Installing New Seacock's (A New Photo Based How To Article)

Discussions about Cape Dory, Intrepid and Robinhood sailboats and how we use them. Got questions? Have answers? Provide them here.

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Troy Scott
Posts: 1470
Joined: Jan 21st, '06, 01:23
Location: Cape Dory 36 IMAGINE Laurel, Mississippi

space-age seacock grease

Post by Troy Scott »

Kurt,

By recommending the Dow Corning silicone grease you have probably already done what I've been trying to accomplish, because Dow Corning regularly updates/upgrades their products. However, if you've been using the same tube for 30 years, you haven't taken advantage of this. But, If I follow you're recommendation I will get the latest version!

It could also be that Morey's Red is made by a company that constantly updates and upgrades.......

Do any of you guys have experience with this silicone grease in salt water?

Regards,
Troy
Regards,
Troy Scott
Boyd
Posts: 403
Joined: May 9th, '05, 10:23
Location: CD 30 MkII

Stick with Morey's Red

Post by Boyd »

Hi All:

I bought some of that rediculously overpriced Dow silicone grease and used in on all of my seacocks. To put it politely, its lousy. All of them either seized up or started leaking profusly in a few months. I repacked them all with Morey's Red. Morey's Red lasts between a year and two years in Fla. I usually haul out between two and three years instead of the annual that the northern sailors do.

Dont get me wrong the silicone is great for O rings and hatch gaskets but its a disaster in Spartan seacocks.

The kitchen drain seacock has become such a problem that I am going to replace the brand new Spartan seacock with a ball valve at next haul out. No matter what I do it will not hold for more than a few months.

Boyd
s/v Tern
CD30 MkII
Fort Lauderdale, Fla.
Kurt
Posts: 188
Joined: Feb 8th, '05, 11:12
Location: 27' Cape Dory (Alerion),
9' Dyer,
Grosse Pointe, Michigan

Sorry to hear about your bad luck with the Dow grease

Post by Kurt »

Boyd,
I'm sorry to hear about your negative experience...I believe I'm the one the recommended it to you in the first place. But so help me god...I've been using the stuff for 30 years and have always had nothing but the best of luck with it. I don't see where salt water would make it perform differently.
Kurt
User avatar
tartansailor
Posts: 1528
Joined: Aug 30th, '05, 13:55
Location: CD25, Renaissance, Milton, DE

Viscosity

Post by tartansailor »

Kurt

There is the thick stuff and there is the thin stuff.

Boyd probably found the lower viscosity grade like
the grades used for electrical work, while the higher
grades are specifically designed for stop cocks, and
high vacuum sealants, which you undoubtedly have.

I believe that the only substance in existence less
reactive to salt water than teflon, is silicone.

Boyd's stuff just flushed away.

Dick
Troy Scott
Posts: 1470
Joined: Jan 21st, '06, 01:23
Location: Cape Dory 36 IMAGINE Laurel, Mississippi

Morey's vs. heavy silicone

Post by Troy Scott »

Dick,

You didn't say, but in your opinion, how does Morey's Red compare to The heavier silicone grease you mentioned for Spartan seacock maintenance?
Regards,
Troy Scott
Boyd
Posts: 403
Joined: May 9th, '05, 10:23
Location: CD 30 MkII

Silicone

Post by Boyd »

Hi All:

I used a heavy, thick grade. I think it was 804 but will have to check. As far as I can tell from the corrosion patterns on the plug the water cuts a series of channels through the silicone grease which become the leak points. Morey's seems to fail by slowly oozing out and hardening up inside the valve. The silicone grease doesn't seem to bond to the bronze like the Morey's does.

Exercising the valve regularly with the Silicone doesn't seem to extend its life.

Sure would like to figure out what I am doing wrong. Rebuilding that seacock every 6 months has become a chore. The mystery is why the seacock that is the most difficult to access is the one that fails most frequently. :(

Boyd
s/v Tern
CD30 MkII
Fort Lauderdale, Fla.
Oswego John
Posts: 3535
Joined: Feb 5th, '05, 20:42
Location: '66 Typhoon "Grace", Hull # 42, Schooner "Ontario", CD 85D Hull #1

You've Got Me Thinking

Post by Oswego John »

Boyd,

Hmmm. You've got me thinking about this. I wonder if water pump grease might do the job?

O J
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tartansailor
Posts: 1528
Joined: Aug 30th, '05, 13:55
Location: CD25, Renaissance, Milton, DE

Perspective

Post by tartansailor »

Without seeing Boyd's stop cock failure mode, and just
going by theoretical values, thick stuff can be compared
to cold molasses, while the thin stuff would resemble Vaseline
in flow rate.

My suspicion is that Boyd's situation is something other than
lubrication, like perhaps; and this is only a guess; some kind of distortion or fracture line in the bronze. The only way to resolve that would be for a machine shop to hone the surfaces, because I doubt that it could be done with acceptable precision by hand. IMHO
Boyd should not be having that problem in a proper stop cock.

So the recommendation would be to pull the assembly, UV it for fracture, and if a pass, hone it on a rigid machine.

Dick
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Steve Laume
Posts: 4127
Joined: Feb 13th, '05, 20:40
Location: Raven1984 Cape Dory 30C Hull #309Noank, CT
Contact:

Post by Steve Laume »

Too tight? I know the first time I rebuilt my seacocks I erred on the side of too tight. It forces most of the grease out and doesn't leave much room for adjustment later. I am splashing today or tomorrow and plan to be there for a final check and adjustment on stuffing box and seacocks. I spent some time last night grinding down a wrench for the spartan check nut. A standard wrench doesn't quite work. By the time I quit boating I will be pretty good at it, Steve.
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