SailNet Community banner

1 - 20 of 29 Posts

·
Registered
Joined
·
1,000 Posts
Discussion Starter #1
I know I know... But I haven't had a haulout other than to cradle ship my boat and I still have one gate valve for the galley sink drain. It finally gave up the ghost today. You can turn the handle all you want forever and ever and ever :eek: I think the gate is lodged about 1/4 shut but of course there is no way to tell. So now I have to either schedule a haulout ASAP or hope the tides are right to dry out on the grid. Temps are around freezing so I can't do any glass work or painting. What a waste of a haulout...

Let this be a lesson to all you procrastinators!!! I know you are out there...

Replace crappy substandard valves ASAP!!!

Don't wait, DO IT NOW!
 

·
Registered
Joined
·
315 Posts
Do I understand correctly from your comments that you are in Alaska but don't haul your boat for the winter?
I changed all my gate valves in my 1978 27 footer this spring. It was a time consuming and fairly expensive venture but worth it in my mind. The gate valves looked brand new when I took them off but I still like the piece of mind I get from proper seacocks. They were in fresh water only.
Wait for Maine Sail to chip in here on this subject... it should only be a few minutes or so. He has an excellent site providing great instructions on how to do this. You shouldn't need to do any painting or fibreglass work but I used some West System epoxy to set my new bedding / backing plates.
 

·
Registered
Joined
·
1,000 Posts
Discussion Starter #3
Year round sailing in Alaska... What sucks is I had plans (always got plans...) to replace all the mushrooms and backing plates and install real flanged seacocks for every thru-hull. Now I get to just band-aid the problem and save it for later by putting a new NPT ball valve on the old mushroom.
 

·
Registered
Joined
·
2,708 Posts
At least it isn't on an engine cooling intake. Had a fellow sail club member recently tell me about the time a gate valve failed on a boat he was on, on the engine raw water intake. IIRC, the alternator bracket failed, the alternator fell off and broke off the raw water intake's gate valve's handle. They jury-rigged an alternator bracket (they were "at sea"), but did not realize that when the gate valve's handle was broken off, the gate fell closed. Luckily, it turns out impellers are usually tougher than we give them credit for.

Jim
 

·
Registered
Joined
·
5,607 Posts
"proper" seacocks are better but not perfect! i have several that are stuck, frozen. and they are in extremely difficult areas to reach.

you MUST excersize all valves
 

·
Owner, Green Bay Packers
Joined
·
1,000 Posts
There is nothing inherently wrong with using gate valves on a boat as a sea ****. The problem arises with the quality and design of valve used. What is commonly seen is a brass valve suitable for home use. There are high quality gate valves available in a variety of materials and construction methods. and they'll work just fine properly installed.

Small boat sea cocks serve their purpose well if maintained. Ball valves work easily but sometimes too easily if they're mounted to something that is subject to vibration and movement, like a boat. They can be either closed or opened inadvertently. Most of them commonly found are of no better construction than the lowly gate valve from the hardware store. Being a ball valve does not inherently make it safer...just easier to use.

There are no ships that use the same type sea cocks you'll see on boats; there's no effective way of operating them absent power. Gate valves are used almost exclusively, with the telescoping thread type being most common. Butterfly valves are often used but not for sea cocks. Butterflys are commonly power driven and suffer the same weakness that most, other than gate valves, suffer; a potential inability to close by manpower alone. Those long stems you see on gate valves are what gives them their mechanical advantage. Thus one man can easily open or close a valve that may be serving a 36" diameter pipe.

Here's a site I found buy simply googling gate valves: http://www.velan.com/products/pdfs/vel-api603-99-web.pdf
Further research will reveal the tremendous variety of suitable gate valves, even for your thru-hulls.
 

·
Registered
Joined
·
66 Posts
I know I know... But I haven't had a haulout other than to cradle ship my boat and I still have one gate valve for the galley sink drain. It finally gave up the ghost today. You can turn the handle all you want forever and ever and ever :eek: I think the gate is lodged about 1/4 shut but of course there is no way to tell. So now I have to either schedule a haulout ASAP or hope the tides are right to dry out on the grid. Temps are around freezing so I can't do any glass work or painting. What a waste of a haulout...

Let this be a lesson to all you procrastinators!!! I know you are out there...

Replace crappy substandard valves ASAP!!!

Don't wait, DO IT NOW!

yep! still trying to figure out the best way to fix my situation. I can sail, but the cooling system is closed for now: http://www.sailnet.com/forums/gear-maintenance/47301-will-my-boat-sink-what-should-i-do.html
 

·
Registered
Joined
·
1,000 Posts
Discussion Starter #8 (Edited)
There is nothing inherently wrong with using gate valves on a boat as a sea ****.
There are several inhearant reasons not to use gate valves where a Teflon seated ball valve is available:

-No definite position indication
-mating surfaces will leak if damaged
-takes a lot longer to open or close
-prone to jam on backseat
-damage from freezing more likely
-more corrosion prone (more wear surfaces)
-more parts involved (more point of failures, as in my case)


 

·
Owner, Green Bay Packers
Joined
·
1,000 Posts
I think you'll find that subs use butterfly valves that are backed up by gate valves. Double valving thru-hulls is common practice on ships. I've never seen a square head **** or a ball valve on any ship..at least in a major piping system.
 

·
Owner, Green Bay Packers
Joined
·
1,000 Posts
Thanks for that link, bubb2. The picture is illustrative of how you can have a three foot diameter gate valve and still allow one man to close it! It can also be noticed how the stem rises up through the wheel as it opens which allows it to be lubricated periodically. The packing in the stuffing box is replaceable and the box itself is adjustable for wear and compression of the packing to prevent leaks.

Here's a non-rising stem model approved by Lloyd's fro marine use.
http://www.johnsonvalves.co.uk/Data/Data Sheet No. 06.05 - IW3 Gate Valve.pdf
 

·
Registered
Joined
·
1,000 Posts
Discussion Starter #14
How did this thread turn into "Here is the gate valve I use on my 1020 foot ship?"

Anyways. I got another question for you all.

Here are the givens:
6 hours of working time on a tide grid
35-40 degree air temp. Water 42F.
Glass work not possible.
Any use of sealants questionable..

Gatevalve is non functional and stuck open.


Should I:
A: replace it with a standard bronze ball valve being careful not to tweak the mushroom and break its seal

B: Cut down the mushroom. Undo the nut on the mushroom. Carefully thread a Groco seacock on and hope for a good seal. If I do it this way I will leave the current backing plate in place which is glassed wood. One big problem is it is barley the size of the base of the seacock. I also could not thru bolt it at this time.

C: Do nothing and have a boat with an 1 1/4" thruhull that can't be shut for the next 6-8 months until the weather allows for a real haul out and glasswork.


Hmmm. I am leaning heavily to option "A" but these are my choices. I have a 12 foot tide noon in two days so hopefully I will be able to get a spot on the tide grid and get to work. If I miss this next tide window it will be another month before I can try again! Eek...
 

·
Owner, Green Bay Packers
Joined
·
1,000 Posts
Either option 'A' or why not just plumb in a valve after the stuck-open one until permanent repairs can be effected?
 

·
Telstar 28
Joined
·
1,000 Posts
I think adding a second valve is probably your best temporary fix. If you try removing the existing valve and break the seal on the through-hull, you'll have an annoying and persistent leak that will put a strain on your bilge pumps and batteries. :)
 

·
Registered
Joined
·
1,000 Posts
Discussion Starter #17
There is no direct path to the bilge where it is so if it did leak the water would end up all over the cabin floor.... ick.... But due to space restrictions it isn't possible to add a second valve. Heck, it is hard enough to get in there and work on the first one. The closest thing to that idea that I though of was to remove the hose barb and cap it. This isn't satisfactory in my mind. I have a nice pair of vice grips that are meant for working on pipe I can use to keep it from moving. Worst case I can pop it off, get some fast cure 5200 and stand there in the rain and rising tide with a heat gun :)
 

·
Owner, Green Bay Packers
Joined
·
1,000 Posts
Either leave it alone then or put a plug in the thru hull from the outside. I'm getting confused here. Are you worried about the gate valve rupturing, with the bonnet popping off and flooding the boat or are you concerned that you've a thru-hull you cannot close if necessary? If the former, then you need to replace it or plug it, period. If the latter, and the rest of the piping between valve and sink is in good condition, you can add another valve anywhere, even under the sink.
 

·
Registered
Joined
·
1,000 Posts
Discussion Starter #19 (Edited)
The problem valve: About 4" above is blocked. There is about 6" on either side to work with, and as you can see the area behind the valve quickly tapers off to nothing. This valve is about 12 - 18" below static waterline. The ball valve in front of it is for the holding tank discharge.



I am concerned about having a thru-hull that can't be closed. I also can't winterize the system properly. The sink drain is 1 1/2" exhaust hose that appears to be in good condition, but then it tees off. This is a really tight area. It passes through a bulkhead about 6" after making a 90 degree turn, and then under some cabinetry and then to the sink. The other problem is not being able to winterize the system. I usually pour RV antifreeze into the sink. It does get cold enough to freeze sea water here!


Would life-caulk cure in time? It looks like I am going to be on the grid for about 12 hours. The next high tide isn't high enough to float off. Weather looks like chance of rain. Highs 45 low of 36 Shorepower is available so I could use a space heater if necessary at least inside the hull.
 

·
Super Moderator
Joined
·
6,764 Posts
Would life-caulk cure in time? It looks like I am going to be on the grid for about 12 hours. The next high tide isn't high enough to float off. Weather looks like chance of rain. Highs 45 low of 36 Shorepower is available so I could use a space heater if necessary at least inside the hull.
We answered this question last year in another post you made about tide grid & changing of seacocks.

Here's what I wrote last time after calling both 3M and Boat Life..


I called both 3M and BoatLife and spoke with tech support about cure times & launching. I did this because neither site really specifies launch time's or windows before launch and I would like to add this info to my article. Here's what I was told by each..

BoatLife: When I spoke with boat life they very clearly stated to me that a full cure of between five to seven days with Life Caulk is what they recommend before a launch. The tech support guy would not budge on this point even when I told him 3M 4200 and 5200 will finish curing under water. I could not get him to budge on this and he said tack and cure are two different things and cure times are very dependent on ambient temperature. He also stated that the air & hull temp can't drop below 40 degrees during the cure process and must be perfectly clean before application.

3M: I spoke with Tom about 4200, 5200 and 101. He advised against 101 due to it's very long cure time in a short window situation or regular 5200.

As for 3M 4200 & 5200 Fast Cure he stated that while they will still cure under water they don't advise running the boat, as in water movement over the hull, until cure has been completed because it can erode any sort of fillet or seal thus causing a leak and possibly moisture entrapment. I think a slow motor to your dock would not hurt as he was mostly referencing power boat failures.

3M also stated that a 40 degree minimum of both hull and air temp should be adhered to and that the lower the temperature the longer the cure time. The hull must also be bone dry & free and clear of any paint, dirt or oil when you are applying it.

3M's official policy on underwater use is to let them fully cure but this guy was being quite honest. He did say they have seen failures on quick launches that's why he advised NOT moving the boat after launch (no water flow across the hull).

Again, 3M's OFFICIAL LEGAL STATEMENT POLICY IS TO LET IT FULLY CURE BEFORE LAUNCH. I say this because I don't want people running around saying 3M told me it's perfectly OK to launch in one hour even though it probably is if you're smart about it....
 
1 - 20 of 29 Posts
Top