The 1" seacock for my raw water intake drips once every 90 seconds. I have determined that it is coming from the barrel. I do not want to overtighten it so I cannot close it, so I let it drip all season. While not a problem I would like to replace it or fix it. I read that you can reseat the plug by using automotive grinding paste. HAs anyone done this? Also, I would like to replace it with the same type of tapered plug bronze seacock rather than the newer ball type. Where can I find them?
BSinskie@aol.com
Fixing or replacing barrel/tapered plug type seacocks
Moderator: Jim Walsh
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Larry DeMers
Re: Fixing or replacing barrel/tapered plug type seacocks
This is a common problem with seacocks that were not winterized correctly, or simply have been used a lot. They are easily repaired with lapping compound from Spartan Marine..the original makers. Call 1.800.325.3087 and order their catalog too. You should not have any dripping at all when done. Contact me via e-mail for procedure if you need it..would be glad to help.
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Sailing Lake Superior..highs tomorrow?? 28 deg.!~~~
demers@sgi.com
Cheers!
Larry DeMers
s/v DeLaMer
Cape Dory 30 ~~~Sailing Lake Superior..highs tomorrow?? 28 deg.!~~~
Brian wrote: The 1" seacock for my raw water intake drips once every 90 seconds. I have determined that it is coming from the barrel. I do not want to overtighten it so I cannot close it, so I let it drip all season. While not a problem I would like to replace it or fix it. I read that you can reseat the plug by using automotive grinding paste. HAs anyone done this? Also, I would like to replace it with the same type of tapered plug bronze seacock rather than the newer ball type. Where can I find them?
demers@sgi.com
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Kurt
Re: Fixing or replacing barrel/tapered plug type seacocks
Yes, valve grinding compound will lap the moving parts to a close tolerance...then lubricate the moving parts with heavy wheel bearing grease...the grease will lub and waterproof the valve...you might just try using the cleaning and greasing your seacock before using the ginding compound
kjlgpw@aol.com
kjlgpw@aol.com
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Jay Hubbard CD 28 Rope
Re: Fixing or replacing barrel/tapered plug type seacocks
Copy of Spartan's Maintenance Instructions have been sent to your E-Mail address as attached GIF file.
JHH
mailbox1@worldnet.att.net
JHH
mailbox1@worldnet.att.net
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Don Craig
Why rescue a device that doesn't work right?
I guess those bronze relics are sorta salty; all 3 of my previous sailboats had them. But they're such a nuisance. They leak. They corrode. They don't open and close properly when you most need them to. They NEVER work right, even after seating and coating with grease. Unless next my boat were a floating museum with tarred marline and baggywrinkle in the rigging--I'd change all those damned tapered plug seacocks to ball valves: stainless ball in teflon seat encased in bronze. They don't leak, they're positive, and Lloyds and UL seem to think they're safe.
Brian wrote: The 1" seacock for my raw water intake drips once every 90 seconds. I have determined that it is coming from the barrel. I do not want to overtighten it so I cannot close it, so I let it drip all season. While not a problem I would like to replace it or fix it. I read that you can reseat the plug by using automotive grinding paste. HAs anyone done this? Also, I would like to replace it with the same type of tapered plug bronze seacock rather than the newer ball type. Where can I find them?
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Scott
Re: Why rescue a device that doesn't work right?
Replacing a seacock is not trivial. Depending on the sealant and corosion, the old sea cock may have to be cut off in pieces. Compared to all that, it's worth a try to clean and lube it. If you have to haul the boat, you may as well lap it too. I disassemble, clean, and lube mine (1980 CD27) whenever the boat is hauled and they don't leak as far as I can tell. I haven't tried to lap them in the 4 years I owned the boat, but they appeared in good condition (no detectable "hour glass" shape in the barrel.
Don Craig wrote: I guess those bronze relics are sorta salty; all 3 of my previous sailboats had them. But they're such a nuisance. They leak. They corrode. They don't open and close properly when you most need them to. They NEVER work right, even after seating and coating with grease. Unless next my boat were a floating museum with tarred marline and baggywrinkle in the rigging--I'd change all those damned tapered plug seacocks to ball valves: stainless ball in teflon seat encased in bronze. They don't leak, they're positive, and Lloyds and UL seem to think they're safe.
Brian wrote: The 1" seacock for my raw water intake drips once every 90 seconds. I have determined that it is coming from the barrel. I do not want to overtighten it so I cannot close it, so I let it drip all season. While not a problem I would like to replace it or fix it. I read that you can reseat the plug by using automotive grinding paste. HAs anyone done this? Also, I would like to replace it with the same type of tapered plug bronze seacock rather than the newer ball type. Where can I find them?
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Larry DeMers
Re: Why rescue a device that doesn't work right?
Well, we have all bronze seacocks, and grease them each spring. I have one that has been lapped to help it fit better, and that was easy, fast and it worked! Relics? Hardly! There *is* a reason that they are still the standard in long distance boats.
Larry DeMers
s/v DeLaMer
Cape Dory 30
demers@sgi.com
Larry DeMers
s/v DeLaMer
Cape Dory 30
Don Craig wrote: I guess those bronze relics are sorta salty; all 3 of my previous sailboats had them. But they're such a nuisance. They leak. They corrode. They don't open and close properly when you most need them to. They NEVER work right, even after seating and coating with grease. Unless next my boat were a floating museum with tarred marline and baggywrinkle in the rigging--I'd change all those damned tapered plug seacocks to ball valves: stainless ball in teflon seat encased in bronze. They don't leak, they're positive, and Lloyds and UL seem to think they're safe.
Brian wrote: The 1" seacock for my raw water intake drips once every 90 seconds. I have determined that it is coming from the barrel. I do not want to overtighten it so I cannot close it, so I let it drip all season. While not a problem I would like to replace it or fix it. I read that you can reseat the plug by using automotive grinding paste. HAs anyone done this? Also, I would like to replace it with the same type of tapered plug bronze seacock rather than the newer ball type. Where can I find them?
demers@sgi.com
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Leo A. MacDonald
Chloride Crevice Corrosion
RE " . . stainless ball . . . ".
I am not an expert on this, but have talked with a few that are. Stainless Steel is NOT the preferred metal for constant exposure to seawater w/o an air supply. The US Navy uses Monel, sailboats use bronze. I would recommend you have a chat with Roger Winowsky of Bristol Bronze about Chloride Crevice Corrosion. Roger did a wonderful (abet long) seminar this summer for the CD Rend. 2000. He may be willing send or e-mail you a copy of his handout on the subject.
ALL my underwater fittings are Bronze and will stay that way.
Fair Winds,
Leo MacDonald
CD30K #57 Heather Ann
macdola@gwsmtp.nu.com / macdore@aol.com
I am not an expert on this, but have talked with a few that are. Stainless Steel is NOT the preferred metal for constant exposure to seawater w/o an air supply. The US Navy uses Monel, sailboats use bronze. I would recommend you have a chat with Roger Winowsky of Bristol Bronze about Chloride Crevice Corrosion. Roger did a wonderful (abet long) seminar this summer for the CD Rend. 2000. He may be willing send or e-mail you a copy of his handout on the subject.
ALL my underwater fittings are Bronze and will stay that way.
Fair Winds,
Leo MacDonald
CD30K #57 Heather Ann
macdola@gwsmtp.nu.com / macdore@aol.com
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Larry DeMers
Re: Chloride Crevice Corrosion
You are correct, judging from what I have read about S.S. It's called crevice corrosion. You specify chloride crevice corrosion, and this seems to imply that it only happens in salt water. This is not so unfortunately. S.S. will corrode in any water if deprived of oxygen. It will occur faster in salt water of course, but the danger does exist in fresh also. Fresh water has enough impurities and minerals in it to behave similarly to salt water..only slower.
An example: On Superior: Guy down the dock wrapped his standing rigging with plastic tubes slightly oversized to allow the tube to slip on to the stay . Years later..perhaps 7, he removes them and finds the whole area covered by the tube is corroded with a dull white powder showing. Cleaning and then using a 20x power binocular microscope, pits and connecting voids were visible on the wire rope. It was then replaced.. all uppers and lowers.
The better way to do what he wanted to do is to use a spit bamboo tube placed over the stay, and then taped to itself only. This allows the tube to freely move up and down and around, while air circulates easily inside the tube, as there should be 1/8 in. or more space available for the air.
Check out your prop shaft and rudder shaft, and make certain that no portion is shut off to air, or the oxide that protects the metal will not form (reform if scrubbed off).
Larry DeMers
s/v DeLaMer
Cape Dory 30
demers@sgi.com
An example: On Superior: Guy down the dock wrapped his standing rigging with plastic tubes slightly oversized to allow the tube to slip on to the stay . Years later..perhaps 7, he removes them and finds the whole area covered by the tube is corroded with a dull white powder showing. Cleaning and then using a 20x power binocular microscope, pits and connecting voids were visible on the wire rope. It was then replaced.. all uppers and lowers.
The better way to do what he wanted to do is to use a spit bamboo tube placed over the stay, and then taped to itself only. This allows the tube to freely move up and down and around, while air circulates easily inside the tube, as there should be 1/8 in. or more space available for the air.
Check out your prop shaft and rudder shaft, and make certain that no portion is shut off to air, or the oxide that protects the metal will not form (reform if scrubbed off).
Larry DeMers
s/v DeLaMer
Cape Dory 30
Leo A. MacDonald wrote: RE " . . stainless ball . . . ".
I am not an expert on this, but have talked with a few that are. Stainless Steel is NOT the preferred metal for constant exposure to seawater w/o an air supply. The US Navy uses Monel, sailboats use bronze. I would recommend you have a chat with Roger Winowsky of Bristol Bronze about Chloride Crevice Corrosion. Roger did a wonderful (abet long) seminar this summer for the CD Rend. 2000. He may be willing send or e-mail you a copy of his handout on the subject.
ALL my underwater fittings are Bronze and will stay that way.
Fair Winds,
Leo MacDonald
CD30K #57 Heather Ann
demers@sgi.com
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D. Stump, Hanalei
Re: All about Corrosion...its' many forms...long
Leo and Larry,
In case your interested,, here is some material I use in training nuclear power station operators about Corrosion:
1. Galvanic Corrosion: is the dissolution or attack of a metal which results when two dissimilar metals in electrical contact are placed in an electrolyte. The reaction is similar to what occurs in a battery. A current of electrons flows as one metal acts as an anode and loses electrons to the electrolyte, while the other metal acts as a cathode and gains electrons from the electrolyte. The net result is dissolution or attack of the metal which acts as an anode(zincs are anodes).
2. Pitting: is a type of corrosion which involves a deep attack on a small area of the metal surface. It does not involve two dissimiliar metals, but is similar to galvanic corrosion.
3. Crevice corrosion: involves a localized attack on a small area of metal at a mechanical crevice. Corrosion products collect in the crevice. The metal in contact with the corrosion products acts as an anode and a localized attack on the metal occurs. Another mechanism which causes crevice corrosion develops when the oxygen concentration of the solution in the crevice is less than the oxygen concentration of the rest of the solution. This occurs because there is little mixing between the solution in a crevice and the rest of the solution. (Might be what ya saw on the shrouds, the plastic stopped the free exchange of oxygen)
4. Chloride Stress Corrosion: is a type of intergranular corrosion which occurs in austenitic stainless steel in the presence of oxygen, chloride ions and a tensile stress. It involves selective attack of the metal along grain boundaries. It is believed that, in the formation of the steel, a chromium-rich carbide precipitates at the grain boundaries, leaving these areas low in protective chromium and thereby susceptible to attack. The pressure of a tensile stress opens up intergranular cracks and accelerates further corrosion. Cloride stress corrosion is a particularly significant problem in the operation of nuclear power plants, due to the wide use of austenitic stainless steel and the inherent presence of high tensile stresses associated with pressurization. Chloride Stress Corrosion Cracks
(CSCC)have been known to propagate in austenitic stainless steel at stresses of about one-fifth yield strength with chloride concentrations of less than 50 ppm.
Bet you're sorry ya started this discussion. Really, I'm sorry this is so long, but thought it might be interesting to ya!
I'll continue to use bronze in salt water!!!!
Dave Stump
Captain Commanding
In case your interested,, here is some material I use in training nuclear power station operators about Corrosion:
1. Galvanic Corrosion: is the dissolution or attack of a metal which results when two dissimilar metals in electrical contact are placed in an electrolyte. The reaction is similar to what occurs in a battery. A current of electrons flows as one metal acts as an anode and loses electrons to the electrolyte, while the other metal acts as a cathode and gains electrons from the electrolyte. The net result is dissolution or attack of the metal which acts as an anode(zincs are anodes).
2. Pitting: is a type of corrosion which involves a deep attack on a small area of the metal surface. It does not involve two dissimiliar metals, but is similar to galvanic corrosion.
3. Crevice corrosion: involves a localized attack on a small area of metal at a mechanical crevice. Corrosion products collect in the crevice. The metal in contact with the corrosion products acts as an anode and a localized attack on the metal occurs. Another mechanism which causes crevice corrosion develops when the oxygen concentration of the solution in the crevice is less than the oxygen concentration of the rest of the solution. This occurs because there is little mixing between the solution in a crevice and the rest of the solution. (Might be what ya saw on the shrouds, the plastic stopped the free exchange of oxygen)
4. Chloride Stress Corrosion: is a type of intergranular corrosion which occurs in austenitic stainless steel in the presence of oxygen, chloride ions and a tensile stress. It involves selective attack of the metal along grain boundaries. It is believed that, in the formation of the steel, a chromium-rich carbide precipitates at the grain boundaries, leaving these areas low in protective chromium and thereby susceptible to attack. The pressure of a tensile stress opens up intergranular cracks and accelerates further corrosion. Cloride stress corrosion is a particularly significant problem in the operation of nuclear power plants, due to the wide use of austenitic stainless steel and the inherent presence of high tensile stresses associated with pressurization. Chloride Stress Corrosion Cracks
(CSCC)have been known to propagate in austenitic stainless steel at stresses of about one-fifth yield strength with chloride concentrations of less than 50 ppm.
Bet you're sorry ya started this discussion. Really, I'm sorry this is so long, but thought it might be interesting to ya!
I'll continue to use bronze in salt water!!!!
Dave Stump
Captain Commanding
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Greg Dalton
Valve grinding compound works
I have used valve grinding compound and it worked. I had a 1965 Alberg 35 and one of the through hulls weeped badly after a while.
I tried to clean it and sand with emery cloth and of course I made it worse. I thought I was going to have to replace it. When I looked at this job I was not encouraged. A motor head friend took one look at it and saw that there was plenty of extra plug material. While hauled we took the plug out and coated the plug and the lining with medium grit compound. The end of the plug for the handle was square so we used a socket that fit and a ratchet handle. We spun it for over an hour and a half replenishing the grit every ten minutes or so. When we were done it looked and worked like new. I'm quiten sure replacement would have taken a lot more work
Greg.Dalton@efi.com
I tried to clean it and sand with emery cloth and of course I made it worse. I thought I was going to have to replace it. When I looked at this job I was not encouraged. A motor head friend took one look at it and saw that there was plenty of extra plug material. While hauled we took the plug out and coated the plug and the lining with medium grit compound. The end of the plug for the handle was square so we used a socket that fit and a ratchet handle. We spun it for over an hour and a half replenishing the grit every ten minutes or so. When we were done it looked and worked like new. I'm quiten sure replacement would have taken a lot more work
Greg.Dalton@efi.com