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Seam gaps...
http://www.hobie.com/forums/viewtopic.php?f=14&t=45005		 Page 1 of 1
Author:  paxfish [ Mon Sep 17, 2012 6:53 am ]
Post subject:  Seam gaps...
So we had a fun time Saturday in high winds. My son and I hit 17 knots on the GPS.

A bit later we had 3 of us on the boat, and apparently 200 pounds of water in the starboard hull! This became apparent when we were slowly tacking back to the shore, and we nearly rolled the boat over backwards! We hauled it out, pulled the plug and it drained a very high volume of water for a very long time.

After close examination, I found a gap under the lip of the deck/hull joint, under the tramp, halfway down the hull. Several gaps actually, the biggest about an inch long and 1/4" wide. Air easily flows through this gap (and thus water, when under a heavy load..)

Image

Yesterday I routed it out with the Dremel and filled it with thickened epoxy - should be good. By all appearances, the gap has been there since day 1 (which was 35 years ago). This boat was very lightly used during those years, and it seems we are shaking out defects that should have been taken care of long ago.

If any of youze with more experience in this particular defect would like to comment, please do so!

Anyway - here is what it looks like with a heavy load of people and water in high winds. You can see that starboard hull is pretty loaded! she really starts to boogie around 25 seconds in....

[youtube]http://www.youtube.com/watch?v=NX9Z_-nlScs[/youtube]
Author:  sunvista [ Tue Sep 18, 2012 5:29 am ]
Post subject:  Re: Seam gaps...
I'm no expert but I'd start looking for another boat.
Author:  paxfish [ Tue Sep 18, 2012 6:07 am ]
Post subject:  Re: Seam gaps...
sunvista wrote:
I'm no expert but I'd start looking for another boat.


Tell me why you're thinking that, Bud. Do you believe this is an unrepairable safety issue? I've routed it out and filled with thickened epoxy....
Author:  srm [ Tue Sep 18, 2012 6:41 am ]
Post subject:  Re: Seam gaps...
It's hard to tell from your picture what exactly you routed out. If the seam failed, then you really shouldn't need to rout anything, you just spread the seam apart, fill with epoxy, and clamp the seam together (and hope you applied the epoxy thoroughly). The problems with trying to glue the seam back together are 1) prepping the surfaces adequately- you don't have access to sand and clean the seam and 2) ensuring sufficient epoxy coverage - you basically just squirt epoxy in the seam, clamp it together, and hope for the best. Clamping the hull and deck together sufficiently can also be a challenge.

In your case, I'm not understanding what you routed out. If you cut through a large amount of fiberglass fibers, then that would be a bad thing. If you just spread the seam apart and used the router to help clean up the bond surfaces, then that would probably be fine. Again, real hard to understand what you did from your picture.

sm
Author:  paxfish [ Tue Sep 18, 2012 7:12 am ]
Post subject:  Re: Seam gaps...
Gotcha - sorry about that.

There doesn't seem to be any structural integrity issue. For example, clamping would not move the two layers any closer together because of the Epoxy that was already in place. None of the epoxy is cracked or anything.

I believe they just "missed" that area when bonding the hull to the deck.

Using the Dremel and a long skinny grinding bit, I cleaned out the gaps that you see to a depth of maybe 1 inch. I then cleaned with alcohol - let it evaporate, and pressed in a thickened epoxy mixture similar to Marine Tex.

I'll check it periodically over the next year, and let the forum know if that was effective.

Remarkably, I believe the extra ventilation may have saved this hull from delamination - the port hull had three areas of delam that I have subsequently fixed....

Here is a slightly different perspective (iphone this time)

Image
Author:  jonh [ Tue Sep 18, 2012 7:30 am ]
Post subject:  Re: Seam gaps...
Hi paxfish,

Just so I'm clear - are you talking about these - were these holes that went through the hull?

Image


I'm trying to imagine this in cross section (referencing these pix http://www.thebeachcats.com/pictures/?g2_itemId=10731)

.
Author:  paxfish [ Tue Sep 18, 2012 9:22 am ]
Post subject:  Re: Seam gaps...
Yeah - this would be a gap in the thickened epoxy they used in the upper right corner of the hull picture below. The deck -to- hull joint. Air and water was flowing freely through those holes into the hull. Especially when the hull is in the water, under heavy load and ripping along like in the video!

Image
Author:  sunvista [ Tue Sep 18, 2012 12:52 pm ]
Post subject:  Re: Seam gaps...
From your photos it looks like an earlier repair after a collision or something. Like it has separated before and someone has filled it with Marine tex or something that has fallen out in places (gaps as you say). I don't think this is anything that ever came from the factory.
Author:  paxfish [ Thu Sep 27, 2012 6:43 am ]
Post subject:  Re: Seam gaps...
Thickened epoxy resolved the issue for this hull. Maybe two cups of water after a few 2 hour sail in rough conditions.

Now, that port hull - haven't found the leak yet and will try the soap bubbles this weekend...
Author:  Sail Revolution [ Thu Sep 27, 2012 7:55 am ]
Post subject:  Re: Seam gaps...
Barring any serious structural issues, that's what I would have done. Grind out the filler, mix some thickened epo, and smush it in there. You may try a syringe, I've had good luck going that route.

I don't see any obvious damage, and I know that that filler gets brittle after 30+ years. Sometimes all it takes is a little bump to dislodge it.

Do a bubble test, and carry on!
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