We make custom leather sheaths for anything metal detecting!  http://leathersheaths.weebly.com/

These are the signals you will get on your f2 and what they probably are. 
0-15 Is iron Iron

25-28 Pull-Tab ( Or gold! ) 

28-32 Nickel (Or gold)

36-42 Pull-Tab (old type) (Or Gold)

58-62 Zinc, Penny ( Larger gold so dig those zinconlns!)

68-72 Dime & Wheat Cent Or silver jewelry 

78-83 Quarter/silver jewelry /can slaw 

86-90 Half Dollar/ Can slaw

91-95 Silver Dollar/ Can slaw 

Everyone that metal detects finds zinc pennies also called zincolns.And once in the ground they get eroded fast. A good way to clean these is by getting a rock tumbler. Hobby lobby has one for 30$ that works fine. Then get some gravel and dish soap, put the zinc pennies in with the gravel and dish soap and add some water, then wait 1 day and go back and wash the pennies off, You will be surprised at how clean they will be. www.bigboyshobbies.com

My finds with my fisher f2. And some tips for your F2. And some of my best finds. Tips to help clean your finds.