Blakes seacocks, relapping

[Peter]

Got to relap a couple of these seacocks. Any particular grade/type of lapping compound I should be using. And before refitting should they be grease coated?

Thanks

Peter

 

[john_morris_uk]

[ QUOTE ]
Got to relap a couple of these seacocks. Any particular grade/type of lapping compound I should be using. And before refitting should they be grease coated?

Thanks

Peter

[/ QUOTE ]

1. If the seats are badly scored, then lap them with coarse and then fine compounds. (I have used car valve lapping paste in the past, and it worked perfectly) If they are not scored too much, a quick go with the fine paste will probably be sufficient.

2. Yes the cones need greasing. Later Blakes sea-cocks had grease nipples fitted, and it might be worth retro fitting some if your engineering is up to it. Otherwise just uses a waterproof grease. Don't do the retaining ring clamp thingy up too tight. It squeezes all the grease out and you should be able to move the lever with one finger.

When they are lapped in and greased properly, Blakes sea-cocks are a joy to use.

 

[pampas]

Assume that the valve is already out. Look and feel right down at the bottom of the bore and see or feel if there is a ridge, if there is ,lapping in will not be very effective as the plug will stop on this ridge and fail to give a good reseat. Mine was like this,so I machined the bottom of the moving taper to give a clearence overr this ridge allowing full face engagement, then lapped in and cleaned and greased,now have a good,easily operated valve for the last 5 years. Thought I might pass on my solution to everybody.