Tech Wiki

Ice Box and Galley Sink Drain Improvement

by Stu & Cory Jackson, Aquavite #224

We have written in the past to the List and Mainsheet about connecting the galley sink drain to the existing ice box drain line which runs to the foot pump under the galley sink. Older boats have a foot pump under the galley which was originally ONLY connected to the ice box drain. The galley sinks drained, VERY slowly, directly to the through hull. Many owners have improved on the basic galley drain problem. This is a description of the basic "untouched" galley drain piping with a foot-pumped "assist."


The previous owner of our 1986 boat had made a new "T" connection into the ice box drain line to the foot pump with the galley sink drain. This originally made a lot of sense to us when we first bought the boat two and a half years ago: the galley sinks never did originally drain very well by gravity, so whatever help we could get from the foot pump was very welcome, and using the foot pump that was ONLY dedicated to the ice box drain by connecting the galley sink line to the foot pump made draining the galley sink a lot faster. Recently, we experienced a back drain of galley sink water INTO the fridge. This became a major cleanup project. This necessitated a rethinking of the connections.

We discovered that the end cap from the ice box drain pipe to the drain line was not tight, which had allowed the water from the sink to rise up into the ice box. This was a relatively easy fix. By tightening the plastic lock nut of the through fitting against the wall of the inside of the bottom of the box with a 15/16" box end wrench and a parallel clamp on the end cap (which also required standing on our heads to get down that far down into the ice box), we stopped the backup. Tightening the end cap of this line was an easy first, and simple, choice. But what could we do to improve the arrangement? We noted that there wasn't a shut off valve between the galley sink line and the ice box line. It was only an open "T" connection. A valve could be installed to keep the "cold" in the ice box, and with the removal of the end cap on the drain line inside the box, this new valve would avoid water backing up into the bottom of the ice box from the galley sink drain; in the valve-closed position only the galley would be drained by the foot pump; when the new valve was opened, we could also drain any water from the bottom of the ice box.

We replumbed the connections between the ice box drain and the galley drain to the foot pump with about $11 of plastic plumbing parts from a hardware store. Mixing 1/2 inch and 3/4 inch fittings, we fabricated a brand new connection assembly. The most challenging part was to find a 1/2 inch to 3/4 inch adapter. The only available one was a 1/2 x 3/4 brass bell fitting, but that was needed because of our existing fittings. It could easily be done all in plastic. The brass does, however, lend a "bit o' class" to an otherwise dreary part of the yacht!

If you have an older boat, or haven't used Al Watson's new galley sink drain idea, or if you only use your "ice box" as a fridge (as we do with our Adler-Barbour), this could work for you. If you use your ice box for "real" ice, it will also work, and may be a lot more useful -- you'll have more water in the bottom of your box from melted ice that you will need to remove.

Somehow, somewhere, wet stuff WILL get into the bottom of your "ice box": either condensation from your cooling coil, or from real ICE which tends to melt, even in Alaska, I hear.

The installation of the shut off valve and the fittings is relatively easy. If you remove the two drawers, and open the lower door, there is room to maneuver with tools. The hardest part is finding the parts: our local hardware store was a better, and less expensive, source than a marine store. The plastic ball valves are very helpful. They are available in many sizes, and for our boats 3/4 inch and 1/2 inch sizes are just right.

We lubricated the inside of the ball valve before we installed it in the piping assembly to assure that the valve worked easily.