The gasket should cover all mating surfaces from inside edge to outside. I  
believe the material is 3/16" thick or there about.
 
Rummy
 
 
In a message dated 6/7/2013 1:20:02 P.M. Eastern Daylight Time,  
steverayj at hotmail.com writes:

[broken link to nabble content:http://rhodes-22.1065344.n5.nabble.com/file/n45862/centerboardmineapart02.jp]
g