[jp08]

Hey guys,

I recently noticed a strong smell of gas fumes on my jacket after I stored it in the bow compartment of my skiff. I checked all the fuel hose connections and they are good and tight. I did not notice any gas smell in the bilge area nor did I see any fuel under the tank. I did notice there was blistering of the powder coat around the fuel filler stem.

My question is, could that blistering in the powder coat be the cause of any gas smell? Should I take the fuel tank out and have it re-coated or treated to avoid future corrosion? If so, does any one have a shop they recommend near the Miami area?

 

[Smackdaddy53]

I would check hose barbs first

 

[DuckNut]

It looks suspiciously like the gasket is leaking and that is causing the blistering.

 

[Smackdaddy53]

It looks suspiciously like the gasket is leaking and that is causing the blistering.

They drilled holes through the powdercoat and ran stainless screws into aluminum. Dissimilar metal corrosion under any coating is like cancer. A little TefGel would have prevented that.

 

[lemaymiami]

Any tank service (or tank builder ) can pressure test your tank and tell you whether it’s still okay. “Blistering under your powder coating could be a sign that your tank has corrosion problem....

 

[DuckNut]

They drilled holes through the powdercoat and ran stainless screws into aluminum. Dissimilar metal corrosion under any coating is like cancer. A little TefGel would have prevented that.

I agree with the dissimilar metal part but disagree with it because of stainless.

Still it would have been best to weld the bung on rather than screw it.

 

[Smackdaddy53]

I agree with the dissimilar metal part but disagree with it because of stainless.

Still it would have been best to weld the bung on rather than screw it.

What do you mean you disagree because of stainless? Now I need to read this because as long as I have been dealing with dissimilar metal corrosion it was between aluminum and stainless and even more so in a saltwater environment because the salt accelerates the “battery effect” that causes the corrosion.

 

[DuckNut]

Aluminum and ss will corrode but the surface contact is usually large. An insulator will slow the process and there is a gasket under the bung. Galvanized will corrode quickly

Here is a different twist. Each of these screws has rust around it. These screws could be steel or cheap ss.

Anyway, this tank has issues at this bung, the sensor does not have the same issues.

Smack- when you see corrosion between ss and aluminum, is it normally rust color or just that ugly whitish pitting?

 

[Smackdaddy53]

Aluminum and ss will corrode but the surface contact is usually large. An insulator will slow the process and there is a gasket under the bung. Galvanized will corrode quickly

Here is a different twist. Each of these screws has rust around it. These screws could be steel or cheap ss.

Anyway, this tank has issues at this bung, the sensor does not have the same issues.

Smack- when you see corrosion between ss and aluminum, is it normally rust color or just that ugly whitish pitting?

White powder oxidation. Yeah cheap stainless is magnetic but will still introduce corrosion and once it’s under a coating it’s hard to neutralize. I ran a hurricane shutter business for 7 years and had lots of education on aluminum and stainless with paint and powdercoating. Most shutters on the side of the house facing the water would corrode around the fasteners. The shutters that got more rain to wash the salt off lasted longer.

 

[DuckNut]

Thanks @Smackdaddy53