Re: Back to O rings

[Royce Woodbury]

Peter Foley wrote:

Before making new cylinders, why not make new pistons?  That, to me, 
would be a considerably easier exercise, would it not?

regards,

pf

Thanks for responding, Peter.  The groove as designed by Gordon Watson, 
is smaller than the ID of the Oring.  This led me to believe that it is 
undesirable to not allow compression (from contact with the bore of the 
cylinder) to the inside of the Oring.  By increasing the groove OD to 
enlarge the Oring OD, you capture the Oring between ID and OD.  It is my 
understanding (and I could be wrong) that this is not the way Orings are 
designed to work.   But if this is OK, then you bet, I'll make new 
pistons rather than new cylinders.

PS.  the Orings supplied by Gordon Watson (viton) were the correct OD 
(.438).  I bought some Buna-N orings at the local tool supply store and 
they are undersize.  I concluded that they wouldn't work UNLESS the OD 
of the piston groove were increased to bring the OD up to .438.  Again, 
I ruled this out based on the logic above.  But if it is OK to capture 
the Oring, please let me know before I make new cylinders.

Thanks again you guys.

royce in SB
and back to work