Sea Cock lube

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ralphyost

Senior Member
Joined
Oct 18, 2007
Messages
261
Location
USA
Vessel Name
Say GoodBye
Vessel Make
21 Mako
How are sea cocks best lubed? Boat is on the hard for the winter.
I understand they can be taken apart for lubing.
What kind of lube is best?
What about installing a lube nipple?
R.
 
I have used Lubriplate water pump grease, it white , and has gone 4 years between haulouts , but I do move the handles every few months.

No corrosion , no scars on the mating surfaces.

FF*****************
biggrin.gif
 
The way I was taught to lube the big bronze seacocks in our Grand Banks was to open the seacock, remove the two suare-headed plugs on either side of the barrel, and with a finger force as much waterproof grease into the plug holes as possible while working the seacock barrel back and forth slightly. The reason for opening the seacock first is to align the hole in the barrel with the through-hull and hose, not the plug openings. So the grease gets worked in between the barrel and the casing, not just shoved into the water passage in the barrel.

I understand that the plugs are there also to drain the seacock if the boat is taken out of the water for the winter and is not going to be in heated storage. Removing the plugs apparently allows any water traped in the seacock to escape so it won't freeze and expand and damage the seacock.

I don't see any reason a grease nipple could not be installed in place of the square-headed plugs. I'd probably want to use a bronze nipple if I could find one to avoid any sort of dissimilar metal seizing.

If your boat has Maralon (sp?) seacocks, I don't know what you would use to lubricate them.

Yes, seacocks can be dissassembled (at least the older style bronze seacocks we have can). They can also be adjusted if they are too loose or too tight. This last bit has to be done in the water, however, because they'll leak if they're set too loose so you need to be able to see that as you're adjusting them.
 
Fred:
How do you get the grease into the sea cock?
R.
 
There disassembled for cleaning and inspected every few years when the bottom gets painted.

Shmeer it on with your finger.

Yes, seacocks can be lubed while open by installing a grease fitting in the side plug threads.

I use SS fittings from the outboard shop and leave them in.Never found bronze ones.

A small hand fillable grease pump is at many bike shops and can be hand filled with Lubriplate .

These do NOT create the very high pressure of a std lever pump grease gun , so have less chance of distorting the thin walls of the barrel if used to free a frozen seacock.

The "best" way to free the barrel is PB blaster a couple of times in the lube hole and on the washers at the end.

FF
 
I dont want to start an argument about lubriplate but in the link I put on above under "periodic inspection in the water" lithuim based or other metal based greases are not recomended for greasign seacocks because of possible galvanic corrosion.
 
Hi Old fish guy,
I guess you use what works and i didn't mean to poop on anyones ideas BUT it is mentioend by the author of the article I posted and MAY be a concern. After all he did say possible galveenic corrosion.
 
So then how does one know if the grease he has is "waterproof" or not?
I used to use a blue colored grease on the spline of my outboard engine where the prop is connected. Could that grease be used?
R.
 
That's what we use in our seacocks--- it's the same blue-gray stuff we use in the bearings of the trailer for our small boat.
 
The really sticky blue stuff is supposed to be waterproof and not rinse off. Judging by how it sticks to my hands I believe them. It is a little more trouble when you haul out and disassemble the valves for a good visual, but I think it's well worth that little effort to know it's not disappearing from the valve in the meantime.

Ken Buck
 
FYI, for the new Groco BV series sea cocks, no lube is required OR recommended. I just had an email from Groco and he said that they use Teflon seats around the ball and no lube is required. He recommends against using lube. See their service bulletin here
http://www.groco.net/SVC-MAN-07/Sec4/BROWSER/bv-wv.htm

I did find the following source for stainless steel grease fittings 1/8" that will fit the side drain plugs of most sea cocks
http://e-fittings.com/18inpithsst.html
 

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For older sea cocks, here is the advice I received from GROCO today
The older seacock, SV series DEFINATELY need lubrication.

So...
With the boat in the water,
*1. Install the same 1/8x27 Stainless Steel Zerk fitting into the side of the valve.
*2. Loosen the wing nut
*3. Open the valve. DO NOT DO THIS WITH VALVE CLOSED! Doing so will fill the plug center with grease and when the system becomes active, will pull the grease into the system. Nothing will be lubricated.
*4. Inject a squirt or two of a Non-Petroleuem lubricant, Silicone grease is good, Lithium is next. Do not use standard wheel bearing grease (oil based).
*5. Work the valve back and forth.
*6. Leave the valve in the desired position
*7. Snug the wing-nut to stop any leakage.

With the boat on the hard,

1. loosen the wing nut
2. remove the two 7/16' Head bolts from the face ring.
3. remove the face ring and wiggle, do not force, the plug from the body
4. knock off any high spots or burrs from the plug with emery cloth.
5. slick up the plug with the grease.
6. using steel wool or fine emery cloth, polish the inside of the body of the seacock.
7. Reassemble
8. drop the boat in the water and check for leaks.
 
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