Engine Room Fuel Tank(s), AC Unit Replacement

The AC unit on the boat was acting a bit weak so we decided to replace it while we were in our ďshipyardĒ with access to tools and facilities.This turned out to be a real good idea as the replacement unit, while supposedly a drop in replacement for something that was twenty some years old, really wasnít.The foot print was the same, but the structure for mounting the return air was different.

Since the AC unit was out, this would be the ideal time to finish off the sound insulation project, requiring temporary removal of the starboard fuel tank.We could take this opportunity to inspect it for any issues.

Guess what.We condemned the fuel tank.After some thought we decided that we didnít need to be carrying around 210 gallons of diesel.Two fuel tanks would suffice if we replaced the third fuel tank with a water tank.We use more water than fuel.

So, we finished off the sound insulation project, gluing the insulation to the overhead as we had done before on the port side.

A plastic tank of a suitable size was ordered, and we made the sleepers and hold downs to keep it in place.

The old fuel fill location, now being replaces with a water fill was directly over the top of the tank so we found a flange that could be mounted to the tank top rather than filling the tank from the side.

Once we had the tank installed we could put the AC unit back in having modified the return air duct work.

We thought that we were done with any work that needed to be taken care of in the engine compartment, but we were wrong.

Round two on the port fuel tank was required as the tank that we had welded (even though we pressure tested it) didnít hold.We didnít put fuel in it in 2013 as we werenít going anywhere and there was no use growing who knows what in an unused tank.Since we were going off cruising in September of 2014 we put some fuel in it at spring launch.Not much, as we still didnít trust the welds.A few weeks later, the tank started to seep diesel.

Ok, out with the old tank again which requires removal of the holding tank.The replacement tank was going to be plastic as this will never corrode and you can see the fuel level in it.20-20 hindsight says that we should have had a custom, direct drop in replacement made.The plastic tank had its fill mounted in the center of the tank, on the top.The hose needed to come in parallel to the top of the tank.In order to do this we needed to have some pretty sharp bends in the hose and were reluctant to have any dips that would allow fuel to pool (or not allow a free flow situation while fueling).


Sleepers and hold downs needed fabricated and a new fuel fill location in our recently repainted deck was required.

Rather than remove the old fuel fill, we made sure it was impossible to ever put anything down the hole.If and when the deck gets repainted we can remove and patchthis area.

We thought we were done so the holding tank went back in, but it wasnít to be.I got thinking about the ground from the new fill to the ground system on the boat,I hadnít grounded that fill.To access the fill from the underside, the holding tank had to come back out.Live and learn.

Then, one day I was reading the fine print on the tank installation and they said to make sure there was room for the plastic tank to expand (2 to 3 percent in all directions).Somebody expertly installed the tank so it was wedged tightly between nicely varnished wooden cleats.Once side I could move, the other side needed to have the wood trimmed down.And by the way, I had to modify the support structure for the Vacuflush vacuum generator that is mounted right alongside the tank.Now we are done.So, the lesson is that if your time has no value, use a pre-fab tank.If you are paying somebody else to do the job, spend the money for a custom tanks otherwise the man hours will kill you.

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