I have found a leak on my propane tank on my 2003 tioga 30ft rv. The leak is on the bolt to the left of the fill valve where the gauge that reads how full the tank attaches. The bolt looks to be in good shape but it is leaking from the threads once I empty tank can I remove bolt and and use some sort of thread sealant or pipe dope to reseal it . I am not familiar with propane tanks any suggestions thank you.