Our 1978 C27 looks to have a very small fracture in the seacock (water intake for engine). When the valve is opened, a very fine spray of water is emitted from the body of the valve. When it is closed, not leak. The seacock is the gate valve type. The through-hull fitting looks okay. The seacock is screwed down onto the through-hull fitting, and there is about 1.5 inches of thread between the hull and the valve. Replacing the valve looks like it will involve unscrewing the seacock from the hull fitting and screwing a new (ball-) valve into place. The marina will hoist the boat out of the water with slings for $110. If all goes well, replacing the valve should take less than 30 minutes. I know it's a big IF, but $110 seems steep. Here's the question: While the boat's in the slip, is there a way to replace the valve without sinking?
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It can be done, it's not that bad.
I did exactly what your describing on my old Ericson 29. I did it on a day when our diver was doing the quarterly cleaning. He placed a plug in the outside of the thru hull, and cleaned away. I took the valve off, and get this, went to the store to ensure I got the correct size! Came back 15 mintues later, screwed it on, reattached the house and good to go. Definitely do able, if your water is warm, you could probably do a quick skin dive and plug the thru hull yourself and away you go.
I did exactly what your describing on my old Ericson 29. I did it on a day when our diver was doing the quarterly cleaning. He placed a plug in the outside of the thru hull, and cleaned away. I took the valve off, and get this, went to the store to ensure I got the correct size! Came back 15 mintues later, screwed it on, reattached the house and good to go. Definitely do able, if your water is warm, you could probably do a quick skin dive and plug the thru hull yourself and away you go.
Not as difficult as it seems.
I did it in the water on my 30-year old Cal's OEM 1-1/4" head discharge a couple of years ago. I had no problems but proceeded with much caution and a certain amount of trepidation. I'm going to set out my procedure as if you are a novice, but I am definitely not assuming that you actually are one. Some folks that may be tempted to try this procedure may be. First, I used kerosene liberally overnight to soak all of the threads inside and out (it is the 'active' ingrdient of many rust solvents). I also made arrangements with the yard for an emergency haulout if things went sour. I had an emergency bung ready, all parts prepared, batteries charged, pumps ready and crossed my fingers. It is very important that your new valve does not have tapered pipe threads. Through hulls have British straight threads and a pipe valve will not seal without undue pressure...and even then, you will only have about three threads engaged, making a very vulnerable joint. I installed about two feet of hose on the inboard side of the valve and opened it fully. I then snugged down the nut on the throuh hull fitting (and was surprised to find that it would actually tighten a little). You will want to be very careful not to turn the body of the through hull. Leave a wrench on the nut when removing and replacing valves in order to help prevent the through hull from turning and to keep from damaging the threads by putting a wrench on the body of the through hull fitting. I was able to wedge that wrench against a bulkhead, freeing both hands. Next, is a trick that I learned in my youth while working with a steamfitter. Tighten...yes...tighten...the old valve with a smart rap of a hammer on the end of the handle of the wrench. This is the most effective way of loosening an old thread that I have ever learned. You will likely need to reverse the wrench on the nut if you are using a pipe wrench. The old valve should now come off easily. As you get near the end of the threads, water will start coming in with increasing pressure. Don't panic...it is far less volume than it would appear. When the old valve comes free, pound the bung in the through hull and take a deep breath. Reverse the wrench on the through hull nut again and ready the new valve. The purpose of the hose and open valve is to reduce water pressure while threading on the new valve. The hose should extend above the water line. As soon as the valve and fitting make contact, very little force is required to keep the leaking down to a minimum. This allows you to thread on the valve easily without cross-threading. When the valve is screwed down all the way, it doesn't require a lot of torque to fully tighten it...so don't overdo it. You could loosen the seal on the through hull fitting and end up with an annoying leak. I doubt that I took on more than a half a gollon of water in the process and have had no problems since.
I did it in the water on my 30-year old Cal's OEM 1-1/4" head discharge a couple of years ago. I had no problems but proceeded with much caution and a certain amount of trepidation. I'm going to set out my procedure as if you are a novice, but I am definitely not assuming that you actually are one. Some folks that may be tempted to try this procedure may be. First, I used kerosene liberally overnight to soak all of the threads inside and out (it is the 'active' ingrdient of many rust solvents). I also made arrangements with the yard for an emergency haulout if things went sour. I had an emergency bung ready, all parts prepared, batteries charged, pumps ready and crossed my fingers. It is very important that your new valve does not have tapered pipe threads. Through hulls have British straight threads and a pipe valve will not seal without undue pressure...and even then, you will only have about three threads engaged, making a very vulnerable joint. I installed about two feet of hose on the inboard side of the valve and opened it fully. I then snugged down the nut on the throuh hull fitting (and was surprised to find that it would actually tighten a little). You will want to be very careful not to turn the body of the through hull. Leave a wrench on the nut when removing and replacing valves in order to help prevent the through hull from turning and to keep from damaging the threads by putting a wrench on the body of the through hull fitting. I was able to wedge that wrench against a bulkhead, freeing both hands. Next, is a trick that I learned in my youth while working with a steamfitter. Tighten...yes...tighten...the old valve with a smart rap of a hammer on the end of the handle of the wrench. This is the most effective way of loosening an old thread that I have ever learned. You will likely need to reverse the wrench on the nut if you are using a pipe wrench. The old valve should now come off easily. As you get near the end of the threads, water will start coming in with increasing pressure. Don't panic...it is far less volume than it would appear. When the old valve comes free, pound the bung in the through hull and take a deep breath. Reverse the wrench on the through hull nut again and ready the new valve. The purpose of the hose and open valve is to reduce water pressure while threading on the new valve. The hose should extend above the water line. As soon as the valve and fitting make contact, very little force is required to keep the leaking down to a minimum. This allows you to thread on the valve easily without cross-threading. When the valve is screwed down all the way, it doesn't require a lot of torque to fully tighten it...so don't overdo it. You could loosen the seal on the through hull fitting and end up with an annoying leak. I doubt that I took on more than a half a gollon of water in the process and have had no problems since.
Outer plug won't work b/c of grill-like cover
Jim, the outside opening is protected by a grill-like cover. As such, I won't, unfortunately, be able to block the hole with a plug. Dick, the plunger sounds reasonable, but how do you keep it in place. I doubt the suction would be sufficient, not to mention the vaccuum would be lost once the valve is removed. Chris's idea sounds like it might work well, although the water gushing through the open hole before being plugged will certainly be stomach-knot provoking.
Jim, the outside opening is protected by a grill-like cover. As such, I won't, unfortunately, be able to block the hole with a plug. Dick, the plunger sounds reasonable, but how do you keep it in place. I doubt the suction would be sufficient, not to mention the vaccuum would be lost once the valve is removed. Chris's idea sounds like it might work well, although the water gushing through the open hole before being plugged will certainly be stomach-knot provoking.
Careful
BE careful trying to plug a thru hull from outside. On the inside of most thru hulls there are two knobs to allow for a wrench to hold the thru hull from the inside while turning on the valve. Unless the bung you pound in is VERY soft it will not seal because of the two knobs and will leak. The threads on a thru hull are straight NPS (or National Pipe Straight). The threads on most ball valves are tapered (NPT or National Pipe Tapered). Do the job right and get a seacock which has straight threads on the bottom and tapered threads on the top. Place a support block over the thru hull to support the sea cock. Note that the threads on the thru hull are straight not because they are British but to accomodate hulls of different thicknesses. If you want the long answer, I posted it a couple of years ago and it is in the archives.
BE careful trying to plug a thru hull from outside. On the inside of most thru hulls there are two knobs to allow for a wrench to hold the thru hull from the inside while turning on the valve. Unless the bung you pound in is VERY soft it will not seal because of the two knobs and will leak. The threads on a thru hull are straight NPS (or National Pipe Straight). The threads on most ball valves are tapered (NPT or National Pipe Tapered). Do the job right and get a seacock which has straight threads on the bottom and tapered threads on the top. Place a support block over the thru hull to support the sea cock. Note that the threads on the thru hull are straight not because they are British but to accomodate hulls of different thicknesses. If you want the long answer, I posted it a couple of years ago and it is in the archives.
Straight vs. tapered threads?
Is it easy enough to distinguish straight from tapered threads by simply looking at the threaded piped sticking up through the hull (onto which the seacock screws)?
Is it easy enough to distinguish straight from tapered threads by simply looking at the threaded piped sticking up through the hull (onto which the seacock screws)?
Not Exactly...
You couldn't thread the locking nut down to the hull if it were a pipe thread. I have never seen a through hull with tapered pipe threads. FWIW, the steamfitter that I worked for always called them (NPS) 'british' threads, though I do not know why.
You couldn't thread the locking nut down to the hull if it were a pipe thread. I have never seen a through hull with tapered pipe threads. FWIW, the steamfitter that I worked for always called them (NPS) 'british' threads, though I do not know why.
The new valve is in!
It's done! With the tips provided, I replaced the seacock without hauling the boat. It was a relatively simple process, once I screwed up my courage (and double checked the bildge pump was working). Here are the steps I took: I spayed the through-hull threads and old valve with Liquid Wrench then let it sit for about 10 minutes. With a wooden plug at the ready, using a small pipe wrench and minimum torque, the old gate valve came off rather easily. (To anyone who tries this method, go slowly to ensure you don't torque loose the through-hull fitting. Also, Chris was right; first "tighten" the valve by a hair, then unscrew it.) Once the valve was off, I jammed a wooden plug into the through-hull fitting. The water that did come through was minimal and at low pressure. The plug worked like a champ. With the plug in place, I used a wire brush on the through-hull fitting's threads, dried everything, then wrapped a few layers of Teflon tape around the threads. With the new BALL valve in hand (and in the "closed" position), I yanked out the plug and screwed on the new valve. Less than a quart of water made it into the boat during the whole process. The new valve is in place, new hose is double-clamped to the valve, and the trusty wooden peg is tied near the valve. Thanks for all the helpful advice from everyone who responded to my question. Together you saved me about $100 in haul out fees. If you lived in my area, I'd buy you a beer. Paul
It's done! With the tips provided, I replaced the seacock without hauling the boat. It was a relatively simple process, once I screwed up my courage (and double checked the bildge pump was working). Here are the steps I took: I spayed the through-hull threads and old valve with Liquid Wrench then let it sit for about 10 minutes. With a wooden plug at the ready, using a small pipe wrench and minimum torque, the old gate valve came off rather easily. (To anyone who tries this method, go slowly to ensure you don't torque loose the through-hull fitting. Also, Chris was right; first "tighten" the valve by a hair, then unscrew it.) Once the valve was off, I jammed a wooden plug into the through-hull fitting. The water that did come through was minimal and at low pressure. The plug worked like a champ. With the plug in place, I used a wire brush on the through-hull fitting's threads, dried everything, then wrapped a few layers of Teflon tape around the threads. With the new BALL valve in hand (and in the "closed" position), I yanked out the plug and screwed on the new valve. Less than a quart of water made it into the boat during the whole process. The new valve is in place, new hose is double-clamped to the valve, and the trusty wooden peg is tied near the valve. Thanks for all the helpful advice from everyone who responded to my question. Together you saved me about $100 in haul out fees. If you lived in my area, I'd buy you a beer. Paul
Berth Control?
Paul wrote: "I spayed the through-hull threads and old valve with Liquid Wrench....." I guess we won't have to worry about a litter of seacocks since you spayed the through-hull threads. (Sorry, couldn't resist.) Congrats on a job well done. Steve
Paul wrote: "I spayed the through-hull threads and old valve with Liquid Wrench....." I guess we won't have to worry about a litter of seacocks since you spayed the through-hull threads. (Sorry, couldn't resist.) Congrats on a job well done. Steve
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