Another question for the brains trust: on the Moeller fuel tank installation instructions for the sender unit (www.jamestowndistributors.com/userportal/document.do?docId=1105) it states "Secure sending unit to tank, tightening mounting screws into place just until white sealant shows beneath the screw head."

However, it doesn't specify what this mysterious "white sealant" is, nor can I find any info on fuel-safe sealant for applying between a nylon tank and a nylon/rubber(???) gasket. I installed this tank a while ago without sealant but found some leaking at the gasket when the tank is full, so I've just kept it below about 80% but would rather have this sealed, obviously.

Any ideas?