Gas Tank Help

[MYNantucket]

Yes I think so Dave, will have to look at it closer. I move slowly on things like this as I have to get it all laid out in my mind. I really appreciate your help and everyone’s input on this situation as I go forward.

 

[MYNantucket]

So I’m back at the boat looking at tank dimensions ... Well the tank dimensions, Tank is 96” long x 22” tall x 22” wide at top and buried 6” under the gunnel... If I lifted the engine into the salon it would have to stop at the counter top in the galley... It’s 38” from the floor to the counter top and the engine is about 32” that only leaves 6”... The engine would have to be moved to the other side... Then the next problem is the hatch is only 66” and the tank is 96”... Where do you go with it ? Puzzeled !!!

 

[MYNantucket]

Gunnels are only 12” wide so there is no way to go up through there... ugh

 

[MYNantucket]

They built the boat around the tanks... lol

 

[Comodave]

Yes, that is very common. The builder doesn’t care about 20 to 30 years down the road when a new gas tank is needed. I think yours was a gas powered boat so that makes it difficult to cut the tank up in place. I am not an expert on how to cut up a gas tank, diesel is pretty easy since it most likely won’t explode like a gas tank will. Have you done much research on how to cut up a gas tank? The problem is how can you be sure that even if you do everything possible to clean out the gas fumes, how can you be sure you got all of it? I wouldn’t want to make the first cut... If the tank is too big to come out of the hatch and cabin then cutting it up may be your only option, or get a diesel boat. Maybe make a mock-up of the tank out of luan plywood and see if you can find a way to wiggle it in and out. Good luck.

 

[Pete Meisinger]

With a twin engined boat I would certainly suspect there is another removable floor section. It may not be as obvious as the primary access but it almost has to be there. Go underneath and take a closer look.

pete

 

[Giggitoni]

Yes, that is very common. The builder doesn’t care about 20 to 30 years down the road when a new gas tank is needed. I think yours was a gas powered boat so that makes it difficult to cut the tank up in place. I am not an expert on how to cut up a gas tank, diesel is pretty easy since it most likely won’t explode like a gas tank will. Have you done much research on how to cut up a gas tank? The problem is how can you be sure that even if you do everything possible to clean out the gas fumes, how can you be sure you got all of it? I wouldn’t want to make the first cut... If the tank is too big to come out of the hatch and cabin then cutting it up may be your only option, or get a diesel boat. Maybe make a mock-up of the tank out of luan plywood and see if you can find a way to wiggle it in and out. Good luck.

After purging with dry ice (CO2) have someone, a registered and insured individual, IMO, with a LEL (lower explosive limit) meter measure the percentage of explosive vapor still remaining. Should the concentration of remaining vapor be below the explosive limit, you’re good to cut. It’s still nerve numbing!

 

[rslifkin]

To add to that last bit, if you can keep purge gas flowing during the cutting process, that's probably a good idea. Just have to make sure not to suffocate the person doing the cutting.

 

[Giggitoni]

 

[Comodave]

If it is a gas tank then I would definitely have a professional do the work of cutting it up.

 

[MYNantucket]

Thanks to all for the feedback, yes I’m going to have the Marina people estimate the cost of removal . It doesn’t have to be done right away as I am only in a lake and not the Great Lakes and not headed to the Bahamas. Lol Yeah Dave I should have got a diesel boat... Oh hell my mistake

 

[MYNantucket]

After purging with dry ice (CO2) have someone, a registered and insured individual, IMO, with a LEL (lower explosive limit) meter measure the percentage of explosive vapor still remaining. Should the concentration of remaining vapor be below the explosive limit, you’re good to cut. It’s still nerve numbing!

I’d just take a blowtorch to it and cross my fingers... ha ha

 

[boatpoker]

When I was about 16 I found the foot of a guy who tried to weld a gasoline tank in place.

I also have a friend who made the medical journals world wide when he had a new face grown from pig hormones at Toronto Sunnybrook Burn Center. He loved it. He looked 15yrs. younger.

 

[MYNantucket]

When I was about 16 I found the foot of a guy who tried to weld a gasoline tank in place.

I also have a friend who made the medical journals world wide when he had a new face grown from pig hormones at Toronto Sunnybrook Burn Center. He loved it. He looked 15yrs. younger.

It’s good to see someone has a sense of humor ... lol

 

[Comodave]

Too bad about the tank. Just take your time and plan it out very carefully. If you make a mistake you won’t get a second chance to do it right.

 

[FF]

Then the next problem is the hatch is only 66” and the tank is 96”...

Half of 96 (two tanks) would ease the install, and be cheaper to ship.

Although a long round tank , no corners, might hold near enough fuel , and slip in.

Big truck source.

 

[slowgoesit]

When I was about 16 I found the foot of a guy who tried to weld a gasoline tank in place.

You should have offered to give him a hand!

 

[Comodave]

What was it Clint Eastwood said “Do you feel lucky?”

 

[MYNantucket]

When I was about 16 I found the foot of a guy who tried to weld a gasoline tank in place.

I also have a friend who made the medical journals world wide when he had a new face grown from pig hormones at Toronto Sunnybrook Burn Center. He loved it. He looked 15yrs. younger.

Thanks, Was that foot inside the tank or your back yard ? Lol

 

[boatpoker]

Thanks, Was that foot inside the tank or your back yard ? Lol

it was in the parking lot next door (200' ?). It was the biggest piece found.

 

[FF]

A gas tank filled with water will not explode.


Patch it externally , drain it and have fun.

 

[MYNantucket]

A gas tank filled with water will not explode.


Patch it externally , drain it and have fun.

Patch with what ?
If I filled it with water then cut it I would have 150 gallons of water in the bilge.. lol

 

[OldDan1943]

They built the boat around the tanks... lol

Yea Navy if famous for doing that.

 

[STB]

To purge a gas tank, I think they normally fill it with water and then drain.

I'm not sure how much concern there should be about purging the rest of the gas in the nearby systems and hoses that can make for a lot of fumes. That seems manageable by ventilation to me.

But, to be clear, I've never done something like this, nor dovI know anyone who has.

 

[Art]

Some years ago I researched "sealed tank implosion"... re possible need to replace boat fuel/gas tanks. If I ever need to replace our tanks, would review thhis possibility further.

From what I read: Boat gasoline tank [well cleaned out and pre filled with inert gas such as CO2] or a diesel tank can have a vacuum pump attached to collapse it so it can be removed out of rather tight spaces.

Rental Vacuum Pumps | US Vacuum Pumps

An implosion is simply the opposite of an explosion. In an explosion, matter and energy fly outward, but in an implosion, matter and energy collapse inward. ... So in short, implosions are caused by having a greater pressure on the outside of an object than on the inside

 

[MYNantucket]

Gas tank begone

I finally cut my old 150 Gallon 8ft tank out of the boat, I just cut it up with a cutoff wheel . The gas was so old it had crystallized and was not explosive. It took me about 6 hours a day for 5 days to get her out. Mission accomplished !! Now I need info on experience tank builders that can build me 5 tanks with threaded ports at the bottom to connect them together. Any suggestions ?

 

[motion30]

I made my own tanks with G10 fiberglass board, used epoxy and unidirectional glass for the corners top and bottom. It worked out well ,they look professional and certainly do not leak

 

[Art]

I finally cut my old 150 Gallon 8ft tank out of the boat, I just cut it up with a cutoff wheel . The gas was so old it had crystallized and was not explosive. It took me about 6 hours a day for 5 days to get her out. Mission accomplished !! Now I need info on experience tank builders that can build me 5 tanks with threaded ports at the bottom to connect them together. Any suggestions ?

"The gas was so old it had crystallized and was not explosive."

That's a new one on me. Was the tank left completely empty with air flowing through for so long... i.e., to the point that all gasoline fluid had dried up and all fumes disappeared?

 

[OldDan1943]

"The gas was so old it had crystallized and was not explosive."

That's a new one on me. Was the tank left completely empty with air flowing through for so long... i.e., to the point that all gasoline fluid had dried up and all fumes disappeared?

Lucky but, it does happen

 

[rslifkin]

I made my own tanks with G10 fiberglass board, used epoxy and unidirectional glass for the corners top and bottom. It worked out well ,they look professional and certainly do not leak

Fiberglass tanks aren't ideal for gasoline. Ethanol will hurt epoxy, so you have to find an appropriate coating to protect it.