Lubricating through hull valve

[northern]

I recently had boat out of water. The person beside me sprayed Lithium grease into his through hull valve from outside the boat. Said he has been doing it once a year for the past three years to lubricate the valve. Has any one done this and will it damage the rubber in the valves. If the seats in the valves are Buna rubber petroleum will make the Buna swell.

 

[northern]

No one lubes there valves?

 

[PlayDate]

Okay…. The old style Buna valves eventually will seize or leak over time. Nothing will stop it short of rebuilding them which in my opinion is a waste of time.

The ball style valves use a stainless ball and a Teflon sleeve. If they are not normally exercised…..the surface of the ball becomes corroded and interferes with the Teflon sleeve resulting in difficulty in opening and closing the valve. In addition the shaft on a ball valve can also corrode which results in hard opening and closing.

Use WD-40 on the shaft inside the boat and it will help keep the shaft lubricated. It does nothing for the ball valve itself which can benefit from your friend’s approach if the valve is closed when it is sprayed and cycled a few times.

Just my opinion.