Fifty Feet of Grey (steel)

[MapisM]

But that isn't necessary and is quite fussy

I'd call that idea brilliant rather than fussy, but I'm a tad biased.
And after all, pleasure boats as a whole are fussy things, I reckon...

 

[Robg71]

 

[Robg71]

Superstructure going on, and fore deck supports....

:encouragement:


ill sit down and type some feedback later, Im off to the pub... I deserve it

 

[Robg71]

Seawater only passes thru heat exchangers, not the actual engine.

Unusually I also have freshwater flushing so when the boat is at rest for more than a few days the heat exchangers are sitting in fresh water not seawater. But that isn't necessary and is quite fussy

That is actually quite a marvellous idea, and fairly simple to implement... Especially after looking inside my heat exchangers after 30 years of not being apart...

 

[vas]

I'd call that idea brilliant rather than fussy, but I'm a tad biased.
And after all, pleasure boats as a whole are fussy things, I reckon...

+1

was thinking how to implement it in a non-manual way, but it's currently on hold since I've still got no idea how much water I should be flushing through per engine. I wouldn't like to empty half my fresh water tanks on doing that!

cheers

V.

 

[Robg71]

I think you probably wont need much to do the job Vas, much less than anticipated. Even just watering it down, so to speak, would make a big difference...

 

[rustybarge]

It will be two pack, yes. Airless spray is most likely, but will be from paint spec that dictates. Some form of glossy finish though.

Is airless finish somewhere between roller finish, and super shiny car spray finish?

I'm just wondering if you will need to grind the welds flat to fair the hull, or will you leave them proud of the finish on the hull and superstructure. The welds can look quite nice, as they divide the hull up into sections, just like they do on large cruise ships.

The problem with a Superyacht finish is the work involved in keeping it shiny.:ambivalence:

 

[jfm]

Rob, fantastic progress with the hull. Exciting times!

The fresh water flush is easy. Here are before/after pics on one of my gensets. I just replaced a bronze elbow with a T, and the stub end of the T has a bronze ball valve and a Hozelock/Gardena standard hosepipe connector nipple. I drag the hosepipe* into the E/R and have an on/off tap on end of hosepipe. Then connect the hose with a "click push" Hozelock or Gardena type fitting and open the hosepipe valve. Then, with genset running of course, I simultaneously shut the seawater seacock** and open the freshwater ball valve (red handle in picture), and bob's your uncle. Also I make sure to turn off the hosepipe water supply a few seconds before shutting down the genset - this leaves the inside water passages a bit drier and also avoids any risk of hydrualicking the engine

I'll post pic of main engines set up later

* I have freshwater supply inside e/room so I might use that instead of hosepipe from dock. Still experimenting
** The seawater seacock is not visible in pics. It is underneath the U shape white trim in the floor, under the raw water strainer

BEFORE

WITH FRESH WATER FLUSH MOD

 

[MapisM]

Nice setup indeed.

Just another thought: if you would fit a second valve after the T (let's call it "new" valve, as opposed to the "existing" one), you could use it as follows:
1) seacock left open;
2) new valve closed;
3) attach fresh water hose;
4) open the existing valve and flush;
5) close seacock before leaving the boat.
This way, not only you would leave fresh water also in the filter (talk about being fussy... ), but you also get an automatic cleaning of it, by backflushing.

PS, in reply to Vas question: for fresh water, neither total quantity nor the flow volume should be a problem, also for the mains, since they would run at idle while flushing.
We already debated that when the idea was discussed, but I must rush out now. Will search the thread tonight, if you don't find it in the meantime.

 

[Keith-i]

One of these Groco SSC units looked interesting. http://www.jamestowndistributors.com/userportal/show_product.do?pid=14693

 

[Robg71]

Is airless finish somewhere between roller finish, and super shiny car spray finish?

I'm just wondering if you will need to grind the welds flat to fair the hull, or will you leave them proud of the finish on the hull and superstructure. The welds can look quite nice, as they divide the hull up into sections, just like they do on large cruise ships.

The problem with a Superyacht finish is the work involved in keeping it shiny.:ambivalence:

the welds will be ground flush on anywhere visible.
Airless spraying gives better adhesion and penetration, the finish should be similar.
Looking at Hempel and Awlgrip paints. The yard have been taking with them, but I'm not fully up to speed on that yet.

 

[rustybarge]

the welds will be ground flush on anywhere visible.
Airless spraying gives better adhesion and penetration, the finish should be similar.
Looking at Hempel and Awlgrip paints. The yard have been taking with them, but I'm not fully up to speed on that yet.

For the internal hull paintwork get a price on International Industrial 2 pack paints, the stuff they use on bridges and large steel structures. The grey 'zinc' primer and top coats are very thick and go on very fast with rollers and brushes.

Obviously not suitable for the external gloss finish, but I think you will find it very cheap in comparison to marine paint.

 

[MapisM]

Will search the thread tonight, if you don't find it in the meantime.

Vas (and anyone else interested, of course): this is the thread where we began discussing the idea:
http://www.ybw.com/forums/showthread.php?237755
Blimey, it was almost FOUR years ago. Doesn't time fly...?
Btw, I'm pretty sure that more recently we discussed the flow requirements in more details, but I can't find that debate.
Maybe it was in the M2 build thread, I'm not sure.... It's just too long to browse all its pages!

 

[Robg71]

For the internal hull paintwork get a price on International Industrial 2 pack paints, the stuff they use on bridges and large steel structures. The grey 'zinc' primer and top coats are very thick and go on very fast with rollers and brushes.

Obviously not suitable for the external gloss finish, but I think you will find it very cheap in comparison to marine paint.

Thanks very much.
We wil also be using a sound deadening paint internally. so need to take there advice as regards any incompatibility issues. Although Im not expecting any. Its also good for preventing condensation as a thermal barrier.

 

[jfm]

if you would fit a second valve after the T (let's call it "new" valve, as opposed to the "existing" one), you could use it as follows:
1) seacock left open;
2) new valve closed;
3) attach fresh water hose;
4) open the existing valve and flush;
5) close seacock before leaving the boat.
This way, not only you would leave fresh water also in the filter (talk about being fussy... ), but you also get an automatic cleaning of it, by backflushing.

Actually, if you think about it, the "new valve" is completely pointless and unnecessary. The street mains water pressure is typically 7-10metres head, and the back pressure of the seawater in the strainer is say 2m, so if you want to backflush then you just open the main seawater seacock for say 20 seconds while the hosepipe is running. The hosepipe water will then flow BOTH ways - thru the engine heat exchanger AND backflushingly through the strainer.

Regardless of whether you have the "new valve", the pressure in the hosepipe needs to be higher than the head of seawater, in order to backflush. If it is higher, as is invariably the case with a street water supply, the "new valve" itself brings nothing to the party.

That is in fact how I use them - I just didn't write it up that way because it seemed too complicated to explain!

 

[MapisM]

The hosepipe water will then flow BOTH ways - thru the engine heat exchanger AND backflushingly through the strainer.

Mmm.... Don't want to teach granny to suck eggs, but the water flow depends also on the hose section, not just on the pressure (leaving aside other factors).
If you're saying that you backflush while the engine is running, I think that the engine pump would suck from both the fresh water hose and the seacock.
IIRC, we discussed that in the thread which I couldn't find (possibly M1 or M2 build, not sure), and agreed that even if the fresh water hose would supply less water than the pump could draw, it would still be enough for flushing.
But of course, if the pump capacity is higher than whatever the hose can supply, with the seacock left open there would be no backflush at all.
Probably also for the genset, but sure enough for your two 32 liters monsters - unless you connect a MUCH bigger fresh water hose to them?
Otoh, I'd rather not leave the fresh water hose open with the engine not running, to avoid any hydraulicking risks (albeit probably small), as you also mentioned.
Sure, such risks would be even smaller with the seacock open, but all considered, another valve would be a cheap insurance, and by sending the whole fresh water flow back through the strainer, also the cleaning is bound to be more effective...
Anyhow, I did say it was just a thought, and that it's a nice setup also as it is....

 

[vas]

thanks for all the ideas guys!

my measly 7lt diesels run off a 1.25inch intake and I'm pretty sure the 15mm pipe that reaches the e/r and the small pump in the lazarette, wont cut it.
Since I've no idea what capacity the pump sucks at idle and considering I'm about to redo the link pipe between the two 250lt fresh water tanks at the lazarette (1.5inch valves/pipes), I'll tee off a 1.25inch pipe running at keel level 3m up to the intakes. There I'll tee after the strainers and with a nrv at the lazarette I should be able to try the system. I could do one engine at a time so that I'll skip the extra isolation valve on the supply line

Obviously with engine sucking from the bottom of the freshwater tanks, there's no way for hydraulicing them but there's no backflush to the strainers.
I'm not too fussed about that as I chickened out anyway and got some 40euro plastic strainers and not the Quidi (sp?) 250 a pop ones, so I can let them rot
Any problems with this method?

cheers

V.

PS. MM, must have been some discussions on M2 thread, wasn't following the forum in 2010.

 

[MapisM]

Any problems with this method?

None that I can think of.
Mind, actually I don't think it's necessary to supply as much water as the engine needs through its whole operating range and load (which is the rationale behind your 1 1/4 intake).
We are only talking of supplying enough fresh water to fill the raw water cooling circuit, with the engine running at idle and unloaded.
Which is a matter of minutes, and quite likely the "s" for the plural is actually wrong, even if you would supply fresh water at a rate lower than the one the pump can normally handle.
Just look at jfm genset arrangement: the gardena style connection says it all about the fresh water flow that the hose can supply to the engines, even considering that the pressure would be higher than the sea water coming from the strainer.
And don't be mistaken, his gensets are powered by pretty decent size engines - 3.5 litres, IIRC....?

PS: LOL, I tihnk Guidi is the strainer builder you're referring to.
But actually, my suggestion for the backflush arrangement was more for cleaning, rather than removing the sea water to avoid rotting - which hopefully won't be a problem anyway, with your plastic things!
Just think of when you suck a lot of weeds from the seacock (very rare in the Med, but can happen): rather than opening the strainer cover and get rid of them manually, you could simply attach the hose and flush them back...

 

[vas]

None that I can think of.
Mind, actually I don't think it's necessary to supply as much water as the engine needs through its whole operating range and load (which is the rationale behind your 1 1/4 intake).
We are only talking of supplying enough fresh water to fill the raw water cooling circuit, with the engine running at idle and unloaded.
Which is a matter of minutes, and quite likely the "s" for the plural is actually wrong, even if you would supply fresh water at a rate lower than the one the pump can normally handle.
Just look at jfm genset arrangement: the gardena style connection says it all about the fresh water flow that the hose can supply to the engines, even considering that the pressure would be higher than the sea water coming from the strainer.
And don't be mistaken, his gensets are powered by pretty decent size engines - 3.5 litres, IIRC....?

PS: LOL, I tihnk Guidi is the strainer builder you're referring to.
But actually, my suggestion for the backflush arrangement was more for cleaning, rather than removing the sea water to avoid rotting (which hopefully won't be a problem with your plastic things!).
Just think of when you suck a lot of weeds from the seacock (very rare in the Med, but can happen): rather than opening the strainer cover and get rid of them manually, you could simply attach the hose and flush them back...

good,

so I can save a few euros and get a 3/4inch pipe up to the strainers then

Actually it's probably going to be easier to stick to 1 1/4 as I'll spend more money and trouble fitting all these reduction pipes and connectors.
I'll stick to this system as it means I can do it single handed without having to rush up and down to open and close valves and seacocks and start/stop engines

OK, enough of a thread drift from me, where are the deck pics then Rob?

cheers

V.

PS. yes Guidi are the ones, could only afford the 3/4inch ones for geny, aircon, watermaker, et al

 

[Robg71]