Seacocks checks

[NPMR]

We had the engine seacock condemned by an engineer clearing a blockage of seaweed this summer. We replaced the whole thing as soon as we found it, with the plan to replace the others during winter refit - now in progress.

Having just scraped all these skin fittings back to bare metal, they look bright and shiny yellow. They are situated several meters away from the seacock that proved faulty. The seacocks operate cleanly, smoothly and show no signs of degradation.

So do I trust them or just bite the bullet and replace the lot regardless?

 

[Plum]

We had the engine seacock condemned by an engineer clearing a blockage of seaweed this summer. We replaced the whole thing as soon as we found it, with the plan to replace the others during winter refit - now in progress.

Having just scraped all these skin fittings back to bare metal, they look bright and shiny yellow. They are situated several meters away from the seacock that proved faulty. The seacocks operate cleanly, smoothly and show no signs of degradation.

So do I trust them or just bite the bullet and replace the lot regardless?

Are all the other seacocks of the same age, material, design and make as the one condemned? Why was that one condemned? You said you scraped the skin fittings but not the seacocks, do you know they are of the same material/age?

Anyway, if you have already bought new good quality seacocks and skin fittings and you are worried, just change them all for peace of mind.

 

[Sandy]

What issues did the 'engineer' find with the engine sea cock and why did s/he condemn it? (I am assuming s/he is a member of an engineering institute and has a raft of qualifications to back up her/his condemnation or was s/he a mechanic or fitter. Sorry, it is a personal rant of mine; the title engineer. Oh, a really good mechanic/fitter is worth their weight in gold.)

Have the other sea cocks caused you any problems? How old are they? How often do they get used? Why are they the material that they are and what material is your hull? I am not a fan of metal through hulls and sea cocks in plastic hulls.

Do you have pictures of the other sea cocks in situ?

 

[Tranona]

Proximity to other seacocks is irrelevant. Each one is "free standing" from the point of view of corrosion. Unfortunately the condition of the external surfaces are not a good indicator of any dezincification as this almost always occurs in the hidden internal threads of the fittings and the valve body. However this only happens if the valves and fittings are plain brass. If they are DZR or bronze then there will be no dezincification.

Suggest you first determine what caused the failure of your engine inlet. Then the material of the other seacocks. That may be difficult as it is not not necessarily obvious from external examination, so if they are old or of unknown history then replace them.

 

[Bandit]

You don't give much info to go on, new boat or an old boat, age of skin fittings, material of skin fittings etc.

A lot of new boats are built in europe with brass skin fittings.

Look for weeps of water into the boat, corrosion and "sweating" of the fitting which would indicate dezincification.

Use a minimum of DZR for all skin fittings, bends, ball valves and hose tails, all the same material and quality do not mix with brass or the brass will corrode even quicker.

Surveyors and insurance companies expect metal skin fittings to be removed dismantled and inspected for condition every 6 or 7 years. Insurance co's can get arsy if you have ancient skin fittings in the case of a flooding or sinking claim.

If you are removing dismantling and inspecting skin fittings and valves you may as well replace with new all DZR. Do not use gate valves.

There are two schools of thought to bond to an anode or not to bond, if you bond use quality wire fittings and tinned wire.

If it says CW617N this is brass, replace them.

 

[Stemar]

Take a rubber mallet and give each one a good welt. If you don't break them, they're good for another year.

 

[vyv_cox]

If the valves are silver in colour they are brass, zinc plated. You say yours are yellow which suggests they are DZR, in which case they will be marked either CR or DZR. Bronze valves are more of a pink colour (red brass in American)

 

[NPMR]

The boat, Jeanneau, has 13 seasons in water. All seacocks except holding tank are silver on yellow metal skin fittings and connectors to pipework.

All are clean as can be, virtually no verdigris or staining anywhere.

The engine seacock having become blocked by seaweed in Salcombe, was cleared from inside the boat but the exit pipe crumbled to pieces as the mechanic undid the pipework.

When replaced this winter, the engine service engineer failed to save the actual seacock and so I didn't see the state of the valve bit.

Your useful comments have reassured me of my decision to change them regardless. But given the long life experienced to date, will not spend money on bronze or non-metallic units.

 

[vyv_cox]

The boat, Jeanneau, has 13 seasons in water. All seacocks except holding tank are silver on yellow metal skin fittings and connectors to pipework.

All are clean as can be, virtually no verdigris or staining anywhere.

The engine seacock having become blocked by seaweed in Salcombe, was cleared from inside the boat but the exit pipe crumbled to pieces as the mechanic undid the pipework.

When replaced this winter, the engine service engineer failed to save the actual seacock and so I didn't see the state of the valve bit.

Your useful comments have reassured me of my decision to change them regardless. But given the long life experienced to date, will not spend money on bronze or non-metallic units.

Since your boat was built, skin fittings, valves and hose tails are now available in DZR. Make sure that what you have is identified.

 

[Laysula]

Take a rubber mallet and give each one a good welt. If you don't break them, they're good for another year.

Best not to do it when you're afloat though.

 

[Graham376]

Take a rubber mallet and give each one a good welt. If you don't break them, they're good for another year.

Mine were hammer tested by surveyor, all passed but his advice was to replace them anyway as boat was about 25 years old then and all skin fittings appeared original fit. Decided to change at the next spring lift and one broke up when removing, with very little force.

 

[Poecheng]

Pay particular attention to the toilet outlet seacock. What passes through appears to cause greater than normal problems.

 

[Tranona]

Pay particular attention to the toilet outlet seacock. What passes through appears to cause greater than normal problems.

Yes, that is because contaminated seawater sits on top of the exposed threads of the fittings and the ball valves making them vulnerable to dezincification if made of plain brass.