Blakes seacock keep plate

[mogmog2]

Hi, I'm just about to order some rudder bushes from Trafalgar & noticed they have keep plates for Blakes seacocks which I was minded to add to the order.

When I dismantled mine, it wasn't flat and had sealant on. I don't know if this is designed in to apply the correct pressure, or has been overtightened, but now cleaned off & replaced & it leaks. I have plans to lap it. If the overtightened, can I bend it back? - hammer?, vice?, heat? (I have brazing torch)

EDIT, on reflection, the keep plate only keeps the bung under pressure & is not involved with sealing - therefore it's a lapping issue presumably. Do I have to buy a pot of special lapping paste or is there a (non-marine) alternative like valve-grinding paste: are either of the grits suitable? I've read that it doesn't need to be too fine as the scratches/grooves are needed to retain the grease.

Many thanks

 

[earlybird]

Don't see why you shouldn't straighten slight bending, but be aware of possible cracking. Heat will anneal and soften the material, so don't overdo.
Valve grinding paste from an Auto-shop is where I'd go for abrasive, often 2 grades in a tin. I'd reckon the fine would be OK, 200/250 ish at a guess.

 

[Spirit (of Glenans)]

+1 for auto shop valve grinding paste. When you reassemble, coat the bung liberally with waterproof grease and don't tighten down completely , so that the grease doesn't squeeze out too much. As the season progresses, check from time to time for drips, and tighten up slightly if necessary. If you accelerate the tightening process, you will find that the valve becomes very stiff as the end of the season approaches

 

[Tranona]

The leak is more likely to be because the cone is not seating properly in the body. That is what the grinding paste is for. Clean the cone and the body of grease, apply grinding paste to cone and rotate in the body under a bit of pressure until you get a clean ring of paste showing that the cone is seating all the way round. Clean off paste, grease cone and insert. The keep plate does not need to be totally flat as all it does is apply pressure to the cone, although if seriously distorted may not apply even pressure. Tighten the keep plate down until you can turn the handle with one finger. Job done.

 

[Kukri]

Concur with above advice. Keep plate should not be under any load.