Replacing main engine seacocks

[Seapig100]

I am looking for the size of the thru hulls and seacocks on the main engines on my 1969 45c it has 8-71 naturals. I plan on replacing them in the next few weeks. I would also appreciate any advice on the job also. Thanks in advance.

[jim rosenthal]

Probably two inches to three inches. Use Groco, Conbraco or Apollo. Use made in USA, no import stuff. Backing plates and through-bolting the flanges is very important/. Use 4200 to seal. Be aware of the difference between NPT and NPS threads and don't mix them. The right ones are cast silicon bronze with stainless ball valves. If you want to fit a strainer, it should be separate and supported sturdily; you will need a lot of bronze hose barbs to hook up all the hoses. Double clamp everything with AWAB clamps. Use the best hose you can buy, I have found Vetus to be the best so far.

[Seapig100]

Thank you.

[MadHatter53]

Why are you replacing them?

[Seapig100]

They are frozen open and I have made several attempts to get them moving again with no luck. I am planning on storing in the water next winter and I need all my seacocks to be in good working order. There are no sea strainers on the mains and I would like to do this at the same time. And last but certainly not least the plumbing from the seacocks to the engines is not up to marine standards and it bothers me every time I look at it. There is copper tubing attaching the seacock to the hose and copper tubing being used to create a 90 degree bend. And all this is in 4 inch hose to accommodate the tubing. The fittings at the engine is smaller so the previous owner just clamped down the hose to fit the engine and that is stressing the hose.I figure it’s going to cost me about 3500 bucks to change all the seacocks, IMO it’s money well spent.

[racclarkson@gmail.com]

Frozen seacocks are common. My boat surveyed frozen main seacocks. They now open and close with just a finger or two. I was able to bring mine back in the water. You may not want to try. But if you do, I’ll be glad to explain what worked for me.

[jim rosenthal]

They are frozen open and I have made several attempts to get them moving again with no luck. I am planning on storing in the water next winter and I need all my seacocks to be in good working order. There are no sea strainers on the mains and I would like to do this at the same time. And last but certainly not least the plumbing from the seacocks to the engines is not up to marine standards and it bothers me every time I look at it. There is copper tubing attaching the seacock to the hose and copper tubing being used to create a 90 degree bend. And all this is in 4 inch hose to accommodate the tubing. The fittings at the engine is smaller so the previous owner just clamped down the hose to fit the engine and that is stressing the hose.I figure it’s going to cost me about 3500 bucks to change all the seacocks, IMO it’s money well spent.

Sounds like you are doing this work for all the right reasons. As RAC said, you might be able to get the current ones moving, which solves part of the problem. You would still need to correct all the plumbing, as you pointed out. That may turn out to be the main issue if you can get the sea valves to open and close. You may not need to replace them.

If you look at some of RACs posts on his engine room, you will get an idea of the quality of work he expects from himself and on his boat. I would feel safe taking his suggestions.

The best source I have found for this kind of hardware is Groco here in MD. (now, part of this is that they are local to me and they make everything here in the USA, although their actual foundry is in PA- but it isn't overseas) Their ARG series strainers are very good. I have several of them and they are very good about keeping spares and gaskets etc for all their products, old and new, in stock. I have a Groco FW system pump, for example, that probably has fifteen years on it, now.

[kelpy]

This type.
31707

[racclarkson@gmail.com]

Sounds like you are doing this work for all the right reasons. As RAC said, you might be able to get the current ones moving, which solves part of the problem. You would still need to correct all the plumbing, as you pointed out. That may turn out to be the main issue if you can get the sea valves to open and close. You may not need to replace them.

If you look at some of RACs posts on his engine room, you will get an idea of the quality of work he expects from himself and on his boat. I would feel safe taking his suggestions.

The best source I have found for this kind of hardware is Groco here in MD. (now, part of this is that they are local to me and they make everything here in the USA, although their actual foundry is in PA- but it isn't overseas) Their ARG series strainers are very good. I have several of them and they are very good about keeping spares and gaskets etc for all their products, old and new, in stock. I have a Groco FW system pump, for example, that probably has fifteen years on it, now.Jim, thanks for the kind words. Let me address the post and your PM together here.

First, freeing a stuck seacock won't be fast. But it is a lot cheaper than replacements.

Spray penetrating oil on the valve assembly copiously and often--maybe every time you pass by for days. Also spray oil on the freeze/drain plug. Also, disconnect the hose from the seacock to the pump at the pump. Stuff a rag down the hose until you feel it at the seacock. Pour in full concentrate phosphoric acid or CLR. The rag helps stem the flow of the acid out the open seacock. Let this stand, and continually refresh solution. Continue oiling valve assembly. As an alternative, a diver can remove the screen and stuff the intake which is a good route. But you may not be able to fully close the seacock until the intake is cleared.

If necessary, make a cheater about a foot in length. Being careful not to round off the valve stem, work the handle back and forth. It may not move for the first few tries (or days). But, most of what you're doing doesn't take much time at any one session. Use a brass hammer and whack the assembly pretty good at anytime during the process. I thought an orbital sandy was a useful tool on helping to free things up.

After a time, the seacock will move back and forth a bit. Don't trying force it. Using a coat hanger, pull the rag out. Now, you can use a torch and heat the seacock. It's pretty massive, so you shouldn't worry about melting your boat. Work the heat all around the body; it'll take a while. Go the whip (hammer). You can wet the base of the seacock and watch for signs of heat rapidly evaporating the moisture as a safety check. Re-oil when it cools down.

Once the seacock is about halfway closed, remove the freeze plug and screw in a zerk fitting. Shoot some grease in the assembly. Most of the grease will go in the water until the seacock is completely closed. Then, grease it well.

Also, once the seacock is closed, add CLR or about a 50/50 mix of phosphoric and let stand overnight. I think you will be surprised at how easy the valve will open and close after a day or two. Exercise regularly and it should become lighter and lighter to the touch.

Seems like a lot of work, but it's really just a couple of hours total spread over time. Good luck.

[TROUBLE]

I was able to spin new valves on my existing thru hulls saved a lot of money and time.

[Boatsb]

Look at the picture

[bigbill]

that does not look like a proper seacock. it should have a flange mounted to the bottom of the boat and the thru hull screwed into it from outside of the boat then a scoop or mounted over that

[Canuck Dennis]

When I had my last survey on the 43 DC in Florida, the main engine seacocks were frozen open, I asked the surveyor if adding a bronze ball valve on top of the existing seacoCk would be acceptable, he said yes go for it just be sure there is a bronze nipple in between. YMMV

[jim rosenthal]

Key thing is remembering not to mix NPT and NPS, because it makes an installation that isn't secure.

[Seapig100]

I was at the boat today and it looks like the seacocks have a female coupling threaded onto the valve. I am going to try and spin off the coupling and add a new valve onto the existing one. If anyone objects to this idea can you please explain your reasoning.

[Boatsb]

Last try here.

Fix it right or stop asking for acceptance of your shortcuts.

If I was to look at the boat with valves on the valves after it sank I'd have to conclude it was a work around or more politically incorrectly a rigg. Id wonder what else was rigged and was that a cause of the failure.

Fix it right. Buy a pair of seackcocks and install them the right way.

[dsharp]

Are you sure that you don’t have the seacocks with the tapered valve in them. If it has a nut across from the handle loosen the nut and strike it with a hammer using a block of wood to protect the threads. If they aren’t carry on with the plan to add a valve to the present seacock

[Seapig100]

I believe they are tapered. I tried to pop them loose using a socket over the threads and backing the nut off. This created a puller of sorts and it did not budge. It will be difficult to strick it cleanly with a hammer because of the engine rails. I am willing to give this another opportunity just not sure I am going about it the right way.

[jim rosenthal]

What I think Scott is trying to say is this:
There is ONE right way to do this. NPS and NPT threads cannot be mixed in this installation, because although they will screw in a few turns, it is NOT ENOUGH to make a secure and tight installation. These parts of boats are subjected to considerable stress and if they fail, your boat sinks. You would be far better to take everything out of the boat and rebuild with new USA-made hardware. Your life and the lives of your passengers depend on it.

The proper method is a seacock, not a ball valve, mounted in the hull using a backing plate AND the through-bolts that secure the flange. Into that valve is threaded a through-hull, which may need to be trimmed in length so that it doesn't bottom out in the sea valve. Use 4200 caulking and make sure all the mating surfaces are clean of grit and oil before assembling everything. Dry-fit all the bits and pieces before final assembly. Final assembly is a two-man job- the installation will try to twist as you secure it, so it has to be held to make sure it stays oriented properly.

Once the seacock and through-hull are in place and the caulking has set up, you can add the rest of the plumbing to the engine cooling system. If you are going to use a strainer, mount it separately; full strainers weigh a lot and will stress the valve and through-hull in a way you don't want. Use all bronze parts, never brass, double-clamp everything (AWAB clamps!) and use the best hose you can (Vetus, in my experience, is better than anything else) These installations are not cheap. But this is one area of a boat in which you should not skimp or try to reduce costs. Any part of a boat in which you have something penetrating the hull should be done exactly to standard. Not only is the boat safer, but if you do it any other way, and there is a disaster and claim, insurance may decline to pay any claim because the installation was not done correctly- even if it can be argued that the disdaster may not have occurred because of the installation.

Look through the Groco catalong on line, also Conbraco and Apollo. I believe all those brands are made in USA. Also Buck Algonquin and Wilcox-Crittenden. You should be able to find all you need between all those vendors.

And remember, NEVER mix NPT and NPS threads. You cannot do a proper install in that fashion. It cannot be done.

Boats sink for one reason and one reason only. They sink because water gets inside them. Make sure it stays outside the boat.

[Seapig100]

Thanks for the replies, my initial thought was to replace it all and be done with it. If I can free the current valve I will correct the rest of the plumbing. If I can’t free them I am going to just start over with all new parts.

[Texastailboard]

I sometimes go against the “marine grade” specifications but that doesn’t mean I will skimp on safety or longevity. Yes it bothers me that a boat yard will charge marine prices for things at times that should be reevaluated. We might own yachts but that doesn’t mean we are all made of money. I have found some short cuts are helpful but some items are designed for salt water and a seacock is definitely something that has to be marine grade category. Not only the specks are different on the threads but the design is for the severe environmental it is in.

[dsharp]

I believe they are tapered. I tried to pop them loose using a socket over the threads and backing the nut off. This created a puller of sorts and it did not budge. It will be difficult to strick it cleanly with a hammer because of the engine rails. I am willing to give this another opportunity just not sure I am going about it the right way.

The big end of the taper should be on the handle side. Can you loosen the nut then hold a heavy back up on the body them hit the other side. I would wait until you haul out then remove and rebuild or replace. Take the time and do it right.

[Seapig100]

I have decided to replace the seacocks. The seacocks are 3 inch valves and I got a 2 quotes to replace them today. First quote is for full flow valves the second quote is standard flow. I am assuming that a standard 3 inch valve will flow more then enough water, is this assumption correct? Also is it worth the extra money for the full flow build quality? My two options are Groco BV bronze full flow model# gro-bv-3000 or Groco fbv model # gro-fbv-3000. Thanks for the advice.

[Boatsb]

You know the answer. Theres no need to ask it. Always use full flow. Always use the best quality available. It's not a bay liner.

[jim rosenthal]

I agree. There is no such thing as too much cooling capacity for a marine engine. It will take what it needs- if there is enough seawater coming through the system.

I realize we are spending a lot of your money, but in this instance, go for the best you can find. It's well worth it.

[Photolomy]

They seem to both be full flow, but what is the difference between FBV and BV? Other than one is twice as much.:)

[Seapig100]

You know the answer. Theres no need to ask it. Always use full flow. Always use the best quality available. It's not a bay liner. Yes you are right I do understand water flow and IMO 300 gallons a minute would be more then adequate to cool an engine. But that’s just my opinion it’s not based on any experience or knowledge. As far as quality I have absolutely no clue what the difference is between the two valves. I have read the information on Groco’s site but to me a seacocks a seacock. So here I am looking for the advice of others that may have a clue and be willing to share their knowledge. If the answer is I should spend the extra money so be it I will, but I find it prudent to ask before shelling out the money.

[dsharp]

It looks like the fbv is a lighter duty valve with a stamped steel handle and the fv has a cast bronze handle. I'm sure their are other differences as well. Not really a place to try to save money. Kind of like exhaust risers.

[Photolomy]

I looked at the two valves in more detail. The BV valve does have a couple upgraded parts, as dsharp noted, but in terms of design, the BV and FBV seem very similar. However, the BV unit can be fully disassembled and rebuilt while still on the boat, and the replacement parts are relatively inexpensive. So, in terms of features, the BV is certainly the nicer valve. Retail (at Jamestown) the FBV is $388 and the BV is $699. These prices are almost 1/2 the listed prices on the Groco site. In any event, the USCG requires the serviceable (BV) series for inspected vessels (vessels that carry more than 6 paying passengers).

Personally, if my boat came with FBV valves, I would be totally fine, but if I was buying the valves, I would go with the BV version. I do read about stuck valves, and the ability to service them seems significant.

Btw, all of the Groco seacocks have grease fittings. Do the ones that came with our boats have them? I haven't really looked at them close enough yet. And if so, do you guys use them? Seems like that would keep them operable forever. Regardless of the series.

[whoover]

Hello, I have Groco strainers with grease fittings, I'm in fresh water but give them a pump of grease each spring. I also carry a full set of replacement seals for each valve. I have found the o rings to be a use once item, after reassembly with the old o rings I always have an air leak and no water flow. Also the Groco customer service has always been great, they were very helpful in getting me the model number for my seacocks when I could not find any documentation on the boat.

Walt Hoover

[jim rosenthal]

X2 on Groco service. They back up everything they sell. Full disc, they are a local outfit in MD but even if they were not, I would still use and recommend their stuff.

[Seapig100]

Parts ordered thanks for all the help.

[jim rosenthal]

Take some before and after photos. If you don't mind. Documenting big jobs on your boat esp the ones that add value to it is a good idea. I think this kind of thing adds value. Others may not agree.

[Seapig100]

I removed the old frozen seacocks along with the dwv vent pipe that was getting pretty thin. I am glad I decided to tackle this project this year because I am now realizing how bad this was. I also learned of what I think is a new problem (to me) but more on that in another thread.The dwv pipe was threaded into the valve with a short section of copper tube soldered to it. There was also, a copper 90 that had two short pieces of 3 inch tube soldered into each end it. The purpose of the short sections of copper tube was so he could connect it to the rubber hose. So instead of a barbed connector gripping the hoses, it was perfectly smooth. This entire setup was 3 inches in diameter, and the raw water intake on the back of the engine is only 2 3/4 inches in diameter. I bet you can figure out what that connection looked like. I called jamesTown distributors today and fixed the order my new 3 inch valves will be here in a few days along with with 3 inch to 2 1/2 inche bushings and 2 1/2 thread to 2 3/4 barbed. This was the only way groco could get me to 2 3/4 to match the engines. JamesTown was also able to get 2 3/4 raw water hose for me. I decided to also change out the AC thru hulls so I ordered those also. I spoke with Patrick at Groco for about a half hour and he explained to me in great detail exactly how to reinstall the new valves including what adhesives to use. He gave me the part numbers for everything I needed to complete the job. Here are the old valves ready for the scrap yard.

[racclarkson@gmail.com]

I removed the old frozen seacocks along with the dwv vent pipe that was getting pretty thin. I am glad I decided to tackle this project this year because I am now realizing how bad this was. I also learned of what I think is a new problem (to me) but more on that in another thread.The dwv pipe was threaded into the valve with a short section of copper tube soldered to it. There was also, a copper 90 that had two short pieces of 3 inch tube soldered into each end it. The purpose of the short sections of copper tube was so he could connect it to the rubber hose. So instead of a barbed connector gripping the hoses, it was perfectly smooth. This entire setup was 3 inches in diameter, and the raw water intake on the back of the engine is only 2 3/4 inches in diameter. I bet you can figure out what that connection looked like. I called jamesTown distributors today and fixed the order my new 3 inch valves will be here in a few days along with with 3 inch to 2 1/2 inche bushings and 2 1/2 thread to 2 3/4 barbed. This was the only way groco could get me to 2 3/4 to match the engines. JamesTown was also able to get 2 3/4 raw water hose for me. I decided to also change out the AC thru hulls so I ordered those also. I spoke with Patrick at Groco for about a half hour and he explained to me in great detail exactly how to reinstall the new valves including what adhesives to use. He gave me the part numbers for everything I needed to complete the job. Here are the old valves ready for the scrap yard.Hall of Shame material

[kelpy]

Those seacocks can be taken apart, cleaned up and relapped to äs new"condition with a few hours of labor and simple hand tools.

[Seapig100]

I would need all the details I am not against doing that. Will I need parts for them?

[kelpy]

Simplified, clean up the exterior with some dilute muriatic acid to get rid of the green, remove the end cap and knock the cone out of the body with a mallet without boogering up anything. Lightly clean up the bore and cone with 800 wet or dry paper but don't remove too much. Use some fine (0000) water based lapping compound and lap the cone to the bore until it just cleans up - no more. 80 - 90 % cleanup should be sufficient. Clean the bore and cone throughly with soap and water and then clean them again. Lightly coat the bore and cone with a good (not cheap) marine waterproof grease and reassemble. Exercise the valve each month to keep it operating freely. During the next haul out, disassemble, clean and relube. They will outlast you if taken care of. Don't forget the bonding wire.

[jim rosenthal]

SP, spray the new ones with Corrosion-X, the pump spray kind in the red bottle, and they will not turn green. Do it yearly. You’ll be amazed. The stuff really works well.

[jim rosenthal]

Those were good valves when they were installed. If you don’t want to go to the trouble, someone else might refurb them. But since you are replacing them, I would put cleaning those up low on your priority list.

[kelpy]

I disagree. After cleaning and refurbishing the old ones, they will be as good or better than the new ones that he can now return and get $$$$ back. YMMV.

[jim rosenthal]

Sure. But he might want to get his boat back in the water. Either way, he’ll have a much improved boat with either new or restored sea valves and much safer plumbing for the seawater inlets. We can agree on that.

[kelpy]

Completely agree with you Jim. But a few hours spent refurbishing them shouldn't make much difference on the haulout timeline. That type of seacock is the only way to go. Easy to operate and if maintained, will last a lifetime. When a ball valve fails, and they all do, it goes in the trash.

[Seapig100]

Good morning, thank you all for your advice. Either route I take I have a few hours of work to do if I change out the valves I need to fix the old bolt holes. This means sanding the holes out, then filling the holes, and then glassing in the plugs from both sides. This probably would have taken a few hours by the time I was done, and cost me 1600 bucks for new valves. So I have decided to refresh the old valves and reinstall them. I have taken them apart this morning and the cone is frozen inside the valve. I am assuming that a little heat will motivate it to come out is this assumption correct?

[kelpy]

Some heat on the body will help. Sometimes a small press will speed things up. Take your time and don't damage anything. They will come apart and you will only have to do this once.

[jim rosenthal]

Soaking them in Blaster might help a bit, too. Or Kroil. Or WD40. Or Marvel Mystery Oil, which is my favorite for this. Or a mixture of ATF and acetone, which, I suspect, is basically what MMO actually is. :)

[Seapig100]

One hour in a bucket of Muriatic Acid, and plenty of heat and they are apart. Lapping grease will be here tomorrow. Any advice on lapping, I am all ears.

[kelpy]

Keep the parts as matched sets. Don't allow them to get mixed up.

Wet sand the scale off of the mating surfaces with 600 - 800 paper. Don't go overboard..

Apply a thin coat of lapping compound to to the cone and bore. Insert the cone and lightly turn the cone back and forth about 20 times. Rotate the cone 70-120 degrees and repeat. Keep the mating surfaces wet. Don't spin it around and only use light hand pressure. The compound will do the work.

Reapply compound as needed and keep it wet. You will hear and feel the difference as the mating surfaces clean up. Wipe the parts off occasionally to see your progress. The surfaces will become shiny and smooth all the way around. Don't get carried away and go farther than needed. If there are some relatively deep scratches on the surfaces, don't attempt to completely remove them. Again, patience is required.

When finished, you will have more or less a locking taper no matter the position of the cone in the bore. Have fun!!

[Seapig100]

When amazon gets here I will lap them.

[Seapig100]

I have lapped the valves and one loooks new, the other has some black at the outlet side of the valve. If I close my eyes and run my finger over it I can’t feel it. Is this ok to leave? The intake side is perfect.

[kelpy]

I might try just a bit more to see if it cleans up around the port lip. The other one looks great. Did the cones clean up as nicely?
What grade of lapping compound are you using?

[Seapig100]

I used 280 grit compound. Assembled them without grease and they weep just a little water. I assume that the grease will seal them and make them water tight. Is this assumption correct?

[kelpy]

The grease will seal them but if it washes out, you have a leak. Finish them off with some 600 grit compound and they will be leak free. With the cone lightly tapped into the bore in the closed condition, they should be leak free. Patience is required.

[jim rosenthal]

They look great. I think you were right to keep the originals- not what I thought previously but I think this WAS the right way to go.

[Seapig100]

Thanks everyone for the help on this project I spent far too many hours getting them to look like that so, I think I will make lamps out of them. I spent hours and hours yesterday lapping them and polishing the insides and they are still leaking. Now I am certain if I keep at it I can get them to stop leaking but I need to move on with the spring maintenance. I am not just doing the main seacocks this spring, all the seacocks and Thru-Hulls are being replaced with Groco BV valves, and I am also recoring the deck from the bow to the first hatch. So I threw in the towel on this one and bought 2 1/2 inch valves. I went with 2 1/2 because I need 2 3/4’s at the engine, and the only was to get there is with a 2 1/2 thread to 2 3/4 pipe to hose connection. I doubt I will not have enough water with this set 290 gpm at 20 and over 400 at 40 psi. Tomorrow I will repair the holes and glue in g10 boards, and prep the rest of the holes for the new Thru-Hulls, backing plates, and valves.

[Seapig100]

A quick look at my deck.

[Seapig100]

More photos.

[UNIQUE_NAME]

after following this thread i figured id take a look at my old groco seacocks and grease them.
maybe the zerc fitting came in later models? just a drain fitting on mine.
groco instructions say to remove the drain plug and pump grease into the zerc until you see the grease at the drain hole.
any opinions on what my plan 'B' should be?

thanks

[racclarkson@gmail.com]

after following this thread i figured id take a look at my old groco seacocks and grease them. maybe the zerc fitting came in later models? just a drain fitting on mine. groco instructions say to remove the drain plug and pump grease into the zerc until you see the grease at the drain hole.any opinions on what my plan 'B' should be?thanksZerks aren’t watertight. Get one with same threads and install in drain hole for greasing then remove. Valves can only be greased when closed.

[Seapig100]

Removed all the seacocks yesterday and I will prep the hull for the new ones this weekend. Jamestown distributors has told me all parts will be in today. I am hoping to have all projects wrapped up next week and looking to launch by the 15th. Looking forward to getting these two projects finished and checked off the lists.

[krush]

She's lookn' good!

[jim rosenthal]

She looks great. You're doing good.

[Seapig100]

All the paint is ground off and she is just about ready to be glasses and fared.