Water and fuel don't Mix

Brock · Posted: Wed Jul 18, 2007 10:51 pm Post subject:

John,

Yes, those are the same vents that came with my TC. But the location is somewhat different. My vents are located just above the rub rail, not below. The surface of the hull is actually angled a little skyward at this point, which I believe added to their tendancy to take in water during heavy rain.

Maybe your water did come from waves splashing up to the rub rail and entering the vent from below. The location of my vents would seem to lessen the likelihood of saltwater entering from below, but apparently increased the chance of freshwater entering from above.

I ordered the Perko vents through a local marina. They're pretty cheap. Just had to make sure I got the 90 degree elbow fitting in the right size to fit the vent pipe. My fuel lines do not have any kind of "riser loop" between the vents and the tanks, as suggested in the article. Sounds like the way it ought to be to avoid water entry from above or below.

Brock

Forty Two · Posted: Thu Jul 19, 2007 3:35 am Post subject:

We have more than 400 hours on our engines, and not a bit of water has shown up in the fuel filters. And we have been is some fairly tough water late last season and early this one. So far so good.

I looked at our vent hoses when I was getting the boat ready this spring. Each has a loop in it - one of them was too tight, and had kinked the hose. Perhaps not the greatest quality control - but on the other hand access to the vents and the top of the tanks is terrible on the TC24.

Perhaps your vent hose is not looped at all?

John S · Posted: Thu Jul 19, 2007 5:18 am Post subject:

flagold · Posted: Thu Jul 19, 2007 10:06 am Post subject:

Joe:

The only thing the bladders did for us in planes was make us have to rock the wings and install more drains to check for water. The bladders are on hangers, they don't collapse with the fuel, and tend to trap water in ridges, so you drain your tanks to check for water -- and it's still got water unless you rock the wings. Water forced me to glide in for a landing in one of these after takeoff . . .

It performs much better with the engine running.

Pressure fuel is another matter, but not used outside of the military (and only the fighters there).

The only solution to water in aircraft is topping off the tanks and checking before each flight as all tanks sweat inside when partially filled.

flapbreaker · Posted: Thu Jul 19, 2007 12:21 pm Post subject:

Wow, I'm surprised the vents are located below the rub rail.

As far as siphoning fuel. You might go to your local hobby shop. One that carries gas RC cars or airplanes. Buy yourself a good length of their fuel tubing (buy the stuff rated for gas and not glow fuel) and then buy the weighted clunk that is used in the tank. You should be able to lower the clunk to the bottom of the tank. They make hand crank fuel pumps that you could use to pump some fuel out. Just make sure you adequately secure the clunk your your will have a different problem.

Clunk

Bulb type pump:

Crank type pump:

Towerhobbies.com also carries these

Creekside · Posted: Thu Jul 19, 2007 3:19 pm Post subject:

I'm glad to see this problem being addressed, although I most sympathize with others. Water in fuel has been a big problem for me all year in my second year of ownership of "Passages", CD 25 Cruiser. My fuel vents are exactly as pictured, and I've run through some pretty heavy seas this year and last. I've also suspected water in fuel from a little local convenience store, but not proven. I installled extra large Dacor filter at my 200 service; the bowl fills after only 2 or three hours. I've been trying to burn off the mixture before adding good gas, but I'm at the stage now, I think I better pump it out. I'm at a quarter tank now, so could be affected by more condensation. I'm wondering if our builder has been invited to chime in. It seems to be a big problem. for a lot of folks.

John S · Posted: Fri Jul 20, 2007 3:38 am Post subject:

Brock · Posted: Fri Jul 20, 2007 8:04 am Post subject:

I ordered the Attwood vents but was unable to use them since the existing vent holes on my TC are too close to the underside of the gunnel. I could have relocated the holes but decided to go with the Perko vents to keep it simple. So far so good...

Brock

John S · Posted: Mon Jul 30, 2007 9:47 am Post subject:

I just wanted to give a quick follow up on this subject. I repositioned the vent so it doesn't face forward anymore.

We then lauched the boat for a 4 day 300 NM trip. I stopped often and drained water from the Racor, but the amount of water seemed to decrease.

The new vents are on there way and another big benefit is that they will let the automatic shut off work on gas pumps without squirting out the vent.

Thank you everyone for all the help and suggestions.

John

Fun Patrol · Posted: Mon Jul 30, 2007 12:02 pm Post subject:

Some time ago we had some posts on water in the fuel tanks on 22s. Turns out the tank vents and their installation were one of the main culprits. The vents were of a similar style and location as yours. The vent hoses ran downhill all the way to the tanks. Not that big a deal yet, but forget to pull up a nearby fender when you get underway and...depending on the fender location...it would splash considerable water right into the vent, and thus to the tank. The solution was to 1) remember to pull up the fenders, and 2) create an anti-syphon loop above the vent opening. This may be difficult if the vent is at the highest part of the gunn'ls.

In my case I discovered water in the port tank and racor. There was about a pint in the tank and the old filter was FULL! After they fill, they just bypass the water through. I replaced my old can filter with one with a see-thru bottom, removed both tanks and cleaned them, and replaced the fill and vent hoses. In my case there was room for a loop above the vent level.

I think that scenario would more often affect the port side because it's harder to see from the pilot's position. "It's the crew's fault, I got my side" :-)

Good luck, Roy

BrentB · Posted: Wed Aug 01, 2007 8:07 pm Post subject:

I thought the fuel bladders were pressurized.

John S · Posted: Sun Dec 23, 2007 12:33 pm Post subject:

Thought I would revive this thread, because the problem is not completely resolved.

I don't think I'm getting any new water now, BUT........this new Attwood vent SUCKS! It was supposed to make the automatic fuel pumps shut off when the tanks were full.

Instead fuel comes erupting out from around the fuel nozzle, doesn't matter what rate you are using to fill, the results are the same. I confirmed this vent was truely awful with some idependent testing I found on the internet at this link on the Boat U.S. site
So this leaves me looking for another fuel vent solution again.
Here's a photo of the guilty party:

Ted Osborne · Posted: Sun Dec 23, 2007 1:40 pm Post subject:

Our solution for many yrs has been to use a "No Spill Fuel Saver" that is a plastic bottle that attaches to the hull with suction cups and covers the fuel vent. (WM). In fact our fuel dock has one for people to use. We carry our own.
The other method we use is to put our ear down near the fuel nozzle when we think it is getting near full and when you start to hear it "gurgle" you STOP.
We also keep records on how much gas we take on in each tank VS what the fuel gauge on the boat says and we can come close to know how much gas we will be taking on. Have never had an over flow and never more that a dribble into the No Spill Fuel Saver. Works for us.

flapbreaker · Posted: Sun Dec 23, 2007 4:34 pm Post subject:

Same thing happens on my boat when the tank nears being full. Weird thing is the gas doesn't run out the vents but like yours, it erupts from the fuel port. I can't trust the automatic shut off.

rogerbum · Posted: Sun Dec 23, 2007 4:40 pm Post subject:

Never trust the auto shut off when fueling a boat - period. A spill in the water is a worse problem to deal with than one on land and depending on how the boat is loaded (and where everyone is standing at the time), you can't be guaranteed that the high spot on the tank is where the fill tube is at. Most boat fuel tanks (at least on small boats) have a less than ideal path between the fill port and the tank and almost all can spill over either at the fill port or the vent. Fuel slowly and stay there with your hand on the pump the whole time.