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Islander 32 #241

Posted: Wed Nov 12, 2008 9:14 pm
by JohnS
After hunting around for local marinas to pull my mast and repeatedly being told that they didn't have a crane, I decided to take matters into my own hands. I couldn't simply do it by hand as it is too big and heavy (wood box beam). So I built a tower on the boat to lift it off.

Image

More pictures of the tower and the mast can be seen here:
http://picasaweb.google.com/thugdrummer ... 4999746930

I made the legs 24' long to be certain I was lifting from above the balance point. (Actually I cut a foot off the forward legs to account for the raise in the forward deck.) I bolted a short 4x4 across the top, and tied a fiddle block from my boom vang to it. I attached the other vang block to the side of the tower for a turning block. I had a good long length of 1" braided rope for lifting which I ran through the blocks and back to a primary winch.

There were a lot of creaking noises as we started cranking, and I was prepared to dive overboard in case it collapsed, but it held. And so did the mast. I ended up having to unbolt the step from the cabin top and then stomping around it before it popped loose and shot a foot above he deck.

Once it was free everything worked smoothly. The mast weighs probably 200-300 pounds. I tied the boat stern to the dock and three of us carried it off and into the yard.

Now the fun begins. [/img]

Posted: Wed Nov 12, 2008 9:37 pm
by Hirilondë
Give me a lever long enough and a place to stand and I could move the Earth (paraphrase of a quote from some old Greek)

Well done. Where there is a will there is a way.

Posted: Wed Nov 12, 2008 9:44 pm
by Rachel
Neat-o! That has a great erector-set quality to it.

R.

Posted: Wed Nov 12, 2008 10:24 pm
by Peter
From a fellow mast-craner ... Job well done! It always amazes me how easy it was, after it's down. BTW, getting it up with that crane should be pretty easy too!

Looking at the pictures of your mast: Would it be better to look for a good used aluminum replacement? Just my thoughts.

Posted: Wed Nov 12, 2008 11:43 pm
by JohnS
Believe me, I've thought about aluminum. I could probably put a hinged step on it, and be able to raise and lower it easily w/ two strong guys.
But

A) a lighter mast would reduce the sea-kindliness
B) with all the wood and bronze on the boat (including a varnished boom) I don't think aluminum would look right.
C) The mast doesn't really appear to be in that bad shape structurally.
D) It should be cheaper to fix what I've got than to replace it. If I had money, I would have paid a crane driver to come out and pull the mast.

Of course, I'm foolishly thinking of varnishing the mast instead of painting it, which I'm guessing will require more frequent maintenance.

At this point the seasons over as far as painting and epoxying is concerned. We might get an occasional warm weekend day between now and next spring, but I won't be able to take advantage of most of them. It's in the yard next to my dad's house, and I'm not sure he'd be enthusiastic about me building a 34+ foot long tent to work on it.

Posted: Wed Nov 12, 2008 11:57 pm
by JohnS
Rachel wrote:Neat-o! That has a great erector-set quality to it.

R.
One of my favorite toys as a kid! Hopefully, when I get the boat all back together it won't reflect that erector-set quality.

Posted: Thu Nov 13, 2008 7:19 am
by Tim
JohnS wrote:...a lighter mast would reduce the sea-kindliness
It'd probably be the opposite, actually. Excess weight aloft is never desirable. Not that there's anything wrong with the weight of your existing mast for the design, but a lighter one, should that ever be the way you end up going, isn't going to adversely affect your boat. Your other reasons for not wanting to make a change are sound, but avoiding something lighter aloft is not.

I think it's generally accepted that removing one pound of weight from the masthead is roughly equivalent to adding 4 pounds of ballast in the keel, or something along those lines. There's a reason spar builders have been striving for (and continue to strive for) lighter weight rigging all these years.

Posted: Thu Nov 13, 2008 7:43 am
by Tim
Peter wrote:Looking at the pictures of your mast: Would it be better to look for a good used aluminum replacement? Just my thoughts.
JohnS wrote:The mast doesn't really appear to be in that bad shape structurally.
After looking at some of your mast photos, I have to agree with Peter: that mast's condition looks quite suspect. If one can see that much bad on a painted wooden mast, imagine what might be hidden elsewhere beneath the paint.

It might be salvageable, but I would stop very short of calling it "sound" as is. Inspect it with care.
JohnS wrote:Of course, I'm foolishly thinking of varnishing the mast instead of painting it, which I'm guessing will require more frequent maintenance.
Actually, you'll probably be surprised to find that it might be the opposite.

First of all, varnish on vertical surfaces takes much less abuse than on something like a deck hatch. Varnish on masts can last a long time, though maintenance is of course always needed on a regular basis--just as it would be with paint.

More importantly, though, a paint finish on spars is notorious for hiding bad problems in the wood of the mast--as witnessed by your mast's current condition. With varnish (and proper inspection schedules), you're going to notice water intrusion beneath the finish far earlier, which gives you the opportunity to correct the problem before it becomes more serious than simply a cosmetic issue. Many of the issues that I can spot in your mast photos would have been avoided if the finish had been clear (varnish) and if the mast hadn't been neglected.

Traditionally-constructed wooden masts like yours should only be varnished in my opinion--not so much for looks (though they do look nice) as for the value of improved maintenance and mast structure longevity.

Posted: Thu Nov 13, 2008 7:46 am
by Hirilondë
JohnS wrote:
Of course, I'm foolishly thinking of varnishing the mast instead of painting it, which I'm guessing will require more frequent maintenance.
Not so foolish. Most wooden boat owners, even if the have no other bright work varnish their spars. It allows them (you) to keep tabs on the structural integrity of them.

Posted: Thu Nov 13, 2008 8:33 am
by Tom Young
JohnS wrote:
Of course, I'm foolishly thinking of varnishing the mast instead of painting it, which I'm guessing will require more frequent maintenance.

At this point the seasons over as far as painting and epoxying is concerned. We might get an occasional warm weekend day between now and next spring, but I won't be able to take advantage of most of them. It's in the yard next to my dad's house, and I'm not sure he'd be enthusiastic about me building a 34+ foot long tent to work on it.
As you were able to pull that stick like that, I have faith you can save your spar. After all, it's just wood. After you strip it, you'll see what needs to be done.

Varnishing the spars is one of the easiest maintenance items I have with our boat. As others have said, any surface not directly aimed at the sun holds up well. I put a single coat on each spring, that's it. I wooded each spar about 6 years ago. The previous coating went more than 15 years before failing.

The nice thing is as Tim mentioned, any defect is easy to spot. The slightest movement in a glue line pops right out. These spars are nearly 50 years old.
The main mast is stored outside next to the boat under an enclosure I build.


Image

Posted: Thu Nov 13, 2008 10:16 am
by Quetzalsailor
Ditto all kudos for a job well done. Ditto the comments favoring varnish over paint.

Check out previous posts, a couple years ago now, by Hirilonde etc, about restoring screw holes under mast tracks.

Explore carefully how the glue lines work. Normally, I think, the front and backs are rabbetted and the sides drop into the rabbets. This makes a better glue joint that aligns the components but is tougher to reglue. (I've recently popped a Hinckley B 40 mast apart to harvest the wood.)

Inspection

Posted: Thu Nov 13, 2008 12:54 pm
by JohnS
I'll certainly give it a more thorough inspection, but initially the only rot I've found is what you see in the pictures, and those areas should be easily fixed. The first step is to remove ALL the paint, but at this point, there's not much paint left on it. From the halyard sheeves to the base of the mast, I haven't yet seen any evidence of seams or scarf joints opening. I'm confident I can work w/ wood and epoxy to fix what's needed. And I'm glad to hear that varnish is the preferred coating.

As for sea-kindliness, maybe I'm using the terminology wrong. There was an article in the Sep/Oct issue of Good Old Boat by Ted Brewer describing the difference between sea-kindliness and seaworthiness. In a nutshell, it states that more weight aloft reduces stability, but it also increases angular inertia/momentum, which slows down the reaction of the boat to waves and gust. With less weight aloft, the boat snaps back to vertical more quickly, making for a more bumpy ride. With more weight, the rocking and pitching is less violent. Seems to make sense from a basic physics perspective.

Posted: Thu Nov 13, 2008 1:49 pm
by David
God save us from Good Old Boat magazine.

Posted: Thu Nov 13, 2008 3:22 pm
by JohnS
David wrote:God save us from Good Old Boat magazine.
Hmmm, okay. I'm not a subscriber, I just grabbed a freebie at the boat show. I have noticed in the past their articles tended to be over-simple. I certainly respect the knowledge and opinions of some of the folks here more. But I do suspect Ted Brewer knows a little something about the subject. Anyhoo, the boat behaves just fine with the wood spar, so I'm not inclined to change it.

Posted: Thu Nov 13, 2008 3:26 pm
by bcooke
With less weight aloft, the boat snaps back to vertical more quickly, making for a more bumpy ride.
That is true. More weight aloft also reduces seaworthiness because it retards the tendency of a boat to come back up.

The actual effect is most likely negligible in your case. Are you planning on battling many gales? I wouldn't lose much sleep over it.
God save us from Good Old Boat magazine.
I tend to agree about the magazine in general. Great topic, poorly executed.

Ted Brewer excites some people and inflames others. There isn't a question that he knows some stuff. Its just that it all gets down to the details, and really, the details (for most of us) aren't that important.

Posted: Thu Nov 13, 2008 4:21 pm
by David
Great topic, poorly executed.
Exactly.

Re: Inspection

Posted: Thu Nov 13, 2008 5:43 pm
by Tom Young
JohnS wrote: As for sea-kindliness, maybe I'm using the terminology wrong. There was an article in the Sep/Oct issue of Good Old Boat by Ted Brewer describing the difference between sea-kindliness and seaworthiness. In a nutshell, it states that more weight aloft reduces stability, but it also increases angular inertia/momentum, which slows down the reaction of the boat to waves and gust. With less weight aloft, the boat snaps back to vertical more quickly, making for a more bumpy ride. With more weight, the rocking and pitching is less violent. Seems to make sense from a basic physics perspective.
I didn't see the article but I've read similar things that refer to a dampening effect. At any rate, I suppose Brewers article was comparing non racing cruising designs to tricked out racers. Of course a lighter rig is faster and will make for a stiffer boat.

I don't know exactly how much my 50' main mast weighs but assuming about 2bd ft of spruce needed per foot of stick, it's probably around 230 pounds or so. I know it weighs quite a bit more with all the standing and running rigging, winches, hardware, furler, etc, because that's how we have to move it around.

Posted: Thu Nov 13, 2008 7:13 pm
by bcooke
As for sea-kindliness, maybe I'm using the terminology wrong.
You are using the term correctly.

Sea-kindliness is how comfortable the ride is. Sea-worthiness is the ability to survive rough conditions. That's my interpretation anyway.

Posted: Thu Nov 13, 2008 9:30 pm
by Chris Campbell
Weight aloft can contribute to sea-kindliness, for sure. It slows the boat's angular acceleration down, making her roll less quickly (or less snappily is more accurate - once moving a roll can be plenty quick, and harder to stop!). In the after-the-disaster analysis of the Fastnet tragedy, one of the conclusions was that the boats with heavier rigs were less likely go get rolled over, since a breaking wave on their beam wouldn't have as good a chance of rolling them right over.

Of course a taller mast is more effective for this than a heavier one, and I'm no naval architect, so I'd better stop now...

Posted: Thu Nov 13, 2008 9:43 pm
by Chris Campbell
Just found some references to weight aloft: Desirable and Undesirable Characteristics of Offshore Yachts, pgs 61-62, 67-68, and 78-79. Seems that the limit of positive stability is negatively impacted but the "roll gyradius" is increased, which makes teh boat more comfortable in a seaway (sea kindly) and less likely to roll in response to a breaking wave.

I think.

Ok, so "sea-kindliness" isn't such a big factor

Posted: Thu Nov 13, 2008 10:34 pm
by JohnS
I was listing my reasons for sticking with my old wood spar in increasing order of importance. I could (and probably should) have left that one out. :)

Re: Ok, so "sea-kindliness" isn't such a big facto

Posted: Fri Nov 14, 2008 9:04 am
by Tom Young
JohnS wrote:I was listing my reasons for sticking with my old wood spar in increasing order of importance. I could (and probably should) have left that one out. :)
You can replace it John with no more pinging halyards.

Posted: Fri Nov 14, 2008 3:46 pm
by Rachel
I'm not arguing for more weight aloft here, but on the other hand, when you read sailing books (written by knowledgeable sailors) and they talk about how to handle a potential dismasting, they always mention that one of the first things you should do is take something for sea-sickness (or at least to be aware that you will be more prone to it). This is said to be because a sailboat with no mast aloft gives you a really sea-sicky ride, compared to one with the stick in place.