincification – the pink colour of the remaining metal is a giveaway. You can see the salt crusting where the weakened skin fitting had been leaking. It snapped off under light manual force.

Dezincification in a failed skin fitting allowed this seacock to be simply snapped off Quality ball valves from a reputable supplier will be DZR (dezincification resistant) and marked CR (corrosion resistant)