Dismantled Blakes Seacock - what next ?

[aidancoughlan]

Many thanks to those who answered my recent post looking for a Magic spanner - (I think it's probably a Basin wrench)

While taking a break from the offending seacock and waiting for the yacht club bar to open, I turned to the Blakes seacocks in the heads. Took off the nuts on top, removed the 'keeper ring' thing, and sucessfully removed the plug & handle for cleaning & greasing.

I was going to stop there, but getting brave, and still being new to boat ownership, I thought I'd have a go at removing the whole thing with a view to replacing it (20 yrs old) - after much grunting, I removed all the nuts on the flange on the bottom - but one of them has sheared off. I can't budge the seacock housing itself by hand or foot.

I'm unsure what to do next - could I just bang the bolts down with a hammer & expect them to come out the bottom of the boat (they seem to be visible on the outside of the hull -with round heads, cant unscrew them there). If I do that, will the whole assembly come free then? Am I likely to do more damage than good by trying to do this myself. I'm new to this, but I suspect it's not impossible if I persevere - anybody done this before or know what to expect if I get the hammer out?

have a look-see....
.... why do they hide things that need maintenance in places like this ?

Heads outlet, Blakes Seacock with plug & handle removed, nut sheared off

 

[alec]

If you replaced like with like, you are looking at around 80 UK pounds to replace each one.

Mine are still giving great service after 30 years.

Are they weeping a bit when the boat is in the water ? If so, try the following.

I clean and degrease them each year, then I lap them in with Brasso. I finish off using Blakes Seacock grease.

Only do up the 'keep bolts' finger tight. Should be able to move the levers with one strongish finger.

Best of Luck

Alec

 

[aidancoughlan]

Hmmm... Maybe I've been a bit too eager to take them out. I havn't had the boat in the water yet, so I dont know if they leak or not, although the boat was dry when I visited it in the water. I hadnt intended to take the whole thing out, I was just going to service them, the handles were seized open, and i just thought by the look of the whole assembly that maybe they were past it. It sounds like maybe this is not necessarily the case - although I wonder if I can back out now since one of the flange nuts has sheared off. Maybe I could push the bolt through, replace it and the nuts on the other ones and put the whole this back as it was before I interfered.
I dont mind spending the money to plug an important hole the boat, but no sense in wasting it either.

 

[Guest]

Post deleted by danfoley

 

[aidancoughlan]

SEVEN in two full days !!, what are you doing next weekend!? I'll pay the Ryanair flight from Bournemouth if you fancy doing a few more...!

Thanks for the tip, sounds like pushing the bolts down by force will do the job. Not sure I'd fancy putting it back with just the 3 bolts, so I might persevere, just to be sure. At least I know there's light at the end of the tunnell. If I take it all off, clean it up & it seems ok then maybe I'll get the £9 kit from blakes & put it back rather than change the whole thing.

ps. Why did you change all seven on your Nic? Is there a point where it's considered best to replace them as a preventative measure, even if they still work ?

 

[sequena1]

Re removing that sheared bolt: there shouldn't be anything holding it in apart from hardened sealant (though that can be pretty tough after 20 years). Why not try and get the other bolts out first. First partially replace the nuts to protect the threads and tap/welly them out. That should give you a reasonable idea how firmly they're in place. Then use a rod /bolt of the same diameter to drift out the sheared one. Once out, you can remove the outer bronze disc and if its been fitted correctly there should be about 3 to 4 mm of the seacock body protruding. Tapping from outwards/inwards should free the whole thing. (do use a piece of wood between the hammer and the bronze).

Please note the large number of "shoulds" in this post. However the method worked for me.
You could always place a "swear-box" next to the job. It could pay for a new seacock!

 

[aidancoughlan]

Good to hear that this worked for you - gives me more of an idea of what to expect. ie. I now know from above posts that this seems feasible to attempt as a DIY job.
ps. I like the "swear-box" suggestion .... I think it might just replace the full set of seacocks by the time I'm finished!.

 

[poter]

Re: Dismantled Blakes Seacock- Dismantle some more!

I still don't understand this mystique around Blakes.. as if they are the be all of stop valves.
Personally I wouldn’t touch em with the proverbial.

Don’t sod around with holes in your boat if its an older Westerly, just bite the bullet & replace ALL the thru hull fittings below the waterline. /forums/images/graemlins/laugh.gif

Get really good thru hull fittings preferably bronze only around a tenner each then a separate ¼ turn valve either bronze or plastic, (crane valves or GF for plastic here ) that can be replaced easily. As you have already found valves in inaccessible places are crap to work with, & dont function as they are supposed to, ie turn off & on.

poter

 

[Shantyman]

Re: Dismantled Blakes Seacock- Dismantle some more!

We're back to the £10 "bronze" fittings again.

I don't believe you can get a genuine bronze job for £10.

Regards,

Shantyman.

 

[aidancoughlan]

Re: Dismantled Blakes Seacock- Dismantle some more!

From what I can gather too, most of the 'cheap' versions of thru-hull fittings and seacocks are made from inferior materials not suited to marine use, or have some components which are inferior - many in chandlers are OEM items of unknown origin. The Blakes ones are DZR Bronze as far as I know. There are also several DZR Bronze ball valves available which seem to be a good option, and are what I am considering for replacements in the galley and engine area (around 1/3 -1/2 of the price of Blakes).
A specialist supplier has recommended to stick with Blakes for the heads, which is probably what I am going to do (either clean/service/refit what I have or replace). If nothing else, it'll probably mean less hassle replacing like with like.

My boat's "only" got 5 holes in the bottom, and I'd be wary of plugging them with £10 fittings. I've read about the plastic seacocks which seem to have a lot of advantages, and come highly recommended by some, but it just doesnt feel right for me.... so genuine brozne it will be!

 

[tugboat]

Been there - got that T-shirt! The bronze bolts can dezincify with age. You will probably see that the core of the broken one looks a bit pink in colour. If one is like that the other 3 need replacing too. Get the proper ones from Blakes. Before 'wellying' the bolts as suggested, I would urge you to brace the hull from outside first. A stout length of timber firmly jammed between the ground and the outside plate, leaving clear the heads of 2 bolts. Drift those out, shift the bracing timber and then drift out the other 2. Just banging away without supporting the hull could cause stress cracking of the local gelcoat. When knocking the inner and outer fittings to release them, suggest a wooden mallet rather than a hammer, if you need a chisel use a blunt one - mistakes can be expensive. Good luck - let us know how you get on.

 

[gandy]

Do all bronzes contain zinc?

Tony S

 

[aidancoughlan]

I came across some old posts recently relating to the metallic content on Bronze, brass etc. Just did a search, and its totally confused me!. Apart from the Zinc thing, it seems Blakes seacocks are not what I thought they were (Its suggested in several places that what I called 'DZR Bronze' is actually specially treated brass).

Incidentally, one of the plugs I removed from my Blakes seacocks is pink in colour along half its length. From tugboat's comments above & calders book this spells corrosion.

I dont know what to think, I might give Blakes a call and call Aquafax who seem to have some knowledge in this area.

 

[VicS]

Bronzes are alloys of copper and tin although other elements present may include zinc. Brasses are alloys of copper and zinc but other elements may include tin.

Note, however, that so called manganese bronze is really a brass.

 

[gandy]

This was on Blake's web site. They call it "brass", although it looks like retailers do
call it "bronze". So I guess that's what Tugboat was referring to, rather than to dezincification of real bronze.

"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."

Tony S

 

[AndrewB]

[ QUOTE ]
Do all bronzes contain zinc?

[/ QUOTE ]Traditionally, bronze is an alloy of copper and tin while brass is an alloy of copper and zinc. But the distinction between them is now blurred. Most modern grades of 'bronze' do contain zinc although for the most suitable marine types the proportion is low. For example in gunmetal it is around 5%, in phosphor bronze it is ½% - 1%, depending on grade. By comparison DZR is 36% zinc, and is more correctly spoken of as a brass.

While dezincification resistant brasses may have worked well in the past, arguably the greater continuous use of electricity aboard yachts in marinas is making them more vulnerable to electrolytic corrosion.

As I've reported here before, back in November a yacht in my marina nearly sank as the result of failure of a DZR seacock - luckily spotted in time by another berthholder. The insurance company have refused to pay for the damage done, on the grounds that it was failure of maintenance rather than fortuity.

 

[tugboat]

Some years ago when I was restoring a wooden boat I removed all the hull fittings as a matter of course. The underwater fittings (2 Blakes toilet and 1 engine inlet) all had bronze bolts that had gone pink and crumbly whereas the fittings themselves were fine. It's possible a previous owner had used the wrong type, I don't know, but you said that one of yours broke and it seemed pertinent to suggest that you may have the same problem and should replace them all.

 

[john_morris_uk]

I've had the same experience on more than one boat. Blakes Seacocks with dodgy bolts.

I would emphasise that I have never ever had a problem with a genuine Blakes seacock degrading underwater on wooden or GRP hulls. However I have had problems with the bolts. Perhaps someone has been selling dodgy bolts at sometime in the past? The genuine bronze ones cost an arm and a leg!

I have also never found a Blakes seacock that couldn't be refurbished with a bit of elbow grease and some grinding paste on the cone.

The latest ones have a grease nipple built in but I still can't afford to buy the new ones though!

 

[aidancoughlan]

I called Blakes today and the 'Kit' to replace the bolts, strainer plate etc. is approx £mid-thirties+vat. Still expensive, but a lot cheaper than replacing the whole lot. I'm going to persevere next weekend, finish removing the assembly, and have a look and clean it up with some grinding paste like you suggest.
They make 3/4inch, 1.5 inch seacocks nowadays, but no longer support the older 2" ones they used to do.

For the other gate valves, in my continuing confusion I have settled on replacing them with ISIS DZR seacocks from Aquafax http://www.aquafax.co.uk/pdfs/01_cat.pdf, this seems to be a quality product at reasonable prices, is Lloyds approved and certified CZ132 which is explained here... http://www.hghouston.com/coppers/brass75.htm

I think this would be a good subject for PBO to do a review on & help clear up the confusion.

 

[john_morris_uk]

Once you've ground the cone back into the body of the valve with the grinding paste, clean it up and apply a good waterproof grease. Only do up the screws on the retaining ring (by the way they should have lock nuts on them as well) enough to leave the valve operable by easy hand action.

The seacock should be smooth and easy to turn and shouldn't leak at all.