Bilge Pumps Versus Holes In The Hull

[Cap Erict3]

One of the first items I installed after buying the boat was a high bilge alarm. One should be mandatory on every skippers list.

[sanibel sailor]

Am I the only one that thinks the universally recommended "tapered softwood plug tied the the seacock" makes little sense with proper seacock installation? If the hose tears/fails/bad clamp, etc, just turn the seacock off. Likelihood of the seacock simply falling off is close to never. To have much chance of being secure, they need to be driven in from outside. Additionally, most of the ones I see sold are a pretty hard wood. Should be soft pine in order to conform and jam in place.

[Cap Erict3]

My bag of plugs reside next to my hammers in the E/R parts locker.

[Dockhead]

Originally Posted by sanibel sailor

Am I the only one that thinks the universally recommended "tapered softwood plug tied the the seacock" makes little sense with proper seacock installation? If the hose tears/fails/bad clamp, etc, just turn the seacock off. Likelihood of the seacock simply falling off is close to never. To have much chance of being secure, they need to be driven in from outside. Additionally, most of the ones I see sold are a pretty hard wood. Should be soft pine in order to conform and jam in place.

Actually "seacock simply falling off" is not all that rare. The problem can be caused by dezincification of the through-hull tail. A lot of mass produced European boats now have ordinary brass (not DZR brass or bronze) through-hulls, which bizarrely fulfill the CE standard requirements, and which are particularly susceptible to this problem.

Tapered softwood plugs are intended for that problem, or to plug any hole which you might need to plug in an emergency. It's a good idea, and like most sailors I carry a good selection of them.

I do not, however, tie one to each seacock, which would be a bit ridiculous since I have 18 or 19 through hulls in my boat. I keep them under the companionway stairs. You can block a broken through hull with your hand while someone brings the plug. Or once you've located the broken through hull, your boat will not likely sink in the 15 seconds or so it takes you to get to the bag of plugs.

[sanibel sailor]

A better solution might be to replace the bad seacock/thruhull rather than prepare for its emergent demise. A bad thruhull should still not be a problem is the seacock is bolted.

[Dockhead]

Originally Posted by sanibel sailor

A better solution might be to replace the bad seacock/thruhull rather than prepare for its emergent demise. A bad thruhull should still not be a problem is the seacock is bolted.

Naturally -- an ounce of prevention is worth a pound of cure.

The problem is that you can't know how fast this process proceeds. A through-hull might last decades or could be gone in a couple of years. So will you replace all of them, every couple of years? I would definitely replace any plain brass ones, which are just crazy. Good naval bronze or DZR brass is far safer. But still you never know, so it's better to be prepared for the worst.

As to the consequences of a bad through-hull -- sea cocks through-bolted through the hull are fairly uncommon. Most of them are supported by the hose tail of the through-hull. Even the through-bolted ones are not immune -- they can also break if dezincified.

Here's a good article: http://trip.ayy.fi/wordpress/wp-cont...8/Seacocks.pdf


In any case, the risk of a failed through hull (or sea cock) is never zero. An inexpensive bag of plugs is very, very cheap insurance.

[sanibel sailor]

Interesting that the majority of article's pictures are not seacocks but ball valves installed on a nutted thruhull. Those are reasonable for a plug, but better scheduled for proper replacement.

[Pete7]

A good bag full of wooden bungs should always be carried along with a mallet to bang them home before the water expands them.

However, I have also a small umbrella device which goes through a hole and then opens sealing against the outside of the hull. Only problem for the life of me I can't find them now. It looked such a simple idea that could be used to change a valve whilst in the water since the umbrella will fit through the new valve to recover.

In the mean time some alternatives:

http://www.admiralyacht.com/admiral-...at-sinking.pdf

[Pete7]

Got it, seems a little pricey though much cheaper for those in the US now

Seabung Breach Control - Sheridan Marine

[Mainebristol]

Look, I know it's a little off-topic, but the other side of this is that the pump needs a good float switch, just in case you are not there/asleep. And the little flipper switches are broken the day they are made, in my opinion. I like the Ultra switches, but others likely prefer something else. In any case, do not neglect this vital safety link.

Apologies for the digression.

[Dockhead]

Originally Posted by sanibel sailor

Interesting that the majority of article's pictures are not seacocks but ball valves installed on a nutted thruhull. Those are reasonable for a plug, but better scheduled for proper replacement.

Ball valves used to regulate the flow of sea water are also called "sea cocks". There are different types of sea cocks, and the flanged and through-bolted type is not the only type.

The problem with "scheduling for proper replacement" is that you cannot predict their lives, so you can't "schedule" with 100% certainty. Dezincification does not occur at a standard rate, and is often not detectable. Electrolytic corrosion also kills through hulls and sea cocks, sometimes very fast. They can last 30 years or can be killed in a few weeks, or anything in between, and you can't always tell from looking at them, that there's a problem.


At the end of the day, it's a risk management question, where cost of course is an important factor. Is it good risk management, even with brand new through-hulls and sea cocks, to not keep a $5 bag of plugs on board? Everyone will have to decide for himself, but most sailors do not find that a difficult decision to make. If you want to save $5 on the assumption that nothing could possibly ever happen to your sea cocks -- well, it's your boat.

[S/V Alchemy]

Originally Posted by Viking Sailor

I believe that standard battery boxes are designed to have an air pocket to keep the terminals dry when submerged and level. Thus, allowing the batteries to continue providing power while being underwater.

I'm installing tall L-16 batteries at present on a platform six inches above my keel tanks. Said air pocket in the boxes is only one inch (2.5 cm). If my batteries get overtopped, we are already in the raft because that's just about the point of no return.

[basssears]

Originally Posted by Dockhead

I do not, however, tie one to each seacock, which would be a bit ridiculous since I have 18 or 19 through hulls in my boat. I keep them under the companionway stairs. You can block a broken through hull with your hand while someone brings the plug. Or once you've located the broken through hull, your boat will not likely sink in the 15 seconds or so it takes you to get to the bag of plugs.

I'm with you on this... granted, I only have a 32' boat and only 5 through hulls below the water line, but to me it seems to make a lot more sense to have a damage control tool bag with everything I need in it that I can grab and head to where the problem is. Otherwise, I'm looking at a few different sized wooden plugs, a Forestar Sta Plug, and a hammer at EACH through hull... I'd rather have all my equipment consolidated just like a ditch bag, that way I have everything I need.

After watching this maybe I'll even put a carrot in there:

https://www.youtube.com/watch?v=H5PDuXvqL7c

[basssears]

Originally Posted by Mainebristol

Look, I know it's a little off-topic, but the other side of this is that the pump needs a good float switch, just in case you are not there/asleep. And the little flipper switches are broken the day they are made, in my opinion. I like the Ultra switches, but others likely prefer something else. In any case, do not neglect this vital safety link.

Apologies for the digression.

This is spot on... it's actually on my "arrive on the boat" checklist to test my float switch (along with exercising and inspecting my sea valves).

Test your float switch, then test it again!

[reed1v]

Most small boat bilge pumps are not designed for continuous operations beyond several hours. They will go beyond that, but the likelihood of burnout becomes highly probable. Second, unless you are also continually recharging your battery, it to will start to lose charge, thus slowing down the pump, and as it heats up and draws more power, the drawdown becomes a critical factor. Best tactic is an engine driven pump system that has a flow regulator so you can adjust for small, medium, or Oh My God levels of flooding.