Catalina 470 Owners Association

Tanks-Senders-Hatches

Supplied by Bill Martinelli, Voyager #11


If you change from the sender that is recessed down into the tank, to one that is mounted on the top of the tank, you will get more accurate readings as to when your tank is full. The diagram shows you why this doesn’t happen with a recessed sender.

Go to KUS-USA (formerly Wema USA) to find replacement senders. The stainless steel screw thread type was a model S3U (Wema designation) – you may or may not need a thread adapter kit – the Wema unit that we replaced screwed directly into the old threads. If you wish to mount the senders in the top of the tank, use the SSL or SSS stainless steel units. In both cases you need to select a sender length. If you opt for placing the unit on top of the tank, get a gasket for the sender from the manufacturer. To install, you’ll need a hole saw large enough to allow the float to go into the tank. After that all you need are five stainless sheet metal screws to hold mount the unit.

Tank #1 showing sender position if you want to install a full height sender as opposed to the one that is recessed below the top of the tank you may do so just to the right or just in front of the original one. The full height unit uses five screws to hold it down. By using the full height unit you will get correct readings as to when the tank is full. Both this photo and the one below were taken before I changed to the top mounted senders.

Above, water tank #4 under the galley sole; you can also replace this sender with a full height unit.

This is where tank #4 used to reside under the galley sole. It is now a storage area that measures 54′ long by 26″ wide and ranges 6″ to 13″ in depth. A milk crate and some liquor bottles will stand upright under the deepest area of the forward hatch. The storage compartment extends all the way underneath the midship refrigerator and is a great place for long-term wine storage.

Above is the galley sole showing with two hatches installed to access the storage areas created after removal of the water tank.

Above, (former) water tank #5 – located in the companionway between the stairs and aft head – at a capacity of just 15 gallons meant it always ran out when you were in the shower covered in soap! A wine cellar is a much better solution. Also you can fit in an additional sump pump to help drain the aft shower. (It also helps if you add an additional drain to the outboard side of the shower drain pan, for those times you are on port tack.) Outboard of the wine compartment we are also able to stow a folded Fortress #23 anchor and spare auto-pilot ram and other items.

I replaced the #2 water tank (port side of salon) with a factory supplied 60 gallon aluminum fuel tank. Above also shows a closeup of the tank sender, fuel feed and return. This is the same sender you can mount in the top of your water tanks.


Below is an overall photo of the fuel tank installation, the large opening with the small hose sticking out is where the new 16k airconditioner is being installed.

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