Well she's come and gone. In general I think the damage here in RI was minimal compared to some of our neighboring states, but we certainly did not get out of this one totally unscathed. I saw one boat on the beach this morning in my hometown of Wickford, RI and the poor fellow that owns this sailboat at Brewer's Cowesett Marina, where my office is located, had to face this little mess this morning....

Rapid Anode Consumption, Bottom Paint Blistering and More! Yikes!

This series of problems was brought to us from one of our readers last week. We need to share this one because there is a lot going on here, and power or sail, some of the tips here can help you along the way if some of these symptoms crop up. So here's the note from our reader:

"Hi Ed, I am ABYC-Marine Electrical certified and was recently asked to look at an '01 Sea Ray 28 w/ 2 Merc Alpha 1 Gen 2 stern drives in CT. Water is salt/brackish depending on the tide, anodes are all active aluminum and their mating surfaces are paint/oil free. Erosion of the anodes on both the drives and the trim tabs has been a tad excessive, 2 month replacement shows 75-90% wear.

The problems were: 1. Bottom paint was blistering around all metal thru hull fittings 2. Stern drives literally rotted off the boat galvanically after new owner failed to note the excessive anode wear 3. Batteries continuously "boil", even when the converter is not on any source of AC power over the course of two days!

The steps taken: Drives/ transom assemblies replaced, Mercathode units were installed on both assemblies as well as the factory anodes. Hydro-Coat paint was stripped and repainted w/ a harder, non-ablative paint. All thru hull fittings were replaced with Marelon fittings, and the converter was replaced with a Xantrex programmable unit, set to the lead-acid charge curve. All batteries were replaced, lead-acid, non-PVR. Bonding throughout the boat was tested and in great shape. Galvanic Isolator tested ok and was installed at the factory correctly, but unit was replaced anyways. Again, problem seems to occur even when the boat is unplugged from shore power/ generator not running .

The hull problems seem to have vanished, and the silver/silver chloride test is nominal until the anodes get about 2 months of erosion on them; dead center in the range supplied by the manufacturer. However, the batteries keep "boiling", by which I mean venting electrolyte all over the tops and eventually drying themselves right out if water isn't added almost daily. Eventually the batteries won't hold a charge, as the electrolyte has become diluted by constant refills by the owner. Ambient temperature seems to have no effect on the rate at which they "boil" off. Frustrating!

Could these problems be interrelated? It’s all DC which makes sense, but we have tested and/or replaced everything we know of. No other boats on the dock seem to have a problem, so unless they are ALL using this poor boat as a sacrificial anode, it doesn’t appear to be a dock related issue.

Any ideas? Thanks Ed, great blog!"

Wow, what a bad string of events. OK, so here is what we know about some of these problems. First, the blistering bottom paint. We have known this to be a problem for some time now, especially with bottom paints that have a cuprious oxide content that is over about 55%. We have also noted that this seems to occur more frequently with black colored anti-foulant. Two things seem to work to mitigate this problem. One is to strip the bottom paint off the metalix fittings and re-paint them with some epoxy barrier coat. Then re-apply anti-foulant. Another cure we have seen work is to back off on the sacrificial anode voltage potential for the cathodic protection system. Get it down to about a maximum of -650 mV when tested in saltwater with a silver chloride reference electrode. In this case, our reader replaced all the fittings with Marelon through-hulls. OK, that will work as well. It also reduces the amount of metal that needs protection with anodes. All good on that count.

As for the seemingly rapid anode consumption, I think that our reader needs to double check that the galvanic isolator is truly OK and able to block galvanic currents. Otherwise the boat's anodes are indeed helping to protect all the boats on the same dock and will surely eat up any sacrifical anodes.

The battery issue is a mystery with the information provided. A new set of batteries and a new and programmable carger installed and they're still boiling over? Demons, it is near Haloween after all. More info needed on this one. 

First, sorry to all for my absence during the last two weeks. I've been totally engrossed in several of my favorite things, IBEX, the premier industry show here in the US for all things boats, and the Annapolis Boat Show, and my involvement with the Cruising World Magazine Boat of The Year program. I got to sail 24 different boats as a part of that little gig, but perhaps more important to you all are the hundreds of photos that I took of the "innards" of these boats. These as many of you know are things I share throughout the year, both the good and the bad. So, with that said, let's start with a good one.

For me anyhow, this is something so simple I'm mad at myself for not thinking of it. I'm talking about a really easy and quite effective way to keep those circle clips used to hold clevis pins in place all over a boat's rigging and yet allow them to be removed easily at the same time. Also, a means to keep these things from "biting" after they have been on and off for a few times and end up with an open end. I've been lacerated by a few of these things over the years.

So, the photo above says it all I think. Basically you assemble the clevis pin and install the circle clip. Then take a piece of appropriately sized heat shrink tubing and slip it over the ring. Heat it up and it will shrink down to lock everything in place nicely. When you need to remove the clip and pin for service a pocket knife will easily slice off the heat shrink to allow access. Simple, and effective. I love it!  

Inductive Amp Clamp Detail Orientation

We received a question the other day about the proper orientation of a DC amp clamp on a conductor that's worth sharing because it can be a bit confusing and could have some real ramifications on your diagnostic capabilities if you get it wrong. The question is which way the amp clamp should be oriented around the wire you are checking. In the photo above you can see the amp clamp I use most of the time now. Its my Blue Sea model 8110. Notice the "plus" sign and the arrow embossed on the jaw of the clamp. This is Blue Sea's way of illustrating the orientation on their tool. The arrow is pointing in the presumed direction of current flow, assuming a flow from positive to negative, the accepted convention in modern electrical work. (Electron flow is actually from negative to positive, but that's a long story we won't tell here.)

I'm not aware of any definative rule in the world of meter manufacturers that dictates that this is the only way to mark these clamps. If I recall, some meters will just have an arrow that may be pointing to the "source" of power.

So, what's the answer here? Assume nothing, read the instructions for your specific meter to be sure on this. What you don't want to do is get this wrong and then think that current is flowing out of you battery when it should be flowing in when the charging system is turned on; as an example of what could go wrong is this gets misapplied.

Last week while I was traveling Leo wrote in with a good question about his boat's battery. His query came from a statement I made some ten years ago when I wrote the updated edition of the book shown here:

By the way, you can get your own copy of this book or any of my books by clicking on the Amazon.com link at the lower left side of this page. Once at the Amazon site, click on Minor Brotherton's name to get this book.

Ok, so now that I've made the shameless plug to try and sell some more books, back to Leo's good question.

Basically Leo wanted to know why I've said that it's not such a great idea to leave your batteries hooked up to a trickle charger all winter while they are out of service. Besides it being a waste of electricity, depending upon the charger design and its specific output characteristics you run the risk of just boiling the battery to death. His point to me was that the risk of boiling is low if the current and voltage outputs from the chargere are quite low. His concern is plate sulfation.  I have written about that issue here and a review of several earlier posts is probably in order, so check these two out to get a feel for all of my thoughts on this topic:

http://www.edsboattips.com/maintenance-a-diy/242-putting-the-battery-to-bed  and:

http://www.edsboattips.com/maintenance-a-diy/218-pulsetech-seeing-is-believing

OK, so here's my regimen for batteries. I now use one of the Pulsetech Extreme chargers in the fall and charge up both of my batteries to 100%. The Pulsetech approach takes care of any sulfation issues and I must reiterate that I've extended my battery life two-fold uing these chargers on a variety of my boat's over the last ten or twelve years.

Once the batteries are fully charged I disconnect I turn off my battery master switch. My parasitic loads add up to milliamps so I don't worry too much about them, but every boat is different so a mid-winter recharge is sometimes in order. alternatively, you can simply disconnect the batteries completely and leave them in place, but remember that any of your electronics that have memories needing power are going to have to be re-programmed in the spring.

The days of leaving batteries of any variety on charge all winter are way behind us.