Seacocks - my concern and the cost

[so32foot]

The Dutch importer of Trudesign says: no problem, will fit perfectly, as long as it is BSP, not tapered.

[Caxton]

Nov 19, 2013 22:54:08 GMT jack35 said:

Hi All

Thanks for your discussion above.

We're having similar issues in our SO35 2005, but as she is ex-charter anything could have been done, however it had to pass QLD Survey, however ...

I suspect the tail is brass in this engine intake seacock.



But when removed there remains a flush insert in the hull :



The skin fitting is an integrated strainer which became full of mussels hence low water intake to engine :



We have harbours on Port Philip that have lots of seagrass which get ingested.

This is the first time we've had problems with the mussels - very warm water last year.

But I'm reluctant to refit strainers, however I can not see how to replace with mushroom skin fitting as the head is very small and wouldn't cover the insert above hence not tighten up on the hull.

Does anyone know if the flush insert is a Jeanneau feature and how it is fixed to the boat and what to do.

Thanks JJ

[dnickj]

hi it looks as though the sea cock is also brass

if it where on my boat and looked as bad as that i would change the whole lot including the skin fitting

[Caxton]

Replaced my raw water intake to the diesel with a Forespar Marelon Valve 931144 which has a 1" O.D. hosebarb.  I also installed a strainer 906062.  I had to make a slightly bigger through hull hole.  Also used a G10 fiberglass backing plate. Used 3/8" stainless screws to mount the strainer.

As a note, there were some nasty burn marks in the raw water hoses going from the valve to the sea water strainer and from the seawater strainer to the impeller.  Replaced the hose with Trident Flex Wet Exhaust hose.

Original


Old strainer removal


Making the hole bigger



Installing Through Hull to New Marelon Valve (used G10 backing disc and lots of 5200)




New Valve, hoses, strainer (Replace both hoses to and from big sea strainer)

it was raining!

Old hose with burn marks:

Caxton

[yachtingtypes]

I am replacing my thru hulls this year on my 2003 SO43 DS with Groco bronze. The yard has done a great job although I received an email today saying they could not replace the forward 2" holding tank seacock without relocating it. They stated:

"Just to give you a quick update, we have installed all of the thruhulls, except the last 2” one in the fwd head. On this one, given the position (see in attached pictures), we would have to cut the stringer just to remove it, and then have it re fiber glassed. I had the fiberglass sub here this morning to look at it, and it makes sense to move the thru hull fitting back about a foot towards the aft of the boat. We would just need to run a little extra hose, and install the new thruhull where there is plenty of room to access it."

I hate to start cutting new holes in either the hull or stringer and I have not seen this problem in the forum. Does anyone have an idea what problem the yard is encountering?

[dakota1]

Can you post the pictures that the yard references?

[yachtingtypes]

This is the link to the photos

goo.gl/photos/SEVV6E4Cu8HQyoH36

[MickeyB]

I am honestly not an expert in this area, but I cannot see a problem in removing those....would love to know the reason.

[timeflies]

Hi Caxton

I am new to the forum but have the same issue as you on my 36i and was looking at converting everything over to the Forespar Marelon valves as a replacement. All of the thruhulls on my C&C are marelon from the factory and they are simply fantastic. No corrosion, no bonding, no electrolysis.

Did you just replace the engine water intake or did you do the whole boat? And please don't tell me that you really did use 5200 to seal them. If so, they are now permanent and will be next to impossible to replace or service later on.

[yachtingtypes]

Its not so much that the old one cannot be removed its that to install the new seacock it needs to be screwed onto the thu valve. As its hard against the bulkhead this cannot be done. The factory must have installed these prior to fitting the bulkheads. The solution is to move the thru hull aft and glass the old location. This seems reasonable to me.

[dakota1]

I replaced our 'factory' thru hulls with Groco, which were a bit beefier, so I could see how that might take up the amount of space necessary to thread the valve onto the thru hull. Argh!

[Caxton]

Mar 17, 2016 12:04:54 GMT timeflies said:

Hi Caxton

I am new to the forum but have the same issue as you on my 36i and was looking at converting everything over to the Forespar Marelon valves as a replacement. All of the thruhulls on my C&C are marelon from the factory and they are simply fantastic. No corrosion, no bonding, no electrolysis.

Did you just replace the engine water intake or did you do the whole boat? And please don't tell me that you really did use 5200 to seal them. If so, they are now permanent and will be next to impossible to replace or service later on.Y




Hi timeflies,


I only replaced the engine water intake as all the others looked ok.  I may go after more next haul out.  Yes I used 3M 5200 as recommended by Forespar and the boatyard.


Caxton

[timeflies]

Hi Caxton

Yeah. I wish boatyards and people in general would stop recommending 5200 for everything. It is a permanent bonding "adhesive." When the time comes for that seacock to be serviced or removed, it will literally have to be cut out of the boat. Creating a major headache and minor surgery at best. 3M states and I can attest that the bond can only be separated by "mechanical means".

Boatyards fail to warn owners that it is a permanent bonding adhesive. It makes their lives easy ( no way it will leak ) and yours a nightmare down the road. I walked away from a 2009 36i when I was shopping because the owner proudly claimed that he had resealed all the windows with 5200, unknowingly making future window maintenance or replacement virtually impossible without destroying the decks.

When or if  you do the others, I would highly recommend researching some sealants that are not adhesives. You only need a sealant, not an adhesive.

Should you ever need it, here is a link to a product that claims it can chemically break the bond of 5200. No idea if it works though. In fact I am highly skeptical but if I needed to remove something bonded with 5200, I would spend the money to try it before getting out the crowbar and jigsaw.

store.marinebeam.com/3m-5200-sealant-and-adhesive-remover/

Certainly not trying to preach, only pass on my experience when it comes to dealing with things bonded with 5200.

Cheers

Paul

[blueeyes]

Mar 17, 2016 14:34:27 GMT yachtingtypes said:

Its not so much that the old one cannot be removed its that to install the new seacock it needs to be screwed onto the thu valve. As its hard against the bulkhead this cannot be done. The factory must have installed these prior to fitting the bulkheads. The solution is to move the thru hull aft and glass the old location. This seems reasonable to me.

I had a similar issue with my 36i a couple of years ago as the holding tank seacock, elbow & thru hull are located under the shower seat in a narrow compartment. No way to turn a wrench to disconnect it. My solution was to cut out the old seacock and thru hull nut with an oscillating multitool. I then assembled the new valve, elbow and hose fitting outside the boat. After fabricating a backing plate out of G-10, I installed it with epoxy to stiffen the hull. Then I loosely threaded the nut on the thru hull, inserted it into the elbow/seacock assembly and tightened it from the outside using a flat iron bar as the thru hull wrench. Finally, I tightened the thru hull nut to the backing plate using an "end wrench" cut out of flat iron with a short handle. I used Sikaflex 291 as a sealant and Groco valve and fittings. It's been through 2 seasons so far with no issues.

I'm not sure if this would work for you but it might be better than cutting another hole in the boat.

[so32foot]

Blueeyes: could you include a picture of the tool you used to  tighten the thru hull nut to the backing plate with an "end wrench" cut out of flat iron with a short handle?

And did you tighten the nuts fully immediately after installing the thruhull or did you do the final tightening a day later to avoid that the Sikaflex was presse away between the hull and the flane?

I purchased also Groco seacocks and fittings in bronze. The seacocks can now also be equipped with a grease nipple to enter grease against growth on the balls.

[blueeyes]

so32foot:

This is the tool I fabricated (behind it is a thru hull step wrench - unfortunately not big enough for the 2" thru hull):



I used an a 4.5" angle grinder with a cut off disc to cut it out of scrap steel. Once on the nut, the handle was tapped with a small hammer to help tighten it.

This is the completed installation:



I tightened the nut right away. I think waiting to later would break the bond/seal of the Sikaflex to the hull and fittings. The tightening should force the Sikaflex to fill any void between the thru hull and the hull and fittings. Not sure this is the best way but it is how I did it. 

Here is a link to some good articles on replacing seacocks from someone that knows a lot more than me: 

www.pbase.com/mainecruising/boat_projects
In particular, see:
     Seacock & Thru-Hull Primer/Pre Information
     Replacing Thru-Hulls and Seacocks
     Seacock Backing Plates / Alternate Method / No Through Bolts    

I haven't seen the Groco grease fittings yet - can they be added on in place of the drain plug or only factory installed?

[so32foot]

Blueeyes: many thanks for the pictures, it's very helpful to make my tools for a 1 1/2" thruhull. On your pictures I can see a white paste on the thread of the elbow and around the nut of thru hull: is that Sikaflex? I wonder if I will fix the tread with Loctite 5776 (liquid) or 55 (hennep with teflon)

Regarding the grease nipple: Groco calls it zerk. It isn't mounted in the drain, but in the larger screw of the seacock, see picture. I also attached a picture with description of the grease nipple. I couldn't find it on the Groco site, but I received the information by mail from their German representative. The grease itself seems not to be on the market yet, but may be a propeller shaft grease is also suitable.

[blueeyes]

so32foot: The white paste is PTFE Paste Thread Sealant (PTFE is a generic name for Teflon). The brand I used was Real-Tuff by Hercules but any quality pipe tread sealant can be used.

I will look into adding a zerk fitting. I searched for U-Lube by Groco and only came up with an oil change pump system.

[so32foot]

Blueeyes,

I have send you a personal message!

[so32foot]

Groco advised to use Molycote 111 or Poly So PST 511 to grease the seacocks. however, that are very expensive greases. So I found in the Netherlands some alternative silicongrease for maritime usage for better prices. I will try it.

Blueeyes, you mentioned to have used a PTFE Paste Thread Sealant for the tread sealant: if there is a reason to dismount the seacocks, is that  more easy if a PTFE paste sealant has been used instead e.g. Loctite 577?

[blueeyes]

The PTFE Paste, according to the package, is non-hardening and withstands expansion, contraction and vibration. It also says it lubricates and helps assembly and dis-assembly. Since the Loctite is also thread locker, my guess is the PTFE would be easier to dis-assemble. On the other hand, I suspect the Loctite would be more vibration resistant. Groco's service bulletin for installing thru hulls says to use TFE (same as PTFE) tape. I actually chose to use the PTFE because I already had it - one less thing to buy.

[callisto]

I have just completed a change of most but not all of the skin fitting on my 2006 SO 40.3 owners version (twin heads!) so change the inlet/outlet on forward heads + outlet for sink (all below the waterline) also engine inlet where the spigot had collapsed!! and then the inlet and outlet on the aft heads so 6 in total - I went for bronze all the way through to overcome the mix of metals - I also replaced all the inlet and outlet hoses for both heads. Used Siclaflex 291 and Loctite 577 - the only thing you have to take into account is that the Loctite goes off very quickly and I mean very quickly. We pre measured and tightened all joints before doing is again with sealant to ensure sizes were correct and we had to machine some of the threads to adjust as some of the bronze fittings were larger (especially the 2" from the holding tank) launched last week and no leaks and all working well - but this is not an easy job and need thought and preparation. I bought all my parts including hoses from asap supplies in the UK ([e-mail] ) very fast delivery, very helpful and it all came just under £600 delivered. I did not want to post until I knew all was ok!

[callisto]

sorry meant to say I replace skin fittings, seacocks and spigots all in bronze!

[so32foot]

Callisto, I've send you a private message!

[vasko]

I've check all my seacocks yesterday just before antifouiling and all seems OK - I do not think I have a rocket science sea cock just the standard bronze ones  and I guess about 10 years old..  all colour is nice goldish ....