Has anyone repaired Cross beam crack On Hunter 34

Jan 24, 2017
666
Hunter 34 Toms River Nj
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I have had what I thought was just a delaminated gelcote section on the forward fiberglass cross beam on my 1983 Hunter 34. This started out about 15 +years ago as just a bulge in the gelcote. It never got any worst and simply just looked to be cosmetic. I
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Recently I dropped something on the floor and chipped off a small piece of the gelcote to revile that there's a void in the cross beam.
The gelcote is about 1/16" thick and fiberglass core is only approximately 1/8" behind it. The cross beam does not have any cracks in or along the hull anywhere in fact it appears just as solid as the other two midship and aft. The beam has no twist or other apparent defects. The hull also has no apparentl defects.
I believe that the cross beams are in place to stiffen up the hull.

Note that I have no compression post issues as other boats of the era.

My thoughts were to drill out the damaged area and glass in with west sys epoxy sand smoth and epoxy in a few layers of carbon fiber on top then gelcote over it.
Any other suggestions are welcome.
 
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Nov 6, 2006
9,884
Hunter 34 Mandeville Louisiana
Sounds like a good plan.. Did water freeze in there?? That is a strange looking fracture..
One of the forum guys, Brian, I think, had a rear cross beam failure that was the result of the boat hitting some rocks.. He repaired his and posted some great pictures of the repair..
 
Jan 24, 2017
666
Hunter 34 Toms River Nj
Kloudie1
No it started as a small blister in the gelcote and a slight crack about 15+ years ago. I drilled a small relief hole in the gelcote above and below the crack years ago to keep it from spreading and filled it in with marine tek gelcote repair kit. It was fine for 15 + years until I chipped off the blister and it reviled that there is practically no fiberglass behind the blistered area.
The boat is 34 years old now and I am the original owner it's probably been like that sense it left the factory. It seems to be just a poor quality control issue when they made to boat. The boat has never been in any accidents or hard groundings. It is a hurricane Sandy survivor and took a beating from that however the blister was never any worse. Marine survey was done and they noted that it appears to be a gelcote blister and that the integrity of the cross beam doesn't appear to be compromised. They indicated that if it was damaged that there would be cracks and dimpling on both sides of the beam and the fiberglass would have soft spots.

So I plan to repair it better then when it left the factory, I really don't think it a a structural issues more cosmetic, but I still want to strengthen the area a bit better than the factory did.
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
Is it in the vicinty of the keel? Do you have plan of the boat that you could markup?
Something is going on down there. It looks like something has expressed it self from either keel or the side stays or the mast.
I'm not sure where it is? I don't think it's just cosmetic.











 
Dec 28, 2016
33
Hunter 34 MiddleR
Captain, Have you noticed anything different at the Cross-beam overhead ? Something major is going-on for such a crack to open up like this. The glass is pretty thick down there. I wouldn't be surprised if wasn't something associated with the Compression Post .
Barn-dog
 
Jan 24, 2017
666
Hunter 34 Toms River Nj
Did some exploratory surgery on this bulkhead under the sink area and on the othe two bulkheads midship and aft. Found that all the bulkheads fiberglass are approximately 1/2 " thick not including the gelcote.

Where the crack/blistered area is the fiberglass is less then 1/16 "- 1/8 " thick and all the other areas of this bulkhead that I drilled pilot holes into are the same thickness as the rest of the bulkheads 1/2" or thicker.

As I mentioned before the bulkhead shows no signs of other fractures or stress nor does the bulkhead above the compression post. The blister/ crack has been like this for well over 15 plus years. I believe that this blister/ crack is a result of not enough fiberglass was laid in this cross beam section when the boat was made 35 years ago. I believe that over the many years slight flexing in this weaker area of this bulkhead section caused the blister/ crack to develop.

Now here is the big question?

How can I reinforce the inside of this bulkhead so that the fiberglass thickness is the same as the core samples.

1) If I cut an access hole through the top will that weaken the bulkhead? Then how do you fix the access cutout?
2) If I cut away the blistered / cracked effected area, fill the cut away area with fiberglass and resin, will that strengthen the area or will the repaired area just fracture again?

I don't work with fiberglass and resins however my understanding is that the fiberglass gets its strength from numerous layers of cloth laid in different directions.
I don't think that plugging a hole with fiberglass will strengthen this bulkhead and it will simply crack again. I plan to visit a few auto body repair shops for some structure ideas.

Anyone that has any suggestions, please let me know.
 
Sep 21, 2009
385
Hunter 34 Comox
Robbie, You have to grind the hole all around until you find the 1/2 in thickness in the surrounding area. Then feather the edges back say, about an inch if you can. Then start laying a heavy cloth slightly larger than the main hole. Let that set up and then lay slightly larger patches until you have reached the size of the feathered area. A really good U Tube site is Boat Works Today
He will take questions and there may be a video to show you what I tried to explain.
 
Mar 29, 2017
576
Hunter 30t 9805 littlecreek
You put a piece cardboard on a string with knot to hold epoxy from running away into void
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
Isn't it supposed to be a cored stringer with fiberglass as the "skin"?

The fact that Hunter didn't get that it right when they laid up the hull would seem to be better corrected

I am pretty sure that crack and hole didn't happen because of some blistering.

What is the extent of the lack of core?

It would only make sense if it was some intentional wire way. I doubt that is the case for a whole bunch of reasons.
 
Dec 28, 2016
33
Hunter 34 MiddleR
Robbie,
Your picture of the crack does look like it was caused by some kind of flexing in the hull. You should grind-out the entire area of the crack (and a larger area around it) as mentioned above, and rebuild it with good epoxy. If you don't want to tackle this, get a good glass man who works at a marina. Just filling the hole will not be adequate.
Barn-dog
 

SG

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Feb 11, 2017
1,670
J/Boat J/160 Annapolis
I thought the beam was farther forward, near the mast? If it's just a fiberglassed-integral-tube-beam, with out core, then you need the wall thickness to brought-up to spec discussed above.

It could have failed, not because of thickness only; but, rather from a "mix" problem which localized

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