Rebuilding Nikki’s Icebox

Twenty-four hours into my first three-day weekend on my recently purchased 1974 Cape Dory 28, Nikki, the ice was gone, the butter was mush, and the drinks were warm. In Florida, in July, I soon discovered that the icebox couldn’t hold 20 pounds of ice for a single day; the melt rate was about a pound an hour. Fixing a bad icebox—and most old ones are very bad—is no small matter. But it’s worth it. After about a month of part-time work and with very little money, I multiplied Nikki’s box efficiency by a factor of five. Now, providing that I start with a bit of dry ice that will super-freeze some of the food and all of the ice before setting out, I can sail to the Yucatán Peninsula with fresh provisions all the way. Here’s how: Step 1: I started by drilling a few .75-inch holes through the top, bottom, and sides of the icebox so I could extract and examine a core sample for each hole. I needed to see the details of what kind of insulation had been used and if the spaces between the box, the hull, and adjacent bulkheads had been filled with foam. To measure those spaces (which were completely empty voids), I simply inserted a small dowel until it made contact with the hull or solid structure. I discovered that my icebox had been made by lowering a laminated interior box liner into the outer molded fiberglass retainer, making a box within a box. The space between the two boxes, a mere 1 inch, was filled with closed-cell urethane foam. The boxes provided zero insulation, and the foam wasn’t much better.