Gasoline in bilge :-(

[Kesh]

Re: Gasoline in bilge :-(

hmmm... I have an outboard evinrude 225 hp, 1994 with vro...

 

[Hooty]

Re: Gasoline in bilge :-(

Yo Kesh,<br />I just read your post. Before ya go "mucking about" (learned that from the Aussies here on the board) in the bilge, get yourself a good source of CO2, like a fire extinguisher, and lay down a good heavy blanket of tha stuff. This will displace the oxygen and reduce the possibility of a real nasty situation.<br /><br />g'luck & c/6<br />Hooty

 

[Boatist]

Re: Gasoline in bilge :-(

Kesh<br />Sorry I was assuming a I/O. Some where I herd the deffinition of assume.<br />Good Luck.

 

[93bronco]

Re: Gasoline in bilge :-(

maybe this mite help alittle. fuel leak

 

[Kesh]

Re: Gasoline in bilge :-(

Excellent information, thanks.

 

[Kesh]

Re: Gasoline in bilge :-(

Bad news. I checked this morning all fuel hoses (fill, vent, out). Found no evidence of leak. I opened the fuel level sender port and gasket looks like it has been sealing in perfect condition. No evidence of leak there. I inpected the clamps of fill hose where it enters the tank. No evidence of leak there. Also inspected the vent line where it enters the tank. Found no evidence of leak there.<br /><br />I confirmed that the tank is fibeglass construction.<br /><br />So, my last resort is to make the air pressure test. I will do it tomorrow.<br /><br />This afternoon I will try to find the manometer and necessary connections/plugs to make the test.<br /><br />If the tank needs to be repaired do you suggest to build a new one? what material?? (aluminium, rebuild fiberglass, stainless steel)?? I read the article on the link posted above by 2K Boat. I'm inclined to aluminium. The problem is I don't know if I will find alloy 5000 series. Maybe downhere nobody has a clue about aluminium alloys.<br /><br />If I decide for aluminium, I will make sure the tank rests on big pieces of 1/2 to 1 inch rubber supports, and will ensure support is firm, and no stress is applied to hoses.

 

[18rabbit]

Re: Gasoline in bilge :-(

Kesh – my gut feeling is optimistic. I am thinking the source of your leak may be other than the tank. Properly built fiberglass tanks don’t corrode. And if properly supported, that tank is there for life. <br /><br />If it turns out your tank is compromised, it should be very repairable. You may not need to replace it. Just me being optimistic, again.<br /><br />Please review the PSI recommend in that excellent link 2K Boat posted above. You don’t need much positive pressure, couple of pounds. You just need to see the pressure doesn’t leak out.<br /><br />Please let us know how it goes…

 

[18rabbit]

Re: Gasoline in bilge :-(

Kesh – the mailman just brought me a copy of the mil spec for the pressure testing of the tank in my boat. Spec requires 3-psi pressure to hold for 1-hour. The tank is made from welded plate aluminum 5068. Can’t suggest psi for your fiberglass tank but whatever you decide, holding at that pressure for 1-hour should tell you if it still good.

 

[Kesh]

Re: Gasoline in bilge :-(

Now I have another problem. Can't find a manometer with the appropriate range. All I see is 5-55 psi or 5-200.<br /><br />The link above says DO NOT EXCEED 3 PSI...<br /><br />I am wondering if I can use 10 psi....or is there any risk involved???

 

[Kesh]

Re: Gasoline in bilge :-(

^^^^^^^^

 

[18rabbit]

Re: Gasoline in bilge :-(

I definitely would NOT use 10 psi. One square foot of your fuel tank surface area is 144 sq in. At 10 psi that translates into 1440 pounds of pressure (3/4 ton!) pushing out on just that one sq ft of fiberglass fuel tank.<br /><br />How to build one? You should be able to figure this out… ever see an old fashion barometer? It’s a curved piece of glass tubing with 1 gram of mercury in it. As the atm pressure changes, the mercury rises and falls.<br /><br />Hint: 1 foot of water exerts .455 psi…figure ½ lb per foot. What would happen if you got some cheap flexible clear tubing and hung it over the side of your boat and put some water in it? Mark the water level on the tube. When it’s risen 4-ft, you have 2-psi pressure. Another hint: the smaller the diameter of the tubing (cheaper!!!) the greater the resolution of detecting a leak. After pumping up the tank, mark the water level on the tubing. If it drops…problem. You don’t even need to know the exact pressure. Use 1 ft = ½ psi as a guide. It’s linear, so ½ ft = ¼ psi. The tubing needs to be vertical.

 

[18rabbit]

Re: Gasoline in bilge :-(

On second thought…<br /><br />If the end of the tubing is unsealed, you would be lifting the weight of the water, not the pressure it exerts…

 

[BillP]

Re: Gasoline in bilge :-(

You cannot visually inspect fuel or vent lines and always tell if they are bad. They can get tiny pinholes and still look great. <br /><br />My bet is you have a bad hose. 10yrs is about normal to start seeing bad hoses. Replace the hoses now to check, then put them on the new tank if you find it is the tank. Fill hoses seem to last forever and just get stiff.

 

[Kesh]

Re: Gasoline in bilge :-(

Well, I only removed the out hose. The fill and vent hoses are still in place. I think I'm going to air pressure test prior to touching those two hoses. I hope I can use water and soap on the clamps area to see if they leak there.<br /><br />I just want to find the leak BEFORE removing anything else, so I can be sure what was the problem.<br /><br />I think I'm going to build the water column manometer suggested by 18rabbit.<br /><br />18rabbit: I made the calculations, and a 1 ft column of water produces a pressure or 0.433 psi. I confirmed that on the link: http://www.infodotinc.com/fluid/ch1e.htm <br /><br />To have the 3 psi I need almost 6.92 ft of water, which is a manageable size. I plan to use a 2x7.5 ft = 15ft clear hose, placed vertical bended at the mid lenght point, with the "U" bend on the bottom. I will fill with water to have a "U" water column with aproximately 3.5ft on each side, both upper sides opened to air. I will connect one of the tips to the vent hose of the tank and will apply air pressure through the out fuel hose. Once I make the "U" water column displace to a single side of the "U", forming a vertical column of water, I will have near 3 psi. Then I will mark the level reached by the top of the column of water and wait one hour to see if it drops.<br /><br />Thanks for the idea !!!

 

[Kesh]

Re: Gasoline in bilge :-(

...if tomorrow I'm in the lazy mood, I will try to find a suitable manometer on monday, when some other hardware stores are open....lmao

 

[18rabbit]

Re: Gasoline in bilge :-(

If you get in a lazy mood, check the plumbing supplies, sewer section. That’s where you should be able to find a manometer in the 0-5 psi range.<br /><br />If you make your own, you do not have to go to 3 psi. If the tank leaks, you should see a drop in the water level before you ever reach that point. You just don’t want to exceed 3 psi. No sense in stressing a healthy fuel tank if that's not the problem.<br /><br />You are right about the .433 psi of water…FRESH!!! (sorry) 1-ft of seawater is .455 psi. Anyway…you are on the right track.

 

[Kesh]

Re: Gasoline in bilge :-(

just wanted to share two links I found related to the testing of tanks using water manometers:<br /><br /> http://my.execpc.com/~cjh/leaktest.html <br /><br /> http://www.k-sea.com/images/manometer6.pdf

 

[18rabbit]

Re: Gasoline in bilge :-(

I’m sure you already know this…you need the water to be on both sides of the curve like in the picture with the red water, otherwise you are lifting the weight of the water’s volume. Also, I would still use 1-ft = ½ psi. It affords you a little safety margin so you don’t exceed 3-psi. You are not engineering a fuel tank; you are checking for a leak…however, a man and his toys knows no bounds. Now, if you really want accuracy, use distilled water… <br /><br />Thanks for the links!!!

 

[Kesh]

Re: Gasoline in bilge :-(

Hey 18rabbit !!!<br />I built the water column manometer!!! (a sturdy support base and a vertical aluminium angle to hold the transparent hose, pair lined, tied with tie raps but not tight so the hose is free). I'm still at home, and can't go to the marina today.<br /><br />It works great, except for the following (I will try to explain):<br /><br />I will connect the manometer to the vent hose of the tanks, using a piece of pipe and clamps. I foresee no problem doing that.<br /><br />On the other hand, I will pump air inside the tank system through the fuel-out hose. I arranged a home water valve and some pipe adapters to fit that hose. I can connect a bicycle pump and then close the valve to retain the pressure inside the system. Sounds great, but took me a lot to seal and tight all pieces so no leak is present (at least there is not visible leak with the water and soap test). However, THE COLUMN STILL DECREASES WHEN THE VALVE IS CLOSED. Damn. After resealing my adapter "masterpiece" I still get a 1 inch drop in about 30 minutes.<br /><br />Do you think I still can proceed and check the boat even with that little potential leak? (I say potential, because it may be present when I will setup the water column manometer at the boat).<br /><br />I guess I will see a fast decrease of the water column if a leak is present. I will test all connections with water+soap at the boat hoping to find the leak, and not end up cutting the deck of the boat to inspect the tank.

 

[Kesh]

Re: Gasoline in bilge :-(

maybe a disadvantage of the water column manometer it is the fact that one end is open to the atmosphere....maybe changes in atmosphere will affect the reading...