Stainless Steel Grease Zerks for Seacocks

I'm thinking of replacing the factory threaded-plug fittings on the side of all of my seacocks with stainless steel zerks so the seacocks can be lubricated and be easier to operate. Two plugs on each main, one on the generator, one on the a/c, and one on the raw water washdown/watermaker. It's a 1999 Jefferson. Don't know the brand on the seacocks. Has anyone done this? Do you know the size? Threads, metric or standard?

Thanks.

John

Are the seacocks bronze? If so,Make every effort to go with Monel, not SS.
I bought mine from McMaster -Carr. They survived just fine, and they spent their entire life underwater on an external rudder system.

diver dave said:

Are the seacocks bronze? If so,Make every effort to go with Monel, not SS.
I bought mine from McMaster -Carr. They survived just fine, and they spent their entire life underwater on an external rudder system.

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Yes, bronze. Dissimilar metals issues?

MV Wanderlust said:

Yes, bronze. Dissimilar metals issues?

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Yes, and crevice corrosion. Toss the iron, put in copper/nickel.

Zerk fittings in SS are available at most outboard shops.

If the Zerk is serviced the grease seems to keep SS just fine.

If you are a belt and suspenders type simply remove the usual 1/8 inch pipe plug , put in the Zerk , grease away , and reinstall the plug.

The drain plug is to drain the fluid on the boat side of the valve seat to prevent freezing. Not sure adding a zerk there will do anything but put grease in the hose.

FF said:

Zerk fittings in SS are available at most outboard shops.

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And the corollary, you don't want monel on aluminum. Use SS on outboards.

Grease is wonderful, and can prevent stupid designs from failure; IF, it's greased.

The alloy selection on the fitting is not so important. What is the most important is that they are packed with Marine rated grease. General corrosion needs oxygen to make the chemical reaction of "oxides". Most zerk fittings and seacocks fail due to lack of motion. Keep them packed, coated and used. And never "clean them" with any solvents from the outside.

Groco used to say to never use a zerk fitting to grease their ball valve seacocks. They said the high pressure could blow out the seals. Now they ship them with zerk fittings. I’m confused.

Don’t forget to have the seacock open when you grease it. If the seacock is closed when you pump the grease in, you’ll just fill the opening with grease and not get any on the outside of the ball or cone.

Hard to be sure exactly what seacocks we are talking about here. My classic old stuff was made of a tapered bronze section that had no elastomeric seals. I had to annually remove the rotating taper metal piece, sand it and the fixed piece with 220 ish paper, winch grease it, then reinsert and then tighten the two bronze nuts. I frankly can't imagine a simple grease shot from a zerk would actually travel around the taper. But, I could be wrong, having not done that experiment.

"I had to annually remove the rotating taper metal piece, sand it and the fixed piece with 220 ish paper,"

The tapered plugs in classic sea cocks can usually be cared for with auto valve grinding compound .

Sanding may remove too much surface , and they wont last 50-75 years!

FF said:

"I had to annually remove the rotating taper metal piece, sand it and the fixed piece with 220 ish paper,"

The tapered plugs in classic sea cocks can usually be cared for with auto valve grinding compound .

Sanding may remove too much surface , and they wont last 50-75 years!

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That’s a good tip. And we should already have a valve grind tube for fitting props.

HopCar said:

Groco used to say to never use a zerk fitting to grease their ball valve seacocks. They said the high pressure could blow out the seals. Now they ship them with zerk fittings. I’m confused.

Don’t forget to have the seacock open when you grease it. If the seacock is closed when you pump the grease in, you’ll just fill the opening with grease and not get any on the outside of the ball or cone.

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I phoned Groco several years ago and talked to a technical guy there and he said that a zero fitting wood work. I bought the zerk fitting from them but never installed it. The important thing is to get the correct lubricant and use nothing else otherwise the Teflon seat is ruined. I have the stuff in the ER. Can’t remember what it is called, but it was expensive.

I took mine apart while on the hard and lubed it accordingly.

Jim

I used to have the tapered plug type of seacock on 2 previous boats, installed the grease fittings and greased the cones.

I used SS and never had any sign of trouble. I understand enough about the interaction but the fittings were so full of grease that as far as I could tell water never got to them. I did pull them and checked periodically.

For winterizing the seacock just pull the fitting to drain any water unless your have two plugs so you can just pull the other side.

I agree Monel would be better but at that time they were not available to me and I didn't even understand what that was.

The grease fitting, Zerk, is installed in the drain hole, usually 1/8" NPT thread.
The seacock must be open so when you pump in the grease so it will be pushed between the valve body and the plug. Exercise the handle and the grease will spread. The cone will free up a lot unless it too far gone.

Just don't go overboard as it take a very small amount of grease to do the job.

Yes. I started a thread on this topic here:


http://www.trawlerforum.com/forums/s32/groco-bv1500-ball-seacock-26139.html

They recommended using Dow Corning molycote 111 for regular lubrication.

Jim