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Hull Repair


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I have been enjoying and learning from this site for a month now but this is my first post. I was given an early 1970's sunfish with all of the hardware and a good sail with only two quarter size holes in it. The boat was very heavy when I rescued it. I have since installed two four inch ports in the deck, vacuumed out all standing water and have had a fan blowing in one of the ports for two weeks except for the rainy days. Needless to say the boat is much lighter and if the hull were not compromised it is at a sailable weight.
I found two full cracks in the foot well and two holes in the hull where the trailer, after the wood rotted away, dug into it.
I wanted to ask if I have prepped the holes properly so that I can begin to build up the fiberglass. Installing fiberglass cloth backer in the hull holes will not be too complicated but installing backing material in the foot well is going to be more difficult. Any advice or guidance on how to proceede will be most welcome. Thank you in advance,
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I am at a loss as to what epaxial cloth or epaxial tape is. Could not find anything except that epaxial muscles, which lie dorsal to the septum. Epaxial muscles include other (dorsal) muscles associated with the vertebrae, ribs, and base of the skull. In humans, the erector spinae, the transversospinal muscles (including the multifidus, semispinalis and rotatores), the splenius and suboccipital muscles are the only epaxial muscles.

Can you send a link?


Well-Known Member
I am at a loss as to what epaxial cloth or epaxial tape is.
I'll try to use the word in a sentence:

If you try to tear bi-axial cloth by hand, you could damage your epaxial muscles. :oops:

(Some words get converted in the mind of a Zoology scientist...! ) :p

Here are the instructions from the previous link. My buddy's a regular boating fiberglass user—emphases are his:

"WEAR A GOOD RESPIRATOR, not just a dust mask FOR ALL GRINDING AND SANDING OPERATIONS!!!! Wear nitrile gloves to keep the epoxy off your skin. Clean hands with vinegar as it is kinder to your system than alcohol.

Grind away the fiberglass at least 4 inches on either side of the crack. Six inches would be better so that the glass is paper thin at the crack and tapers evenly to the original thickness at the outer perimeter of the ground area. Cut a piece of fiberglass to cover the ground area. Cut additional pieces of glass each successively smaller than the previous one. The number of layers and amount each one decreases in size will depend on the weight of cloth (use cloth or biaxial not mat or woven roven) used. Orient the fibers so that they cross the crack at 45 degrees so as both the warp and fill contribute to the strength of the repair.

It is for this reason that biaxial tape is best for this type of repair as there is no crimp to the fibers. Clean the ground area with alcohol, not rubbing alcohol as it has glycerin. Apply mixed epoxy to the ground area and lay down the fiberglass using the largest piece first and working to the smallest piece. Make sure each layer is completely saturated before applying the next.

If you do not complete the lamination in one go you will have to wash the area with soap and water, sand and alcohol wipe before continuing. Mix in a coloring agent for the last 2 layers.

Sand smooth and paint and go sailing. "

signal charlie

Well-Known Member
Staff member
You should be able to get a backer patch into that middle repair in the cockpit. For the forward repair area you can probably get a small backer patch in the aft area and might consider putting an inspection port on the forward cockpit bulkhead to work on the other area. You can also access the daggerboard trunk from that area which is a common area for repairs.

Good luck