Replacing Sea Cocks Through Hulls/ How to tell Size?

[brianontheroad]

There are some great posts on this forum already for Sea Cocks and Through Hulls -- but being a bit a newbie to this I have a few questions. I'm going to haul my boat out next weekend and replace my bronze sea cocks, they're completely frozen, totally corroded and in general scary looking I need to go ahead and order them, the yard charges $35 a day for my boat to be there and I'm on a tight budget (aren't we all......) soooooo..... how do I determine what size they are in advance so I can order good replacements?

Any thoughts on brands or places to order them?? this Groco with a triangel flange looks good.....

Groco Bronze Seacocks Tri-Flange

I'll post pictures soon of the existing sea cocks in hopes that will give you guys some more to go on...

as per usual,

Thanks!

[T34C]

I don't mean to sound rude, but I'd start by measuring them. If you can't get to them to get an accurate measurment you could measure the outside with a pair of calipers.

[brianontheroad]

not rude at all....I was wondering how to measure them....I can't measure them from the outside, they're under water until I get the boat hauled, for the sea cocks can I just measure the tube coming out of it? Would the output be the same as the input?

[JT1019]

Personally I order everything I can from Defender. They will have whatever you are looking for and have the best prices. If you like Jamestown of West Marine just tell them the Defender price and they will match it.

I replaced all my seacocks last year with the Forespar Marelon and I love them. They might cost a little more but I thought they were easier to work with and won’t corrode. I’m also a massive fan of not having to ground them since they are not metal.

As far as getting the old ones out? GOOD LUCK! I ended up using a drill, hack saw and dremel to destroy them. It took about an hour each to get the old ones out and clean up the mess but it was well worth the effort.

[sailingdog]

Measure them with calipers. The Grocos are good... You do need to get the matching through-hulls to use with those seacocks.

Sailnet sells the Perko seacocks with matching throughhulls HERE.




The Marelon ones are good if you have decent access and can properly maintain them... Forespar makes much the same as the above in a single package...

[badsanta]

I am a big fan or the triangle flange. If you are replacing the thru hull also, cut them off. I used a sawzall and cut off the valve and then split the thru hull in half made it easy and fast. My thru hulls were fine, but I destroyed the seal when I attempted to remove the valve. You are right to replace both. As to not grounding because someone is using a plastic valve, The thru hull is bronze and in the water, do you not want to protect that also?? As to the size, the measurement is the inside diameters, a 1-1/2 thru hull should have a 1-1/2 hole through it and should be close to 2" on the outside. Can you remove a hose from the sea-****? it is normally the same size as the thru hull. If you buy to big you can drill out a larger hole, but harder to make it smaller.

[stuffinbox]

You want the inner diameter right?
Often its cast into the seacock. If not what's the ID of the hose from the seacock? You only have to match that right, unless you are going to upgrade your internal plumbing too.

Unless your valves are in tip-top condition, now would be the time to replace those too. My yard recently replaced mine -- it looks like as they twisted off the old valve or twisted on the new one, they damaged the through hull caulking (water weeps in from under the backing plate and now I have to re-haul to fix it.)

Don Casey has a nice webpage on replacing seacocks at...
umm... sailnet says I can't be trusted to posted links in my message. Let's see if this works:
http : / / www . boatus . com / boattech / casey / 07 . htm

- Stu

[brianontheroad]

what valves should I replace? Any other thoughts on things to work on while I have the boat out of the water? The bottom is recently painted and I'd like to not have her hauled again any time soon :-D

Thanks,
Brian

[sailingdog]

Check the rudder, rudder stock, bearings, etc. Also check the prop, cutless bearing, etc... Those and the through hulls are most of what cause you to get hauled...

[Maine Sail]

You should really consider using the Groco flanged adapters as opposed to a solid seacock. Why? In ten years when they need work or replacement you won't need to haul the boat! Simply remove & replace the seacock/bronze ball valve and the rest of the assembly stays put!

Read this: Replacing Seacocks (LINK)

Ad This: Thru-hull & Seacock Primer (LINK)

Groco Flanged Adapter: