Water tank access cover leak

[brokesailor]

One of the access covers on my aluminum water tank is leaking grossly. It used to have a rubber gasket. I replaced it with a "paper" gasket but still leaking badly. What is the best gasket to use and where do I get it? Do I need to seal the gasket to bolt thread area?

[PaulfromNWOnt]

A rubber gasket is the way to go.

[RichH]

Best gasket material to use is 'food grade' silicone rubber or 'food grade' BUNA, etc. All such food grade rubbers compatible with potable water can be found on many 'industrial supply' sources on the internet: Grainger, etc.