Should I replace old gas tank ?

[tmh]

I'm not looking for extra work, but I thought I should ask the question while my floor is out just in case.

My boat is a 1985 Mark twain 19' BR. I have the floor out and will be replacing in the spring. It has approx 33 gal. aluminum (I think) rectangular gas tank with square corners. I know zip about gas tanks other than a leak is real bad. I see no damage but I can basically only see the top as it is enclosed with the stingers/bulk heads. I don't smell gas or see any sign of leaks.

Is there any likelyhood it should be replaced? If so, with what and how big and costly a job is it? What would one do with the old tank for disposal?

 

[iwombat]

Re: Should I replace old gas tank ?

Doesn't sound like a replacement is in order. A well constructed aluminum tank should last decades at the very least.


If you're really concerned about it though you can treat the inside with a fuel tank sealant. These products are mostly for steel auto tanks though, so you may want to check for compatibility with aluminum.

I use the stuff from the restomotive guys: http://www.por15.com

 

[tashasdaddy]

Re: Should I replace old gas tank ?

has it been a fresh or salt water boat. if salt i say replace.

 

[tmh]

Re: Should I replace old gas tank ?

oh yeah, fresh water only. That may make a big difference, Thank

 

[Lou C]

Re: Should I replace old gas tank ?

Keep in mind it is 22 years old. Did the bilge stay wet, and was there bilgewater under the tank all the time? If you can re-do the floor so you can build an access panel, that is as wide as the tank, that could be removed if the tank leaks, then you wouldn't have to rip up your newly installed floor to replace it. My old Four Winns was set up this way, and I just duplicated it in the rebuild, so that if the tank ever leaks, I can easily replace it. Is it foamed in screwed into the stringers or frames?

 

[andy6374]

Re: Should I replace old gas tank ?

This is your one opportunity to at least inspect the tank, use it! Pull the tank and clean it off with a light scuffing and give a good eyeball. Then give it a pressure test. Don't use anymore than 2-3 psi's. Spray some soappy bubbles around the all welds and pickup's and then watch for leaks. It should also be able to hold the pressure for at least 12 hours. If it doesn't replace it, if it tests out good then go ahead and coat it with a few coats of coal tar epoxy or truck bedliner to protect it from corrosion.

 

[Bondo]

Re: Should I replace old gas tank ?

This is your one opportunity to at least inspect the tank, use it! Pull the tank and clean it off with a light scuffing and give a good eyeball.

Absolutely,........ I Agree.........

Aluminum Tanks have a tendency to form Pits,.... Anywhere that it sits on it's mounts, or Under the retaining Straps......

What would one do with the old tank for disposal?

Cut it into Panels with a Circularsaw, with a Carbide Wood sawing Blade.....
Wash it out with Water 1st,... But there's Little or NO danger,.. Aluminum doesn't Spark when you Saw it......
Keeping it Cooled with Water or Snow/ Ice will stop the Metal from building up on the cutting tips of the blade,....
Just keeping the metal Wet, a few inches from the cutting area will make a Huge difference.....
Then you can either use the Panels for Projects,.... It's probably some nice .060" stuff.....
Or, About Any Scrap Yard will Buy it from you......I Think Aluminum is up around $.40 or .50 @lb. now.....
Maybe More........

Btw,..........
IMHOpinion,......
Plastic Tanks are the Only Way to Go.......
I'll Never install another Metal Tank again.......
Problem I have it finding the Right Size,+ Port-openings.....

 

[Chris1956]

Re: Should I replace old gas tank ?

TMH, Inspect the tank. If it has pits (doubtful in fresh water) replace it with a plastic tank. If no pits, it should last another 22 years. If you must trash it, remove the sender, recycle the gas in the mower or car, and wash out the tank with soap and water. Here in NJ, we just clean 'em and put 'em in the trash. A junk yard may want it as well.

 

[tmh]

Re: Should I replace old gas tank ?

Crap!!!! More work for me, thanks to all YOU guys.

Thanks for the advice. I'll have a good look at it at least. I hope it's OK because my floor replacement project is snowballing out of control with more upgrades, etc. I DO want to actuallt use the boat next year!