I live in warm waters so I could do this today, I do not want to haul the boat out of the water to change a seacock (not flanged). I need to plug a 3/4" thruhull, what is the best way to do it?
In water SEACOCK replacement
- Thread starter Peter Fridman
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Anchor the vessel in shallow water at high tide. As the water drops, you may be aground enough that the thru hull is above the waterline. If you have everything prepped, swiftly remove the old one and install the new one, them mop up. I have done that quite successfully. Otherwise, plug it with a soft wood plug from the outside and take your time. bob
Well
You can wood plug it from outside
BUT whats the plan B when the fist fight to get it apart goes bad
You can wood plug it from outside
BUT whats the plan B when the fist fight to get it apart goes bad
Plugging it from the outside is the easy part. What is the plan B when the through hull starts to spin and breaks the sealant bond? It can be done, just have a plan B. I would advise the use of two pipe wrenches one to hold the thru-hull from moving and one to turn the valve off. This will bugger up the thru-hull threads but it's better than breaking the sealant bond.
When you re-install use both wrenches and teflon tape and pipe dope as you likely have mis-matched threads to begin with.
When you re-install use both wrenches and teflon tape and pipe dope as you likely have mis-matched threads to begin with.
For pipe wrenches on thruhull threads wrap the threads with a strip of turkish toweling, the thicker the toweling the better.
Definitely do not break the caulk bond of the thruhull .... use TWO wrenches to loosen the valve.
Outside temporary plug: wad of 'plumbers putty' shoved into the thruhull. Most times can be 'released' with a plumbers helper or air pressure.
Definitely do not break the caulk bond of the thruhull .... use TWO wrenches to loosen the valve.
Outside temporary plug: wad of 'plumbers putty' shoved into the thruhull. Most times can be 'released' with a plumbers helper or air pressure.
I have successfully heeled the boat in the slip using a bridle on the main halyard and a line to a piling two slips away, run a line up to a snatch block on the bridle and down to a snatch block on the rail , then back to a primary winch. With the boat heeled 15 degrees or so, the thru hull was exposed and held inplace with a slotted piece of copper pipe that fit the inside diameter of the thru hull.
then using a wrench to hold the backing nut and a wrench on the lower part of the OEM gate valve, I was able to remove the valve, clean the threads and install a bronze ball valve with sealant on the thru hull threads. Make sure you match up the thread type (NPS does not work with NPT).
then using a wrench to hold the backing nut and a wrench on the lower part of the OEM gate valve, I was able to remove the valve, clean the threads and install a bronze ball valve with sealant on the thru hull threads. Make sure you match up the thread type (NPS does not work with NPT).
If there's no flange
I doubt it's a seacock. It sounds like you're changing out a valve that's threaded onto a thru-hull. Mis-matched threads, right MS?
It could be a wrestling match, thereby endangering the thru-hull-to-hull sealant bond. More likely it'll twist right off having been held on with only two, maybe three threads. You sure you just want to put one right back on?
I doubt it's a seacock. It sounds like you're changing out a valve that's threaded onto a thru-hull. Mis-matched threads, right MS?
It could be a wrestling match, thereby endangering the thru-hull-to-hull sealant bond. More likely it'll twist right off having been held on with only two, maybe three threads. You sure you just want to put one right back on?
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mine in my ericson was worst case scenario, redefined. i took her to municipal docks. a dive service told me estimate 1 day 2 guys. ended up 2 days 4 guys and perfect. was an original 1979 fitting with corrosion from years and mickey mouse repairs gone bad.. so done correctly now and perfect. is easy when there is a guy with a plunger handy.
I managed to do it using the soft wood plug from the bottom trick while out cruising this summer. Had to. Am going to replace the through hull this haul out. Fortunately everything worked out fine.
several months ago I saw an entire thru hull changed in the water. It did require a diver on the outside and someone on the inside. They used a clear plastic tube inserted into the thru hull that was longer than the inside water level. there was surprisingly little water in the bulge when finished. Fortunately the old thru hull came out cleanly and the diver didn't have much scraping to do around the hole. This was temporary until the boat could be hauled but once they got through there was no water leakage at all. I was amazed to say the least.
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