Gas station tank black inside?

[The motor guy]

They were tearing up the fuel tanks of an old gas station that closed down by me. I didn't take a picture, but I could tell the tank was fiberglass and it had this black residue inside the tank. Wondered what it was By residue I mean the interior wall of the tank. I don't think it was any type of coating, but more of a black residue. Now I couldn't tell if it was a gas or diesel tank, but maybe it's just that black residue you get with old gasoline? It was definitely a fiberglass tank because you could see where the excavator ripped it open. Looked like it was cut in half also. Guess they wanted to make sure it didn't get used for something else? Anyways, opinions? There's another old gas station by me where they removed the pumps and I believe the tanks also. I think the tanks are required to be replaced after a certain number of years. Maybe older gas stations opt to not replace them with new ones and just don't sell gas anymore? I've never really understood why they put a gas station on every corner of an intersection. Makes no sense.

 

[JohnnyG]

Epoxy coating.

 

[The motor guy]

Epoxy coating.

for what? To prevent leaks?

 

[Chris142]

for what? To prevent leaks?

Or some sort of required barrier.

 

[JohnnyG]

for what? To prevent leaks?

Probably, since they were taking them out, that coating was likely a past attempt to repair the tank and get a few more years out of it.

 

[The motor guy]

Probably, since they were taking them out, that coating was likely a past attempt to repair the tank and get a few more years out of it.

They tore the gas station down completely. Probably still was a past repair

 

[JohnnyG]

Back on topic, that black residue, as the you describe it can indeed be just DIRT (i.e. MOLD). This is less common in gasoline tanks, but fairly common in diesel fuel tanks, especially old ones. It could be a black mold growth. There are treatments to kill that mold, if that's what it was, but it might not have been being used or the tanks sat empty/unused for a long time.

 

[The motor guy]

Back on topic, that black residue, as the you describe it can indeed be just DIRT (i.e. MOLD). This is less common in gasoline tanks, but fairly common in diesel fuel tanks, especially old ones. It could be a black mold growth. There are treatments to kill that mold, if that's what it was, but it might not have been being used or the tanks sat empty/unused for a long time.

I had some diesel fuel I kept in a pickle jar for like 8 years. The stuff turned red and looked like intestins inside the jar. I know a friend that sees the same thing because he takes old diesel fuel from old boats that haven't been used in a while

 

[Dave Hess]

I had some diesel fuel I kept in a pickle jar for like 8 years. The stuff turned red and looked like intestins inside the jar. I know a friend that sees the same thing because he takes old diesel fuel from old boats that haven't been used in a while

I thought algae can form in gas or diesel over time due to moisture.

 

[The motor guy]

I thought algae can form in gas or diesel over time due to moisture.

No, you just get phase separation in gasoline.

 

[Nessism1]

Sounds like some polysulfide tank coating. It's commonly black. Used in the aviation industry commonly as a fuel tank sealer. It makes perfect sense to use it inside gasoline storage tanks.