Blakes seacock getting tighter

Tim O

Tim O

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Hi...

I have a standard "large" Blakes seacock on my toilet waste outlet and I've noticed over the last few weeks it is getting harder to open and close, requiring either a lot of effort or slightly slackening off the keep-nuts and bolts that hold the pressure plate thing down....i tighten them up hand tight again once i have shifted the lever.

Being a cautious type I actually open and close it every time I leave the boat - I live aboard so effectively that is pretty much every day.For info....no "solids" go down it.

It was well greased with Ramonol white grease before the boat went in the water a year ago.

I am wondering if this is just the effect of colder weather contracting the metal or making the grease less "liquid"?

Any thoughts....????
 
If working the seacock every day, most likely more than once a day you have probably worked all the grease out so there is less lubrication. This is completely normal on regularly closed blakes. My blakes that are used regularly do the same and I will often repack with grease during a mid season scrub.
 
hmmmm......

If it is the case that I have worked all the grease out, is there any way of getting more grease IN without lifting the boat out of the water...I dont have any plans, or current need to do that his winter and its certainly not worth the cost of a lift out just for this! More than happy to pay £16 for some proper Blakes grease

For instance...if I took the hose off with the seacock closed, i could squish some grease down onto the visible part of the cone, then put the hose back on,slacken off the keep nuts and work the seacock back and forth????...id get some drips but thats not a huge problem.....then tighten keep nuts again???
 
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Tim O said:
hmmmm......

If it is the case that I have worked all the grease out, is there any way of getting more grease IN without lifting the boat out of the water...I dont have any plans, or current need to do that his winter and its certainly not worth the cost of a lift out just for this! More than happy to pay £16 for some proper Blakes grease
Click to expand...

Use your emergency wooden bung. Undo the keep plate, pull the cone out, insert bung. No different from taking a log impeller out to clean it. Bit of water may come in but easily mopped up.

I am assuming you have an old pre grease nipple valve.
 
oh yes....good plan....my brain hasn't had enough coffee to work properly yet today..!...yes , pre-nipple type valve!
 
If / when you can arrange to block the outlet from the outside (Brrrrr!) you can clean the cone and the housing and then lap them together. Shouldn't take more than ten minutes or so.
The grease that I used when I had Blakes was called "PBC" (polybutyl cuprisil) simply because I had it since my apprenticeship days at a dockyard. It sticks like the proverbial. Although it is meant for slow-moving steam machinery I found that it performs well under water; never had a problem with it and the boat was constantly in the water except for three weeks every two or three years.

Added:

"Product Information

POLY BUTYL CUPRYSIL

PBC- organo-metallic complex for the prevention of seizure. Effective up to 1200°C. Protects screw threads, linkages, pivots and mating surfaces generally subject to severe temperatures, salt, water, chemical and galvanic corrosion. PBC may also be used as a non-melt lubricant on slow moving heavily loaded bearings at temperatures up to 150°C. Also available in aerosol Form.

Extreme Temperature Resistance
High Load-carrying
Reduces Fretting Corrosion
Resists wash off
"
 
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Thats another good (?!) option......don't think my outlet is more than a foot or so below water line so could possibly work from my avon dinghy, reach below and push in a bung of some kind then do this.....
 
Another tip for 'temporary bungs' is to use the cylinder of silicone that almost invariably results when the unused sealant goes solid. If necessary, it can easily be carved to fit and can be 'screwed' by hand into an opening without the use of a hammer; they seal very well because they adapt to uneven bores. I prefer them to the traditional wooden bungs.
 
Tim O said:
Thats another good (?!) option......don't think my outlet is more than a foot or so below water line so could possibly work from my avon dinghy, reach below and push in a bung of some kind then do this.....
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Heel the boat. The nearer the skin fitting is to the surface, the less water pressure there will be. If you can heel the boat enough to get the skin fitting out of the water entirely, so much the better!
You could achieve the heeling by placing all your heavy gear on the opposite side of the boat, or more effectively by tying your main halyard to a strong point on the quay or a pontoon about a boat-length away, (you'll need to extend it with a warp), and winch it in until the boat is sufficiently heeled. Don't worry, your mast and rigging is built to withstand such forces.
 
ghostlymoron said:
I would replace these antiques with ball valves at the next haul out. Trouble free, maintenance free and good flow characteristics.
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Why on earth would you want to do that? Blakes are still the best seacocks for this application. It will take 15 minutes to regrease them afloat and if the right grease is used they require no maintenance between haulouts.
 
Tranona said:
Why on earth would you want to do that? Blakes are still the best seacocks for this application. It will take 15 minutes to regrease them afloat and if the right grease is used they require no maintenance between haulouts.
Click to expand...

Absolutely agree! I suspect this sea-cock has been happily doing its job perfectly well since the boat was built in 1984 - no reason to replace it just for a bit of stickiness that can be solved with a bit of ingenuity and grease.

Replacing it would probably be a £200 job and I'd rather save my money for the dozens of other things that need doing that ARE beyond my diy skills (new sacrificial strip, new sprayhood, repair to bulkhead, engine mounts and realignment,...etc etc)

Methinks some posters were taking the proverbial Mick...... ;)
 
ghostlymoron said:
I would replace these antiques with ball valves at the next haul out. Trouble free, maintenance free and good flow characteristics.
Click to expand...

The plug valve has been in use since the 1930's marketed as 'Lo Torq' valves by the likes of FMC and Halliburton. Today it is mass produced and used in many refineries and drilling rigs because it is low cost, low maintenance and an easy to use valve, far superior to ball valves. The plug is of course a taper and that means, like flywheels and propellors, it requires very little force to make a seal (providing the faces are good) or bind. Indeed, over tightening the fasteners that clamp the plug into the house by less than 1/8 of a turn will easily jam the plug tight. It is a superb design, being simple and reliable.
 
I don't see that any of that makes the conical plug valve superior to that ball valve. With modern seal materials there is no need to adjust the seal pressure and the straight through configuration gives a superior flow characteristic. No maintenance is required and replacement is cheap when required.
 
ghostlymoron said:
I don't see that any of that makes the conical plug valve superior to that ball valve. With modern seal materials there is no need to adjust the seal pressure and the straight through configuration gives a superior flow characteristic. No maintenance is required and replacement is cheap when required.
Click to expand...

The problem with most of the ball valves we can buy is that the balls and levers that control them are not made of corrosion resistant materials, even if the bodies are corrosion resistant. The better ones are not cheap to replace. Tjay also suffer from seizing due to lack of regular use as deposits build up around the ball making them impossible to turn with the small lever provided.

If you are aware of their shortcomings they are perfectly satisfactory, but tapered plug valves such as Blakes last indefinitely with the minimum of attention. Flow rates are not an issue if they are sized correctly. Remember they were designed for sea toilet use and the 3/4" inlet and 1 1/2" outlet are perfectly adequate for that use.

Of course there are other applications on a boat such as cockpit drains or seawater intakes where a ball valve is a better, or in some cases the the standard plug valves are not the right size for the flow required.
 
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