Had a hard grounding on the reef today and damaged the centerboard box. Anybody have schematics or info about how the repair should be done? Front of the box needs to be rebuilt.
Jim Kloss
s/v Ambivalence
S2 7.9 #8
Centerboard box
Moderators: Tim Bosma, Tom Elsen
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grandillusion
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Re: Centerboard box
OUCH!!, might be time for an email to Scott at Tiara and your insurance Co.
S2 7.9 216, H 16 80127, Star 6188
Re: Centerboard box
Repairs will start next week after a professional inspects for sources of water intrusion other than the obvious damage to the front of the board box. I worry about some chunks of an odd material I've found floating in the bilge -- it's hard, brittle, dull black in color, smooth/flat on one surface, lumpy and completely unfinished on the others. Anybody have any idea what this stuff is and where it was used inside the boat?
Jim Kloss
s/v Ambivalence
S2 7. #8
Jim Kloss
s/v Ambivalence
S2 7. #8
Re: Centerboard box
Hi Jim, Sorry about you boat. Can you show us some pictures of the damage?? What is the story that goes with it?
Re: Centerboard box
That's what I was wondering too.
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Tom Elsen
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Re: Centerboard box
Jim -
Where'd that happen? Salt River? Over by the Yacht Club? Elsewhere? I'm really sorry to hear about it.
Clearly some of the damage won't be evident until you can pull the board. Pay special attention to the area aft of the trailing edge. Look for compression damage to the outer skin there.
But the good news is that there's a very good chance you didn't damage any of the core. That area in front of the board box is solid. The really tricky part is in repairing the inside of the board box and sealing the whole thing so that you don't get intrusion.
Dave - what do you think about cutting a piece of that ultra high density plastic board to fit in and use as the leading edge of the box? If you cut out the damaged area, you could spray (very liberally) the board front with mold release, and ease it down in to position. Then, set that plastic piece in place first and fit some roving mat pieces in to conform to the rest of the interior shape using the board as a male mold. You'd need to paint that section of the interior of the box with some heavy duty bottom paint to assure you don't get intrusion.
Jim, I'll volunteer some hours to assist when we're down in March, if that will help.
Where'd that happen? Salt River? Over by the Yacht Club? Elsewhere? I'm really sorry to hear about it.
Clearly some of the damage won't be evident until you can pull the board. Pay special attention to the area aft of the trailing edge. Look for compression damage to the outer skin there.
But the good news is that there's a very good chance you didn't damage any of the core. That area in front of the board box is solid. The really tricky part is in repairing the inside of the board box and sealing the whole thing so that you don't get intrusion.
Dave - what do you think about cutting a piece of that ultra high density plastic board to fit in and use as the leading edge of the box? If you cut out the damaged area, you could spray (very liberally) the board front with mold release, and ease it down in to position. Then, set that plastic piece in place first and fit some roving mat pieces in to conform to the rest of the interior shape using the board as a male mold. You'd need to paint that section of the interior of the box with some heavy duty bottom paint to assure you don't get intrusion.
Jim, I'll volunteer some hours to assist when we're down in March, if that will help.
Best wishes,
Tom
Tom
Re: Centerboard box
Tom, parts of your plan sounds good but I'm still wondering why there would be excessive damage to the FRONT of the box!?!? 
The most important part of any repair is cutting/grinding out ALL of the damaged laminate so that the new laminate has something permanent and sound to adhere to, AND grinding far enough back into the good laminate to achieve a good surface bond. That will be tough to do in there, I would like to see pictures of the area!!!! One thing though, what do you mean by "heavy duty bottom paint"? Bottom paint, as in antl fouling paint is NOT waterproof, not even very water resistant. If you mean a good barrier coat then I would agree, just stay away from ANYTHING that contains coal tar: that stuff blows! Actually, any good quality Vinyl ester or epoxy resin is as good or better than any commercially available barrier coating, so I don't see much of a water intrusion issue as long as either is used in the repair. The board itself can of course be used as a male mold but I would use at least 7 coats of mold release wax with at least a half hour dry time between each one in cold weather and then spray that same area of the board liberally with something like Sailkote just to make sure that it doesn't stick! 
PVA works great as a release agent but I wouldn't rely on it completely in this application because when the board is dropped into place and comes to rest on the repair area there is a slim possibility that it [the PVA] could be skinned back. Waxing underneath is always smart but some other non stick insurance would make me a little more comfortable.
Pics?????
The most important part of any repair is cutting/grinding out ALL of the damaged laminate so that the new laminate has something permanent and sound to adhere to, AND grinding far enough back into the good laminate to achieve a good surface bond. That will be tough to do in there, I would like to see pictures of the area!!!! One thing though, what do you mean by "heavy duty bottom paint"? Bottom paint, as in antl fouling paint is NOT waterproof, not even very water resistant. If you mean a good barrier coat then I would agree, just stay away from ANYTHING that contains coal tar: that stuff blows! Actually, any good quality Vinyl ester or epoxy resin is as good or better than any commercially available barrier coating, so I don't see much of a water intrusion issue as long as either is used in the repair. The board itself can of course be used as a male mold but I would use at least 7 coats of mold release wax with at least a half hour dry time between each one in cold weather and then spray that same area of the board liberally with something like Sailkote just to make sure that it doesn't stick! PVA works great as a release agent but I wouldn't rely on it completely in this application because when the board is dropped into place and comes to rest on the repair area there is a slim possibility that it [the PVA] could be skinned back. Waxing underneath is always smart but some other non stick insurance would make me a little more comfortable. Pics?????
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Tom Elsen
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Re: Centerboard box
Dave, great ideas.
The front of the board box gets damaged in a grounding because the board pivots just like a hammer held between your fingers, just below the head - push back on the lower part of the handle and the head pivots forward.
I agree about coal barrier coat. Was thinking more along the lines of a catalyzed Interlux product.
Do you know the trade name of that ultra dense, tough, white board product? What bonds to it?
The front of the board box gets damaged in a grounding because the board pivots just like a hammer held between your fingers, just below the head - push back on the lower part of the handle and the head pivots forward.
I agree about coal barrier coat. Was thinking more along the lines of a catalyzed Interlux product.
Do you know the trade name of that ultra dense, tough, white board product? What bonds to it?
Best wishes,
Tom
Tom
Re: Centerboard box
Tom, this is what I know of: http://www.coosacomposites.com/
I was under the impression [for whatever reason] that he had grounded and moved on, not sat there and beat back and forth. THAT can be bad news!
I still would like to see some pics. Can they be posted here like other forums?
I was under the impression [for whatever reason] that he had grounded and moved on, not sat there and beat back and forth. THAT can be bad news!
I still would like to see some pics. Can they be posted here like other forums?
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Tom Elsen
- Site Admin
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- Joined: Fri Dec 20, 2002 5:42 pm
- Location: Minneapolis, MN & Chicago, IL
Re: Centerboard box
Coosa, that might be the stuff. Was that what you were going to use under the mast step?
RE Jim's accident, it was a 'simple' grounding so far as I know. Damage to the front of the box is exactly what happens in a hard hit. When the bottom leading edge of the board hits, the aft upper section jams back in the trunk. That creates a pivot, a cantilever. The forward upper section (the 'head' of the daggerboard) gets forced forward and down.
There are lots of wicked, virtually invisible small reefs and coral heads down on the north side of St Croix. They aren't hard to find 'the hard way'.
RE Jim's accident, it was a 'simple' grounding so far as I know. Damage to the front of the box is exactly what happens in a hard hit. When the bottom leading edge of the board hits, the aft upper section jams back in the trunk. That creates a pivot, a cantilever. The forward upper section (the 'head' of the daggerboard) gets forced forward and down.
There are lots of wicked, virtually invisible small reefs and coral heads down on the north side of St Croix. They aren't hard to find 'the hard way'.
Best wishes,
Tom
Tom
Re: Centerboard box
Okay, I see what you mean. I was thinking that the damage was at the outside forward section of the trunk, but you're saying inside, and that makes since if you sit on something and rock. Sounds to me like another design flaw, followed by the mast step and how the board was made. I hope that the new boats address ALL of these, not just what I've read about the step, and yes, Coosa Board is what I'm going to use if I ever get back to rebuilding the mast step.................................. and the REST of the boat!
Re: Centerboard box
Still no pictures?
Re: Centerboard box
My attempts to send a "private message" have failed and I don't know how to post photos to this BB. Dave, if you send me your email address, I'll send you the sad photos. My email address is jdkboats45@yahoo.com.
Thanks for your advice.
Jim Kloss
s/v Ambivalence
S2 7.9 #8
Thanks for your advice.
Jim Kloss
s/v Ambivalence
S2 7.9 #8
Re: Centerboard box
Done!
All, I use Photobucket and it's fairly simple to add pics to forums once you do it the first time. Here's a pic I took last race day of Garry Roberts and crew at Lake Maumelle. The main is WAY too full and his 4th needs to be hiking but the point is, I got the pic to post!
All, I use Photobucket and it's fairly simple to add pics to forums once you do it the first time. Here's a pic I took last race day of Garry Roberts and crew at Lake Maumelle. The main is WAY too full and his 4th needs to be hiking but the point is, I got the pic to post!
Re: Centerboard box
Tom, I got the pics: MAN, that's some SERIOUS damage!!!!! I would do as Tom suggests as a means of getting the form back on the inside of the trunk but then I would DEFINITELY do some serious grinding and glassing on the inside!!!!!! I've always wondered how beefy that section was and now I now: NOT BEEFY ENOUGH!!!!!
It's hard to tell from the pics how much room/space there is to work with but heck, if you can take pics of the damage you can also get a grinder to it. Even if you have to remove or cut out some sections of the interior, I WOULD NOT trust any repair done just from the inside of the board trunk and then just semi cosmetic cleaning up and fixing the interior. Good luck on this........................................ it needs to be done RIGHT!
Tom, this would be good for the new builder to look at. Jim, go to http://www.photobucket.com and see if you can figure out how to post these pics on the forum. Everyone should see them! If you need some help just let me know and I'll see what I can do. It's pretty easy.
I've always wondered how beefy that section was and now I now: NOT BEEFY ENOUGH!!!!!It's hard to tell from the pics how much room/space there is to work with but heck, if you can take pics of the damage you can also get a grinder to it. Even if you have to remove or cut out some sections of the interior, I WOULD NOT trust any repair done just from the inside of the board trunk and then just semi cosmetic cleaning up and fixing the interior. Good luck on this........................................ it needs to be done RIGHT!
Tom, this would be good for the new builder to look at. Jim, go to http://www.photobucket.com and see if you can figure out how to post these pics on the forum. Everyone should see them! If you need some help just let me know and I'll see what I can do. It's pretty easy.