Blakes Seacocks

[ddodg]

One of my Blakes seacocks from 1997 needs replacement due to pitting on the face of the cone.
I have looked at the Marelon as a possible replacement but not possible to fit in the space available so am replacing with another Blakes.
My question is what reasonable life span can I expect from a new Blakes seacock. Seems a lot of conflicting opinions on DZR.
Thanks

 

[Tranona]

Almost certainly your existing Blakes are DZR unless they are pre 1980 or so. DZR will last just as long as the earlier bronze ones. Is the pitting so bad that it does not seal when ground in and greased?

BTW there are no conflicting opinions on DZR - it does what it says. The confusion arises because many "commentators" including surveyors who write in the mags don't know the difference between 60/40 brass (which does dezincify) and DZR which looks virtually the same but has a crucial extra ingredient (arsenic) which does not.

Sensible to stick with Blakes despite the cost - I had exactly the same situation where the cost and complication of getting alternatives to fit was too much. It is a better product overall compared with almost all alternatives anyway.

 

[Birdseye]

I agree with Tranona. Never had an issue with Blakes but the Marelon in my new to me boat are a complete PITA.

As for the pitting - have you wired them to the boat anode? I have never bothered and never had any sort of pitting.

 

[Fire99]

Chances are these won't fit but I recently replaced one of my heads seacocks with a Trudesign 'plastic' one. I really rate them as it's one less thing to worry about electrical corrosion etc. But they are quite chunky so perhaps not for everyone..

 

[Snowgoose-1]

A nice feature of more up to date Blakes seacocks is they contain a grease nipple.
My current boat had seized Blakes seacocks when purchased with the added complication of being glassed in to the hull.

Perhaps if they were the new kind , us boat owners would be more inclined to grease them more often. When I come out every two years, I always dismantle and grease/lap as necessary.

 

[vyv_cox]

My Blakes date from.1985, almost certainly DZR. They remain perfectly effective.

Pitting can probably be ground out but bear in mind that they do not need to seal perfectly. A minor leak is of very little consequence.

 

[ddodg]

Thanks everyone for your replies.All very helpful.
Seacocks not wired. The cone was pitted when I acquired the boat 10 years ago and is beyond grinding out. Now starting to dribble a little so decided it was time to replace.
Many thanks

 

[Kwik Decision]

On our previous 1984 model Sadler 29, which had 4 blakes seacocks presumably from new, it was the heads outlet where the cone got pitted. I'm guessing it was due to something nasty sitting against it due to too little pumping after using the heads. It was replaced with a new blakes, with the grease nipple as somebody has described, best part of 15 yrs ago now, and the pitting didn't return during our ownership. I was a bit draconian in enforcing the plenty of pumping rule for the heads though.

 

[Poey50]

My 1986 Blake's are badly pitted but Blake's own seacock grease is so thick and glutinous, it compensates for the pits. I've never had a problem and I don't expect to change them.

 

[Snowgoose-1]

My 1986 Blake's are badly pitted but Blake's own seacock grease is so thick and glutinous, it compensates for the pits. I've never had a problem and I don't expect to change them.

I seem to remember Blake's recommending a particular grade of grinding grit to ensure that some grease is held captive in the cone and body. So your pits can hold a nice quantity of grease.

 

[Bristolfashion]

 

[penfold]

View attachment 167311

IIRC Blakes recommend medium grade, but without offering a clue what medium means.