SailNet Community banner

1 - 20 of 23 Posts

·
Registered
Joined
·
3,184 Posts
Discussion Starter · #1 ·
I'm missing several drain screws on my Wilcox Crittenden seacocks.

One rotted away due to a bonding wire that wasn't actually attached to anything except the drain screw!

They look like M6 in bronze, which appears to be impossible to find.

Has anyone found a source?

I have two alternatives :

Fill the holes with epoxy (no winter here, so no need to drain)

Install stainless or brass machine screws.

Any thoughts would be most welcome.
 

·
Registered
Joined
·
541 Posts
Hey I am in the same boat so to speak. Mine is also WC and are pretty corroded - it seems the PO could not find them either, so he used plain steel ones. Scary. I have not bought them yet and could not find anything (that I could trust) in bronze - some people call bronze brass. This what I found:

You have a choice of a grease fitting or plug and I think they are 1/8 npt:

Grease nipple
McMaster-Carr
Threaded plug
McMaster-Carr
 

·
██▓▓▒▒░&
Joined
·
13,645 Posts
Mark, I'd try any M6 screw first to see if that's the thread you need. If it is just a drain screw, you might also be able to get a nylon screw for it, which would end any corrosion problems too.

Of course, any real machine shop should be able to knock off some M6 threaded bronze rod for you and put some slots in for heads. Sometimes, they'll even do it cheap if you can come back to pick it up "next week".
 

·
Registered
Joined
·
7,861 Posts
I doubt they are metric. Wilcox Crittenden was American and metric was pretty rare in North America in their day - probably still is.
 

·
Super Moderator
Joined
·
6,803 Posts
Check with Paul at Spartan bronze. IIRC Spartan uses the same oddball threaded bronze screws. From memory, and conversations with Paul, I recall the bronze screws are made from the same alloy as the seacock, which is 85-5-5-5 bronze. Those screws are simply not available on the open market and are custom made to match the alloy of the seacock..
 

·
Registered
Wauquiez Gladiateur
Joined
·
51 Posts
Is this a chronic problem with these seacocks? Mine corroded as well.. I got replacements from WC which appear to be correct, but they do not fit. I assumed there was still some corroded pieces of the old plug left. Are the seacocks themselves dissolving?
 

·
Registered
Joined
·
3,184 Posts
Discussion Starter · #8 ·

·
Registered
Joined
·
3,184 Posts
Discussion Starter · #9 ·
Is this a chronic problem with these seacocks? Mine corroded as well.. I got replacements from WC which appear to be correct, but they do not fit. I assumed there was still some corroded pieces of the old plug left. Are the seacocks themselves dissolving?
I believe they often corrode out when they are used as connection points for bonding. Interestingly, though, all the ones on through-hulls that are properly bonded are solid.

I one case I found that the bonding wire is disconnected elsewhere - so I had 2 feet of wire, that's all, connected to the drain screw. Both drain screws on that through-hull were badly corroded. Could that ungrounded length of wire promote galvanic corrosion?
 

·
Super Moderator
Joined
·
6,803 Posts
I believe they often corrode out when they are used as connection points for bonding. Interestingly, though, all the ones on through-hulls that are properly bonded are solid.

I one case I found that the bonding wire is disconnected elsewhere - so I had 2 feet of wire, that's all, connected to the drain screw. Both drain screws on that through-hull were badly corroded. Could that ungrounded length of wire promote galvanic corrosion?
Please understand that these are DRAIN SCREWS they should NOT be used for bonding. Lots of builders made this mistake as do DIY's but those are for winter draining of the cone so as to prevent a freeze and split. You can not develop a proper seal if using them for bonding and they will leak and corrode the dissimilar metals causing issues. To bond this style of seacock you put a ring terminal on the through bolt ear bolt preferably on a double nutted through bolt and the ring placed between the two bronze nuts..
 

·
Registered
Wauquiez Gladiateur
Joined
·
51 Posts
My guess is that these plugs are of a slightly dissimilar metal from the seacocks and in the absence of good bonding they act as the sacrificial anode. The question is, are the seacocks safe?
 

·
Super Moderator
Joined
·
6,803 Posts
My guess is that these plugs are of a slightly dissimilar metal from the seacocks and in the absence of good bonding they act as the sacrificial anode. The question is, are the seacocks safe?
The original screws were made from the same bronze as the seacock 85-5-5-5 bronze. This is why they are not easily replaceable.
 

·
Registered
Wauquiez Gladiateur
Joined
·
51 Posts
Then why did they deteriorate so quickly on a what seems to be a large number of seacocks?
 

·
██▓▓▒▒░&
Joined
·
13,645 Posts
Mongo-
Perhaps it is something as simple as a quality control issue, with the bronze rod used for the screws being cast in one lot, and stockpiled, while the seacocks are cast in other lots. All it takes is one sloppy casting, one alloy off a bit, and you've got different metals.

If you chase the threads to make sure they are clean, and then replace with nylon screws, that would ensure no galvanic corrosion could happen there again. Unless there's a disadvantage I don't see in this...it would make that problem simply not able to repeat.
 

·
Super Moderator
Joined
·
6,803 Posts
Then why did they deteriorate so quickly on a what seems to be a large number of seacocks?
I've got piles of WC & older Spartans I service that are beyond 40 years with zero issues. I have never seen a rotted nor needed to replace a factory drain screw unless the builder or owner did something snd caused issues:

*People winterized, lost the screw and replaced it with a substitute

*People or builders insist on using drain screws for bonding


Heck I even have a box full of old tapered cone sea clocks in use from the early 1930's to 2006 on an old wooden boat... The valves look awful but still perform perfectly and have no corrosion beyond a harmless layer of verdigris....

Proper bronze seacocks if taken care of can literally outlast a boat...
 

·
Registered
Wauquiez Gladiateur
Joined
·
51 Posts
Just because you have never seen it does not mean it does not happen. I put in two WC seacocks (different sizes) installed the same way , one intake and one outflow. It was about ten years ago. There was no bonding for either, as I have an outboard. After about 8 years, the saltwater intake drain screw rotted, the other is fine. My guess is that there was a bad batch of screws with just enough dissimilarity to act as an anode.
 

·
Super Moderator
Joined
·
6,803 Posts
Just because you have never seen it does not mean it does not happen. I put in two WC seacocks (different sizes) installed the same way , one intake and one outflow. It was about ten years ago. There was no bonding for either, as I have an outboard. After about 8 years, the saltwater intake drain screw rotted, the other is fine. My guess is that there was a bad batch of screws with just enough dissimilarity to act as an anode.
I did not imply it can't or does not happen if something goes awry. WC made the screws from the same alloy as the valve body and cone and if someone replaced the screw or if something else was substituted then yes that could happen. Could have been a bad lot at the factory too. Lots of crazy stuff went on in the last few years of the WC foundry.

My main point was that these drain screws are simply not known for rotting out ahead of the rest of the seacock...

If you put in WC tapered cone seacocks ten years ago they were simply old stock and perhaps had the screws robbed and replaced with inferior screws. Lots of parts "shopping" occurred when WC stopped production and a lot of this occurred to in-stock old stock...

WC tapered cone seacocks have been gone from production for at least 25 years. Spartan's are still readily available but made in very small batches......
 

·
Registered
Joined
·
541 Posts
I am reopening this thread hoping that someone had better luck than I.

I am still looking to replace my corroded WC seacock drain plugs (the boat is on the hard).
I just spoke with Spartan, and they said that there is no such thing as bronze 1/8 npt, only brass. So I guess once you loose the original, you are out of luck. My only option then is try nylon, as I would not trust having a brass plug.
Any other recommendations?
 

·
Registered
Wauquiez Gladiateur
Joined
·
51 Posts
I put epoxy in the hole, temp fix until I take the boat out of the water next spring and replace the whole thing.
 
1 - 20 of 23 Posts
Top