Paint problems

[Desert Rancher]

I sprayed some Rustoleum on the exterior of my Grandby to cover some scuffed spots. However, some of the original paint started to bubble because of this.
Any suggestions?

 

[SunMan]

I've done lots of touch up on my 03 using Rustoleum and haven't had any issues. Haven't seen this issue here before.

 

[fish more]

Buy some sandpaper.