Above water thru hull fittings / valves

[NYSail]

For Above waterline discharge thru hull fittings, what type of shut off valves are typical?? My last boat all bathroom showers and sump pumps were discharged above water line however there were no shut off valves. Current boat, everything discharges below water line...... considering changing configuration to reduce below water fittings and feel shut off valves are a good idea.

Thanks!
Greg

 

[SG]

Assuming you have vented-loops on those above water through hulls, I don't think there is anything magic about just installing a marine grade gate valve in the hose along the way to the thru-hull.

If you have vented-loops, occasionally using some white vinegar and clean-in the "duck bill" valve in them is something you should occasionally do. They sometimes get gunked-up and they stop aspirating properly. I had a shower sump drain that I noticed was back siphoning this Fall (I hadn't cleaned it for 20 years).

 

[dlochner]

Is there something wrong with the current through hulls? Removing the through hulls and repairing the hole properly is a big job. The hull has to be ground down to a 12:1 taper , fiberglassed, faired, barrier coated, and bottom painted. A high quality bronze through hull and a bronze ball should be more than adequate. Groco is among the best.

 

[Captain Larry-DH]

Is there something wrong with the current through hulls? Removing the through hulls and repairing the hole properly is a big job. The hull has to be ground down to a 12:1 taper , fiberglassed, faired, barrier coated, and bottom painted. A high quality bronze through hull and a bronze ball should be more than adequate. Groco is among the best.

What he said.
Greg, since you have that much free time, please come over to CT I have some projects, and when we finish I'll buy dinner

 

[Benny17441]

...... considering changing configuration and feel shut off valves are a good idea.

Thanks!
Greg

Why? Valves are rarely used in above water thru-hulls but you could use PVC ball type valves.

 

[justsomeguy]

Current boat, everything discharges below water line...... considering changing configuration to reduce below water fittings and feel shut off valves are a good idea.

Yep, it's a good idea to have shut-off valves below the waterline.

 

[NYSail]

Yep, it's a good idea to have shut-off valves below the waterline.

I was referring to having shut off valves for the above water line thru hull fittings. ..... of course everything below has them.

 

[NYSail]

Yep, it's a good idea to have shut-off valves below the waterline.

Well if your boat was ever grounded and put on its side, water could flow into the fittings if open and flood the boat. I watched a boat this past summer..... he was not fully on his side but all his above water line fittings were under water. He said he had water coming in.......

 

[NYSail]

I was considering since they would be rarely used just basic HD vinyl ball valves would suffice.

 

[rgranger]

Inter

Well if your boat was ever grounded and put on its side, water could flow into the fittings if open and flood the boat. I watched a boat this past summer..... he was not fully on his side but all his above water line fittings were under water. He said he had water coming in.......

interesting! A good point...
I dont have them on my H26. All are above the water line. But I am also a swing keel boat that can be beached so ... going aground would not lay me on my side

 

[justsomeguy]

Current boat, everything discharges below water line....

Gee, I wonder why I misunderstood?

 

[Kings Gambit]

So, you wish to remove, grind, glass-over, fair, and paint the bottom where two (?) factory-installed thru-hulls backed by ball valves are, to create two new holes in the topsides with new valves to do the same job?

My sumps discharges are virtually on the water line when the boat is at rest, where the thru-hulls are each backed by a ball valve (fwd & aft heads). Also, each sink drain in the fwd and aft head are likewise. When heeled, those on one side or the other are submerged.

 

[jssailem]

It might depend on where the fitting is located. I have two new holes, one to dump a dehydrator water outflow and one to empty the cockpit seat drain. The seat drain is a scupper drain and has no valve cover. The Dehydrator drain has a screw on cap that seals the thruhull. I put it on when disconnecting the dehydrator hose. Both are high on the hull side. I would need the boat laid on her sidebefore water could get up that high. Just in case, I have wooden plugs on the boat to fill these holes in the off chance they are needed.

 

[Tally Ho]

The above water discharges on my boat don’t have valves. This would include things like scupper drains, propane locker drain, sink in the head, shower drain.

Greg

 

[Charlie Jones s/v Tehani]

The ONLY two openings I have in my hull are deck drains that exit above the water line. Both have ball valves on them. EVERY other opening below water has been glassed over.The head is plumbed for pumpout, the sink lifts out and is dumped. I don't worry about through hulls leaking

 

[jssailem]

Charlie... you have simplified your systems.

 

[Kings Gambit]

The main risk of flooding via thru-hulls comes from attached hoses that tear, break, or come off when the backing valves are open, etc. Shut the backing valves when the thrus are not in use and the risk is very minimal. Not zero, however, as when there is no thru-hull at all. Of course, if the thrus themselves are “corroded”, one might snap off if hit hard by some lateral force. Time for the wooden plug!

 

[Charlie Jones s/v Tehani]

Charlie... you have simplified your systems.

Exactly, but then I'm sort of an anachronism. No AC, no 110 aboard- 32 watt solar panel that provided elec for 3 years of cruising. I try to keep things very simple.

 

[Scott T-Bird]

Living dangerously … my small boat has a total of 17 openings thru the hull (not including the rudder tube)! 7 are below the waterline, 6 are mid height above WL or close to deck joint, and 4 are just above WL. I have not looked at the 4 that are just above the WL at rest, but just below the WL when the boat is motoring or sailing. They have never been serviced or even checked AFAIK, except for the exhaust. I suspect that they may be a source of minor leakage while underway, so this winter I will be taking apart the whole stern area to look closely and probably replace at least the clamps. They are the exhaust, the bilge discharge and the 2 cockpit drains. The exhaust and bilge are looped. The cockpit drains are obviously not. It will be useless to put valves at the cockpit drains because it is impossible to reach them without taking apart the whole stern area bulkheads. This would be way to complicated for regular observance.

The other thru hulls above WL are 3 vents at the deck joint, an anchor locker drain, an ice chest drain next to the helm, and the vanity sink drain. The vanity sink drain is the only one above WL that has a plastic ball valve (that I have never closed). Obviously, all the below WL thru hulls have valves (Marelon), except the 3 'ducers.

 

[Dalliance]

Is there something wrong with the current through hulls? Removing the through hulls and repairing the hole properly is a big job. The hull has to be ground down to a 12:1 taper , fiberglassed, faired, barrier coated, and bottom painted. A high quality bronze through hull and a bronze ball should be more than adequate. Groco is among the best.

I agree, with one possible exception. If the through-hull is in such a hard to reach place that the added ball valve shut off would rarely if ever be used, it would be worth the effort to move the through-hull to a more convenient location. Any through-hull below the waterline at rest or occasionally below the water line when under way by power or sail should have a ball valve that you can get to and actually use.