Loose Seacock

[High Hopes]

Expert advice needed.

I was removing a very stubborn fitting from a seacock. A 14" pipe wrench was employed. I got the old fitting out and the new one in. However, now the seacock can be twisted clockwise and back with a wrench. The range of motion is about 5 degrees.

No water leaks in. Should I assume that the hull-through is still in good shape and just twist the seacock to the right and make sure it is tight, or do I need to pull the boat and replace the hull-through? As I understand it, the seacock screws into the hull-through. Or am I wrong about this?

Help!

Steve

[msauntry]

I'm assuming you can't get the seacock separated from the thru hull, but can only rotate it a bit. If I'm wrong and you can remove it, just coat the threads with a little sealant and reinstall it.

The concern is if the seacock is rotating the thru hull, or just unscrewing a bit from it. I'd just screw it back and keep an eye on it until the next haul out when you can determine if the thru hull is turning or not. That would mean the seal is comprimised, but no harm should come of that... If your hull is cored (unlikely) a leaky thru hull might get water in the core. If its solid fiberglass (most likely), then a little water isn't going to hurt anything in the worst case scenario that it does leak a bit. I can't imagine any gap would be created that would let more than a drip in. Not worth a haul out until you see water coming in.

Does the seacock flange have holes in it for screws or thru bolts? That would keep it from rotating.

[High Hopes]

I'm assuming you can't get the seacock separated from the thru hull, but can only rotate it a bit. If I'm wrong and you can remove it, just coat the threads with a little sealant and reinstall it.

Micah,

Right now the boat is in the water, so I haven't tried really doing anything except to leave it alone. Yes, the hull is fiberglass.

Does the seacock flange have holes in it for screws or thru bolts? That would keep it from rotating.

Yes it does. Unfortunately, there are no screws in them. I just visited a great site about thru-hulls and seacocks.

http://www.pbase.com/mainecruising/seacock_primer

Thanks for the information that the hull won't get damaged. I was worried about that. I'll take a picture of it the next time I am at the boat.

Steve

[tenders]

I'd guess you've broken the caulk seal between the mushroom thru-hull and the boat. This let the mushroom spin a bit while you were working the fitting off, and it's loosened itself a few degrees from where it was tightly threaded into the seacock.

As msauntry points out, it probably won't leak, in the sense that it lets a lot of water in, but eventually it's probably gonna weep--perhaps when the weather gets warmer.

You'll be able to fix it on a short haul if you have a step wrench or a piece of pipe with a slot cut into it to remove, recaulk, and tighten the mushroom from the outside. But while you're at it, why not mount the seacock properly with bolts through the hull into those unused holes. To do it right you'll need a countersink bit and silicon bronze fasteners, and while you've got it all apart you'll probably want to replace the backing plate that's in there with a new one. I know that Mainesail guy likes to make his own out of fiberglass and epoxy, but my favorite is a G10 doughnut.

[blackdove]

Hi Steve,

I've had the same thing happen a number of times and agree with the previous posts. It may weep after a while, but the repair is really simple and shouldn't take too long. Just keep watching the seacock. I'm presuming you will pull your boat for winter. If not, I'd do a short haul and make the correction before the real cold gets here.

Blackdove

[Dave O]

Does anyone have an idea as to what is involved getting the old backing plate off (as posted by tenders?)

I am replacing my 1/2" thru-hull with 3/4". The 1/2" thru-hull is not well centered on the existing backing plate, and I will likely have to remove and replace the backing plate in order to get the larger 3/4" thru-hull centered securely.

My backing plate is made a wood. It appears to be glassed into the hull, or at the least very well glued and painted over.

Wood chisel? Or is it likely so well bonded to the hull that isn't an option? I want ot make sure that I avoid damage to the hull itself.

[sastanley]

DaveO,
It depends on how much work you want to put into the boat..the fact that you have a backing plate is a leg up on many. (I just cut 4 new ones today, as my boat only had one in 4 of the thru-hulls and it is rotten) - however, that gate valve is bad news and not safe for a boat.

In my particular case, I am getting a lot of advice from friends that I may be over-engineering everything. I want it to be safe, but the boat is 30 years old, and my list is so long, that I am worried about splashing the boat and going sailing in April. It floated this long without 'proper' backing plates and seacocks that I may jinx it.

If the block is sound, then leave it! Some advice I've received is to bang (ultimately sacrificing) a wooden bung into the hole (after you remove the existing thru-hull) and use that as a guide for the hole saw for the new (bigger) thru-hull...You can choose to just catch the edge of the old hole and move a bit more towards the center of the wood block with your new hole to improve the situation. The guide drill in the center of the hole saw digs into the bung so you can guide the hole saw as necessary for the new hole. Again, I don't think I'd go thru the hassle of replacing the wooden block if it is glassed in already and in good shape. I just coated mine in epoxy today in the garage so they hopefully don't rot anytime soon after I install them.

Most importantly, get rid of that gate valve...they are dangerous!!!!

Hard to explain without pics...hope that helps!

[blackdove]

Easy Centering

Take the thru hull out. Mix up some mish-mash (epoxy with silica and lather it in the hole from the inside (put some masking tape on the exterior of the boat to keep the mish-mash from falling through. Once hardened, you have an area that can be drilled on center for the larger, 3/4" thru hull. If you want to make sure the back support stays and does the job, before drilling lay a couple of rows of matt/roving across it. Good luck. This should take about two hours to complete and really provides a good base for the fitting.

Blackdove

[tenders]

That backing plate is odd in that it isn't centered over the hole! As you say, the boat has held up this long with that arrangement and once you get the fitting out if the wood looks good (ie, dry and not saturated, not rotten) I'd soak it with really thin epoxy around the fitting to really make it waterproof, then follow Blackdove's instructions.

If the plate is punky I'd cut the edges bonding the wood to the hull with a Dremel and then be ruthless with a chisel.

[jhwelch]

I'll put in my two cents and see what people have to say. It seems to me
that a flanged seacock would eliminate the need for a backing plate.

http://thump01.pbase.com/g4/84/622984/3/91533229.WxOG0NYy.jpg

There's a well-written and -illustrated tutorial on this here (including
many good photos):

http://www.pbase.com/mainecruising/seacock_primer

[High Hopes]

Thanks for the help everyone. I will have the boat on the hard in a few weeks and will take a look then. So far no leaks.

Tenders, I suspect your assessment may be right. I just want to be sure the thru hull is still sealed.

JW, I have a flanged seacock, unfortunately, the screw holes to stop it form rotating were not installed!

Thanks again everybody.

[Baltimore Sailor]

What's the danger with the gate valve? I've still got one remaining on my 33-year-old Newport (on the raw water intake, natch), and while I am planning on replacing it next year when I pull out for repainting, it looks innocent enough just sitting there.

What treachery should I be on the lookout for?

[Dave O]

Apparently several things.

1. You can not tell when a gate valve is open or closed. Even though you can turn the handle till it stops it may be jammed and you would not know it. A ball valve indicates position by the position of the handle.
2. The valve is not fastened (bolted or screwed) to the backing plate and hull. It could thus be broken off more easily than a proper flanged seacock which is both flanged and connected to the backing plate.
3. The valve (in my particular case) is 30 years old so after 30 years ... ?

The web site that is noted in an earlier post by Steve on 11/19 helps describe the situation. In my particular case I'll have to change both the thru-hull and the valve. The valve is easy ... the thu-hull (naturally) is not.

[sastanley]

Good list DaveO...most of the gate valves are not suitable for extended use in a marine environment either..meaning they will corrode more quickly than bronze. Although expensive, I decided to go with marelon flanged seacocks (4 holes)

I just cut a new hole in my boat this weekend..it also appears that Catalina didn't check to see if their holes were 'square' to the hull, as my new thru-hull's mushroom head isn't flush with the hull..I may need to close up that hole and re-drill it. I think the larger one I extended (from 1-1/4" to 1-1/2" fitting) is OK, but I was hoping to only have to re-drill one hole instead of two.

Slow going, this boat repair stuff!