Fuel Tank Vent Trap

[Witzend]

Speaking of cobbling up something from some of the many SS pipe fittings my dad collected from the DuPont dump, here is how I plan to improve my fuel quality. I'm convinced that I'm getting water in my fuel tank from the poorly designed vent. See... the vent in our 310 goes strait down to the tank. This is a poor design, it should first go up before it goes down to back drain any liquid water that may invade. In my design there are (2) separate traps, one for liquid (a clear bottle that is easily monitored) and one for vapor that will migrate through the vent saturating the fuel. I will use hygroscopic substances that are used to remove water from the air called desiccants. These are readily available in packets that can be opened and pored into the hold. The desiccant will need to be replaced frequently to be effective, but, hey we have no protection at all right now. Don't over fill the trap because the desiccant will expand as it takes on water and block the vent. The trap will mount directly under the vent thru-hull in the aft port locker. I will hang the assembly with a strap from one of the port cleat bolts ends that stick through the deck. I will take another pic once I install.

 

[rpwillia]

Plans when complete would be nice

Witz, I have never had a problem with my fuel, but it never hurts to be prepared. Would like to see what the finished product looks like.

 

[Witzend]

Inspect the bottom of your Rayco if you have one that has a clear bowl. I bet you will find some water in it. It is not always easy to see, so use a flashlight.

 

[New Horizons]

Water in Racor Filter

When we bought our boat in June, the surveyor found water in the Racor Filter. The yard changed the filter, checked the fuel tank, took the boat for a test run around the harbor and swore there was no more water in the fuel. But after motoring a while on the first day of our trip up Long Island Sound to our home port of Bristol, the Racor was over ½ full of water. We found a marina and the mechanic checked everything. He removed the sending unit on the fuel tank to put a stick down to the bottom to check for water and said there was no water in the tank.

(Is there any other way to check to see if there is water in the bottom of the tank?)


After motoring the next day, there was about ½ inch of water in the Racor. I drained that and since that time, have never had any more water in the filter for the rest of the season. I never did figure out where that water came from.


But I am now gun shy of water in the fuel, so I am interested in your design Witzend. Thanks for sharing it.

 

[Witzend]

Yes, this exactly what I,m experiencing. I have pulled the sending unit on the tank and pumped a number of times and never got any water, so a real mystery? After checking the obvious sources, I have come to the conclusion that water is coming into the vent. I will be empting the tank soon, and getting fresh fuel in the spring.