FREE Advise is just that - take it or click 'delete' and move on down the road... I LIKE THIS ONE

When you find good advise you want to share it so others can benefit - if the shoe fits - wear it - otherwise just click 'delete'.

I participate on the Morgan's Cloud forum because I like participants and subject matter... we all mess about in boats! What I'm going to call "hands-on' real world advise.

So here are some good tips and advice I'd like to share - Attainable Adventure Cruising on Morgans Cloud website - http://www.morganscloud.com

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Tip #1, Up-Size Your Gear

What can you do? Yes, you guessed it, go up a size from the manufacturer’s recommendation, or maybe two.

Now let’s talk about hulls:

Benefits of Steel

One of the interesting things I have learned lately is that some materials have what is called a fatigue limit, and, as Martha Stewart would say, that’s a good thing. Mild steel is one of those materials.

What this means is that if you build a structure out of steel it will initially lose strength from cycle loading until it reaches its fatigue limit, and after that it will stay at the same strength no matter how many times you cycle load it.

And since most steel sailboats are insanely overbuilt simply because it’s difficult to source or weld steel below a certain thickness, steel yachts don’t generally suffer fatigue induced failures because the hull is still strong enough to withstand the loads after the fatigue limit is reached. Of course they rust and lose strength from that wastage. Sigh—nothing’s perfect in boats.

What About Aluminum?

Aluminum doesn’t have a fatigue limit, meaning that no matter how strongly you build a structure from aluminum it will continue to forever experience some diminishment of strength as you cycle load it.

But wait, I know that, despite having somewhere in the region of 170,000 miles on her, Morgan’s Cloud seems as stiff and strong as she was the day I bought her 20 years ago, and that, touch wood (had to bring that material in too), she has never experienced any sort of structural failure. And that we have aluminum boats like Carina andWar Baby that have two or three times as many miles on them as our boat, that are still going strong. What’s happening here?

Here I get to play the salty old guy and come at that quandary from the experiential angle, and try and guess the engineering that explains what I have observed in the real world:

• Engineers understand fatigue in aluminum alloys and how to plan for and ameliorate it very well because of its use in aircraft where a failure can ruin your whole day.
• Because aluminum is so light for its strength, it is possible to dramatically overbuild aluminum structures and still have them meet their performance goals.
• It is very hard to weld thin aluminum well, so most boats, at least at the relatively small size this site focuses on, are plated and framed with gauges that are more driven by workability than minimalist engineering and so are way over-strength.

These reasons, coupled with the way the fatigue curve for aluminum flattens as the strength of the structure goes up, means that a well built aluminum boat will last, even when sailed hard offshore like Carina, for many decades, maybe even a century.

So What About Fiberglass?

There’s an enduring assumption in the offshore voyaging community, at least partly based on bitter experience, that fiberglass boats will not last, or at least stay stiff and strong, as long as metal boats.

I suspect that the reason that there are so many fatigued and soft fiberglass boats out there is that it’s (unlike with metals) very easy to build a fiberglass structure that is only just strong enough to meet the required initial failure limits before fatigue weakening is factored in. In other words, to just get through the warranty period. But it does not have to be that way.

In fact, good fibre laminates have a fatigue limit—remember, that’s a good thing—that is, according to the reading I have done (one example), at about 400%.

What that means is that, if you build a fiberglass boat four times stronger than it needs to be not to fail when new, it will still be plenty strong enough after it reaches the point where no more fatigue induced weakening occurs.

This might explain why some very old, very thick hulled, fiberglass boats like Seawind Ketches, some of which are coming up on half a century of hard use, are still going strong.

The fly in the ointment is, as I understand it, that a 400% safety margin of the laminate significantly exceeds common practice and even standards like those from ABS.

Now I’m not suggesting that every part of a voyaging boat built out of fiberglass should have a 400% safety margin. I’m guessing that that would be impractical from both a cost and weight perspective.

However, high stress areas like the rudder and its mounting area, mast step, chain plates area, and hull to keel joint should be built massively to the point that the laminate strength is below the fatigue limit—remember, being below is good. Of course, if you do this up-strengthening, you will also have to be very careful to adequately taper those massive areas into the rest of the hull to avoid hard spots. A process that will result in a very strong hull in all areas.

Practical Tips

Here are my conclusions about voyaging sailboat building and buying that I have drawn from all my reading and learning, after mixing in my (years of) experience:

Tip #2, Hull Form

It’s a good idea to avoid hull forms (shapes) that rely on lightness for adequate performance and concentrate on those that can be built heavily and still sail well.

Tip # 3, Stiff is Good

Boats that show any signs of flexing should be avoided like the plague. Yes, you can strengthen the hull, like Poor Stupid Bob did, but you can’t fix the strength degradation already caused by the flexing.

Tip #4, There is No Best Hull Material

The constant debate about which hull material is best for a voyaging boat is not useful since what matters is that the engineering design and build execution yield a hull that is built with very high safety margins, whatever material you select. All three materials generally used (steel, aluminum, and fiberglass) can be used to achieve this goal and all have benefits and drawbacks—that’s a subject for a different post.

Tip #5, Spend Your Money Wisely

If you want to be safe and have a low cost of ownership, put your money into hull strength and cut corners on interior fit out and gear.

Tip #6, Race Boats Don’t Make Good Voyaging Boats

Most boats that were originally built for the race course, where lightness is king, should be avoided.

Tip #7, Avoid The Seventies

It is probably a good idea to avoid many fiberglass boats built in the seventies when the cost of hull materials skyrocketed due to the OPEC oil embargo and builders were therefore tempted to make boats thinner.

Tip #8, Refits

As Poor Stupid Bob found out the hard way, buying a fiberglass boat that is “proven” by a bunch of miles offshore and then refitting it may be a really dumb thing to do, since you could be pouring thousands of dollars (pounds, euros, kroner, whatever) and thousands of hours into a hull that has been irrevocably weakened by cycle loading induced fatigue.

Rather than succumbing to the broker’s siren song ad copy of “just back from a circumnavigation and ready to go again” you may be better off to look for that poor neglected barnacle-encrusted hull of the same model languishing unloved in the corner of some marina or boat yard, that has never been anywhere outside of the bay, to lavish your attention on.

GREAT Comments are online at - http://www.morganscloud.com/2013/05/03/cycle-loading8-tips-for-boat-and-gear-buying/?utm_source=feedburner&utm_medium=email&utm_campaign=Feed%3A+AttainableAdventureCruising+%28Attainable+Adventure+Cruising%29

Thanks John!!!