Replacing gate valve

1985 31 foot Hunter. For safety reasons I am about to replace the non-fuctional "stock" gate valve used for overboard holding tank discharge with a seacock. The gate valve is "frozen" in what I believe to be the closed position... The stem turns..and turns... and turns. Obvously not connected to the gate. The T shaped gate valve is located under the head sink right up against the head-vberth bulkhead... No room to swing off the thru-hull fitting without hitting bulkhead. (looks like Hunter put plumbing in first, then placed bulkheads up against plumbing) Has any one replaced this gate valve without disassembling the head bulkheads?? I have searched the archives under gate valve with no luck.

replacement

Doing the same thing. The gate valve is a way to cut costs---eventhough every surveyor and seasoned marina engineer told me it's maddness to use these things. Using Marleon seacocks and have the same problem. Can't offer any advice except to perhaps backpeddle and use yet another gate value. Make sure your insurance is paid and you attend church regularly. Regards....

Gate Valves...

Okay,I just did this very thing last weekend in preparation for the big April 1 launching. I have an 84 Hunter 31 in which the previous owner replaced the original head with a new potty and plumbing. The new layout is a straight potty to holding tank layout and eliminates the holding tank gate valve/sea cock deal. The original gate valve is/was a disaster waiting for the most inopportune moment. It was cracked (didn't know at the time) had a broken stem (obviously someone had tried to replace it before) and it was caked with green salt from leaking.Here is the procedure and then I will tell you the real story. If the valve has been leaking seawater it is probably caked with salt. This can be removed using vinegar and a toothbrush. What you want to do is break the salt seal so the "Liquid Wrench" can get to the valve treads. "Liquid Wrench" works pretty well, but you have to be patient and allow it to soak and do its thing. We are talking about a couple of hours between soakings and being sure you are really soaking the joint threads.While this process is happening, you must remove the valve handle, stem, and gate. If the handle just spins, the stem is probably already broken, so loosen the cap below the handle and remove the handle, stem, and cap in one piece. This is not too difficult (yeah right!) because you can reach the top of the valve with a crescent or small monkey wrench. With a fairly solid wrap with a hammer, it should break loose. If not, apply the vinegar, Liquid Wrench, patience process above and try again.The top of the valve has a cap through which the valve stem passes and the cap is threaded onto the valve. Remove it using the same process...vinegar, LW, patience... if the wrench and hammer doesn't work. With the top off the valve, the packing material and gate can be removed from the valve guts. This will allow space for the valve to turn on the through hull when it loosens and not hit the forward bulkhead.Now, here is the real story... I cussed and fussed, and soaked, and cussed, and banged, and cussed and soaked some more. You notice I didn't mention any "patience"! When I finally got the handle, stem, top, cap, gate and packing material out of the way I used a small monkey wrench (spanner, pipe wrench thing) and a hammer...the valve eventually broke loose. I suspect it was more to giving the Liquid Wrench time to act (forced patience) than to any great strength or planning on my part.Now, this is IMPORTANT be watchful of the through-hull. You don't want to break/twist the through-hull or it will need repairing. So you need someone on the outside of the hull with a good tool to give the through-hull support while you are wailing away to break the valve loose. That "tool" depends on what kind of through-hull you have, but something to give the through-hull encouragement to hold in place.Okay, all said and done, I believe if I had to do it again, I would pay some yard plumber to do it for me... I know that is breaking the mucho guy thing, but...my swimming isn't all that good! Best luck!

Thanks Captn Sam, another question

Thanks for your advice: I think I will look into having the yard do it. Avoiding the frustration may be worth it. In fact I am finishing a job initiated by the previous owner who simplified the plumbing like you did. It makes it compatable with the Chesapeak. The existing layout is now straight from the potty to holding tank eliminating the overboard discharge gate valve (I want it that way). The previous owner never finished the job. I am trying to clear out the remaining old smelly dead plumbing. He removed the wye valve connecting the topside pumpout, the holding tank outlet and the line that goes to the manual pump. This later line continues from the manual pump to the vented loop - then to the gate valve. He connected the holding tank outlet directly to the topside pumpout (good). He left all the old plumbing in place stuffing the entrance to the manual pump with a rag (Bad, the old plumbing stinks!!!). I assume he gave up when he got to the gate valve. Left the rest in place I assume to keep the boat afloat. If the gate valve is is frozen open then the vented loop is keeping me water tight (until the old hose fails)!!! Question: Once I get the gate valve out, must I replace with a seacock? Is there a SAFE and SECURE cap fitting available that I can place over the thru-hole tail that will simply seal it off? Since I have no intention of using this thru-hole in the foreseable future, the only advantage for adding seacock is it rapidly allows non-intentional (or ntentional) scuttling. Not a high value feature.

Fast Boat in Harm Way...

Bill,Rapid scuttling can be a benefit if you are run contraband to/from some banana republic liberation front, but I suggest you use a different boat...like one with big engines and stealth technology. As for capping the removed gate valve, West Marine and others sell a bronze threaded cap that should fit the male end of the through-hull. If the through-hull survived the valve exotericism, just capping it should provide for safe operation. I would still keep a couple of rags and a damage control plug or two close at hand. A rabbit's foot and cleaning living helps, too! In my situation the previous owner did the potty to holding tank thing and deep six-ed the leftover parts. Likewise, he ran a hose from the Gate Valve to a point above the water line and left it. My surveyor wasn't real impressed with arrangement, but I see why it was left for the "new" owner to fix. Whatever happened to the wye valve and hand pump is anyone's guess. If I had all the bits and pieces, I would probably opt for the original configuration and just replace the gate with a ball valve. This would allow you to flush your holding tank at some point (like over three miles at sea!) and give it a good cleaning.Good luck....CaptnSam

Cut it out with a sawzall

I changed all the gate valves on my boat in the water. Plugged them with a wood bung, cut the old ones out with a sawzsall, replaced them with ball valves and pulled the plugs. Trick is, cut off the part of the gate valve that hits the bulkhead first, then split them with the sawzall almost down to the threads, use a large screw driver as a wedge in the cut to stretch the remaining bit (the part with the threads) and spin them right off. I found, that if I removed the handles from the new ball valves, they cleared the bulkheads and other obstructions.

Dremmel Tool To Remove Valve

2 issues ago GOOD OLD BOAT had an article about replacing thru hulls in old boats. They recommended a DREMMEL TOOL with an abrasive cutting disk to cut the old valve off. I like my saws-all but to tell you the truth it kind of scares me a bit. With the DREMMEL it takes a bit longer but you have a lot more control.

Its off...

Well I went down to the boat yard every evening for a week and dolloped liquid wrench all over the the stem threads and the thruhull threads. A good push with an 8" pipe wrench this weekend allowed the cap of the stem portion of the valve to turn right off. Pulled out the stem... It was sheared off as I suspected. I then lightly turned the body of the valve with an 8" pipe wrench and it moved nice and easy with very little applied torque. I guess the week sitting in LW really loosed up things nicely. Since I only had to apply minimal pressure to move the valve I decided that it was safe to continue with out supporting the thruhull externally. Unfortunately, the body of the valve (with stem and guts removed) still hit the forward bulkhead. Therefore, I whent after T sidearm of the valve body with a 41/2" metal cut off blade attached to a Skil power grinder. Cut through the brass like butter. However, this tool didn't have sufficient depth to cut all the way to the very bottom of the T. Had to finish the job with a dremel tool and those tiny cut off blades. Once the T was cutoff the rest of the valve body just twirled right off. Only needed the wrench to get it started for the first 1/4 turn... ther rest was done by hand. All and all it took about an hour of disection to extract the valve carcass. I'll cap the open thru hole with brass 1 1/2 cap that I've just ordered from West Marine.Will teflon pipe tape be sufficient to seal the cap to the thruhull?? The cap will have NPT threads like the gate valve had. I think the thruhull is NPS thread. I don't want to caulk up the treads with something that will make the capoff permanent. I may want to use the thruhull for something in the future. Thanks for all your suggestions.

NEVER CUT ONE OFF, BUT REMOVED SOME

THE OLD METHOD, WAS FIRST TO HAVE THE BOAT HIGH & DRY, ONE GUY WITH A WRENCH ON THE INSIDE, ANOTHER WITH A BOAT JACK ADJUSTING BAR RAMED INTO THE THRU HULL FITTING, SO IT WOULDN'T ROTATE, AND THEY CAME OUT, USINGA GRINDER OR A SAWSALL, SEEMS LIKE A GOOD SOLUTION, BUT WHAT DOES THE THRU HULL FITTING LOOK LIKE AFTER THE CUTTING OR GRINDING, DOES IT NEED REPLACING TOO ???,

Never touched it

I cut the side arm of the gate valve, removing it so the main part of the valve body (attached to the thruhull) could clear the bulkhead. I never when near the thruhull theads.