What to do with bad gas

[psneeld]

Dump phase separated gas in any engine and you will probably be sorry.


Without a sample to observe, it's all a guess.

 

[PPandE]

I've got an old Ford diesel pickup that will burn about anything with BTU value. I mostly run used motor oil mixed with enough gasoline to thin it down, 15% or so. I've used avgas, jet fuel, ten year old gas, turpentine, alcohol... 'ole blue ain't fussy.

If I were looking for a disposal company for my old stuff I'd visit the local garage and ask them who hauls off their old oil. I've seen the cost vary from $1.00/gal to haul it off to getting paid $.50/gal for the old stuff.

 

[psneeld]

Has anyone here who says their "oldie but goodie" burns anything..... poured phase separated gas into their tank?


After towing hundreds of boats with inboards and outboards, carbed and fuel injected that had clogged fuel systems, I bet you haven't.


So after paying to remove and dispose of the bad fuel, there were the hundreds to thousands of dollars of fuel system cleaning or replacing.


I have heard that separated fuel can be pumped, divided, then octane booster added to the original base gas.....sounds like a bunch of work to me with questionable results.


Old diesel and phase separated gas are 2 different creatures. Old, non phase separated gas is a different story too....it may burn but depending on engine and operation could be problematic.

 

[rslifkin]

Phase separated gas is tough to save. If you can let it settle out really well, you can remove the alcohol and water layer, leaving you with just gas. However, that gas will be lower octane than the original fuel. Often low enough that you wouldn't want to use it for anything.

So in general, separated gas is junk. Gas that's old but not separated can often be freshened up and burned if it's not too far gone. But if it's basically varnish, I wouldn't risk any fuel system on it.

 

[psneeld]

Phase separated gas supposedly can be refreshed and to original octane by adding back the ethanol (plus possibly additives and extra ethanol....there are a variety of suggested ways to do it...but again the work, cost and questionable outcome seem to suggest to me...just say goodbye.

 

[rslifkin]

Phase separated gas supposedly can be refreshed and to original octane by adding back the ethanol (plus possibly additives and extra ethanol....there are a variety of suggested ways to do it...but again the work, cost and questionable outcome seem to suggest to me...just say goodbye.

Agreed. In most situations it's not worth trying. Maybe with a skilled person and a very large quantity of fuel, but that's a rare situation.

 

[PPandE]

Has anyone here who says their "oldie but goodie" burns anything..... poured phase separated gas into their tank?


After towing hundreds of boats with inboards and outboards, carbed and fuel injected that had clogged fuel systems, I bet you haven't.


So after paying to remove and dispose of the bad fuel, there were the hundreds to thousands of dollars of fuel system cleaning or replacing.


I have heard that separated fuel can be pumped, divided, then octane booster added to the original base gas.....sounds like a bunch of work to me with questionable results.


Old diesel and phase separated gas are 2 different creatures. Old, non phase separated gas is a different story too....it may burn but depending on engine and operation could be problematic.

By "anyone here who says their "oldie but goodie" burns anything" I assume that you mean me and, yes, I have. In fact, I bought the truck specifically to see what I could get away with burning. Start with used oil, mix in a little of whatever, five stage filter to 0.5 micron and dispense into tank. Let the OEM water separating filter take care of the rest.

When I first started doing this I started with an engine that had a quarter million miles on it and by the time I learned what I was doing I needed a new engine. An Amish guy rebuilt it for about $4000. Eighty thousand miles later it's going strong. That's about 10,000 gallons for under 15cents per gallon. I think I'm ahead on savings.

 

[psneeld]

No I really didn't mean you as I specifically said diesel is different and is burned different and I said "separated gas" which I doubt you put in your diesel.

Sure diesels have been known to run on a lot of things besides diesel, but not many gas engines can swallow the water alcohol goo that forms in separated gasoline.

Which is my real point, just dumping old gas from a boat of unknown origin straight into a vehicle gas tank without a good sampling of it and one might be in for a big ssurprise.

I doubt you would be dumping any of that other stuff instead of fresh diesel in a new $80,000 dollar diesel truck.

 

[Comodave]

Is anyone that is promoting using the old gas willing to step up and offer to fix the engine if it seizes up? Probably not and I would not risk any of my engines with old ethanol gas.

 

[TowLou]

Call a local garage or auto mechanic if you can pump it into cans and ask if they will add it to the waste oil.

 

[OldDan1943]

My Lugger was happy to have 8 year old diesel. Of course I did have a fuel polishing system onboard and I generously treated the fuel too.

 

[Comodave]

Old diesel and old phase seperated gas are two completely different things.

 

[AlpinaRanger]

The thought of using an ELECTRIC drill pump to pump gas terrifies me! If you use a drill pump, better to use an air driven drill with a compressor 30 feet away! Just my take. Once you get the fuel out, I would put in my car 5 gallons/fill up, pouring from the top of the tank if using 5 gallon cans, and if using a 55 gallon drum, leave the last 6 inches or so in drum, pour into a home depot or lowes bucket, if anything is separated, don't use the bottom stuff. Otherwise, in it goes! 5 gallons of old fuel in a 20 gallon or so gas tank is not going to harm anything IMHO.

Agreed. I bought an electric fuel pump at an auto parts store and used that to pump old gas from my boat. Placed it in 5 gal containers and added a bit to my car’s gas tank slowly over time. Issue is you need a lot of 5 gallon containers especially as the OP has a much larger tank than I had.

 

[PPandE]

No I really didn't mean you as I specifically said diesel is different and is burned different and I said "separated gas" which I doubt you put in your diesel.

Sure diesels have been known to run on a lot of things besides diesel, but not many gas engines can swallow the water alcohol goo that forms in separated gasoline.

Which is my real point, just dumping old gas from a boat of unknown origin straight into a vehicle gas tank without a good sampling of it and one might be in for a big ssurprise.

I doubt you would be dumping any of that other stuff instead of fresh diesel in a new $80,000 dollar diesel truck.

To be clear, yes, I've added separated gas into my diesel home brew.

So far, there hasn't been a pick up truck made worth $80,000.00 to me. But, since the use of substandard fuels does reduce the life of the engine, the purchase price of the truck would have to be accounted for in the cost/benefit analysis. It works for me and my $5000 truck.

 

[CooperBrewer]

I used a little green transfer pump, I bought at harbor freight. I think it says it's for water or coolant, but I used it for gas (I bought another for coolant). I think they might have been around $50. Worked great! Pumps fast, 110VAC.

 

[toocoys]

Is anyone that is promoting using the old gas willing to step up and offer to fix the engine if it seizes up? Probably not and I would not risk any of my engines with old ethanol gas.

Watching over $1000 worth of gas get carted off for disposal was certainly a lesson learned. I'll never have that much gas on board for any longer than a few months again. And seeing the condition of that $1000 worth of fuel after two years of being in the tank, I don't even think I would trust that it would ignite for enemy warfare. There's no way I would trust it in my engines... treated, polished, or otherwise.

 

[rslifkin]

Watching over $1000 worth of gas get carted off for disposal was certainly a lesson learned. I'll never have that much gas on board for any longer than a few months again. And seeing the condition of that $1000 worth of fuel after two years of being in the tank, I don't even think I would trust that it would ignite for enemy warfare. There's no way I would trust it in my engines... treated, polished, or otherwise.

Generally, unless we're traveling and I know I'll be filling up again within a month or so, I add stabilizer at every fillup on the boat. Stabilized gas is good for a year with no issues in my experience (in the vented boat tanks, longer in well sealed jerry cans). Right now I'm still burning off the stabilized gas I put in the tanks last October before we hauled for winter.

 

[psneeld]

I don't believe any stabilizer can prevent phase separation of Ethanol gas (no matter what the bottle claims).

Stabilizers are good for varnishing issues and loss of obtain to a degree.

This statement from West Marine agrees with my research and experience.

https://www.westmarine.com/WestAdvisor/Busting-Ethanol-Fuel-Myths


Phase separation with E10 fuel
When E10 gasoline comes into contact with water, ethanol will allow fuel to absorb some or all of that water. This is actually somewhat beneficial, but fuel can reach a saturation point and water can phase separate to form a distinct layer in the bottom of the tank. The upper “gasoline” layer will be depleted of ethanol and have a reduced octane level. The lower “phase separation” layer will be a corrosive mix of water and ethanol. No chemical agent or fuel additive can be added to E10 gasoline, in a reasonable quantity, that will fully prevent phase separation or recombine a phase-separated layer.

 

[rslifkin]

I don't believe any stabilizer can prevent phase separation of Ethanol gas (no matter what the bottle claims).

Stabilizers are good for varnishing issues and loss of obtain to a degree.

This statement from West Marine agrees with my research and experience.

https://www.westmarine.com/WestAdvisor/Busting-Ethanol-Fuel-Myths


Phase separation with E10 fuel
When E10 gasoline comes into contact with water, ethanol will allow fuel to absorb some or all of that water. This is actually somewhat beneficial, but fuel can reach a saturation point and water can phase separate to form a distinct layer in the bottom of the tank. The upper “gasoline” layer will be depleted of ethanol and have a reduced octane level. The lower “phase separation” layer will be a corrosive mix of water and ethanol. No chemical agent or fuel additive can be added to E10 gasoline, in a reasonable quantity, that will fully prevent phase separation or recombine a phase-separated layer.

Correct. Even with stabilizer, E10 will separate if you get enough water into it. But with a full tank over the winter, for example, it would take a good bit of water (more than you'll ever get from condensation, especially in a full tank) to cause separation. Separated fuel typically happens from leaky fill caps or other poor storage conditions rather than just natural condensation.

Ideally, E10 or not, going to a more modern vent setup that's not just an open tube to the atmosphere all the time will increase the lifespan of fuel in the tanks. I've been thinking of ways I could do that on my own boat.

 

[Farandaway]

Thank you

I want to thank all of you for your replies. I do appreciate them. I’ve decided to remove the fuel so with that being said, I have a siphon hand pump and plan to use that. With baffles getting in the way, how do I get the hose down to the bottom of the tank where the separated water probably is and pump all the contents out?
There are two openings. One small 3” diameter inspection port and then there’s the filler tube.

I believe there is a baffle that runs horizontally but because of the port being too small to see inside I’m afraid I won’t get all the way to the bottom through there.

 

[toocoys]

Can you remove the sending unit? That's how mine was done.

 

[psneeld]

In my experience, it takes free water versus humidity to get enough water to cause phase separation. So it has to be a lot of condensation or some sort of leak for fairly fresh fuel to normally separate.

Where I come, 2 schools of thought. First is full tank to lessen condensation, but if for any reason the gas is near separation, even a little condensation or a tiny leak may trigger separation and now you have a full tank of bad gas.

The other is near empty tanks, which seems to have less effect on condensation formation than partially full tanks. That way any chance of separation only results in a small amount of fuel being wasted and having to be disposed of.

Full or empty may depend more on yard policy than one's preference.

 

[Farandaway]

Can you remove the sending unit? That's how mine was done.

Yes, I can do that too but how do I get to the bottom of the tank because I’m fairly certain that at least one baffle runs horizontally about halfway down and I can’t see where the hole in the baffle is?

 

[psneeld]

Yes, I can do that too but how do I get to the bottom of the tank because I’m fairly certain that at least one baffle runs horizontally about halfway down and I can’t see where the hole in the baffle is?

How sure are you of a horizontal baffle?

Pretty unusual on small tanks in my experience.

 

[Farandaway]

How sure are you of a horizontal baffle?

Pretty unusual on small tanks in my experience.

I’m fairly certain. It’s a 129 gallon tank that I can stand on with no give at all. It’s probably 30-36” deep, 36” wide, and 24” long. Unless the view inside is deceptive I see the bottom of a baffle and it doesn’t look like 3 feet of depth.

 

[psneeld]

So it's as tall as it is wide. I am amazed it has any baffles at all with a shape like that unless very thin material where internal structure was needed more so than a baffle.

Sounds like a job for a boroscope to see what you have to deal with.

 

[OldDan1943]

Baffles can be baffling.
Pump out what you can and you may surprised when the space fills up with more gas.

I would have thought the baffles would be port and starboard mounted but, you gotta work with what you have.

You do not have a sight glass nor a bottom tank drain?

 

[rslifkin]

You do not have a sight glass nor a bottom tank drain?

Gasoline tanks wouldn't generally have either. Holes other than in the top of the tank are a no-no for gasoline, only allowed for diesel.

 

[OldDan1943]

Gasoline tanks wouldn't generally have either. Holes other than in the top of the tank are a no-no for gasoline, only allowed for diesel.

Lesson learned.

 

[Comodave]

I did drain the fuel tanks on a previous boat. I disconnected the fuel supply lines and used them to drain the tank. I had to get around the anti-siphon valves but it worked fine and I got almost all the old fuel out. If you have aluminum tanks be careful using any copper tubing since the copper can leave minute particles of copper on the aluminum and set up corrosion. Use some plastic tube instead if you are going to make a dip tube.