Every now and then either I or one of my buddies comes up with a real work of electrical art that we need to share in our hopes that readers here will get the idea that we're watching you and if you mess up, sooner or later one of us is going to expose you. This week's little nugget comes from my friend Dexter who was working on a customer's boat here at the boatyard and discovered a real gem of a double pole circuit breaker installation. This goes well beyond the Tupper Wear plastic box installs we sometimes see. Check this out people:

The interesting part about this first class horror show is that the poor person who now owns this boat just bought it. I wonder if they bothered to get a survey before they jumped into this beauty? If they did, I really want to meet the surveyor so we can have a few words..............

So, for those who are having difficulty understanding what they are looking at, let me provides some details here. ABYC requires a double pole circuit breaker to be installed on the shore power inlet to a boat so equipped (with shore power that is.) So the mouseketeer that did this got that part sort of right. But they didn't get the part right where we require terminations to be made inside enclosures that require hand tools to get at any live terminals. The piece of twine securing the breaker to what I'm told is the diesel fuel tank vent line is really quite stunning. It looks quite snug and tied with good knots...............

Folks, when I see things like this it just further supports a theory that I've begun to embrace more and more as I get older. The term "common sense" is an oxymoron. People, when it comes to shore power voltage potentials, do it or get it done professionally. This stuff is lethal and is no place to cut corners.

Well I hate to say it but it is that time of year again. Time to put the boat to bed for the winter hibernation period. That includes your boat's battery(s).

This little maintenance chore, if done properly can go a long way toward making sure you get the maximum life out of your batteries. Conversely, if you ignore what I'm about to tell you, your batteries are sure not to last as they should.

Let me begin by emphasizing one key point, there is no need or even a desire to remove the batteries from your boat! The habit some old timers got into with this procedure is right up there with setting a bettery on a concrete floor and the concrete sucking the life out of a battery like some sort of vampire. The concrete isn't the culprit and never was, and the need to remove batteries from a boat when it goes into storage for the winter is in the same mis-imformed category.

What is important is that the batteries get a full charge before you lay them up for the winter.

All batteries have what is known as a "self-discharge" rate and although it varies somewhat depending upon the type of battery and it's overall condition, the rate of self-discharge is never more that about 5% per month. So, if you start out at 100% and the boat sits in hibernation for even 5 months, that is still only a 25% loss in charge, bringing things down to a 75% state of charge. That's good enough to keep the battery from freezing in really cold climates and more than adequate to minimize any sulfation tendencies.

An additional concern, especially on newer boats is the matter of parasitic loads that may contribute to a discharge rate greater than the 5% mentioned above. Most boats today will have equipment on them that will have internal memory or some sort of LED display or monitoring light. These things add up and in some cases can create engough of a cumulative load to actually draw the battery down quicker than desired.

So, you need to make the call here. Is mid-winter recharging practical for you? Or, should you just disconnect the battery(s) so that there is no danger of a parasitic load discharging them too far while in storage. Of course if that is the choice, you'll have to reset all the pre-programmed stations on the stereo and such in the spring, but that really shouldn't be a big deal. Personally, I go for the full disconnect on my boat. I get a lot of years of service out of my batteries too.

I received a comment from one of our readers about the post I did last week talking about "Hose Clamps Done Right". It's worth sharing and with a little bit of explaining. First the comment:

Ed,

In this day and age of easily available non-perforated hose clamps, like those from AWAB, or t-band clamps, it is hard for me to accept "clamps done right", as a whole, when the clamps used are cheap perforated hose clamps. While the installation & metallurgy is done correctly those clamps scare me. Customers spending 200k+ should get more for their money.

I have a box full of perforated clamps that have failed, through a variety of failure modes. I share these with customers when they complain that a hose clamp cost them $3.69 vs. $1.09.

As an ABYC technician I can no longer find piece with installing perforated hose clamps, for below water applications, such as a seacock or packing gland.

Your point on the installation is spot on! I just wish more builders would take below water line hose clamps more seriously than they often do.

Thanks, RC

The clamps RC is referring to look like these:

AWAB:

T-Band: 

I did a little checking and the pricing works out to approximately 3X over the cost of a conventional clamp for the AWAB type, the red tail piece is extra. The T-band type work out to approximately 4.5X the cost at a local distributor (Jamestown Distributors).  

RC, thanks for the comment. I don't disagree that either the AWAB and T-band clamps would be a better choice. All I was attempting to illustrate in the photo I used was the reverse bias of the clamp screws. Also, the fact that the clamps be made entirely of stainless and not the garden variety automotive units with stainless bands and cadmium plated screw mechanisms that are guaranteed to rust out in a marine application.

But, I'll tell you that in the real world of production boats, a 3X or 4.5X increase in cost over a product that has decades of reasonably trouble-free service such as the all stainless clamps shown is not going to happen in most cases.

First of all I owe my loyal readers an apology...I've just been too busy the last several weeks to post here. But, the good news is I have been gathering literally hundreds of photos I can share with you over the next year. My excuse is that I was working as a judge for Cruising World Magazine's Boat of the Year competition. Not a bad gig in all, as I got to sail 22 brand new boats this year and tear right into their inner souls.

 This week I'm at the International Boat Builder's Exhibition (IBEX) in Louisville, Kentucky and I'm sure I'm going to find even more good info I can share. So, let's get started with some of my observations. Hose clamps done right is important to insure leaks don't happen and the truth is some folks just plain get it wrong. The photo below shows the right way to stagger double clamps where they are used:

As you can see, the clamps have several attributes that are important. They are made entirely of stainless steel, not the automotive variety which will use a stainless band and a plated mild steel screw mechanism that is going to rust up and make the clamp useless. The clamps are the right size. The "tail" extending out from the screw mechanism is not excessively long and not too short either. Finally, the clamps are offset and staggered in such a way that the puckered hose under the clamp creates a sort of labyrinth which will stop fluid flow in its tracks. Some people like to see all the screw heads lined up like a row of pidgeons on a power line. That looks good, but just doesn't work as well.

First my apologies to our loyal readers. I've been traveling and under the gun with some deadlines that just could not be put off. So, I've been a little lame in the posting area for the last week or so.

Well as usually happens, one of our regular readers and a good friend of mine shot me an email last week talking about a boat he had visited recently that illustrated a problem that can have dire consequences if you miss what is a really important maintenance point. The issue has to do with the electrical termination points on the back of your engine(s) starter motor or alternator. I've talked in the past here about the importance of keeping these terminal studs booted (insulated) but what Wayne observed on his buddy's boat could easily turn into a horror show.

On the boat in question, the owner had recently installed high output alternators. Not a bad thing necessarily. But, in this case the higher output units were a bit larger physically that the original equipment alternators. No surprise there either. Well anyhow the installer had mounted the new units and adjusted the drive belts to an appropriate tension. In the process of doing all of this the stud on the back of the alternator that is normally labeled B + had a boot installed, but to achieve proper belt tension, the alternator had been pulled into a position that wedged this boot up tight against another metal component mounted on the engine.

Due to vibration, its just a matter of time before that boot gets chafed through, exposing a bare metal stud to this engine part. Look at the photo below and in the photo, the terminal actually got bent a bit and forced contact with the engine. The point of contact is identified by the obvious corrosion shown in the photo.

So, the question is so what? Well, in the example above the net result of this corroded connection between the DC positive conductor and the case of the starter motor solenoid in the example shown cost the boat owner thousands of dollars in loss. The propeller shaft that is attached to the engine shown here is shown below:

The really interesting thing about this particular boat was that it apparently didn't take even a week's time for the propeller shaft to end up looking like this. The cause? Not a sea monster chewing on the metal folks but DC stray current corrosion. Even with the obvious low quality connection at the alternator, enough battery level current was able to enter into the engine and migrate right out of the boat via the engine block, transmission and propeller shaft.

So the moral of the story? Carefully, and I mean very carefully, check all of the electrical connections on your engine and make sure they are properly booted or other wise insultated from the engine block itself. And, make sure they are positioned and located such that chafe due to normal engine vibration can't damage this insulating barrier. You do not want to have to go through what the owner of the boat in the two photos above went through. Believe me.

Special thanks to my friend Dudley Gibbs at Dudley's Marine Electric in Puerto Rico for the photos. They were actually found on a boat he was working on about six years ago.