Moving the engine seacocks

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topseaturvy
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Moving the engine seacocks

Post by topseaturvy »

I have a 1986 Trojan 37 Sport Sedan. The engine seacocks are in a very strange place, aft of the engines almost right against the aft engine room bulkhead. You can't access the seacocks unless you lift the floor over each engine to get at them. The genset sits between the engines so there is less than a foot between the aft end of the engines and the forward edges of the genset. With the floors in place, if I stretch out my arm as far as possible I'm still about one foot from the seacock lever. This makes no sense at all. So my plan is to move them along with the sea strainers to the front of the engines. Lots of room there to crawl in and around the far side of the engine even with the floor in place. I'm wondering if anyone else has done this?

The only thing that I'm wondering about is that the inside hull area where the seacocks are now, appears to be almost an inch thinner. An area of about 12in. x 12in. is sort of stepped down right around the seacocks. I'm wondering if that's because the hull is too thick to screw the thru hull fitting into the seacock threads on most bronze thru hulls of the day because they might not have been long enough? That sounds like a stretch, but why else would the hull be thinner right there?

I'm planning on using Marelon for my thru hulls and seacocks. I believe the Marelon countersunk thru-hull 1-1/2” 250 series is 3” long. The backing plate material is about 1/2” thick so hopefully the thru-hull fitting should be long enough in the area of the hull forward of the engines where the hull appears to be about 1” thicker than where they are situated now. Does anyone know the bottom hull thickness of this boat? Is anyone familiar with the area around the seacock being about one inch thinner?
Thanks for any and all replies
Cheers
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Re: Moving the engine seacocks

Post by P-Dogg »

Until someone with ur type of boat chimes in.....

What you are describing is indicative of a cored hull. No core near where (planned) through holes go -- just glass. Keeps moisture out of the core, since core is not penetrated.
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Re: Moving the engine seacocks

Post by prowlersfish »

1986 Trojan 37 Sport Sedan ?? Is this a 11 meter sedan ? If so you have a cored hull . Where the seacocks are now is not cored . Where you plan to move them it is corded . If you do move them you will have to seal the coring and it has to be done right , no room for error , none . Then the bedding on the thru hull has to be done right again no room for error . And when you tighten it down you don't want any "crush" to damage the sealing you have done . Don't get it right and the core get wet , you got a problem .

I would stay with bronze myself .


Can you get in the engine room and then work them ? Its Been a while since I been in a 11 meter engine room but I thought there was a lot of room , But I may not remember correctly .

If it was mine I would leave it be . Just make sure the are free and check them once in while
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Re: Moving the engine seacocks

Post by topseaturvy »

prowlersfish wrote: Sun Mar 03, 2019 6:34 pm 1986 Trojan 37 Sport Sedan ?? Is this a 11 meter sedan ? If so you have a cored hull . Where the seacocks are now is not cored . Where you plan to move them it is corded . If you do move them you will have to seal the coring and it has to be done right , no room for error , none . Then the bedding on the thru hull has to be done right again no room for error . And when you tighten it down you don't want any "crush" to damage the sealing you have done . Don't get it right and the core get wet , you got a problem .

I would stay with bronze myself .


Can you get in the engine room and then work them ? Its Been a while since I been in a 11 meter engine room but I thought there was a lot of room , But I may not remember correctly .

If it was mine I would leave it be . Just make sure the are free and check them once in while
Yes it is the 11 metre and yes I'm convinced that you're right about the coring, but I did come across a thru-hull at the stern with a ball valve, not a plated seacock, that is going right through everything. In other words there is no step down in thickness around the thru-hull. There is a 90 degree coming off the ball valve followed by a small 12 volt pump. But no hose coming off the fitting. I suspect it was for a raw water washdown. Once I get the boat up on the hard. I think it would be good to remove it. I'll grind off the layer of woving, and then take it down to the fibreglass about a foot square, put a 45 degree angle on the core material and layer up a few layers of fiberglass matt. Then fill the hole after I bevel it out at about a 12 to one ratio.
As for the seacocks now. No, Definitely can't get at them without lifting the floor. So they must be moved. Lots of room at the front of the engines and easy access within about 10 seconds if needed once I put them there. I'll use the same method clearing back an area of about one foot square. Then sealing the core on a bevel with several layers of glass matting. Between the hull fibreglass and the new seacock I'll be bedding a backing plate of probably G-10 or G-11 material.

I can't imagine why Trojan would have designed the boat with the seacocks right up against the aft engine room bulkhead and the stringer. Even with the floor up and I'm standing right over the seacock, it's a bit of a challenge to turn the valve because it's hidden under the sea strainer that's mounted right above it attached to the stringer. Very strange location. In an emergency, you'd be screwed.
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Re: Moving the engine seacocks

Post by prowlersfish »

Just make sure they won't suck air where you want to put them .
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Re: Moving the engine seacocks

Post by RWS »

there is likely a REASON the seacocks are located where the factory put them.

Suggest you do as much research as possible BEFORE attempting to re-engineer this system.

+1 on what Prowlerfish said about the BRONZE.

I found the Maleron overboard drains on my boat to be brittle and several were cracked.

suggest this alternative:

1. remove the plugs on the factory seacocks and install angled grease zerks

2. replace the hose from the seacock to the engine room with new

3. replace all hose clamps with T bolt clamps - 2 at each connection

4. splice a ball valve into that raw water hose in a more accessible location


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Re: Moving the engine seacocks

Post by El L Sea »

topseaturvy wrote: Sat Mar 02, 2019 1:18 pm I have a 1986 Trojan 37 Sport Sedan. The engine seacocks are in a very strange place, aft of the engines almost right against the aft engine room bulkhead. You can't access the seacocks unless you lift the floor over each engine to get at them. The genset sits between the engines so there is less than a foot between the aft end of the engines and the forward edges of the genset. With the floors in place, if I stretch out my arm as far as possible I'm still about one foot from the seacock lever. This makes no sense at all. So my plan is to move them along with the sea strainers to the front of the engines. Lots of room there to crawl in and around the far side of the engine even with the floor in place. I'm wondering if anyone else has done this?

The only thing that I'm wondering about is that the inside hull area where the seacocks are now, appears to be almost an inch thinner. An area of about 12in. x 12in. is sort of stepped down right around the seacocks. I'm wondering if that's because the hull is too thick to screw the thru hull fitting into the seacock threads on most bronze thru hulls of the day because they might not have been long enough? That sounds like a stretch, but why else would the hull be thinner right there?

I'm planning on using Marelon for my thru hulls and seacocks. I believe the Marelon countersunk thru-hull 1-1/2” 250 series is 3” long. The backing plate material is about 1/2” thick so hopefully the thru-hull fitting should be long enough in the area of the hull forward of the engines where the hull appears to be about 1” thicker than where they are situated now. Does anyone know the bottom hull thickness of this boat? Is anyone familiar with the area around the seacock being about one inch thinner?
Thanks for any and all replies
Cheers
This is the same location as our 1988 12m sedan. The step down in ours is where it goes to solid glass, similar to in front of the holding tank where the inlets for the generator and A/C are. In our boat the front of the engine is about the last piece of remotely clean water you are going to get, and it gets better as you move back. With our boat, I'm not sure you could draw enough volume of cooling water in too many other locations. If you are going to change them, do yourself a favor and don't put anything going through the hull other than bronze, or maybe stainless. We had Marelon A/C outlet break off. We replaced every single thing going through the hull with bronze below the waterline and stainless above.
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topseaturvy
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Re: Moving the engine seacocks

Post by topseaturvy »

RWS wrote: Mon Mar 04, 2019 7:02 am there is likely a REASON the seacocks are located where the factory put them.

Suggest you do as much research as possible BEFORE attempting to re-engineer this system.

+1 on what Prowlerfish said about the BRONZE.

I found the Maleron overboard drains on my boat to be brittle and several were cracked.

suggest this alternative:

1. remove the plugs on the factory seacocks and install angled grease zerks

2. replace the hose from the seacock to the engine room with new

3. replace all hose clamps with T bolt clamps - 2 at each connection

4. splice a ball valve into that raw water hose in a more accessible location


RWS
El L Sea wrote: Mon Mar 04, 2019 9:52 am
topseaturvy wrote: Sat Mar 02, 2019 1:18 pm I have a 1986 Trojan 37 Sport Sedan. The engine seacocks are in a very strange place, aft of the engines almost right against the aft engine room bulkhead. You can't access the seacocks unless you lift the floor over each engine to get at them. The genset sits between the engines so there is less than a foot between the aft end of the engines and the forward edges of the genset. With the floors in place, if I stretch out my arm as far as possible I'm still about one foot from the seacock lever. This makes no sense at all. So my plan is to move them along with the sea strainers to the front of the engines. Lots of room there to crawl in and around the far side of the engine even with the floor in place. I'm wondering if anyone else has done this?

The only thing that I'm wondering about is that the inside hull area where the seacocks are now, appears to be almost an inch thinner. An area of about 12in. x 12in. is sort of stepped down right around the seacocks. I'm wondering if that's because the hull is too thick to screw the thru hull fitting into the seacock threads on most bronze thru hulls of the day because they might not have been long enough? That sounds like a stretch, but why else would the hull be thinner right there?

I'm planning on using Marelon for my thru hulls and seacocks. I believe the Marelon countersunk thru-hull 1-1/2” 250 series is 3” long. The backing plate material is about 1/2” thick so hopefully the thru-hull fitting should be long enough in the area of the hull forward of the engines where the hull appears to be about 1” thicker than where they are situated now. Does anyone know the bottom hull thickness of this boat? Is anyone familiar with the area around the seacock being about one inch thinner?
Thanks for any and all replies
Cheers
This is the same location as our 1988 12m sedan. The step down in ours is where it goes to solid glass, similar to in front of the holding tank where the inlets for the generator and A/C are. In our boat the front of the engine is about the last piece of remotely clean water you are going to get, and it gets better as you move back. With our boat, I'm not sure you could draw enough volume of cooling water in too many other locations. If you are going to change them, do yourself a favor and don't put anything going through the hull other than bronze, or maybe stainless. We had Marelon A/C outlet break off. We replaced every single thing going through the hull with bronze below the waterline and stainless above.
Thanks for your advice and your experience with Marelon. I had given some thought to using a 6-8" solid bronze pipe after the seacock followed by a 90 elbow, then another 6" bronze pipe facing forward, then a ball valve followed by the sea strainer. I would then build a bracket to anchor that pipe to the bulkhead and stringer to make it secure. This should allow me to reach the ball valve lever and service the sea strainer and the engine with the raw water shut off. Then whenever I did have the floor up I would close and open the seacock just to keep it lubricated. Perhaps I should reconsider that method. I believe the sea strainer would still be below the level of the raw water pump, if that was important. Actually because it is so close to the aft bulkhead and stringer and in a very protected area, I could probably use hardwall engine coolant hose, supporting everything the same way. Rather than using bronze pipe which might be very hard to find.
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Re: Moving the engine seacocks

Post by topseaturvy »

RWS wrote: Mon Mar 04, 2019 7:02 am there is likely a REASON the seacocks are located where the factory put them.

Suggest you do as much research as possible BEFORE attempting to re-engineer this system.

+1 on what Prowlerfish said about the BRONZE.

I found the Maleron overboard drains on my boat to be brittle and several were cracked.

suggest this alternative:

1. remove the plugs on the factory seacocks and install angled grease zerks

2. replace the hose from the seacock to the engine room with new

3. replace all hose clamps with T bolt clamps - 2 at each connection

4. splice a ball valve into that raw water hose in a more accessible location


RWS
I have seen some ball valves/ seacocks come with a grease nipple. I'm assuming it's just a matter of removing that phillips screw and nut on the side and replacing it with the grease nipple ??
Yes I agree with using T bolt clamps.
I'm getting quite a few suggestions of sticking with bronze seacocks, so I think I would be wise to take everyone's advice.
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Re: Moving the engine seacocks

Post by WayWeGo »

If you use T-clamps in a damp location, you need to be careful with your product selection: https://stevedmarineconsulting.com/hose ... selection/

Make sure you are not using brass shutoff valves with pipe threads to connect to the through hulls. Through hulls come with straight cut threads and you only want bronze fittings. If it were my boat, I would want a shutoff right inside the through hull.

Even worse is putting a galvanized fitting in place. This is how our boat came to us -- note the rusty section of the "T" that was seeping salty water onto the bolts for the through hull!
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Re: Moving the engine seacocks

Post by topseaturvy »

WayWeGo wrote: Mon Mar 04, 2019 12:25 pm I note the rusty section of the "T" that was seeping salty water onto the bolts for the through hull!
That's mind boggling that someone would let their hose clamps get into the condition in those images. As for the T bolt clamps with the welded connection as opposed to the ones with the folded over tabs. Interesting theory, but if my clamps, anywhere on my boat were in a state where moisture might affect them, alarm bells would be ringing like crazy in my head. Why is there any moisture there at all and then solve that problem!! For me the advantage of the T bolt clamps is the holding power. The effect of moisture wouldn't be a consideration for me at least, since moisture just isn't allowed around any hose clamp fitting or any other fitting on the inside of my boat.
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Re: Moving the engine seacocks

Post by WayWeGo »

topseaturvy wrote: Mon Mar 04, 2019 3:04 pm For me the advantage of the T bolt clamps is the holding power. The effect of moisture wouldn't be a consideration for me at least, since moisture just isn't allowed around any hose clamp fitting or any other fitting on the inside of my boat.
I get what you are saying about avoiding moisture, but sometimes that is not possible, especially in the bilges of a boat. Steve D'Antonio, who wrote that article, is one of the leading experts in the boatbuilding and maintenance industry and a regular contributor to many magazines including Professional Boat Builder. I have to defer to his experience. Note that he did not say to avoid using T clamps, just that you should buy the type made by AWAB.

For any hose clamped below the water line, I surely don't want to take any chances. If the clamp is difficult to see or service, I use the best I can find.
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Re: Moving the engine seacocks

Post by mikeandanne »

I totally agree with the guys, there is a reason those are located where they are. If you change that there could be consequences like aerating props etc, who knows. Maybe just reconfigure the strainer location to give you some better access while in a hurry if that is possible. Any underwater fittings should be good quality bronze IMO if you are thinking of keeping this boat for the long term.
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Re: Moving the engine seacocks

Post by topseaturvy »

So does anyone see any issues with moving the sea strainers to the front of the engines and leaving the seacocks where they are at the back of the engine room? This would mean a 1 1/4" hardwall rubber hose, same as there is from the factory now. The difference being instead of the sea strainer being about a foot from the seacock as it is now, it would be about 7 feet from the seacock to the sea strainer. I would add a ball valve in that run as close to the seacock as I could and still access it with the floors still in place, ( about 3 feet ) for servicing the engine like changing the impeller or whatever. The issue I can see is that 7 foot run of 1 1/4" hose could get clogged up over time. I could make a scheduled habit of checking that run periodically by lifting the floors and closing the seacock and removing that run for inspection. After a few years I would get a pretty good idea as to how oven that run of hose would need to be cleaned out. Granted that might alter depending if I was cruising in different waters. As it is now I believe the thru-hull has a grate on it if I remember correctly. I don't like the idea of a screen in the seacock, because that could possibly restrict flow to the raw water pump.
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Re: Moving the engine seacocks

Post by El L Sea »

topseaturvy wrote: Mon Mar 04, 2019 9:00 pm So does anyone see any issues with moving the sea strainers to the front of the engines and leaving the seacocks where they are at the back of the engine room? This would mean a 1 1/4" hardwall rubber hose, same as there is from the factory now. The difference being instead of the sea strainer being about a foot from the seacock as it is now, it would be about 7 feet from the seacock to the sea strainer. I would add a ball valve in that run as close to the seacock as I could and still access it with the floors still in place, ( about 3 feet ) for servicing the engine like changing the impeller or whatever. The issue I can see is that 7 foot run of 1 1/4" hose could get clogged up over time. I could make a scheduled habit of checking that run periodically by lifting the floors and closing the seacock and removing that run for inspection. After a few years I would get a pretty good idea as to how oven that run of hose would need to be cleaned out. Granted that might alter depending if I was cruising in different waters. As it is now I believe the thru-hull has a grate on it if I remember correctly. I don't like the idea of a screen in the seacock, because that could possibly restrict flow to the raw water pump.
Do you have diesel or gas? Our boat is diesel and has external strainers that the diver cleans monthly. We do not have the type of "in the engine room" strainers on the motor that are on the genny and A/C.
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