Talmid, our Hans Christian 38, has a small diesel auxiliary which is supplied fuel by two ‘black iron’ storage tanks. One (60 gallons) is located port side forward of midship. The other (85 gallons) is starboard and located beneath the aft quarter berth. They have separate fill ports and are not interconnected but are linked at a valve manifold so as to supply the engine depending on which source is selected.
The forward fuel tank had not been used for several years. All that I knew was that this tank was empty with no trace showing on a screw cap dipstick. The previous owner had explained that he never used the tank. Since I intend to voyage beyond the Bay I need to have this reserve range. It would serve no purpose empty. Some sailors extend their boats range by lashing Jerry Cans on deck but Talmid has lots of capacity. I figure that with a conservative throttle setting the burn rate will be ~1/2 gallon per hour. This Energy will be used for maneuvering, electricity generation, and propulsion when the wind drops.
However, there were concerns. The forward tank wasn’t being used… How about residuel fuel contamination or tank integrity? The supply lines leading aft to the manifold likely contained air if the tank was truly empty and Diesel engines, unlike gasoline engines stop running and won’t re-start if there are air bubbles in the delivery system. The lines have to be ‘bled’ ensuring a steady stream.
The place to do this is in the marina slip as opposed to dead in the water on open ocean while pitching and rolling. After much thought and from the security of the berth since this was my first foray, I proceeded as follows.
- Added a few gallons at the fuel dock ensuring that the unused tank did in fact hold fuel – checking that the bilge stayed dry. (What a clean up mess if it hadn’t!)
- Motor back to the berth on the known good aft tank.
- Acquire a length of 5/16″ short hose and a primer bulb from the marine store.
- Partially drain the Raycor (pre-filter) and disconnect its fuel supply line.
- Connect the make shift pump (primer) to this line and direct the output into an empty plastic water bottle for discard.
This is a juggling act and a bit messy. Diesel is nasty smelly stuff. Laytex gloves, paper towels and containment diapers required. The procedure worked. The first emission was deep red indicating old fuel from the line but quickly gained the healthy pink color of fresh. Further, after drawing off an additional quantity it remained so. There weren’t any debris or contamination to note which was a relief.
Reassembling the Raycor by attaching the tank supply line that I had undone was simple enough as was topping the element bowl and securing the screw top lid.
Since air bubbles were likely introduced at the Raycor, my attention was directed downstream to the engine mounted secondary filter. Disassembly is not required. A bleed screw is installed for this purpose and the procedure is:
- Unseat the bleed screw
- Actuate the mechanical lever of the fuel feed pump to purge the fuel
- Observe the fuel gurgling from the bleed as you pump fuel
- When there are no more air bubbles escaping seal the bleed screw
- Start the engine and check for smooth operation as it runs.
- Shutdown if there are no problems after 15-20 minutes runtime.
- Cleanup and good to go!
Having accomplished this exercise I now have the experience of having done it and verified which tools will be required should a tank accidentally be run dry or a filter need changing. Most importantly designed capacity (145 gallons) is now available.
that I won’t forget…and neither will my crew — imagining various recovery scenarios and outcomes!
