Brass seacocks

danielefua

danielefua

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I recently happened to browse Nigel Warren "Metal corrosion in boats" and was surprised to find a strong article (pp 151-152) against what I think are the best seacocks on the market: the Blake's. Moreover my boat has all B. seacocks and I was thinking of renewing few of them with the same brand. Is my interpretation of Warren right and, if yes, is his criticism still based on hard ground or else outdated?
Daniel
 
Agree. Unlikely they need renewing. Just strip them down, clean them and re-grease. You can get instructions from Blakes. Only advantage of new ones is that they have grease nipple.
 
Frankly Blakes have been making Lloyds approved seacocks longer than Nigel Warren has been heard of (what are his credentials anyway?) Forget it.
 
[ QUOTE ]
what are his credentials

[/ QUOTE ] Naval Architect and author of "Metal Corrosion in Boats" and two or three other less well known books.

It seems strange that he would have been critical of Blakes traditional bronze seacocks but he may have had something unkind to say about them now making them from dezincification resistant brass.
 
Well this popular acclamation makes me feel better! /forums/images/graemlins/smile.gif
I thought Warren's book was a sort of Bible on corrosion but I guess nobody's without a bias. Just curious: maybe he was not referring to the B's at all.

My Blakes are exactly 30 years old too and some of their cones seem to be a bit worn out. Otherwise they still close without problems.

Daniel
 
Also have mostly blakes seacocks from the 70's which are Bronze and you are right new one are DZR brass. I would definatly not change old bronze ones for new brass unless I really had to as I have had problems with this stuff. Resistant is not the same as immune!
 
Whot- ho, Blakes seacocks now made of brass, when did this come to pass? I was thinking of fitting a new one next winter.
PS Where can bronze ones be got?
 
[ QUOTE ]
when did this come to pass

[/ QUOTE ] I don't know when exactly. I don't even know that you can get proper bronze ones now. This what the website says [ QUOTE ]
Q Material specification used on the Blakes seacocks
A The body and plug are made of DZR1 (BSEN 1982 CC752C). A dezincification resistant brass for die casting
If zinc is leached from brass by sea water corrosion, the brass will become porous and fail. DZR1 resists the zinc removal and is approved by Lloyds if used in a marine environment.
The seacock bolts are manufactured from Phosphor bronze.


[/ QUOTE ] No mention of bronze apart from the bolts!
 
I didn't notice this change when I bought one recently. They are still widely described as "bronze", eg by Force4 Chandlery.
Others coyly describe them as made from marine grade materials, approved by Lloyds etc.
 
[ QUOTE ]
I didn't notice this change when I bought one recently. They are still widely described as "bronze", eg by Force4 Chandlery

[/ QUOTE ] You've been had then..
 
[ QUOTE ]
is there an easy way to distinguish the old and new composition Blakes

[/ QUOTE ] Not unless they are marked in some way. They do now have grease nipples but I have no idea if that addition coincides with the material change.

Other than that it's chemical analysis or an instrument such as a Metascope.
 
The new one I bought last year seemed to look more "gold and brassy", but difficult to compare with the old ones.

I investigated bronze through hulls and ball valves and they came out at about the same price as the Blakes, but were too tall to fit the space I had - hence the decision for Blakes.
 
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