Lots of flash rust in gas tank

[shrekogre1010]

Hey Guys,

 

I am restoring a 77 Datsun 280z gas tank. While it took me many days to clean the tank by removing the previous sealer, old gasoline and all prior rust using Evaporust, I was finally ready to coat the tank over the weekend. As per the instructions, I cleaned it with KBS Klean and then followed that with 2 quarts of Rust Blast. While I was rotating the tank every 5 mins, I could see the prior flash rust disappear.

 

But after rinsing with regular tap water, I could see the entire interior with a rust like sheen. I notice this in roughly 50% of the interior. This is yellow and not the white powdery stuff as noted in your instructions.

 

All along the tank was always in a shaded area with no direct sunlight and my outside temp was roughly 73 degrees while working on the tank. Can you please help? What am I doing wrong?

 

BR

Kumar

[KBS Coatings]

1) How long did you rotate the tank with the RustBlast on the inside of the tank?

 

2) RustBlast leaves behind zinc phosphate which is white. The white zinc phosphate mixes with the surface rust (normal for this humid time of year) and creates what you are seeing. As long as this is a dusting, this is perfectly normal. If it is heavier than a dusting, that is not normal.

 

We are looking forward to hearing back from you.