Replacing Sea Cocks and Skin Fittings

[Dockhead]

I hope there's still a lot more sailing in my future for this year, and I've got a nice little cross-Channel jaunt scheduled for later this month. However, it's now September and I'm starting to think about continuing my refit this winter. Although I hate to be prevented from sailing in the winter, I am thinking about leaving my boat on the hard in Cowes this winter again, at least for a couple of months.

I am so pleased at the result of last winter's refit that I want to continue and finish the rest of the things.

I hate to fix what ain't broke, but a recent thread on here about the failure of PSS shaft seals is making me think about just replacing mine, which is 12 years old. Or at least the boots and hoses.

I'm also thinking it might be time to replace sea cocks and skin fittings. Mine are of reasonable quality, real bronze, but they are starting to show their 12 year age. Although I work them often (I never leave the boat overnight with open sea cocks), one or two is starting to stick again. And I worry about corrosion. I have nightmares about those stories of people stepping on a through-hull and snapping it off. It seems to me that it would be a certain comfort for them all to be new.

What do y'all think? How often do you think these things should be replaced? Of course replacing sea cocks and skin fittings also means replacing hoses and clamps. It will be a fair amount of work and expense, which one doesn't want to do unnecessarily.

[nigel1]

I thought that bronze sea cocks would last the life of the boat.
Why not consider removing and overhauling at the next refit, and possibly have an "expert" take a look at them.
If you know the make and type of the valves, it should be easy enough to find out if spares are still available.
A strip down, and good clean and replacement of seals may be all that is needed.

I'm going to have to replace all mine next year, have read too many horror stories about the valves that Beneteau fitted. I'll be looking to use bronze valves and fittings.

[Kenomac]

One of our thru hull fittings did exactly what you feared a few weeks ago; fortunately, it was caught in time. Actually it wasn't the seacock or the actual thru hull fitting, but less suspect... it was the threaded flange which connects the huge elbow coming directly off the seacock to a black water hose. Those connectors are extremely thin and of course the "weak link" which everyone should be worried about.

When the black water hose was being removed, it just snapped off with no real effort in the mechanics hands. I'll post a picture if you can tell me how to do it, but there was nothing left of the entire flange including the portion threaded into the elbow. Without an actual photo, just picture in your mind an entire fitting made up of corrosion... it had disintegrated. It could have blow at any time way below the water line. The bronze fitting sits in pee, poo and salt water most the time, so corrosion shouldn't have been a surprise.

All the through hull bronze fittings will be checked during the haul out this season. Our boat is also 12 years old.

Note to self: Replace those threaded fittings which connect black water hoses once every 3-4 years as a precaution.

Ken

[Dockhead]

Originally Posted by Kenomac

One of our thru hull fittings did exactly what you feared a few weeks ago; fortunately, it was caught in time. Actually it wasn't the seacock or the actual thru hull fitting, but less suspect... it was the threaded flange which connects the huge elbow coming directly off the seacock to a black water hose. Those connectors are extremely thin and of course the "weak link" which everyone should be worried about.

When the black water hose was being removed, it just snapped off with no real effort in the mechanics hands. I'll post a picture if you can tell me how to do it, but there was nothing left of the entire flange including the portion threaded into the elbow. Without an actual photo, just picture in your mind an entire fitting made up of corrosion... it had disintegrated. It could have blow at any time way below the water line. The bronze fitting sits in pee, poo and salt water most the time, so corrosion shouldn't have been a surprise.

All the through hull bronze fittings will be checked during the haul out this season. Our boat is also 12 years old.

Note to self: Replace those threaded fittings which connect black water hoses once every 3-4 years as a precaution.

Ken

Yikes! That is terrifying.

I will certainly be checking those.

[Dockhead]

P.S., Ken, your photos would be most educational, I think.

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[Kenomac]

Originally Posted by Dockhead

I will certainly be checking those.

What initially got my attention, was the odor that was being caused by a pin-hole sized leak further up the hose near the holding tank that was spitting waste into a compartment. I never imagined that the HUGE elbow threaded fitting well below the water line connecting a 2 inch black water hose could present such a risk and problem. When I look down at the fitting, it looks massive.... like nothing could ever go wrong with it.

Even spookier... the plastic ball valve was stuck open and I had to dive under the boat to chip away at it and lube it with grease while the mechanic worked to free it so that it could be closed prior to removing the hose.

Ken

[bob_77903]

Originally Posted by nigel1

I thought that bronze sea cocks would last the life of the boat.

If there Spartan sea cocks they will. Simple periodic maintenance, good to go..

[Dockhead]

Originally Posted by bob_77903

If there Spartan sea cocks they will. Simple periodic maintenance, good to go..

Those are the conical type and do last forever if you take them apart and lap them every year. They are beautiful and expensive. And fussy.

I choose lower maintenance ball valves, and don't really mind replacing them every decade or so if necessary.

[Exile]

Originally Posted by Dockhead

Those are the conical type and do last forever if you take them apart and lap them every year. They are beautiful and expensive. And fussy.

I choose lower maintenance ball valves, and don't really mind replacing them every decade or so if necessary.

All but one of mine are Spartan's. They came with my boat and are probably original (1986). Although the mfg. recommends servicing them once/year, I just went almost 3 years and, with the exception of some binding on the 2 head discharges & the galley sink drain, they were all still moving freely. Spartan sells an inexpensive maintenance kit with special grease, a wrench, and their own (very fine) lapping material. According to Spartan, it's more about the grease than the lapping, and they typically will not need to be lapped. I'm not sure the maintenance schedule has anything to do with their longevity -- given the design & quality of the bronze, it appears instead that they can be serviced indefinitely.

Due to a space limitation when I had to re-power a couple of years ago, I have one Groco with the more modern teflon covered ball valve (I think that's what it is, anyway). It's marketed as 'maintenance-free' but it didn't take that long for it to start binding up. It looks like it can also be serviced, but once the teflon gets scored I would think you'd have to start replacing those components or it will leak. I have so many thru-hulls that I'm grateful to have almost all Spartans which I shouldn't ever have to replace. (I know, never say never on a boat!).

[nigel1]

I'm looking to replace all the skin fittings and valves next year. I dont think I have the space to fit Blakes valves, which I thought were made of bronze, but after a bit of research, it seems they are made from DZR brass nowadays.

If I switch to Marlone type valves, I'll need to go up a size for each valve, and they are expensive.

Seems my choice is (and this is for ease of fitment and costs), is either DZR skin fittings and ball valves, or Gunmetal skin fittings and gunmetal gate valves.
Gunmetal is a bronze, similar to that used in the Spartan valves. Some reference sources quote gunmetal as 88% copper, 10% tin, and 2% zinc, while others describe it as 84-86% copper, 4-6% tin, 4-6%zinc and 4-6% lead.

Any one offer and plus or minuses on the use of these valves

[Crimea Cruiser]

I guess it depends upon maintenance levels, but ball valves I generally find needing to replace in about 10 year +/- max as inferior in design and materials to the old workhorse conicals.
The heavy duty bronze conicals about 30-35 years. Again it seems fixed to prior annual maintenance by a diligent owner. Most boats I have inspected from 60's and 70's still have original seacocks, but most are desperately needing replacement.
Lucky I bought a large supply of Wilcox-Crittenden seacocks and thru-hulls to last my lifetime. One refit left, then just maintenance.

[Kenomac]

Thar she blows. Nothing left of the threaded coupling that the black water hose attaches to. That's more than a two inch elbow you see there that exits right below the aft stateroom bed. The cruddy looking stuff you see in the elbow isn't poo, it's what's left of the disintegrated coupling.

Ken

[poiu]

Originally Posted by Kenomac

Attachment 66262

Thar she blows. Nothing left of the threaded coupling that the black water hose attaches to. That's more than a two inch elbow you see there that exits right below the aft stateroom bed. The cruddy looking stuff you see in the elbow isn't poo, it's what's left of the disintegrated coupling.

Ken

Ugh. How nasty.

The elbow looks ok. Is it? What condition is the through-hull itself? What's the brown grease on the elbow? Is this a one off,maybe a poorly specified repair and are there other fittings and parts like this?

I heard from another owner of deteriorating through hulls at age 12 and he replaced the lot. Seemingly a quality control mistake. Mine are 12 yrs old too and were ok last year when inspected, but this makes me worry. Thanks for the pic and heads up.

My plan up until now was to inspect annually and only replace when necessary. A more thorough inspection is clearly needed to reveal this sort of thing.

[Kenomac]

The haul out is next week, but any work will wait until Spring as the boat will sit on the hard until then. All the major thru hulls will be checked, then depending on what is found, I'll continue with the rest if needed. All of the hose connectors will be examined.

The second head exit fitting didn't have the same issue, thank goodness, otherwise I'd be using a bucket right now. I'm hoping that somehow during construction 12 years ago, some guy grabbed a fitting made of the wrong alloy by mistake that was mixed in with the bronze fittings and the rest will be OK. All the major fittings are bonded against galvanic corrosion, but this is one that wasn't and was up past the plastic ball valve.

I'll be with the boat over the weekend while it's out, so I might try removing the fittings, but the tools I have here in Spain might not be big enough.

The grease was applied by the previous owner, I'm assuming to keep the bronze from turning green... he just over did it.

[HopCar]

Are you sure that wasn't a steel fitting? That sure looks like a broken off galvanized pipe fitting.

"Gunmetal is a bronze, similar to that used in the Spartan valves. Some reference sources quote gunmetal as 88% copper, 10% tin, and 2% zinc, while others describe it as 84-86% copper, 4-6% tin, 4-6%zinc and 4-6% lead."

This is the metal that most US manufacturers use for making seacocks and thru-hull fittings. It lasts vitutally forever in salt water. Most manufacturers just call it bronze. It is also called Gunmetal or Red Brass. The names are very inexact. What you want is an alloy with high copper and low zinc.

"84-86% copper, 4-6% tin, 4-6%zinc and 4-6% lead"
This is commonly called 85-5-5-5. It's fine for use in salt water. The pipe fittings on my seacocks are this alloy and they are over twenty years old.

" I have one Groco with the more modern teflon covered ball valve..."

Depending on the model, Groco uses either a stainless steel ball or a chrome plated brass ball. Neither is Teflon coated. They do ride on Teflon like seals.
The body is 85-5-5-5 Bronze/ Red Brass/ Gunmetal.