How about acid-cleaning & pressure testing a fuel tank?

[btravlin2]

Howdy.......this boat I'm buying, a 1985 21' Chris Craft Seahawk, has an 85 gal aluminum tank. The previous owner says he recently had it acid-cleaned and pressure tested for 24hrs. Sounds good, as far as pinholes go. But that doesn't tell me anything about remaining wall thickness, does it?

On second thought, why would the wall thickness get thinner with age anyway? Is a fuel tank subject to hydrolysis from the fuel in it?

Thanks in advance......

 

[haulnazz15]

Re: How about acid-cleaning & pressure testing a fuel tank?

Are you having an issue with the tank? The fuel can varnish inside due to age, and will typically be subject to absorbing water from the air when the fuel is not completely topped off. However, it's not really much of an issue if you use the boat regularly. Why do you need to know about the wall thickness?

 

[btravlin2]

Re: How about acid-cleaning & pressure testing a fuel tank?

No issues. I just know that at some point older tanks need replacing. I'm trying to determine if cleaning and pressure testing should give me some extra confidence that the tank is in pretty good shape for it's age. The owner said the tank was pressured up to 18psi for 24hrs. Sounds impressive. I guess the point is......if there is no loss of wall thickness, and the tank pressures up well, then that would suggest a few more years of life. Those tanks are expensive.

 

[haulnazz15]

Re: How about acid-cleaning & pressure testing a fuel tank?

I'm running a 1976 boat with a 25 gallon aluminum tank that has never been pressure tested and only pulled/cleaned once. I have no qualms about it lasting another 25+ years.

 

[btravlin2]

Re: How about acid-cleaning & pressure testing a fuel tank?

Good to know. I read a lot of threads about tanks needing to be replaced. Thanks......

 

[Another retired guy]

Re: How about acid-cleaning & pressure testing a fuel tank?

My aluminum tank is also 25 years old - no problems - looks like new! The pressure test should convince you that all is well. If the boat has been used in salt water there could be corrosion on the outside of the tank if salt water got into the bilge. If fresh water, then don't worry about it

 

[Bondo]

Re: How about acid-cleaning & pressure testing a fuel tank?

My aluminum tank is also 25 years old - no problems - looks like new! The pressure test should convince you that all is well. If the boat has been used in salt water there could be corrosion on the outside of the tank if salt water got into the bilge. If fresh water, then don't worry about it

Ayuh,.... Aluminum tanks corrode from water against the outside of the tank,...
'n it don't matter if it's Saltwater, or Sweetwater, they Corrode...

Pinholes develop where it lays on it's supports,...

'n they'll also corrode through, from the Inside,.... from Water in the fuel...

I live up here on the Sweetwater Seas,... I'll never, Ever install an Aluminum tank in a boat....

Plastic, is the Only way to go, considerin' ethanol eats the fiberglass tanks...

I've got a pile of ole aluminum tanks that won't hold gas,... every 1 of 'em has atleast 1 pinhole...
from corrosion...