oil-canning

[Tor]

Excellent! Thanks, Paul.

Tor
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Silver Heels, P-424 #17
http://www.SilverHeels.us
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[Tor]

I’m planning some offshore passages with my boat in the not-too-distant future and would like to get a handle on just how prevalent this forepeak tab-breaking and oil-canning is in Pearson 424’s. In the discussion of this topic last year, online at https://www.pearson424.org/bb2forum/viewtopic.php?t=139&highlight=berth, Rich wrote, “Try to imagine having your boat heeled over until the rail is almost in the water. Then run up the face of a steep 20 foot wave and drop off the back side until everything up the forward section of your boat is in freefall. The flat section of the bow will slap against the trough on the back side of the wave. Now imagine doing that for a day or two.”

It seems to me most sailboats would suffer damage from that kind of repeated punishment. Clearly, those were conditions in which that particular boat was pushed beyond her endurance. Rich, on reflection do you think reefing and slowing the boat down, coupled perhaps with easing off the wind another point, might have prevented the breakage that occurred in the forepeak? I ask because it seems to me the majority of 424’s have not been structurally enhanced in that area, and yet many have logged successful offshore passages over the decades.

Are there any others among us who have taken your boats offshore, who can shed more light on this issue? Have you weathered rough conditions, particularly going to windward, and did your boat suffer damage in the forepeak as a result?

Thanks,

Tor
~~~~~~~~~~~~~~~~~~~~~~~
Silver Heels, P-424 #17
http://www.SilverHeels.us
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[john stevenson]

Tor,
I've got about 10,000 off-shore miles on Sarah and have not experienced any problems from oil canning. Of course very few of those miles involved sailing to windward. I did get caught in a mild storm for a little over 6 hours on the way back from Bermuda in 2001 where we did fall off a few waves. Turned the interior of the cabin into a mix-master, but no apparent problem with oil-canning.

That said, I am sure it is one of the few weaknesses in the hull. You can verify it for yourself if Silver Heels is still hauled-out. Take a anything with a broad surface on a pole, place the surface under the hull in the flat forward sections and push up. You can deflect the hull quite a bit with relatively little force. You can do the same in the flat aft sections as well. I know this because my purchase surveyor demonstrated it and recommended I have those section stiffened, but he didn't put it in the written report.

Every time I've gotten ready for a long off-shore passage I've thought of that demonstration and the fact I've done nothing about it. Then I tell myself I'll do it right after this passage….

Didn't do it this year.

John

On Tue, Feb 3, 2009 at 1:19 PM, Silver Heels < ([email][/email])> wrote:

Quote:

I'm planning some offshore passages with my boat in the not-too-distant future and would like to get a handle on just how prevalent this forepeak tab-breaking and oil-canning is in Pearson 424's. In the discussion of this topic last year, online at https://www.pearson424.org/bb2forum/viewtopic.php?t=139&highlight=berth, Rich wrote, “Try to imagine having your boat heeled over until the rail is almost in the water. Then run up the face of a steep 20 foot wave and drop off the back side until everything up the forward section of your boat is in freefall. The flat section of the bow will slap against the trough on the back side of the wave. Now imagine doing that for a day or two.”

It seems to me most sailboats would suffer damage from that kind of repeated punishment. Clearly, those were conditions in which that particular boat was pushed beyond her endurance. Rich, on reflection do you think reefing and slowing the boat down, coupled perhaps with easing off the wind another point, might have prevented the breakage that occurred in the forepeak? I ask because it seems to me the majority of 424's have not been structurally enhanced in that area, and yet many have logged successful offshore passages over the decades.

Are there any others among us who have taken your boats offshore, who can shed more light on this issue? Have you weathered rough conditions, particularly going to windward, and did your boat suffer damage in the forepeak as a result?

Thanks,

Tor
~~~~~~~~~~~~~~~~~~~~~~~
Silver Heels, P-424 #17
http://www.SilverHeels.us
~~~~~~~~~~~~~~~~~~

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[RichCarter]

Tor
That trip was my only real offshore passage. Its a small sample. I consider offshore to be when you’re outside normal radio communications, maybe 50 miles plus. IMHO, coastal cruising is entirely different. I’ve experiences similar sea states when coastal cruising, but not for extended periods of time. As an example, conditions at the entrance to the Cape Cod canal in Buzzards Bay are similar to what I experienced. The waves are only bad for an hour or two however. The stretch of ocean between the Northeast and Bermuda is known to be rough. Since the wind normally blows from the south, there’s no way to go but upwind if you ever want to get there. Early in the season, it can blow pretty hard from the south and low-pressure centers can run down the gulf stream every couple of days. That’s what we encountered. If I had waited a couple of more weeks before leaving, my experience would have been entirely different. If I had slowed down and waited for the weather to improve, we may have never made it. A Pearson 55 that was a day or two behind us never made it. His bulkheads broke loose and they abandoned ship. Another 30 footer from Virginia was lost with hands, and a boat just behind us lost his mast and had to be rescued.

I don’t think the weather we encountered was all that bad. It blew from the starboard bow at about 40kts apparent for about a day and a half. There were a few 20-foot waves, but most were 10 feet or less. They were steep because of the current however. The other boats listed above didn’t make it to Bermuda in time. It got really nasty just after we tied up at the custom’s dock.

In my opinion, the V-berth flat sections need reenforcing and the boat needs a better cockpit drain. Other than that, its pretty well made. Oh, if you have a sloop or cutter, you need to do something about the backstay chainplate too.

Regards
Rich

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[Tor]

Good grief! What an introduction to offshore sailing. Sounds like you fared very well, considering.

Tor
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Silver Heels, P-424 #17
http://www.SilverHeels.us
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[kalinowski]

Tor:

After reviewing the logs for Lady Leanne, my confidence in the P424 is well founded. The PO ran day charters out of Kaua’i for several years and was in the direct path of Hurricane Iniki in ’92. The entries are spellbinding as he set seven anchors and faced winds of 160+. Besides some damage to the anchor platform, cleats and rig, she rode the storm well. Per his continuous detailed log entries, there was never any oil canning damage. I’ve recently pushed the boat hard around Oahu and never noticed any problems.

Dan Kalinowski
Lady Leanne (#135)
Honolulu

[Tor]

Thanks for that input, Dan. Seems like it takes some pretty harsh treatment to have the kind of breakage Rich (and no doubt some others have) experienced. Still, the fact that Bill Shaw eventually addressed this inherent design/construction flaw with a recommended “fix” suggests it’s not an isolated incident. Certainly it’s valuable to know about it so that a skipper might lighten up and ease off when things get brutal on the nose.

All considered, I think some kind of fix is worth doing for someone like me. Maybe after I’m down islands and don’t feel so compelled to get movin’ and ‘get south.’

Tor
~~~~~~~~~~~~~~~~~~~~~~~
Silver Heels, P-424 #17
http://www.SilverHeels.us
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[Anonymous]

Is oil canning a function of when the boat was built, i.e., are later models–1980 and later–heavier in the bow than older models?

Norris Larson, Easy Reach, #203, 1983.

— On Tue, 2/3/09, Silver Heels <> wrote:

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[RichCarter]

Its my understanding that later hulls are balsa-cored. I don’t know when Pearson switched to cored hulls. In theory, this would provide a stiffer hull. I doublt that it would prevent the oil-canning problem since the forward hull section is flat. I would still recommend reinforcing the forward sections.

Rich

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[rdugger]

Sorry to come into this discussion so late..
I would like to point out other damage that can occur with flexing of the hull ..
Longitudinal cracks on the exterior hull in the area of the V berth floor.

I am aware of three 424's in the Southern Chesapeake that have experienced this phenomenon. Two have been repaired and mine (the 3rd) has not been repaired.

When the hull has a good coat of paint, the cracks can be very difficult to see. These cracks were not identified during our survey.

Attached is a photo of Eclipse when she was trucked to my home for a refit. If you look closely you can see the cracks just aft of the bow jackstand and forward of the hydraulic arm.

'Mobjack Pearl' is a Pearson 424 whose owner made the Bermuda rally a couple of years ago… he experienced the oil-canning phenomenon (including failure of the v berth shelves) when beating on the return trip.

Rick
Eclipse #73

On Sat, Feb 7, 2009 at 7:28 PM, Rich Carter < ([email][/email])> wrote:

Quote:

Its my understanding that later hulls are balsa-cored. I don't know when Pearson switched to cored hulls. In theory, this would provide a stiffer hull. I doublt that it would prevent the oil-canning problem since the forward hull section is flat. I would still recommend reinforcing the forward sections.

Rich

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[madsailor]

Hi Rick,

That looks as if the stringer inside below the cabin sole has become unattached. That's a seriously difficult thing to fix unless your arms are four feet long.

Bob

On Tue, Feb 10, 2009 at 10:44 PM, Rick Dugger < ([email][/email])> wrote:

Quote:

Sorry to come into this discussion so late..
I would like to point out other damage that can occur with flexing of the hull ..
Longitudinal cracks on the exterior hull in the area of the V berth floor.

I am aware of three 424's in the Southern Chesapeake that have experienced this phenomenon. Two have been repaired and mine (the 3rd) has not been repaired.

When the hull has a good coat of paint, the cracks can be very difficult to see. These cracks were not identified during our survey.

Attached is a photo of Eclipse when she was trucked to my home for a refit. If you look closely you can see the cracks just aft of the bow jackstand and forward of the hydraulic arm.

'Mobjack Pearl' is a Pearson 424 whose owner made the Bermuda rally a couple of years ago… he experienced the oil-canning phenomenon (including failure of the v berth shelves) when beating on the return trip.

Rick
Eclipse #73

On Sat, Feb 7, 2009 at 7:28 PM, Rich Carter < ([email][/email])> wrote:

Quote:

Its my understanding that later hulls are balsa-cored. I don't know when Pearson switched to cored hulls. In theory, this would provide a stiffer hull. I doublt that it would prevent the oil-canning problem since the forward hull section is flat. I would still recommend reinforcing the forward sections.

Rich

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[rdugger]

Bob,

Why would you say that a crack in the hull is associated with an unattached stringer?

The prevailing thought at the marina was that hull flexing at the rigid area of the floor caused the cracking.

Rick

On Wed, Feb 11, 2009 at 8:05 AM, Robert Fine < ([email][/email])> wrote:

Quote:

Hi Rick,

That looks as if the stringer inside below the cabin sole has become unattached. That's a seriously difficult thing to fix unless your arms are four feet long.

Bob

On Tue, Feb 10, 2009 at 10:44 PM, Rick Dugger < ([email][/email])> wrote:

Quote:

Sorry to come into this discussion so late..
I would like to point out other damage that can occur with flexing of the hull ..
Longitudinal cracks on the exterior hull in the area of the V berth floor.

I am aware of three 424's in the Southern Chesapeake that have experienced this phenomenon. Two have been repaired and mine (the 3rd) has not been repaired.

When the hull has a good coat of paint, the cracks can be very difficult to see. These cracks were not identified during our survey.

Attached is a photo of Eclipse when she was trucked to my home for a refit. If you look closely you can see the cracks just aft of the bow jackstand and forward of the hydraulic arm.

'Mobjack Pearl' is a Pearson 424 whose owner made the Bermuda rally a couple of years ago… he experienced the oil-canning phenomenon (including failure of the v berth shelves) when beating on the return trip.

Rick
Eclipse #73

On Sat, Feb 7, 2009 at 7:28 PM, Rich Carter < ([email][/email])> wrote:

Quote:

Its my understanding that later hulls are balsa-cored. I don't know when Pearson switched to cored hulls. In theory, this would provide a stiffer hull. I doublt that it would prevent the oil-canning problem since the forward hull section is flat. I would still recommend reinforcing the forward sections.

Rich

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[madsailor]

Hi Rick,

In Pelican (1978), there's a stringer under the floor there. I don't know for sure your stringer is unattached but I'd sure look at it. Between the floor and the stringer is an extremely strong area. I'll stick my head down there today and have a look.

I'd really wonder if the hull was hit there. It's too low down to be really affected by oil canning – the hull there is nearly 3/4″ thick or thicker. Oil canning shows up in the large flats between the caprail and waterline. You'd see cracks like spiderwebbing in the the gelcoat. Also, the framework around the v-berth would be broken away from the hull as others have observed.

But without examining your boat in particular I'm only offering an opinion which may be worth everything it cost.

I would really examine it inside and out quite thoroughly.

Bob

—
Bob Fine
s/v Pelican
Hull #8

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