Overlapping Gator Patches

6"×9" Gator Patch overlapping. I want to cover the hole where the transom fish finder would normally go; using 2 patches end to end, I have about 1" overlap; 1st half was applied & cured yesterday; aside from the sanding prep done on rotomolded polypropylene fishing kayak do I need to further prep the 1" overlap of cured patch B4 applying the 2nd 6"×9" ?