Morgan’s Cloud, our 56-foot aluminum cutter, turned 30 this year, and she and I are coming up on our twenty-sixth year together. One of the amazing things about the boat, and the material she is built of, is that, at least as far as I can see (I look pretty carefully and regularly), she is just as strong today as she was the day she was built with no appreciable wastage.
That said, boats built from aluminum do require care and attention to detail. To help with that, in this three-part chapter I’m going to provide practical tips.
And let me emphasize the word practical. I’m going to focus on what we actually do that has worked to keep our boat in good shape for a quarter of a century, rather than get into a lot of theory.
Here we go:
John,
Thank you for removing some of the mystery behind caring for aluminum boats. An Ovni is high on my list for future cruising, and over time I’ve heard horror stories about caring for them (and similar boats). So these articles are very helpful.
Hi Mike,
Glad it’s useful. As we shall see in part 2, caring for aluminium boats is really no bigger deal than any other material, just different.
That VDO gauge looks nice. Found it at two other French retailers as well. Have asked Summit Racing if they can order it (part YC310) from their VDO supplier. Will ask same of VDO directly and ping thread if responses are noteworthy.
Hi Brian,
Thanks, hope you have luck with your search. When I tried to source one in North America I couldn’t find anyone (including VDO) who would even admit that such a thing existed.
Great article , very timely , have just relaunched my 1989 Ovni after a 2 year refit and are in the process of sorting the electrical system . Could not source the VDO product so using a local Australian made product called Seabis . Can’t wait for part 2 !!!
Hi Ian,
Glad it is useful. I had a look at the Seabis, but have to admit that I was rather put off by the tone of their website and the fact that they make a lot of huge claims for it, but never explain what it does or what the installation issues are.
How was working with them on the installation?
Damn, John, inset zincs? It’s so obvious, but evidently not, as I’ve never seen it before. Aside from the obvious reduction of drag, do you find any other benefit? I have a steel boat and it’s probably not worth doing as “going faster” is a low priority, but I’m willing to listen to persuasion.
Hi Marc,
The only benefit of inset anodes, is, as you surmise, speed. That said, four anodes sitting proud of the hull would have quite a bit of drag so if I was faced with that I would at least try to find streamlined ones.
Thanks John, great info!
Just replaced my inset zincs with alloy anodes, as the boat spends most of the time in fresh water. The old zincs had turned brownish and was told its an indication they stopped working, but not much show of wastage. My isolation transformer gets quite hot (50″C?) is that normal, does the temp. go up and down with the amount of amps use.?
Certainly will try to obtain the VDO gauge you mentioned. Also like to know how often do you haul your boat? I understand yours is always in salt-water. Mine apparently will soon be due for a new barrier coat.
Thanks again.
Rene
Hi Rene,
The only way to know exactly what your anodes are doing is the meter I write about above, but the very fact that they were not showing much wastage may not be good news in that it can just be an indication that they are not working.
As to the isolation transformer, they all get warm and the more current (amps) being passed the warmer they get. That said, 50c sounds too warm to me, but that’s only a guess. I would strongly recommend contacting the transformer manufacturer and asking them if this is OK. Also check the rating on the transformer to make sure it’s big enough for your use.
Our steel vessel had an “Acme” branded isolation transformer aboard, which to my understanding was engineered for land-based construction purposes. It got way too hot for my liking just sitting there with no load. That and other factors spurred me to do an extensive electrical refit. I replaced the Acme with a Charles unit designed for the marine environment — night and day difference. The Charles runs cool, has a powder-coated case, and to the best of my recollection features epoxy potted or transformally-coated innards. I think the Acme transformer was widely used in the 80s as a cheap alternative to the marine units. I have seen photos online of its use on other boats. However, having witnessed the drastic effects of salt air on non-tinned wiring and connectors, the thought of keeping the Acme scared the hell out of me.
As for zincs, ours are teardrop shaped and I “reactivate” them by diving on them twice a year with a stainless steel wire brush to remove any scale and brighten them up.
Hi Brian,
Thanks for the fill on the transformer. We have a Charles too, and it’s 30 years old with no problems so far.
Many (perhaps most) of the boaters who don’t completely neglect their anodes tend to throw them away far too early. Probably more than three-quarters of the anodes I see in scrap bins still have most of their useful life in them.
What matters, for this purpose, is total exposed surface area. If the anodes look brown or gunked-up, just give them a quick scrub with a wire brush to expose some fresh metal. The bulk of the mass is just there so that they won’t waste away to nothing during the intervals when you aren’t checking them.
Re. the isolation transformer. AC power hardware designed for use on land really does not belong in this application. It’s usually not protected from corrosion in any way, and there’s a good chance it won’t be wired properly for marine use (where the ABYC standards are different from the Electrical Safety Authority codes, it’s for a good reason). And while transformers do get warm, the kinds found on boats do not get dangerously hot. If you burn your finger on the case, unplug it and call the vendor.