removing old fuel from tank

[mckinney004]

I recently purchased a 1993 Lund Baron 2100. I got the engine running on an external tank, but I need to get the onboard tank drained. Its 60 or 80 gallons, not sure which or how full it is. It sat for 8 years before I purchased it, so draining, cleaning the tank isn't optional. Any suggestions to do this efficiently?

 

[Chris1956]

If thee boat is on a trailer, the easiest and cheapest way to drain the tank is through the gas gauge sender hole. One of those shake-shake fuel siphons plus a piece of 1/2 copper pipe. Connect the pipe to the end of the siphon and stick the pipe thru the garboard drain. Stick gas cans under the pipe and start the siphon.

 

[Jimwhall]

A bigger question.... what do you do with the old gas? I've had bad gas before but just tried to mix it with newer fuel and slowly burn it away; then check the plugs. But for a full tank that's a little harder. Are there places that take it?

Old gas stinks. Just toxic enough its hard to get rid of and just bad enough its not easy to burn through the motor.

 

[Scott Danforth]

after 8 years it will no longer burn

it may not even burn in a bon fire

check with your local land fill that disposes of solvents, etc.

 

[carburated]

I use my van as an old fuel disposal unit. up to 5 gallons of gas in a 35 gallon tank has never caused an issue. I've dumped pre-mix in it on occasion which I know is a big no-no for the cat, but the original cat from 1998 still passes the smog check. I figure 5 gallons at 50:1 mixed with 30 gallons gas is now... well, a lot less than 50:1 :lol:

Anyway, another option is find a local hazardous waste disposal place. We have 'Toxic Tuesday' around here, first Tuesday of the month you can bring your old chemicals to be properly disposed of. I use that for my old oil and paint and stuff. But gas I'm using, that's $$ right there!

 

[Scott Danforth]

I use my van as an old fuel disposal unit. up to 5 gallons of gas in a 35 gallon tank has never caused an issue. I've dumped pre-mix in it on occasion which I know is a big no-no for the cat, but the original cat from 1998 still passes the smog check. I figure 5 gallons at 50:1 mixed with 30 gallons gas is now... well, a lot less than 50:1 :lol:

there is no way to use 8 year old varnish. it ceased being fuel between 6 and 12 months after it was pumped into the tank.

 

[carburated]

:noidea: I will defer to your 26,000 posts, but my experience is different.

Either way, the proper way to dispose of the old fuel is through an official toxic disposal program like our 'Toxic Tuesday'. Maybe that's not available everywhere though.

 

[wrvond]

60 to 80 gallons is a lot of liquid to transport, let alone dispose of. That could be up to 16 five gallon gas cans if you were to try to transport it all at once.
There are fuel tank pump out services available in many places, but I suspect they'd be pretty pricey.
The hazmat land fill option seems to be your best bet. I'd get a couple 50 gallon drums with enough kitty litter to absorb all the liquid and siphon/pump it into that.

 

[Lowlysubaruguy]

I have a couple of automotive shops the costs for me to legally dispose of bad fuel is hefty eighty gallons would run me about $600 to $1000 maybe more and then it would be hanging around being a fire hazard while waiting for it to be picked up because there not going to just rush over and get it. I’d buy a bunch of gas cans pump it into them and now it’s contained in manageable sizes for transporting and storage while getting rid of it. Out local transfer stations do this hazardous waste disposal thing twice a year that’s no charge no questions asked. I can’t use it but my customers who created the issue can. Six or so new gas cans is cheap insurance to contain it while you’re getting rid of it. If any of it is like real gas advertising it for free on Craig’s list might find some of it a home in an older carbureted truck that gets six mpg. Pumping it into one drum may be cheaper but now you have a hazardous waste that’s difficult to work with and on a commercial level.

 

[Scott Danforth]

after 8 years with an open fuel vent, if it was full, it will be down to about 10-15 gallons of sludge or less

 

[Old Ironmaker]

A bigger question.... what do you do with the old gas? I've had bad gas before but just tried to mix it with newer fuel and slowly burn it away; then check the plugs. But for a full tank that's a little harder. Are there places that take it?

Old gas stinks. Just toxic enough its hard to get rid of and just bad enough its not easy to burn through the motor.

Our county holds a toxic substance drop off day twice a year in a remote location in town, not at land fill. I had about 10 gallons off bad gas to get rid of. The containers I took the fuel in with stays with them. I found that all the places that will dispose of old fuel also take the legal gas cans it was transported in. I wasn't too happy with that but I understood the hazards of transferring the gas safely. One guy filled empty soda bottles and the such with the fuel to save on the cost of the gas cans. They wouldn't take them.