undercoating?

[islandguy89]

I bought a couple of cans of rustoleum undercoating and i am spraying the inside tub of the jeep and the undercaoting isint sticking on the wheel wells any ideas why please help

 

[Hemi 08]

Preparation work inadequate?

 

[54cj3b]

did you sand it or wipe it down with degreaser first that helps alot