Where to Apply Gasket Sealant on Water Pump Gaskets?

[minuteman62-64]

I learned (from my Dad, a mechanic) that when you use gasket sealant you almost always put it on both sides of the gasket.

My Mariner Service Manual, w/regard to the gaskets involved with the water pump (base to lower unit, base to plate and plate to pump housing), says to apply the sealant "... to outer surfaces of gaskets." Does this mean something different than what I've been doing all these years? Is there an "inner" surface of a gasket, or a reason one would apply sealant to only one side of a gasket when the gasket is sandwiched between two metal surfaces?

BTW, the manual specifies "Perfect Seal," but I'll be using the Aviation Gasket Sealant as a result of considerable research on this Forum.

 

[Mikey_B]

Re: Where to Apply Gasket Sealant on Water Pump Gaskets?

I find most water pump gaskets to have a very "waxy" surface when new, and don't really benefit from additional sealant. But if you use it then a very thin layer on both sides, certainly stops the gasket moving around before you bolt the components together if nothing else.

 

[Chris1956]

Re: Where to Apply Gasket Sealant on Water Pump Gaskets?

I always installed Merc Waterpump gaskets dry. I would grease Orings and gearcase grease seals. What manual are you using? What year motor?

 

[minuteman62-64]

Re: Where to Apply Gasket Sealant on Water Pump Gaskets?

I always installed Merc Waterpump gaskets dry. I would grease Orings and gearcase grease seals. What manual are you using? What year motor?

The motor is a 1982 30 HP Mariner. The manual is the factory service manual.