I've just used rustseal on a fuel tank and won't be able to give it a second coat for a few days,it's now to humid were I live to give it a second coat now. When I give it a second coat will I just have to sand between coats or will I have to use etch primer between coats. I will also be using topcoat for a third coat.

Yes, you will want to sand between coats of RustSeal if you let it go over 24 hours. You can also use Fusion Self-Etch Primer if that works easier for you.

There are three effective ways to topcoat RustSeal (with BlackTop, KBS MAXX, or other top coat paints) effectively so that the coatings bond and fuse together. Please choose the one that works for your project.

1. Apply your top coat once the second or final coat of RustSeal is dry-to-the-touch and does not leave a fingerprint (usually 3-8 hours depending on temperature and humidity).
2. Let the second or final coat of RustSeal fully cure (at least 24 hours), scuff the RustSeal with 320 grit, then apply your top coat.
3. Let the second or final coat of RustSeal fully cure (at least 24 hours), dust the RustSeal with Fusion Self-Etching Primer, let the Fusion cure for 30 minutes, then apply your top coat.

Please check out the complete directions for RustSeal and let us know if you have any additional questions.

Would it be beneficial to lightly scuff AND use fusion?

Yes, you could scuff with 300 grit and apply KBS Fusion Self-Etch Primer. That is probably overkill but could also provide peace of mind.

 

Please let us know if you have any additional questions.