Rust encapsulator not turning black

[forestb]

So I used some naval jelly to clean out some rust in my rear cab corners because I couldn't get to it with any kind of scraper. I then rinsed it off and let it dry and sprayed on some 3m rust encapsulator that was supposed to turn black within 20 minutes but it never turned black. What did I do wrong? What should I do?

[chevy_mike]

Did the naval jelly remove the rust? The rust converters need to have actual rust to convert (turn black). If you don't have any and it's clean, bare metal, I don't think it does anything.

[forestb]

I think it still had rust I will have to check again this saurday.

[Richard2112]

Mike is right. Most rust converters/encapsulators rely on the rust. Sometimes, if there is just clean metal, the rust treatment will turn light grey or white.

[Bigdav160]

For me, Rust encapsulator, seems to nothing more than thick enamel paint.