Irwin owner here
After I bought the boat, a 37'er, I found out nothing was ever done to the boat. The PO was dead, and his sailing buddy was only that, knew nothing of repairs.The first year the CB clunked, big time. When I pulled the boat in the fall, a project was to remove the CB and repair it. This is what I found and did:The trunk was never bottom coated so there were zebra mussels in it. I cleaned it out and painted it using a very small roller. The CB was badly cracked and the pivot hole was described as an invisible hourglass laying on its side. Repairing it was straightforward and two repairs, the hole and the CB itself.I bored the original hole of 1" to 2" because that was the smallest size I could go to completely repair the damaged area. If the damage was more, I would have gone with a 3" hole. I epoxied a 2" bronze (should have used stainless) bushing in the hole. Done.For the CB itself, I cleaning out the damaged area and any spider cracks with a dremel tool. Then I washed it removing what was left of the bottom coating in the process (it was mostly gone anyway). Then, I duct taped one side of the trunk and layed it down on sawhorses. I leveled it as best I could, then mixed batch after batch of thickened epoxy and filled in the holes and cracks. Took a gallon!!! I flipped it over after it cured, removed the tape, and filled in that side. Then I faired both sides with a belt sander (Wearing a respirator and a HUGE exhaust fan). The banging caused damage on the inside too. I could see damage on the outside, so I had a pro look at it and make a recommendation. We both agreed it could only be fixed from the inside. Oh joy.To repair it, I had to cut out (destroying both) the perfectly good 75 gallon aluminum fuel tank and the perfectly good 85 gallon aluminum water tank. Then I had to remove 500lbs of concrete ballast (I weighed each bucket) to get to the problem areas. I found four areas of damage. The damage was at either end of the built up area that held the 1" pin that held the board on. The built up area was all fiberglass and it reminded me of 1/2 a tomato juice can layed on it side and cut down the middle lengthwise. At either end of the buildup, where it attached to the CB trunk and the hull, it was delaminated. The repair of this area was a pain. I cut out all the extra fiberglass that held the tanks in, ground down the 4 damaged areas, then washed the mess down with three kinds of soaps, finishing with acetone. For the repair, I cut lots of strips of fiberglass mat and cloth and then began. I filled in the cracks with thickened epoxy, then started building up the pin holder running the mat and cloth up the hull and trunk sides till the whole thing was twice its original size. Done.I left the concrete out so it will make it easier to fix should it go bad. I will eventually add 500lbs of lead from a plumbing supply store to replace the concrete... and found a used 30 gallon water tank that I can remove, and bought a new 25 gallon fuel tank (range 231 miles). I lost 50 gallons of diesel storage but realized I only use less than 15 gallons a year anyway. And for long trips where I know I will have to motor, like going from Cleveland to Miami or the Keys, I will simply put in a temp 55 gallon barrel (it's one of those blue plastic types made for fuel). That would give me 80 gallons and at 3/4 gallon per hour at 7 mph I should have a cruising range of 700 miles. Any questions.