Spend Quality Time With Your Boat Fuel Filter

This voyage I planned for many years

but once it started brought me tears.

My friends all gathered to wish me well

but far off soundings it went to hell.

My tanks were pressed and hopes ran high

until my diesel decided to die

The RPM’s dropped off a bit

and then the iron thing just up and quit,

I checked the filter first in line

and then my heart began to pine.

For what I saw in the sediment trap

looked like molasses in a June brides lap!

Over the years, I’ve lost count of the fuel filter fouls that have plagued various voyages I have been on. Usually the problem is many faceted. Lots of vessels sit at the dock for years with various biological blooms Occurring in their out of sight fuel tanks. These critters slowly multiply in moisture from condensation or possibly contaminated fuel and eventually invade the fuel delivery lines and Filters on dark and stormy nights when things get sloppy and sloshy, I have made it a habit to add the proper amount of biocide at each fueling, but what about the previous owner? Do we know what he or she did? Most of the fuel tanks I survey do not have access plates as per National Fire Protection Association 302-5-4.1 (a) -They shall not have openings in bottom, sides or ends.” (b) Openings for fill, vent, and feed pipes and level gages (if installed) shall be at or above the top most surface of tank (c) Clean out plates shall not be installed (d) Plates used for fittings shall be secured in such a manner that they cannot be used for clean Out purposes. Exception: Diesel fuel tanks shall not be required to comply with 5-4. 1. If you don’t have inspection access to the internal portions of the tank for occasional inspection and clean out, your front line defense is a good filtration system.

I had only one small racor filter between my diesel tank and the engine filter. I wanted to see if I could easily make a manifold that could be used to isolate a filter and add a second one to prevent the slosh by gosh from endangering my vessel or crew. Usually when these filters foul you’re between a rock and a hard spot. The filter is usually in not such a great location unless you have a walk in engine compartment, which I do not. I went to the True Value hardware and purchased two 3/8″ brass T’s, six 3/8″ brass pipe nipples, eight 3/8″ brass pipe reducers, six 3/8″ pipe to hose barb reducers, two 3/8″ pipe unions, four 3/8″ stainless steel ball valves, one roll of Teflon tape and a five pack of 1/2″ tube straps along with enough U.S.C.G. approved fuel hose to re-route my old system. If you have a go at this project, don’t reduce fuel delivery hose diameters or you may be attempting to wean your engine from its desired drink of diesel.

I came from the tank to the top of the system and valved to the inside of two small racors. Other makes will work as well. There are pros and cons to all marine equipment. The outlet side went through valves to an identical T union and to the engine. Some more costly filters have vacuum gauges to tell you when a filter needs changing, but usually an engine will begin to hunt a bit giving you some warning that the engine is going to quit from lack of fuel. Some salvors I’ve met attribute lots of business from too fine a filtration element. Unless you’ve primed a diesel before under the best of circumstances, it can be vexing tied to the dock. If you’re attempting this procedure in a rude sea or between the rock and a hard spot it can be pure panic. Some mechanics I’ve met advocate using the old Fram canisters with filtration elements that aren’t fine enough to stop the engine. Filter elements are rated by micron filtration capabilities. Talk to your mechanic and get his or her opinion as to suggested micron rating. Sometimes a rough running engine is better than no engine at all. The manifold allows you to isolate the fouled filter and put a fresh one on line so you can change the fouled unit at your leisure and not in a panic situation. A simple but effective bit of insurance for older tanks. If you’re planning a trip, there are mechanics who have scrubber systems that for a fee will re-circulate your old fuel through a filtration system and this isn’t a bad idea at all. There are lots of diesel powered boats out there because of location clean out plates aren’t a good option and the home made manifold would work well here. I hope this simple devise will be a good project for some of you out there who are in the same boat I’m in. I am a believer in miracles and guess what, when it was all finished it didn’t leak a drop. Happy sailing and remember the Lord loves sailors.

Neil K. Haynes May 1998

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