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Discussion Starter · #1 ·
Sorry I lost my original detailed post.
Questions. Blake bronze cone seacocks. How much pitting is ok. How much grease? How tight should the bolts holding the cone in be as this influences ease of turning?
The bolts above are threaded into the body, on each of mine only one nut is present for two bolts. I guess I should find more nuts?
Stuart intake filter seacock - seems probably left open longterm and handle resists tentative blows - action?
Seacocks unlikely to be easily accessible ie exhaust cockpit drains bilge both now and in case of a problem ie empty cockpit locker contort to unnatural position and insert plug. I guess I should inspect and service.
Sorry can't give picture Sailnet says size is 254K or some such but I e-mailed it to myself and it is 59K well within the allowable limit.
Thanks in anticipation I have little knowlege of such things.
 

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Telstar 28
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Chris—

A photo of the Blake would help... pitting is not good on the cone.

Does the Stuart seacock have any adjustment nuts on it. If so, try turning them to see if that allows you to turn it... if not, then it is probably toast.

BTW, you really need to get an account on a photosharing website, like Welcome to Flickr - Photo Sharing Image hosting, free photo sharing & video sharing at Photobucket or SmugMug Photo Sharing. Your photos look better here. and then post your photos there and link to them using the IMG tag. I'd highly recommend you read the POST in my signature because it has information like that in it...
 

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Discussion Starter · #3 ·

Ok I hate those sites - in one minute I supposedly have 7 love notes from people in my city.
The Stuart is a cylinder with a knurled top which undoes to show a screen. Near the bottom of the cylinder is a single large nut opposite the handle. That looks like the only possible source of adjustment if any.
 

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Telstar 28
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I'd agree with Maine...those are probably toast. :) Of course, if the seats are in good shape, which I seriously doubt, you could try and just replace the handles and cones... :)
 

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Discussion Starter · #6 ·
I picked the worst patches but yes there is no way the pitting could be ground out. It is hard to see the seats as clearly but I imagine they would wear similarly.
Does this need to be done now while I am out? Any ideas on cost and time involved in doing 9?
 

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Chris—

Yes, it should be done now.

You didn't post photos of the through-hulls, but if they're connected directly to the seacocks, then you'll probably need to replace them. Maine Sail has an excellent primer on replacing through hulls as well as installing seacocks, both are located HERE.

You can probably do the entire thing yourself in a weekend.
 

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Old Fart
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Doesn't look that bad to me. I'd say a good coating of a heavy grease and a snug fit will extend the life of the cone seacocks many more years. Of course keep an eye on them and make sure your bilge pumping system is in good shape.
 

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take the worse ones to a machine shop, my triton has cone type seacocks that were pitted and scored. I was able to take a light skim cut off the cone itself, then an adjustment cut at the bottom and they were as good as new.
You don't need to make the adjustment cut on the bottom unless the small end of the cone sits flat on something, there's normally room there.

The unworn and tarnished section directly under the handle shows you the room you have, don't take it all, just enough to clean up the cone.

It's the reason they used a cone instead of a cylender or ball on the old seacocks and other valves, they were designed to be repaired when worn instead of replaced.

Ken.

Where you see the shadow of the opening doesn't have to be smooth, it contributes nothing to the sealing.
 

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Discussion Starter · #11 ·
Ok some feedback on outcomes. I removed 5 of the 8 that were bronze. The sixth had never been closed and was totally seized and stuffed.

Of the 5 two had previously been repaired and it was questionable whether they could be again given the depth of the erosion. Two might be repairable. The fifth was a cockpit drain again permanently open not bad but showing dezincification.

I took them to a machine shop and was told the seats ie throughhulls would be required to be machined for a fit. The cost being maybe $200 each. As it may not have worked it seemed more economic to replace them.

Now how this arose is interesting.
Blake seacocks are bronze cones. On this boat three are fitted in an area roughly 16" by 5" on the floor of the head.

In fitting some were at 20-30 degrees off vertical ie 340. The cones without measuring them precisely appear to have an aperture of about 120. The po told me that closed was 90 and open 180. This would be so for a ball valve. However for a cone valve at least 120 is required or preferably 180. There would be a natural tendency to assume 90 was off and 180 0n, especially since you could not see the actual direction of the tailpieces without almost lying on the floor.

This with the offset meant that when it was thought to be open it was about 80 degrees short so a third open. When thought to be closed it was about 10 degree closed .

The machine shop thought that being partially open could cause electrolysis by turbulence which is beyond my knowledge to comment on though an electrician friend said it was a known concept. The pattern of erosion was on the edges.

Since there was only one zinc (on the prop shaft) and no grounding of thru hulls there are additional possibilities. Since the prop zinc was good and the prop dezincified, this suggests that the prop zinc had been neglected previously then the prop painted with propspeed.

I won't make any other comments except that others may find similar and you won't know until you find that a wood bung can't be inserted in a limited space.
 
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