Ice Box Design

What better activity for a freezing new years day…

After revisiting some of my older thoughts on ice box features, I have made some changes, most in the interest of reducing complication, cost and build time.

One or Two?

At one point, as the ice box cabinet would have such large capacity, the plan was one half would be a separate icebox, the other half a side opening all-in-one refrigeration unit. Two separate units would provide redundancy. The new plan is to have one large ice box with adjustable internal dividers.  At least one evaporative plate on one side for refrigeration, and a freezer holding plate on the other. The freezer plate provides redundancy should the other fail, and vice-versa. Compressor units would be located in a nearby separate locker.

Insulation Materials/Construction


Past research has discovered many high-tech insulation materials such as vacuum panels, various foams, etc. If one really wanted to push the envelope on R-value and maximize volume, these materials would do it. But they also maximize cost and complicates construction. Therefore, after browsing other boater’s DIY ice box construction (even recommendations from the Gougeon/West System people), I have settled for “keep it simple” and “good enough”.

Construction will be a plywood carcase with the insides layered, from out to in:

  • Mylar radiant reflective sheeting
  • 2 inch foam insulation (like the blue stuff you get at home improvement stores)
  • 1 inch foam insulation (similar, optional depending on final volume)
  • half inch plywood, the “internal” box
  • quarter inch food grade UHMW or PVC liner with welded joints 
  • drain port with hose into bilge
Now, the assembled cabinet cannot fit though the companionway, therefore, it must be cut and “dry fitted” in the shop, disassembled, with final construction performed in the boat “in situ”.


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