Friday, February 6, 2009

Project: Replace the water heater

December 2008 - January 2009

Eolian has a water heater - life onboard would be difficult without one, But this is not the 50 gallon monster you'd find in a house. This one holds 6 gallons, and is electrically heated (10 amps, 110VAC). However, to provide hot water when we are off the dock, there is a separate coil around the tank through which the cooling water for the engine circulates, when the engine is running. Since the engine has a 160 degree thermostat in it, it can get the water in the tank quite hot! But it takes about an hour of engine run time for this to happen. If we have been off the dock doing a lot of sailing and using the engine sparingly, showers onboard don't take very long!

The water heater is located below the dinette seating, on the port side of the boat.

While working on another project (subject for a future post...), I broke off the fitting on the hot water heater where the hot water exits... because I was laying on it. Aside from me getting severely scalded as a result, we discovered that the water heater was failing - the interior was filled with rust. And Jane pointed out that the hot water had been orange for some time.

Time for a new heater. Before the old one (30 years old!) ruptured.

The old heater was about 15" square by 19" long. This posed a problem, since the opening in the settee hatch was only 13.5" wide. After disconnecting the 110V connection, the hot and cold water connections, and the engine heat exchanger connections, and freeing the water heater from the compartment floor, I tried to cut it in half using a sawzall. It was going to take a long time, and the sawzall was difficult to control in the tight quarters. This attempt was abandoned.

A question I always ask myself in these situations is, "So how did the builders get it in there back in 1978?" A close examination of the edge of the hatch opening reveals the truth: They cut a segment out of the seat, and re-attached it. The factory had access to the gelcoat that all the white interior pieces are covered with, so they were able to hide the cut/repair pretty well. But stress cracks revealed the presence of the cut/splice.

Since the boat builders had done it that way, I followed their lead and cut a segment out of the settee seat base to allow the extraction of the old unit (you will note that I made the end cuts at 45 degrees, so that when the cutout piece is re-glued in place with epoxy, it will be supported). It was then dead easy then to lift out the old tank.

The new heater is much smaller - just 13"x13"x16", even tho it has the same capacity as the old one: 6 gallons. I suppose this can be attributed to nearly 40 years of improvement in insulation, and to the more form-fitting aluminum tank instead of a cylindrical steel one. And the size of the new heater allows more storage in the compartment, and will allow extraction in the future through the seat hatch without requiring cutting again.

It looks pretty nice mounted down there, and is producing beaucoup hot water (no longer orange) for us. The engine hot water lines are not yet hooked up in this picture.

The repair to the cutout was not difficult. I mixed up some epoxy, thickened it with chopped fiberglass strand and microballoons, and troweled it onto the mating surfaces (after suitable masking). The masking allows for a clean-looking repair when you have to wipe off the inevitable drips, runs and smears. I clamped a saranwrap-wrapped board underneath to hold everything in good alignment while the epoxy cured.

With a huge effort, I could probably color-match some gelcoat and use it to hide the splice. Some day, I may do that. When it is the highest thing on the priority list.
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2 comments:

Anonymous said...

Greetings Bob and Jane!
Ken shared your blog with me, and I've been checking it faithfully for updates. Good work capturing the why, how and what of it all. I'm finding it very enjoyable!
Jessica (s/v Yare)

Bob and Jane Salnick said...

Hi Jessica!

Thanks for hanging with me as I try out my storytelling wings. I am looking forward to hearing Yare's tails as well. You have some good ones by now I feel certain. We need to split a bottle or two of wine and go to it.

bob

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