Sinking My Boat

[tager]

To quote paraphrase mangomadness, this is a 'noooooo' thread.

I need to remove an illegal head on my boat. Direct discharge. Yes, I know some of you read the thread and debated it's legality. The gist of it is that IT IS ILLEGAL, I researched it and it's true.

I plan on fixing the head without taking the boat out of the water.
The outlet valve is a gate valve that closes fine.
The inlet valve is another gate valve that will not close. It has a length of garden hose attaching it to the head that is pretty long. I am going to dive under the boat in the slip, plug the inlet thru hull with a cedar plug, remove the upper hose clamp on the inlet hose, and drain the water. At this point, I am going to verify that the plug does not leak. So far this procedure is risk free as the hose end will be above the waterline.

Then I am going to remove the old gate valve, and put a cap over the thru hull.

I will have a few contingency plans:
Something to plug the hose with.
Underwater epoxy.
Plenty of different plugs.
Extra caps.

If it works out well, I am going to do it with the outlet thru hull.

[erps]

It would be interesting to take your heart rate before the procedure and around the time your remove the old gate valve. I used to get my heart rate up each time I pulled the paddle wheel sensor thru hull to clean it.

[tommays]

There is a pretty good chance that valve is Not gonna come off in a friendly kind of way and you will be pretty screwed

[sailingdog]

I'm gonna second what Tommays said...what is your plan if, when you try to remove the gatevalve, the through-hull comes loose with it??? Don't be stupid about this... this type of work really requires you haul the boat. If the through-hull isn't attached to a flanged adapter, the chances of breaking it loose are pretty high.

[Faster]

Assuming things go as planned, until the next haul out rather than remove the valve and cap the thruhull, just put a plug into the valve outlet.

[tager]

Sorta like this one? I will try to find one available in nylon or marine bronze.

I discovered through further research that the gate valves, are not marine grade, and are npt threaded, not flanged...

nightmare.


So I am going to go ahead and do the NPT plug for now, and just cap the thing later on.

Yikes.

[Faster]

Originally Posted by tager

Sorta like this one?

Like that one.... but when you do this, you'll be needing to remove the hose barb or nipple from the valve first... Be sure to support the valve with a pipe wrench to prevent it(and/or the thruhull) from turning while doing so. And the same while installing the plug.

You should also be aware that, since the valve is in all likelihood an NPT (ie tapered) thread and the thruhull is not, the valve is probably only hanging on to the thruhull by at most 2 or three threads - avoid torquing that assembly or you may get a bit of a surprise.

Mainesail had an excellent post on just this issue last year.

http://www.sailnet.com/forums/gear-m...w-up-info.html

[tager]

Sweet, thanks for all the help. I am currently planning on buying 2 pipe-wrenches, a 1 1/2" npt plug, and a 3/4" npt plug.

I will make some cedar plugs to go in the thru hulls from outside, and definitely have underwater epoxy putty on hand. As well as some underwater sealant, plenty of hose clamps, an electric bilge pump, and some free time.

[CalebD]

Plan B or C might be: how far are you from a Travel lift or crane capable of plucking your boat out of the water?

[Faster]

No worries...

Most thru-hulls have a couple of small lugs inside the hole to allow a special tool to lock into them to prevent them turning during installation... so a perfectly round plug will have to be quite soft to properly seal.. maybe take a look at one on the shelf to see what I mean.
btw I edited the above post with link in case you missed it the first time.

Originally Posted by CalebD

Plan B or C might be: how far are you from a Travel lift or crane capable of plucking your boat out of the water?

Indeed!....