water in gas tank

[oceanrebel]

Hello all,, I am going to have to drain my gas tank in my boat, I have good access to the sender unit on top of the tank,, my questions are, When I replace the sender unit on the tank what kind of sealant do I use? and the other question is if only a small amount of water is in the tank, 165 gal tank, could I siphon out just the bottom of tank since gas is suppose to float?


thanks in advance for your replies


Phil

[WildeOne]

I would pump out until no water came up ... test while pumping using a clear container ... the water will stay in a separate layer on the bottom. Make sure the boat is undisturbed for a day or so before you start and make sure everything is properly grounded to prevent any static sparking. I have two 90 gal tanks to do next spring and bought a high capacity 12V fuel pump and a Racor filter with a clear bottom and blow down valve. I plan to remove up to ~ 30 gal per tank and will use that gas in my truck, then top both tanks with non ethanol fuel.

Any auto parts place can suggest a proper sealant ... I have an old can of Gasoila, which resists oil and gas. Hardening Permatex will also work fine.

Jim

[katman2860]

Normally if water is in the bottom of your tank and it has ethonal gas in it,the fuel as gone into phase seperation.
If this is your situation,you could blow up your engine by trying to save money and use the low octane gas you leave in your tank

[WildeOne]

Katman, Not where I buy gas. The nominal octane at most marinas is 89 ... ethanol's contribution is ~ 2 octane numbers in E85, so at worst I'll see 87 octane, fine for 99% of motors. This improves if you top up with new 89 octane fuel. I'm not worried at all about blowing up engines, but leaving the crap in the bottom of the tank: a real worry.

[lreops]

As long as the use of Ethanol gas becomes more common, there will continue to be a water in fuel problem because of the nature of Ethanol.

One product that I've used and am happy with is Star Tron. This is not a spam nor do I have any self interest with them, but here are a couple of links for you to check out and then you can draw your own conclusions.

Star Tron Enzyme Fuel Treatment - Ethanol/E10

Star Tron Enzyme Fuel Treatment - READ TESTIMONIALS

Star Tron Enzyme Fuel Treatment - Star Tron Story

[katman2860]

When phase seperation occurs in your fuel tank the gas that is on top of the water only has about 40 octane left in it which will cause your engine to have problems.
The ethonal and water mixture that is on the bottom of your tank has most of the octane and is about 75% ethanol which will cause anything rubber to disolve and anything aluminum to corrode. 3 tablespoons of water in 1 gallon of ethanol gas causes phase seperation to occur.
Wildone not sure of what you are talking about but this is what we see with people that do not listen to us on how to have trouble free boating.
Go to this website and read the info on ethonal and phase seperation.
Fuel Testers - Home - E10 Gas

[WildeOne]

That site is selling snake oil! No way the remaining fuel has an octane rating of 40 when ethanol is removed, since the ethanol (up to 15%) only contributed to an increase of 2 octane numbers at the time it was added. i. e., 85 octane fuel became 87 after the addition of up to 15% ethanol, so removing the ethanol is not going to reduce the octane to 40. No way!

BTW, it's the ethanol that causes the water to be absorbed, since ethanol is hygroscopic and the only way to get rid of the water is to get rid of the crap on the tank bottom. Also, I got my info about how to deal with ethanol and water from a guy who was Director of Power Train Development at Ford for many years, until he retired about two years ago. This ethanol deal is a bad joke perpetrated by DC lawmakers on the public and EPA is on a path to compound it. I am also very familiar with mogas compounding, having sold fuels blending equipment to refiners (Exxon, etc.) for many years. Phase separation has been around a long time before ethanol, but the causes were often quite different.

Jim

[katman2860]

The point I was making is that if you have water in the bottom of you tank it has already gone into seperation because ethonal attracts water to it as all alcohols do.
10% Ethonal can only handle up 0.5% of water volume before it goes into seperation. Since you have been around refiners so long have you ever read the Renewable Fuels Assoc. guidlines written for all in the Fuel Industry,you should.
I have about 600 boats I take care of on regular basis,we teach them how to have trouble free boating and do not have fuel related issues then I have another couple of hundred who only come to see us when it will not run and 98% of the time it is fuel related issues.

[oceanrebel]

Today, I changed the filters, which were mostly water, and pumped 60 gals of fuel out of the tank, the first pint was mostly water, the rest looked good, I was able to put a hose to the bottom of the tank and pumped it from that area, I then ran the motors on a hose at home,, I guess the proof will be in the water when I start to plane and gas level changes so the pick ups will either get all gas or gas/water mix, I do plan on adding stablizer tomorrow,


thanks for everyone's input\\

phil