12 Cruising Boat Maintenance Tips

Richard Passmore, principle at an industrial testing company, holds one of the two chain plate assemblies he tested for us, while arranging another job on the phone with one of his five staff.

As I work away on the multi-part cruising sailboat rig inspection chapters, I keep thinking of cool maintenance hacks I have learned over the years, so here are twelve that will be useful no matter what part of a cruising boat you are maintaining:

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Dick Stevenson

Hi John,
While obsessive cleaning is to be avoided, I would suggest every skipper do his/her own cleaning. The number of usually potential troubles I have discovered over the years is numerous. When cleaning, your eyes are really looking: most other times one is just seeing what one expects to see.
And I would suggest never hiring others to do your cleaning: they will use harsh stuff and/or power washers and other potentially damaging equipment.
Random thoughts, Dick Stevenson, s/v Alchemy

Alastair Currie

It’s a fundamental aspect of Reliability Centred Maintenance, cleaning and observing, which also includes the various non destructive testing methods, alluded to in this article.

Dick Stevenson

Hi John,
I agree about delegating skilled work for sure.
My point was the ancillary benefit of finding budding problem areas which can and do get neglected when you delegate the cleaning.
And perhaps delegating cleaning can work out with a crew you know and trust, but too often I see young underpaid groups descend on a boat with power washers and harsh cleaning agents and go to town.
They would happily blow a loose screw overboard without even seeing it (and deprive the skipper of exploring where it came from) and might not notice a loose fitting that could be allowing water to get into the core.
My best, Dick 

Stein Varjord

Hi Dick,
I agree with all of you here, of course, but would just like to elaborate on the “harsh cleaning agents” point. I’ve seen harbour employees routinely putting acids and other strong remedies in the cleaning water and using even a high power steam washer to clean everything on a boat, making all textiles and ropes age at least 10 years in seconds. When they did that on a 1 year old good quality cat trampoline (not mine) the owner fell trough it the day after the wash.

The wharf said it was sun deterioration (in 1 year in the NL…) and denied they had done anything wrong. They would not pay anything, despite the witnesses and the obvious tracks of the pressure steam blaster. In a court settlement they had to pay waaaay more about a year later. I definitely may let others work on my boat, but until I properly know the individuals, I’ll be extremely suspicious about their abilities and methods, no matter what credentials they might have. My starting point is that they are all useless, careless and ill willed, until the opposite has been proven.

William Murdoch

It was when polishing my painted hull while the yard did more challenging work that I happened to also polish the external chain plates on my Pacific Seacraft 34 that I saw the tell tale dendritic cracks of chloride induced stress corrosion cracking that resulted in the near immediate replacement of all six chain plates.

Similarly, crawling on hands and knees under the saloon table wiping down the cabin sole, I saw a black spot the size of my thumb at the bottom of the white oak compression post. I quick probe with my pocket knife opened up what looked like a mouse hole where water leaking down wiring channel inside the compression post had rotted away two thirds of its bottom end. The boat was not sailed again until the compression post was replaced.

When cleaning every inch of something, it is nearly impossible to not to inspect every inch of it. It leads to an unavoidable level of thoroughness.

Star Tracker

The other big reason for this approach especially in the last paragraph is liability. Even in cases where I am comfortable doing the work myself, there are times I choose not to. With the simple reason being, should a failure result in the loss of the boat would I rather be fighting the insurance company over whether or not my repair was done properly, or would I rather be finding a new boat and letting them figure out who they want to point fingers at? When I do it for someone else, I know it is done to the best of my ability, and that that fact is backed up by a 3m$ in liability insurance. Even with the best documentation available, I wouldn’t give great odds on either of the insurance underwriters wanting to cover a loss of vessel should I have DIY’d something that could have been a contributing factor, certifications and experience be damned.

Graham Burrell

#8 Certainty is the refuge of the stupid

Karl Lewis

I feel a strange compulsion to say that I’m not sure that’s 100% true….

Michael Feiertag

Since there has been much commentary on your observation of those “who are certain”, there may be interest in a book I recently read, On Being Certain: Believing You Are Right Even When You’re Not, by Robert A. Burton, M.D. (2008). Burton is a neurologist, and offers neuroscience, anecdotal examples and patient case reports, and personal informed speculation, to address our sense of knowing something. Also, a fascinating exploration of how much thinking occurs unconsciously, and what controls whether a thought rises to our conscious awareness.

Marc Dacey

We always reassemble, inspect and otherwise prep our mast while on sawhorses before bringing in the crane. You may have seen us installing new standing rigging and a new Harken furler and foil last spring. One of the advantages of having sailed out of a “self-help” club with a good safety record. I make myself a nuisance out here by using the yard staff as little as possible for rigging work, not necessarily because they know less about rigging, and I feel this is an important point, but because we, the owners, know more about our boat and her rigging.Particularly as it’s a custom and slightly eccentric set-up.

That said, we were happy to hand over the bottom work, although I kept a gimlet eye on that, too.

Drew Frye

In the US, at least, NDT technicians are certified by the ASNT (I am for several methods) for each inspection method. Non-certified techs cannot legally perform many inspection services (oil tanks and gasoline tanks, for example). Notice that the ASNT certification of the inspector was listed on the example report.

#8 is funny. In #7 one engineer was sure it was something less than 1/2 strength (I’m sure he had a calculated number), but in #8 no one was willing to say how strong the original mast was or what the required strength was (or you just did not tell us). I would have reported the required bending moment and the estimated moment of the mast section when new, at the very least. There is information missing. What you may be seeing, rather than responsible engineering, is pass-the-buck inspection, where no one will accept any responsibility. They also knew that if they stuck together, the insurance would pay. What would their answers have been if there was no insurance? I see this all the time in refineries. Once something is brought into question, everyone throws their hands up. It may be more a study in business and human behavior than engineering. As you would say, critical reading.

[I’m sure not giving an opinion on the damamge, from a fuzzy photo!]


It’s not cheap to have that kind of inspection and assessment done, but sometimes it’s necessary.

In this particular example, when John first mentioned the damage, I recall thinking “Either you laser-clad that and it’ll be good as new, or you have to scrap the whole mast and replace it, and which answer is correct depends on exactly what kind of damage it is and precisely where it happened. He’s going to get 20 wrong guesses from 20 people, for sure, until an actual expert does the math.”

I see bad armchair engineering all the time. I’ve given up on some online forums because of their tendency to embrace armchair engineering and ignore actual experts, usually based on “well, this feels right to me” or “my buddy did this and he didn’t die” or “it’s too hard/expensive to do it right”.

Sometimes, doing it right means calling a specialist, and paying accordingly. Yes, it hurts. But it doesn’t hurt nearly as much as a spar coming down on your head.

Drew Frye

Yes, all that!

I do refinery and large tank inspections, and thank goodness, the inspection code addresses many of the stress concentration and corrosion concerns based on many decades of expereince on many thousands of tanks. I’ve yet to see a structural failure in a tank or pipe that was any where close to in compliance… but the deviations can be small things that might seem like nothing to the layman. For example, it is reasonably common knowledge that a square patch or backing plate concentrates forces, but people ignore it as something “theoretical.” Well, I have seen perfectly installed square lap patches (installed over steel to cover a no-longer -needed fitting or pinhole), with lovely welds, start tears in the corners of 5/16-inch plate, while operating 4 times below the safe working load. Details matter.

Gregory Thomasson

In the future you can further question the FEA report by asking for that models validation. The methodology of FEA (boundary conditions, loading, vector direction of load, and software) should have direct validation based on lab testing or engineering methods applied to show proper validation.

The report probably showed the max principle stress being halved. Which is bad, but the fatigue life cycle was probably significantly reduced.

In addition you can find a few Surveyors’ that are engineers. I am both, and my friend is as well.

David Branyon

In your 2nd paragraph you lament the analyst for notngiving the required strength and then the available strength, or in other words, the factor of safety of the original and damaged mast.

IMO, this is not a shortcoming but simply the appropriate use of relative analysis vs. absolute.

The actual loading of this part of the mast is a function of MANY different parameters (sail area, sail angle, shroud tension, wind speed) and then the number of loading cycles that must be endured is also unknown. One could spend another $50k or get their PhD trying to quantify those parameters but to what gain? The critical piece is the relative analysis that was given: this damaged piece has less than 50% of the strength of the original. That answers your question (do I need to replace the mast?) conclusively without spending unneccesary effort ($).

And I’d venture that the engineer in his FEA also did not take into account the small-scale stress concentration which is the root of the statement about “the actual strength depends on the damaged surface’s finish.” Again, a LOT more money could be spent on a highly refined FEA with 1000 times smaller elements to get 20% closer to the precise answer, when the necessary information has already been reached: the mast has less than 50% of it’s original strength and, depending on surface finish of the damaged area, could be MUCH less than 50%.

If you have a pressure vessel with a pressure relief valve to protect against over pressure on the other hand, you know pretty precisely what your loads are and the absolute analysis is more appropriate. You also have the corporate funding and liability risk to justify such expenditures.

Different problems, different solutions.

Chuck Batson

Great tips, thank you! Proactively updating the insurance is a fantastic idea.

I would really and truly love to hire the experts when I need them. However, I’ve experienced two major obstacles to this along the way:

1. I’ve never (in my 5 years of boat ownership) been able to find a true expert available and willing help. Most of the time, I never get a response. Other times I’m told they’re too busy or my job too small. This was especially true for me in San Francisco Bay, where I was a small fish in a huge pond. I have therefore been required to compromise on my choice of professional, or do it myself.

2. In the instances in which I did engage a professional, I was less than impressed. Often I find I do a better and more thorough job myself. Why? Probably again the professionals are just busy and rushing. I also naturally invest more care, since it’s my head the mast might fall upon.

Do you have any tips for getting on the metaphorical radar of good, quality experts? Who are almost by definition always booked solid with work? I’m more than happy to pay expert rates — generally though I struggle to find anyone worthy who’s willing to take my money. I’d like to know how you do it.


P.S. I spoke to one very well-credentialed, large-operation rigger about increasing the mast rake by half a degree. The mast is around 47 feet long. When I said something about the masthead moving aft 4 inches, he balked, saying that was “too much” for half a degree. I don’t trust a rigger who can’t do basic trig!

Chuck Batson

Separate comment for a different topic: In the spirit of #5, last time I had the rig de-tensioned, I added nylon washers on the clevis pins to help keep the bearing load on the pins “square” to the chainplates, and minimize movement of the fitting hardware. However, I’m now seeing rust staining where the washers are, perhaps because the stainless is not getting enough oxygen there? There was little to no rust before. Do you have any suggestions? What, if anything, do you do to reduce “play” in fitting-to-chainplate attachments?

Star Tracker

one quick tip: If you don’t know the last time your bilge pumps were replaced, now is a good time to do it along with the float switches, and while you’re at it get rid of the horrid unprotected ones. It is likely overkill, but I replace mine every 3 years, the newer float switches are not as reliable as the old ones. I sell the removed one on craigslist with clear warnings that it was in use from xx to yy dates, and still, I usually get at least half my money back. I have refit one sinker that resulted from hitting something. I have refit many who sank due to what would have remained minor repairs for a nuisance leak if only the 100$ pump or the 60$ switch had been replaced. The last one was way over 100k, boat was perfectly fine except that every system needed replacing, it sat on the bottom for a month before it was noticed, then in a yard for a year. A hatch seal on the aft deck failed(fast tuna chaser with big scuppers), eventually enough rain got into the bilge to drop the stern low enough for seawater to get in, an unprotected float switch had a freshwater hose jammed down on top of it. Insurance surprisingly covered the tab, but I think that may have had more to do with the owner’s high powered lawyers, his main boat they delivered fuel by barge, it was cheaper than running the boat to get fuel.