The windshield washing system features nozzles installed over the windshields that deliver fresh water from a tank and pump mounted in the console of the flying bridge above the cabin. Photo by David Sharp
December 2022
By David Sharp
After some trial and error installing them, we now have windshield washers aboard Carry On, our 2001 Cape Classic 30 trawler. My partner, Nancy, and I usually steer Carry On from her flybridge. However, when things get really rolly, it’s nice to be down in the main saloon where the motion is reduced. But one problem with steering from the cabin has been visibility through the three-section windshield in certain conditions.
Visibility in rain, especially with Rain-X, isn’t a problem, and we can see out the windshield if there is enough spray coming aboard to let the wipers get to it before it dries. However, as is typical with many trawlers, our problem was when the spray was light and intermittent on a hot, dry, sunny day. Now the seawater would dry almost as soon as it hit the glass into thick salt deposits, and the wipers would just smear the salt around to significantly impede visibility.
The standard solution to dried salt on windshields is to flush them with fresh water. So, I bought a marine windshield washer kit made by Sea Dog that includes a plastic tank with an integral electric pump, a mounting bracket, wire, an intermittent-ON toggle switch and two spray nozzles.
These components are clearly designed to mount below the windshield with the nozzles pointing up at the glass as in a car. But the tank-below-windshield configuration had three disadvantages aboard our boat. First, it would require mounting the water tank inside the lower helm console, which has been stuffed with very important wiring and electronics that would not like getting wet if (or more likely, when) something leaked. Secondly, I couldn’t find a way to cleanly route the tubing from the tank to the spray nozzles below the windshields. And finally, it would mean putting half-inch diameter holes in the cored foredeck to mount the spray nozzles that would then protrude and interfere with passengers being able to sit on the deck and lean against the windshields when at anchor.
So, the obvious solution seemed to be to put the tank up under the flybridge console where there is lots of room and nothing critical to soak if something leaks. This would allow me to easily run the tubing through a ¼ inch hole in the front of the un-cored flybridge cowling to the visor, where I could aim the tubing down at the windshields. To make the install even easier, there was a spare wire running from the lower console to the flybridge that I could use to power the pump.
I had a minor setback mounting the switch because Carry On’s lower console is cored and too thick for the supplied switch’s stem. A friend made me a nice cover plate adapter so I could cut a clearance hole for the switch body to go in from the front while cleverly avoiding the thick wire harness inside the console (I do learn).
After installing the switch, I mounted the tank and roughly routed the tubing – all wired and plumbed, I was ready for the trial run. I flicked the switch, the pump came on, and water poured onto the windshields. I let go of the switch, and the pump stopped, but now my grin faded as the water kept drizzling onto the windshields as it was siphoned out of the tank.
Even as high-school kids with a gas can in the `60s, we knew how a siphon worked. The tank is above the windshields, so obviously, when the tubing is full, water will just keep flowing until the tank is empty. In my defense, I assumed that water would not flow freely through the pump when it was off, but it sure did.
So, I either had to break the siphoning effect by letting air into the tubing or install an electrically activated valve. Breaking the siphon seemed the better plan, so I started looking at off-the-shelf solutions. Vented loops and even small valves made for aquariums all seem to work on the rubber joker valve concept, or they use ball seals and springs. But my tubing is only 1/8-inch ID, so there is only the weight of a fraction of an ounce of water available to activate an anti-siphon valve – not enough to vent anything I could find on the market.
I was about to give up and move the tank below when I saw a squiggly plastic Crazy Straw having a curved section that looked like it would be perfect for a vented loop. I cut out a half-circle section of the straw (sorry, granddaughter Harper) and drilled a 1/16-inch hole in the middle of the curve, being careful not to go through both walls of the relatively soft plastic. Bending a loop in the tubing and putting a hole in it may have worked too, but using a rigid tube seems more reliable.
I mounted my homemade vented loop at a height equal to the top of the water tank and tried again. This time the spray stopped when the pump did, just draining the small amount of water from between the nozzles and the vent. A little water squirts up out of the vent hole when the pump is on, but everything is wet when the washers are on anyway.
I wanted water on two of my three windshield panels, so the tubing from the pump goes to a T-fitting with the longer branch routed to the starboard windshield panel and the shorter leg going to the amidships section. Because these legs are unequal lengths, it took a little tweaking to restrict flow in the shorter leg so that both windshields get about the same amount of water.
I first tried clamping the shorter tube with a tie-wrap to restrict its flow. That did not work well, but a better clamping technique would probably do it. In my case, I simply removed the spray nozzle from the tube going to the further windshield and let the water flow directly down onto the glass. Having the somewhat restrictive spray nozzle on the short leg and free flow out of the longer leg results in about equal flow to both windshields.
This washer installation works very well aboard Carry On with her flybridge. I may make it a little more yacht-like by using rigid tubes for the longer runs – but then, maybe not.
David Sharp is a retired Ocean Engineer living in Newport, Rhode Island. He started boating as a child and has owned over 20 boats so far, but Alexis was a favorite. David and his partner, Nancy Grinnell, currently day sail their Pearson Ensign and cruise New England aboard Carry On, a 2001 Cape Classic 30 trawler.
