any ideas on this hull imperfection?

[gards]

Hi all, Was having a boat surveyed today and all were somewhat unsure what we were looking at. Beneteau 281 As can be seen in the photo, there is a visible set of lines horizontally across the hull. To the touch you can barely feel a "wave" in the gelcoat. No one surveyor included was sure what this was. This boat to everyone's knowledge has never been repaired. Sounds solid underneath. No color variation to speak of. Feels the same across the "blemish" except for "wave". Any ideas? Ever seen this before?TIA for any ideas.

 

[Bill Roosa]

Has it been on the hard for a long time?

Can't tell from the photo. If it has been on the hard on stands for a year or two it may just be the flexing of the fiberglass under the stands. If this is the case there could be other "waves" at the usual stand locations.Is the wave a series or just one long one.Is the trough of the wave under a bulkhead?Alternatly, since it is on a trailer it may be the same kind of thing from the trailer supports. If my SWAG is correct, then there is nothing to worry about and I'd use the information to get a lower price. "I mean look at this big wave, that is probably something REALLY serious."But it is a SWAG and I have nothing to lose.

 

[LP]

Check the chainplate attachments

Hmmm, almost looks like it's in the right vicinity... I wonder if when the standing rigging is tensioned, the pull of the chainplates is transferred to the hull. The tension could be causing an oilcanning effect. How about the other side? I've seen this before as a chronic issue on another brand of 28 footer.

 

[Badger N.H.]

Could it be from a tarp?

I may be way off but I had a boat where a flapping tarp had worn waves into the gel coat in just one winter.The rope inside the edge of the tarp had made a dozen or so lines which you could barely see or feel. All the lines were about the same distance appart and about 20 inches long.I finally located the cause as a flapping tarp hitting the topsides.

 

[Bill C320 Papillon]

Can't tell from the picture

I have a 281 and it doesn't have any "wave" in the gelcoat. From the picture, the hull looks to be in pretty nice condition. Is it possible that the wave is due to waxing or something like a Poli-Glow treatment that wasn't done quite right? I used Poli-Glow on mine and it had swirls and lines until I got enough coats on it.Great boats by the way. If you'd like more info on the 281, let me know what questions you have and your e-mail and I'll try yo give unbiased answers.Bill

 

[Cap'n Ron]

Dunno?

Gards, that is a stumper.Bill Roosa could be right, but I kinda think LP is on the right track.Bill's right though without a pic or sum kinda hard evidence you can hardly tell.Shoot an E to Jay not much he CAN'T figure out and he's down thar in The great state of TEXAS with ya'll.Jay Stormer: www.dixielandmarine.com

 

[Capn Dave]

First off It's a

Beneteau. Or as they have been known to be called a bendy-toe. I know I am going to get flamed for this, but facts are facts. The Beneteau's are not known for the thickest hull made. In fact they (Beneteau) say they are engineered to use less glass and resin. It could be just a Bendy-toe thing. I also know the hull sides oil can in the V-berth when beating in some good chop. I had a hard time sleeping during an ocean race because of the movement.Fair WindsCap'n Dave

 

[Jeff]

Similar

I have seen a similar effect on some 88- 89 Oday models. I believe LP is right. Caused by the rigging tension and the way the chainplates where attached to the hull with a rod type set up.May be something in the archives.Good Luck

 

[Jon W.]

Blemish

My hull came new with three slight depressions that might be similar to these. I didn't notice them until a few weeks after I took delivery. They are nearly invisible unless you know where and how to look for them. They about 3 inches high by 6 inches long. Just very slight depressions a foot or two above the water line spaced 3 or four feet apart along one side of the hull. They are not any type of crease or bending of the hull. Just very shallow depressions in the gelcoat or laminate. Kind of like a scratch or shallw gouge was sanded down and re-gelcoated without being built back up. There is nothing attatched inside the hull to account for them.My guess is that they were defects as the hull came out of the mold, and were repaired on the spot. Or the hull had cosmetic damage in the factory that was repaired. I pretty much ruled out shipping damage because I saw the boat just after it arrived at the dealer's. They wouldn't have had time to repair it then.I don't give it much thought anymore as they are not readily noticeable.

 

[Ross]

If you read enough about

building fiberglas boats you come across a term called hard spots. Fiber glass bends much like wood bends but people think that if it keeps the water on the outside it is strong enough. Then they start attaching things to the hull and wonder why they are pulling dimples into the hull.The answer is simple! The hull isn't stiff enough to carry the load without bending. The solution is just as simple add more layers of glass until you have doubled the thicknes in those places that must carry the extra loads.Edited for spelling

 

[Bob W.]

Go Inside

"Gards" Go inside and check the location of any moulded structures to the hull at that location. Judging by the window location it could be a "Hot Draw" of the base of a bench, toilet or counter cabinet during the hull layup.

 

[Bob W.]

Ross--You beat me by a minute!

"Ross-" So much for us engineers who think alike. You are correct and beat me by a minute in your answer.

 

[gards]

not on the hard

The boat has been in a slip for over five years. This picture was taken approximately 30 minutes after we had pulled her out of the water. The broker believes this is an example of "epoxy shrinkage". The "wave is actually two lines. One can be seen in the photo just above the fellows's hand and the second line crosses under his hand. They both extend several feet each side of the port. Thanks for the SWAG.

 

[gards]

chainplates

LP: The other side does not show this and we looked very closely. But if I'm following your thoughts correctly, it could be overtensioned on just one side correct?

 

[gards]

281

Bill, I sure hope your right if its not just oilcanning from a thin outer hull. I can handle putting time/money into refinishing I just want a boat that only requires maintenance not rebuilding. I'll take you up on the offer about info as I come across questions. BTW have sailed the boat twice, once as a sea trail and once to the haul out and back. She is very responsive, quick to heel, and very fun to sail.

 

[Rich]

Oil-can Sam...

I couldn't say whether this spot is from oilcanning, but I can tell you after looking at a number of boats while shopping for one a couple of years back that various models from around 1975-1985 (I noticed Irwins here) are subject to oilcanning while up on jackstands because the hull is relatively thin. I didn't think it a big problem for seaworthiness, but it is a problem for storage because you have to monitor the placement of jackstands carefully and hope the dimples don't become permanent...

 

[Marybeth and Rip]

Reflection?

Dumb thought... Could it be a reflection of a stripe on the boat next to you?

 

[LP]

chainplates

You might expect to see oilcanning from rigging tension on both sides, assuming the hull was laid up similarly port & starboard. But you'd still need to check to see how the chainplate load is distributed on each side. One side, the chainplate may attach to a single point on the hull. The other side, the chainplate load may be attached to a bulkhead tabbed to the hull at various points effectively spreading out the load. Maybe easing off on the standing rigging until it's slack will help you rule this in or out. You could also check some brand specific forums on the web to see if other owners have seen similar stuff.

 

[kendall]

don'y know,

but it looks too low for chainplates.don't think you can have one side too heavily tensioned either as the shrouds pull against each other. was the line there while the boat was in the water?   You look to be sitting on a trailer or dolly, if the bunk is adjusted too high, or the boat isn't sitting plumb with the trailer, it could be flexing the hull in that area and that would cause the line, the other side wouldn't be affected if the keel is bearing weight.  ordinarily loading like that would cause the hull to flex outward, but if there is something in that area,holding that section rigidly, then it will tend to form a stress line in the hull. ken.

 

[Bill C320 Papillon]

How is it sitting?

Kendall may be on to something. All the weight should be on the keel on a level surface and the bunks should only keep it from falling sideways.