Crack in Hull below Pylon

My '83 Hobie 16 had a 8" horizontal crack on the inside of the starboard hull, in line with the front Pylon (4" up from the bottom). I repaired the crack from the outside but the crack reoccured. I then cut an inspection hole and found that there was a diagonal crack in the foam block from the top center to half way down the outer side. It was also apparent that the lower section of foam was not attached to the out side of the hull. I then glassed the front, top & back of the foam block in order to secure the two sides of the hull together. Guess what, the exterior crack came back.

I would be interested to know if any one has had success with this type of repair? How is the Pylon attached to the hull? Do I need to remove all the foam in order to resecure the Pylon to the hull?

This might give you a better visual of the inside of the hull:

http://www.thebeachcats.com/modules.php ... _album.php

It's a hobie 14, but the construction is basically the same.

On another note, none of my foam floatation is attached to my hulls. It all kinda slides around inside. I think to repair the kind of crack that you are describing, you would have to lay up some glass on the inside of the hull, along the crack. Then fill the crack from the outside with an epoxy filler.

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Marcus
H16
Narragansett Bay, RI

Thanks for the link to the pictures on the beachcats.com site. I was also able to fine some cross sectional pictures of a H16 hull in the tech forum. The foam I was referring to is the foam encasing the base of the pylon. I am now thinking the glass attaching pylon base to outside of the hull has broken loose resulting in additional pressure on the inside of the hull resulting in the crack.

rstorkey: I believe your diagnosis is correct. Have you obtained any further insight as to the best method for repair? I apparently have the same problem.....same year model, same hull. Will probably cut the port hole this weekend....

Jerome

The final fix was to remove all the foam from around the pylon. Rebuilt the entire footing for the pylon to the hull. This included fabricating a plate for the pylon to rest on and then securing to both sides of the hull along with high density foam around and up the pylon with more glass all around it. After all that the crack still reappeared so I am at a loss as what else to do. Since then I have been monitored the crack in the gel coat and it has not gotten any bigger.

I have had this happen to two 16's that I have owned. The first time I just cut a piece of wood that fit under the pylon to hold it up, then resined it in. The second time was with a good racing boat that I did not want to get rid of. Iput a porthole in next to the pylon. I then cut the glass away from the pylon. Enough to be able to get a good bond with more glass and resin. Seemed to work fine. Another note: The first time it had an indent in the top deck. Meaning the the top did not let go from the tube, it just collapsed. The ssecond time I could pull up and down on the pylon and witness it move in and out of the hull about 1/4 inch.