Silicone caulk will take a Long Week to dry!100% silicone sealant will take 2 days to cure.JB weld will cure in 1 day,It is sandable,paintable but like 100% silicone,You will probably Never get it cleaned off completely,should you need to later on!Los Angeles to san Diego,We pretty much share the same climate so,Mold/Mildew is Not an issue!There is a Pick-a-part in National City,& Poway & Those junkyards are your BEST bet,Even if you aren't Mechanically Inclined,Bring a Hammer/Chisel with you,Good Luck!