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Ok, I am replacing my sea cocks with marine ball valves as currently i have the old garden variety gate valve. There are a few brands out there, any recommendations? I saw on defender Groco, conbraco, marlon etc... is there any difference between the vinyl sea cocks and bronze? Thanks!
 

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Saurav-

The Marelon (glass-reinforced nylon IIRC) seacocks aren't subject to galvanic corrosion issues, but the handles aren't as strong and can break off.
 

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Discussion Starter #3
So I take it there are no other differences besides price? I am looking at these:

http://www.defender.com/product.jsp?path=-1|51|106370|813148|319675|860854&id=142065

vs

http://www.defender.com/product.jsp?path=-1|51|106370|813148|319675|860855&id=860619
 

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Marelon Valves

Agree. -
The Marelon (glass-reinforced nylon IIRC) seacocks aren't subject to galvanic corrosion issues, but the handles aren't as strong and can break off.
The PO of my boat put one on for the engine sea water sourceso he didn't worry about glavanic corrosion. Last year no issues. This year, when trying to shut the valve, the handle really flexes/bends. I am not sure it really closes all the way. When pulled for the winter, I am going back to a ball valve.

DrB
 

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The Groco has some other features that make it worth more, like being able to use a socket wrench on it, drain plugs on both sides, etc...
 

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Agree. -

The PO of my boat put one on for the engine sea water sourceso he didn't worry about glavanic corrosion. Last year no issues. This year, when trying to shut the valve, the handle really flexes/bends. I am not sure it really closes all the way. When pulled for the winter, I am going back to a ball valve.

DrB
The manufacturer puts a tag on the valves (that the PO probably removed) that says you need to lubricate them twice a year. I love mine, but they really do need the lubrication. Any non-petroleum grease works. Just pull the hose, and dab some on top of the ball with the valve closed and work it back and forth a few times (with the hose replaced, of course). Do the same from the outside when it's on the hard. They move very easily when lubricated.

Eric
 

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Yes..

Yes there is a difference but you have options!

I personally feel, as do many folks, that the Spartan Marine's bronze tapered plug seacocks are some of the finest & longest lasting built. They are however VERY expensive and require maintenance and re-builds.

Lots of people seem to like Marelon for the corrosion factor but I have personally owned a fair number that have failed and Forespar did NOT stand behind the product.

My personal choice is to use a Groco flanged adapter plate and Groco UL Listed Marine Rated bronze ball valves. With the adapter plate I can simply change a seacock any time I need to!! This is a HUGE convenience & safety factor!!

This is a Groco flanged adapter plate. On the bottom where you screw the thru-hull in it is NPSM thread or straight thread and on the top it is NPT, or tapered thread, to match a ball valve.

For more information please read these two articles:

Seacock & Thru-Hull Primer/Pre Information


Replacing Thru-Hulls and Seacocks


NPT Threaded Side:


NPSM Straight Threaded Side:
 

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I have a fibreglass boat currently on loan. Bronze seacocks and brass fuel cocks (it's the Great Lakes and my electrics are sound).

I have a steel boat I am prepping for world cruising. Marelon is a godsend. However, I can think of a couple of better approaches, some of which my boat already incorporates. The Marelon is *only* on the "exit" points for grey water from the kitchen sink and the head sink. Ridiculously overbuilt, but I can live with them.

For the "entry" of water, I have a three inch standpipe, the top of which is sealed with a threaded metal cap and is above the waterline. Off this standpipe are teed off four seacocked hoses, one for head seawater; one for engine pump (there is a Perko bronze strainer to keep the cooties out); one for the March pump to run the A/C, and a spare I will probably use for a watermaker. I will probably further T off the A/C for deck washdown use or cockpit shower as you can't use my A/C off the dock.

The advantages of this system are many. Primary is that you don't have a lot of inaccessible holes in the boat and failure points. Secondary is that you can actually unscrew the cap and fish around (sometimes for fish!) to clear obstructions. For this reason I've purchases a strainer cap I will adhere when next I haul.

The improvement I mention is perhaps to weld on short extensions to the "drains" to bring the Marelon seacocks higher and closer to the waterline while still allowing proper drainage on most tacks. Should a failure occur, I would prefer to have the gushing one foot below WL than three feet, having seen the difference this makes in water pressure.

A final element is not always considered, but should be: the exhaust line. I have my exhaust on the starboard side on the water line. I think it would be a good idea to put a "shut-off seacock" in this line to avoid siphoning water into the exhaust system when sailing on a heel. Some sailboats with the more usual stern exhaust are able to fit a loop under a coaming, some can't. But the situation remains that the engine is usually below the exhaust and seawater in the manifold can ruin your day.
 

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I've always considered Groco top cabin, but this recent recall has me off put.
Why? Were you affected by it? As I understand it from talking with both my area rep and Groco it mostly affected a few manufacturers and a couple of distributors.

The overseas manufacturer decided to change spec without notifying Groco. The spec may have been fine but they still decided to do a full recall. That is above board in my book and MORE than Forespar ever did with Marelon!!

I purchased a number of them from Hamilton marine over a one year period and NONE of them were affected by the recall.

I'd much rather have a manufacture that admits to a problem than one who sweeps it under the rug!!
 

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Groco flanged adapter plates rock. They are the only way to go!!!!! I put them on all my thru hulls. It is the only way I found th get the threads right.
 
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