Seacocks

[peter2407]

I need to replace the port cockpit drain seacock as the handle is broken and it is in the closed position. Other than opening and closing all of the other seacocks as a check, what else should I look for to determine if others should be replaced?

 

[macd]

Why not just replace the handle, if that's all that's wrong? What type of seacock (or valve) is it? Do you know what they're made of?
It's worth opening and closing seacock valves periodically. They like the exercise.

 

[peter2407]

Not sure but will check when I am down there tomorrow. Is there anything that indicates that the seacock and through hull fittings should be replaced?

 

[Chris_Robb]

Before you buy a new seacock, check all your seacocks by scraping them with a blade or file. If they are still a bright barssy colour they are probably ok. If they are pink them change the lot. Do inside of boat and outside. Also use a small hammer to tap - a dead sound will indicate not all is right - especially on a prop which should ring like a bell.

With the one that is stuck, try it with a small ring spanner that fits well. I had one and it just sheared off when pressure was applied - a new one - DZR from ASAP (top notch supplier)

 

[macd]

Is there anything that indicates that the seacock and through hull fittings should be replaced?

As Chris Robb said. The pinkness is a sign that the fittings were brass and have de-zincified. Check out forumite Vyv Cox's excellent website for more information: http://coxengineering.sharepoint.com

 

[peter2407]

Is the pinkiness check before or after or even during the scrape test? If I take a file to them, and they end up being very brassy looking, is all well? I want to look at both the sea cock and the thru hull fitting so want to be sure all is OK. And finally - cause of dezincification - galvanic corrosion? The reason I ask is that the anodes on the boat that I put on c. 6 years ago, apart from being dirty, look new.

 

[V1701]

I'd be inclined to replace any that need it from now on with Marelon or Banjo plastic ones, the previous owner of my boat in Greece fitted them. They seem very well made, well up to the job & no subsequent worries. They're seven years old, no sign whatsoever of any issues & look like they could have been fitted last week...

 

[Chris_Robb]

Is the pinkiness check before or after or even during the scrape test? If I take a file to them, and they end up being very brassy looking, is all well? I want to look at both the sea cock and the thru hull fitting so want to be sure all is OK. And finally - cause of dezincification - galvanic corrosion? The reason I ask is that the anodes on the boat that I put on c. 6 years ago, apart from being dirty, look new.

The pinkness is after you scrape of the greeny oxide. Any pinkness - replace with proper DZR.

Is your Anode wired in to anything in the boat - engine??? Mine have lasted many years - big tear drop type, but show signs of heavy pitting. I have shaft anodes as well, and they last only 2 years, so they are probably taking the onslaught.

 

[peter2407]

There are 3 anodes - one on the rudder, one on the sail drive leg (that four years ago I - probably - mistakenly replaced thinking that it was being ineffective due to having AF painted on) and a "pin" anode inside the SD leg that to be frank havent as yet checked or replaced. Four years ago, the rudder anode (a tear drop shape like yours) was maybe 30% "eaten"?

 

[macd]

cause of dezincification - galvanic corrosion? The reason I ask is that the anodes on the boat that I put on c. 6 years ago, apart from being dirty, look new.

Kind of, but not with other parts of the boat, so your anodes have no bearing in this case. Basically the zinc in the brass disappears, leaving a copper Aero bar with not much mechanical strength.

 

[Heckler]

d

Before you buy a new seacock, check all your seacocks by scraping them with a blade or file. If they are still a bright barssy colour they are probably ok. If they are pink them change the lot. Do inside of boat and outside. Also use a small hammer to tap - a dead sound will indicate not all is right - especially on a prop which should ring like a bell.

With the one that is stuck, try it with a small ring spanner that fits well. I had one and it just sheared off when pressure was applied - a new one - DZR from ASAP (top notch supplier)

A note of caution, I had a bit of pink on one of my seacocks. I changed it. To change it I had to Dremel through the threaded bit where the pink was. It was surface dezinc only. The cutting thru revealed it was structurally ok! The prop on my Bene is not the original, the surveyor commented on it, he said it was proper bronze, quote, "you can always tell, they ring dull when struck" He was right, it doesnt ring! So, sweeping statements not always true!
S

 

[peter2407]

Good news (I think). Having filed off the AF from the outside of the boat that was on the through hull fittings and filed further, I get lovely shiny metal with no pinking. Internally I have done the same, but the fittings look more like cast steel (see pic) or some such. Any ideas?

All of the seacocks turned easily except for the new one from last year - but that is the heads outlet so may actually say more about my diet!

Looking at the cockpit drains seacocks because one has a broken handle and appeared to be in the closed position, I then broke the handle of the other one. Given that I can open and close them with an adjustable spanner, and there are 'internal wooden fittings' that would need to be removed, should I bother trying to replace the handle? Again, pic attached (not the best).

TIA

 

[VicS]

Good news (I think). Having filed off the AF from the outside of the boat that was on the through hull fittings and filed further, I get lovely shiny metal with no pinking. Internally I have done the same, but the fittings look more like cast steel (see pic) or some such. Any ideas?

All of the seacocks turned easily except for the new one from last year - but that is the heads outlet so may actually say more about my diet!

Looking at the cockpit drains seacocks because one has a broken handle and appeared to be in the closed position, I then broke the handle of the other one. Given that I can open and close them with an adjustable spanner, and there are 'internal wooden fittings' that would need to be removed, should I bother trying to replace the handle? Again, pic attached (not the best).

TIA

So you are talking ball valves screwed onto though hull skin fittings ... not cone seacocks like for example Blakes seacocks.

The ball valve in your picture might be chromium plated brass or stainless steel. If its chromium plated its almost certainly ordinary brass rather than dezincification resistant brass.

Ball valves are relatively inexpensive, certainly compared with Blakes sea cocks, so if in doubt not a vast expense to replace them with DZR ... which are often screwed onto bronze though hulls and fitted with bronze hose tails

 

[peter2407]

Thanks Vic. Assuming that there has been no dezincification (assumption - ass u me etc - being that if there were it would have affected the brass through hull fitting ...valid?) - is there anything inherently wrong with a ball valve? Caveat - that is reasonably regularly exercised?

 

[VicS]

Thanks Vic. Assuming that there has been no dezincification (assumption - ass u me etc - being that if there were it would have affected the brass through hull fitting ...valid?) - is there anything inherently wrong with a ball valve? Caveat - that is reasonably regularly exercised?

Not valid if the thu' hull is bronze only if its ordinary brass. You have to treat the two items individually to be sure.

Nothing wrong with ball valves. Most peoples choice now esp bearing in mind the cost of cone seacocks


DO not ignore the sail drive anodes. They must be in good contact with the SD and not painted over. One on the prop as well??

If the SD anodes go the SD can follow fairly quickly

 

[peter2407]

The SD anode looks good, but i may well take it off to ensure good contact - its two semi circular pieces. At the mo, not concerned, but i havent checked the pin anode that is inside the SD as yet so that may change. No prop anode per se as its a matter of inches from the semi circular anodes just mentioned. The anode on the rudder i will take off and check for contact as well.

Visually, what is the difference between brass and bronze?

 

[VicS]

The SD anode looks good, but i may well take it off to ensure good contact - its two semi circular pieces. At the mo, not concerned, but i havent checked the pin anode that is inside the SD as yet so that may change. No prop anode per se as its a matter of inches from the semi circular anodes just mentioned. The anode on the rudder i will take off and check for contact as well.

Visually, what is the difference between brass and bronze?

You may find that there is no electrical connection between the prop and the sail drive leg. Usually an insulating bush in the prop.If so the leg anodes do not protect it. Its some of the fancy folding props with a mixture of metals that seem to need anodes but if one not fitted as part of it no cause for concern.

I'd not take the anodes off unnecessarily but rather check contact with the leg with a multimeter.

Not possible to reliably tell bronze and brass apart visually and VYv Cox has tried to find some simple test without success. I bet the antique dealers can tell them apart though but perhaps there's a difference between the patina that builds up on antiques that people handle and a neglected boat fitting in a damp salty environment.

 

[peter2407]

With a multimeter - how?

 

[rogerthebodger]

The ball valve in your picture might be chromium plated brass or stainless steel.

Stainless steel ball valves generally have stainless steel handles where chrome plated brass will have a mild steel handle and so testing the handle with a magnet
will give a good indication.

I now only fit 3 part ball valves as they are easy to service/dismantle in place without disturbing any piping / skin fitting.

https://www.google.co.za/search?q=3...niv&sa=X&ei=HkPwVLn6JIP1Us2PgIgM&ved=0CDoQsAQ

 

[Chris_Robb]

d
A note of caution, I had a bit of pink on one of my seacocks. I changed it. To change it I had to Dremel through the threaded bit where the pink was. It was surface dezinc only. The cutting thru revealed it was structurally ok! The prop on my Bene is not the original, the surveyor commented on it, he said it was proper bronze, quote, "you can always tell, they ring dull when struck" He was right, it doesnt ring! So, sweeping statements not always true!
S

Prop - I had always thought that a dull thud was not a good sign! I suppose if its pink AND a dull thud, one should be suspicious.