Lubricating Ball Valves

[Malachi]

What's the best method to lubricate the ball valves for the thruhulls?

[Chief Engineer]

Depends on the valve....some have a 1/8" plug that you can put a "zerk" fitting into.

Which thruhulls do you want to lube?

[Malachi]

None of our valves have that plug. We're wanting to lubricate all thruhulls below the waterline. We're currently out of the water.

[Celestialsailor]

Most ball valves have a Teflon or some other plastic seat. If the valves are becoming stiff, it is usually the shaft. I have on occasion removed the handle, backed the nut back and sprayed Triflow lube on the shaft while GENTLY tapping it with a small plastic hammer, tightening the nut back up(not too tight) and reinstalling the handle and working it a little back and forth.

[Dave852]

Hi Jay,

Posted below is an excerpt from a July cruising world article I found on the subject, see what happens when you get your magazines after a year without.

"Plastic or nonmetallic seacocks and through-hull fittings should be made of glass-reinforced polymers, such as Forespar's Marelon. Like brass, such plastics as PVC and nylon should never be used in raw-water applications.
Different kinds of seacocks require different kinds of maintenance. For the kind that's flanged and has a ball valve, little is required in order to keep them operational, although they're liable to become fouled with growth. Their Teflon seals and chrome-plated balls are self-lubricating; like all seacocks, they benefit from monthly exercise or cycling.

Nonmetallic seacocks benefit from periodic greasing, which requires the removal of the hose to expose the ball. Clean the ball, dry it, and coat it with marine grease. My preference for the lubrication of all seacocks except those that use rubber balls or cones is Lubrimatic's Marine Trailer Wheel Bearing Grease (www.plews-edelmann.com); this lubricant is water-insoluble, sticky, and, unlike silicone, lithium, and other "light" greases, it resists washing off. Rubber cone valves call for a lubricant, such as silicone, that isn't petroleum based.

More traditional cone-style bronze seacocks can be disassembled and lubricated for many years of service. Do this annually; certainly do it every three years. Take the seacock apart, clean it with a solvent such as mineral spirits, and sand it with emery cloth to remove any irregularities. Then lap it using valve-grinding compound, apply lubrication, and reassemble.

Some seacocks can be temporarily fit with grease, or zerk, fittings, which can be installed in the drain plugs. With the seacock open, grease is pumped into the cone area. Because most zerk fittings are made of mild steel (or sometimes stainless steel), they shouldn't be left in place. Make certain that the drain plug isn't corroded before it's reinstalled. If a new plug is needed, make sure it's bronze."

Dave