----- Original Message ----- 
Sent: Thursday, August 09, 2007 10:25 AM
Subject: Re: [PSUBS-MAILIST] Double O-Ring On A Hatch
That is Gary's sub. He lives in Michigan. I saw it last year. The hull is 1/2'' thick while the ends are 3/4'' thick. A nice job, but could use more windows. If someone wants a good ''K'' boat, that one is nice.
Brent,
 
 
I concur with Vance, Carsten and Peter ..., a single o-ring witht the correct hardness is the way to go.  See technical note 
http://www.sato riseal.com/Technical/introduction_to_o-rings.htm on how o-ring is design to move within it's machined grove under pressure to seal.  Hatch upper and lower faces need land face to face.    If you are designing a hat ch, pick a standard size so that you do not have to introduce a splice.
 
 
Cliff
 
Great works are performed not by strength but by perseverance. 
Samuel Johnson