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The Galley Sink Drain
This page was last updated on 22 March 2003

During the first two seasons of use since the restoration, the galley sink continued to plague us with annoyances.  The original sink I installed, a wonderful, 9" deep version, was way too deep for the location in the galley--the bottom of the sink was lower than the waterline outside, so the sink always contained several inches of water.  On to plan B:  install a shallower (5") sink.  This worked OK during the first season with the boat, though the water level was still barely below the bottom of the sink.  When we loaded the boat heavily the second season with more cruising gear and provisions, water tended to enter the sink, especially when people were sitting in the cockpit.  Also, when sailing on port tack if the sink drain was open, water would come in alarmingly.  

After dealing with this annoyance, and potential hazard to the safety of the boat, I decided to take the drastic measure of installing a sump chamber and pump in order to better handle the sink drain.  Electric pumps tend to be power hungry and prone to failure, but I didn't see any true choice in this case.  Plus, installing this rig would allow a seacock to be permanently closed and sealed--always a good thing.
 

The first step was to remove the old drain assembly and hose.  In the tight confines of the space beneath the sink, this proved to be fairly difficult, and ended up sawing through the metal tailpiece on the sink to get that end of the hose free.  Once that was done, I could twist it off the seacock tailpiece more easily.  Then, I had to cut the drain off the sink too, since the cheap metal tailpiece and its nut had corroded together from all that salt water.  Again, the relatively tight access (but at least I do have clear access!!) made this a bit tougher than it could have been, but I got it done.

With the old drain out of the way, the first order of business was to seal off the now-unnecessary seacock.  I removed the tailpiece and replaced it with a bronze plug, and shut the seacock.  Should I ever need it again, it will be usable, and I don't intend to remove the fitting itself--a blanked-off seacock is as good as no seacock at all, especially when the through hull and seacock are only two years old to begin with.

seacockplug.JPG (159472 bytes)

sumppump.JPG (180488 bytes)I assembled the various pieces and parts I needed to complete this job.  Earlier, I had purchased an Attwood shower sump system, which consists of a bilge pump and float switch mounted in a sealed plastic container with a variety of hose nipples on one end for intake and discharge.  The directions call for the discharge (overboard) hose to run continually upwards from the sump to prevent airlock or water remaining in the chamber, but should this be impossible, there's a provision for drilling a vent hole in the clear plastic cover.  I spent quite a bit of time considering my various options for where to pump this thing overboard.  The easiest thing would be to install a through hull fitting in the topsides just opposite where the pump is located, which would end up being a bit aft of amidships on the starboard side (where the galley is).  However, I didn't really want to install a fitting here, for several reasons.  First and foremost, this location would surely lead to an unsightly streak of gunk on the side of the hull, a combination of bronze residue, soap scum, and food bits from the sink.  Yuck--and totally unacceptable to me.  I certainly wouldn't consider locating the discharge anywhere but at the gunwale, because nearer the waterline would guarantee that it would frequently be below the heeled waterline, and would allow back flooding.
 

All considerations seemed to point to mounting the discharge well aft, probably in the counter where it would be out of sight and any residue from the fitting would not be particularly visible.  However, mounting the discharge there would mean a much longer hose run, and the impossibility of keeping the whole line running continually upwards (at least not easily).  And the location in the counter could still conceivably allow back siphoning into the pump under certain conditions.  On balance, though, this seemed to be the best location, so I bought enough hose to r each all the way there from the galley.  I also purchased a threaded bronze through hull fitting (3/4"), a bronze shutoff valve, and a bronze 90 tailpiece fitting (all for 3/4" hose).  To complete the sump installation, I also purchased some duplex wire and a switch to isolate the pump and shut if off if desired.  I had to order a new sink drain fitting to replace the one I cut off earlier, since I couldn't source one locally.

thhole3.JPG (167241 bytes)With all the pieces on hand, I chose a nice, very warm afternoon (finally!) to install the through hull fitting.  After hemming and hawing for some time, and looking at the hull in a few places from both inside and outside, I chose the location in the starboard counter near the existing bilge pump outlet, and, from the inside, drilled a small pilothole to the outside.  After confirming the location, I applied some masking tape over the hull on the outside to help control chipping; then, still outside the hull, I cut a 1" hole with a hole saw (the correct size to fit the threaded through hull fitting).  One more hull core sample to add to my collection!

thholeinside.JPG (155253 bytes)After removing the tape, I tried the fit of the through hull--the hole was a bit snug, so I reamed it out a small amount with a drum sander attachment on my drill.  Once the fit was right, I cleaned the inside of the hole, the hull, and the inside of the hull with some paint thinner to remove dust and contaminants.

Next, I preassembled the bronze shutoff (ball) valve with the 90 bronze tailpiece.  I applied some Teflon tape to the threads and tightened the two pieces together, ensuring that the nipple faced the way I wanted it to when it was tight.  I took the time to do this step ahead of time so that I could ensure that the assembly would be properly aligned when I installed the valve on the threaded through hull fitting.  Because this fitting is above the waterline, I saw no need for a flanged, through-bolted seacock, but wanted a solid shutoff valve so that I can close this fitting off should there be following seas or other conditions that threaten to back siphon into the sump through the counter.  For most conditions we expect to experience, this should not be an issue.
 

goopedth.JPG (160188 bytes)With both sides cleaned up, I heavily gooped up the through hull flange with polysulfide caulk, and applied some to the first inch or so of the threads as well.  Then, I inserted the fitting into the hull from the outside; the fit was tight enough that it stayed by itself while I went aboard to install the nut.  On the inside, I applied a bit more caulk around the fitting, then screwed the nut down tightly, first by hand and then with a wrench.  I inserted a bar into the fitting from the inside to hold the mushroom from turning while I tightened the nut.
 
valveinside.JPG (157514 bytes)When the nut was tight, I cleaned off the excess caulk that squeezed out around the nut, and screwed the ball valve assembly onto the remaining threads.  The nut below held the through hull tight enough to prevent it from turning when I tightened the valve in place.  I did twist the whole assembly just enough when it was tight to align the valve handle and 90 nipple the correct direction.
 
cleanedupth.JPG (162483 bytes)Next, I went back outside and down to the ground, and cleaned up the caulk squeezeout around the mushroom fitting.  

 

hoseattached.JPG (159060 bytes)With the fitting all installed and cleaned up and secure, I ran a length of 3/4" black fabric-reinforced hose from the lazarette to the galley, following the path used by the bilge pump hoses.  I secured the end of the hose to the new valve and nipple with  an AWAB clamp, and routed the hose into the locker beneath the galley where I planned to locate the new sump pump.  I let the other end run wild for now, and secured the hose with plastic cable ties in several places along its run.
 

sumppumpswitch.JPG (167608 bytes)I ran a length of 14/2 sheathed safety cable (red and yellow wires) from the positive and negative distribution busses behind the electrical panel over to the galley.  At the positive distribution end, I installed a 4-amp inline fuse, as called for in the pump wiring directions.  Following preexisting wiring runs, I threaded the cable along until I reached the galley locker where the pump was to be installed, securing it every so often with plastic wire ties.  Inside the locker, where it would be convenient if needed, I installed a rocker switch to allow the power to be shot off to the automatic pump.  It should be on most or all of the time, but the switch is a good idea just in case.

Next, it was time for the final sump installation, wiring, and plumbing connections.  First, I secured the plastic top of the sump with six screws, drilling through the top into the provided screwholes along the edges.  With the top now secured in place, it was time to install the sump chamber in place in the locker beneath the sink.  I decided to install it tightly against the rear bulkhead, partly because it was the best location, but also for the sake of convenience; with access to this locker as difficult as it was, and requiring various contortions on my part, installing the sump where I did meant that I only needed to install two of the four hold down clamps to secure the chamber in place.  Fewer fasteners to install whilst standing on one's head is a happy thing.  I secured the chamber with two hold down clamps on one side, and I drove two longish screws into the rear bulkhead just above the top of the sump to effectively hold that side down.  Since I had spare clamps, I installed one at the far end just in case the chamber showed any inclination to slide athwartships.

sumpinplace.JPG (161709 bytes)With the sump now secured in place, I completed the wiring, leaving plenty of extra wire bundled up nearby so that I can pull the sump up on top of the counter for maintenance without undoing the wiring, should such maintenance become necessary.  Finally, I installed the new sink drain to replace the one that I was forced to cut earlier in the process,  and connected the discharge hose to the appropriate nipple on the sump.  The fabric-reinforced hose proved to lack the stiffness needed to make the tight bend between the sink drain and the sump intake, so I rummaged around in the shop and found a length of wire-reinforced hardwall hose left over from something else, and installed that from the sink to the sump.

Project complete.


Update:  2008

After dealing with a variety of ultimately unsuitable modifications to the galley sink setup, I decided to completely reconfigure the system, reverting to a deep sink and locating a new sump chamber in the bilge, far removed from the sink itself so as to address several issues with the "third try's a charm" semi-original setup that I installed in 2003.../maintenance/maintenancelog2009.html#71809

Read more about the newest changes in the winter 2008 refit log.

Update:  July 2009

The sealed automatic switch (non-Mercury, non-float) that came with the Johnson sump chamber failed to work acceptably or even marginally, forcing me to replace it with an older, spare mercury float switch left over from my previous installation.  Read more about the fix here.

 


Glissando, Pearson  Triton #381
www.triton381.com 

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