Skin fitting’s service life
QI have an X43 built in 2004 and as I was at a boat show last month I thought I better ask the X Yacht guys when they recommend replacing the bronze skin fittings. The answer was every 10 years. As the boat is out of the water for six months every year and I can see no sign of anything nasty going on, can I work on 10 years water time? David Mccormick
Ben Sutcliffe-davies replies
AFrom the photos supplied it’s not very clear what they are made from. There is some obvious discoloration and signs of some weepage to the sides of the actual skin fitting. This potentially could be caused from a materials incompatibility issue. The handle on the valve being blue has no real significance unless it has the casting material markings provided. Likewise the valve body from the photos has no obvious markings as to material. The skin fitting and the bit you can’t see, the hose tail should be checked. To be honest, for the cost, it’s prudent to change them and sleep safe at night!
Many companies supply valves and associated fittings that are widely used in our industry that were intended for the gas or water industry and can be viewed with
a safe working pressure and a thread diameter. Not of great help when trying to establish what they are made from.
To be honest I really do like the composite valves like those from Marlon and there are some others that include the Alex valve that are also clever, with a mixture of bronze body and composite valve workings.
If you are using ball valves then bronze are much better. If they had been the old Blake valves I would say don’t change them. Some bronze valves are bronze bodied but have mild steel handles or brass balls, so they would need to be carefully monitored from five years on. It is also important they are not bonded into the vessel’s galvanic protection.
So the advice from your boat builder is about right. When changing, doing the skin fitting and valve and hose tail, not just the valve, is essential.