Theodora's Raw Water Cooling

[Theo]

I have decided, with a little help from freinds here, that I definitely need a stop valve on the inlet. It then occured to me that if I fit a T on the inboard side of this valve with onother valve on the branch I will be able to introduce a relatively small amount of antifreeze to protect the raw water system.

 

After that it occured to me that I might be able to drain the system by turning off the inlet, opening the valve to the branch of the T and then running the engine until water stops coming out of the exhaust.

 

My query is: Is this a reasonable thing to do? Will it drain the system down far enough to provide a good level of protection?

 

I am looking forward to your comments.

 

Nick

[DHutch]

Sounds fair enough to me.

- The conection on out mud box is stright to the valve and onto thew flex hose.

- However, we have somthing very simualr to what you suggest on the boiler blow-down valve.

 

'T' peice welded to the hull, then a valve on each branch, one just terminating in a screw in plug, the other going onto the boiler.

 

 

 

Daniel

[Sir Nibble]

running the engine until water stops coming out of the exhaust.

Don't do this. It will wreck the pump impellor!

[David]

Hi

Should work fine, I have a raw water cooled engine (but in a generator) I have a fitting welded into hull, seacock screwed onto fitting, Tee piece with seacock on "spare" outlet, the other outlet of course connected to the filter and thence to the engine. Shutting the hull inlet seacock and fitting a temporary conection, a hose going onto a bucket, on to the spare outlet you can, by keeping the bucket full of clean water, flush the system (clean out the filter as normal first) and finish of with a dose of antifreeze going round the system.

I prefer to do that rather than just drain down as water can be trapped in lower parts of the system and then freeze, especialy if leaving the boat for a while and/or we are going to be away and heavy frost is expected.

Just adding a dose of antifreeze only takes 5 min's, flushing can take as long as you want.

david

 

Added, seeing above re impellor, I shut engine off just before the last of the water gets sucked out of the bucket so nothing is running dry or uncooled.

Edited February 6, 2007 by David

[John Orentas]

I have decided, with a little help from freinds here, that I definitely need a stop valve on the inlet. It then occured to me that if I fit a T on the inboard side of this valve with onother valve on the branch I will be able to introduce a relatively small amount of antifreeze to protect the raw water system.

 

After that it occured to me that I might be able to drain the system by turning off the inlet, opening the valve to the branch of the T and then running the engine until water stops coming out of the exhaust.

 

My query is: Is this a reasonable thing to do? Will it drain the system down far enough to provide a good level of protection?

 

I am looking forward to your comments.

 

Nick

 

 

That's the conventional way of doing it, I can understand Snibble's concerns but the rubber impeller types of pumps are used partly because they will tolerate this sort of treatment, but obviously don't over-do it.

[Theo]

Thanks everyone. I will get on with it at half term. I cannot carry on with the thought of freezing and Theodora sinking as a consequence. I found myself driving over to Thurmaston at 9.15 last night after bell ringing practice, and running the central heating for half an hour to take the chill off things.

 

I have kept a maximum and minimum thermometer on top of the batteries under the rear deck. When I looked at it last night the lowest recorded temperature was +3deg C. Not too bad really considering that the air temperature was at about -4.

 

I think that to be safe with the pump impeller I will use antifreeze. It is not as if I will have to put gallons in to get a reasonable concentration once I don't have to antifreeze the mud box.

 

Just one thing, though, are there any recorded problems in a really cold spell of the mud box freezing up and causing damage. Obviously this would only be a problem if the canal were frozen up.

 

All the best

 

Nick

Edited February 6, 2007 by Theo

[Yamanx]

What sort of environmental damaged could be caused by pumping anti freeze into the canal? Even small amounts? Any?

[tomsk]

What sort of environmental damaged could be caused by pumping anti freeze into the canal? Even small amounts? Any?

 

 

I don't think it would do the flora and fauna much good, but looking at the oil slicks and other gunge in the cut probably a drop in the ocean (or canal), doesn't mean to say we should add to the pollution tho'

[Theo]

What sort of environmental damaged could be caused by pumping anti freeze into the canal? Even small amounts? Any?

 

 

I would have thought very little. Mammalian livers can be damaged by large amounts. (Remember the German Wine scandal in the 70's). If you are draining antifreeze into a container make sure that the dog can't get at it. the antifreeze tastes sweet and he will drink it and, possibly, die.

 

On reason that the antifreeze may be less damaging to the environment is that is is miscible with water and will rapidly dilute.

 

The reason that I am fitting the T piece and another valve is vastly to reduce the quantity of antifreeze that I will need to add to the environment.

 

All the best

 

Nick

 

Edited for lots of typos

Edited February 6, 2007 by Theo

[Tony Brooks]

I have decided, with a little help from freinds here, that I definitely need a stop valve on the inlet. It then occured to me that if I fit a T on the inboard side of this valve with onother valve on the branch I will be able to introduce a relatively small amount of antifreeze to protect the raw water system.

 

After that it occured to me that I might be able to drain the system by turning off the inlet, opening the valve to the branch of the T and then running the engine until water stops coming out of the exhaust.

 

My query is: Is this a reasonable thing to do? Will it drain the system down far enough to provide a good level of protection?

 

I am looking forward to your comments.

 

Nick

 

 

I have looked back and can not see a post that actually describes the cooling system so I am not convinced about how well this will work.

 

If its a heat exchanger or keel cooled/skin tank system so antifreeze is in the engine at all times and all you are doing is to introduce it into the raw water part it may be fine, but the exhaust manifold may well be full of raw water so stick to the antifreeze routine, not trying to drain down via the T.

 

 

If its a full raw water cooled system with a thermostat there should be a bypass system so the raw water can still be fed to the exhaust (even if its now a dry exhaust) when the thermostat is shut. This may well cause the antifreeze to bypass the cylinder block leaving the block vulnerable to freezing. In this case I think you should remove the thermostat before "antifreezing" or rig an antifreeze recirculating system so the engine can be run up to operating temperature to open the thermostat.

 

I hope its the first type of system - much easier.

 

Tony Brooks

[Theo]

I If its a heat exchanger or keel cooled/skin tank system so antifreeze is in the engine at all times and all you are doing is to introduce it into the raw water part it may be fine, but the exhaust manifold may well be full of raw water so stick to the antifreeze routine, not trying to drain down via the T.

 

Tony Brooks

 

It's this one, Tony. I was slowly come around to this conclusion. With all this cold weather I will be glad when it is done!

 

Nick

 

Thanks everyone. Another satisfactory conclusion!

[blackrose]

What sort of environmental damaged could be caused by pumping anti freeze into the canal? Even small amounts? Any?

 

A few years ago I worked on a research project attenpting to quantify the amounts of household hazardous waste generated by households in England. Along with solvent based paints, batteries, pharmaceuticals, etc., automotive products such as lubricants, brake fluid & antifreeze were also on our sampling list.

Businesses & commercial premises are supposed to used licenced waste carriers to dispose of such hazardous wastes in an appropriate way, but curently as householders you can throw whatever you like in your bin and most of it will end up in landfill (approx 78% of municipal solid waste goes to landfill in England & Wales).

 

These products are hazardous to the environment but many also contain persistent bioaccumulative and toxic chemicals (they persist in the environment and bioaccumulate in food chains and in you!). Although, the concentrations of the hazardous element in many consumer products is low compared to industrial strength products, once disposed of in the landfill site these chemicals can leach out and if not captured by the landfill lining the leachate can get into groundwater.

 

The idea of our project was to gather data because unfortunately these days without such data the authorities will not act - for example to provide better hazardous waste disposal facilities, or to implement programs to separate such waste.

 

Anyway, although this website (http://www.atsdr.cdc.gov/tfacts96.html) and material safety datasheets such as this one (http://www.jtbaker.com/msds/englishhtml/E5125.htm), suggest that ethelyene glycol (the hazardous constituent of antifreeze) will biodegrade in water, I suggest that you do not pump antifreeze into the canal - isn't it possible to have someone on standby with a load of buckets or washing up bowls at the outlet? I know it's a hassle but you could then take it to your local council disposal & recycling centre where there should be a hazardous waste bin.

 

On the other hand, with those references I suppose you could now justify chucking the antifreeze into the canal... Either way it's good to be informed!

Edited February 7, 2007 by blackrose

[Theo]

A few years ago I worked on a research project attenpting to quantify the amounts of household hazardous waste generated by households in England. Along with solvent based paints, batteries, pharmaceuticals, etc., automotive products such as lubricants, brake fluid & antifreeze were also on our sampling list.

Businesses & commercial premises are supposed to used licenced waste carriers to dispose of such hazardous wastes in an appropriate way, but curently as householders you can throw whatever you like in your bin and most of it will end up in landfill (approx 78% of municipal solid waste goes to landfill in England & Wales).

 

These products are hazardous to the environment but many also contain persistent bioaccumulative and toxic chemicals (they persist in the environment and bioaccumulate in food chains and in you!). Although, the concentrations of the hazardous element in many consumer products is low compared to industrial strength products, once disposed of in the landfill site these chemicals can leach out and if not captured by the landfill lining the leachate can get into groundwater.

 

The idea of our project was to gather data because unfortunately these days without such data the authorities will not act - for example to provide better hazardous waste disposal facilities, or to implement programs to separate such waste.

 

Anyway, although this website (http://www.atsdr.cdc.gov/tfacts96.html) and material safety datasheets such as this one (http://www.jtbaker.com/msds/englishhtml/E5125.htm), suggest that ethelyene glycol (the hazardous constituent of antifreeze) will biodegrade in water, I suggest that you do not pump antifreeze into the canal - isn't it possible to have someone on standby with a load of buckets or washing up bowls at the outlet? I know it's a hassle but you could then take it to your local council disposal & recycling centre where there should be a hazardous waste bin.

 

On the other hand, with those references I suppose you could now justify chucking the antifreeze into the canal... Either way it's good to be informed!

 

 

I can certainly collect the water + antifreeze. I wonder if I can make it easier by adding a hose to the exhaust pipe, being careful not to pressurise the exhaust system. Having collected the water Ican then use it again the next time I stop when there is a risk of freezing.

 

Thanks, Blackrose

[Theo]

Went down to Theodora today to do some measuring up. I intended to take the callipers to measure the size of the inlet pipe but forgot them. When I know the size I will need a die to thread the end of the pipe prior to fitting the cock. Is this something that can easily be hire cos I bet they are expensive to buy and I will only use it on this occasion.

 

Nick

[GLYN FORSTER]

Went down to Theodora today to do some measuring up. I intended to take the callipers to measure the size of the inlet pipe but forgot them. When I know the size I will need a die to thread the end of the pipe prior to fitting the cock. Is this something that can easily be hire cos I bet they are expensive to buy and I will only use it on this occasion.

 

Nick

[/quote

 

Depending on the size of the pipe you may be able to buy a gate valve with compression fittings to go straight on it.

[DHutch]

Alternativly, find a willing pumber freind with a pipe threader...

 

 

Daniel

[Theo]

I took the vernier calliper with me today and measured the outside diameter at 27.5mm. I hope that is a standard pipe size and I will be able to thread it and screw on a standard fitting. Does anyone know what it will be?

 

In hopes.

 

Nick

Edited February 11, 2007 by Theo

[GLYN FORSTER]

I took the vernier calliper with me today and measured the outside diameter at 27.5mm. I hope that is a standard pipe size and I will be able to thread it and screw on a standard fitting. Does anyone know what it will be?

 

In hopes.

 

Nick

If its 27.5mm you can use a 28mm compression gate valve it will fit straicht on then a short stub of 28mm copper to push your water pipe onto.

[Theo]

If its 27.5mm you can use a 28mm compression gate valve it will fit straicht on then a short stub of 28mm copper to push your water pipe onto.

 

 

Am I being foolish to prefer a screw fitting? It seems rather more secure on a sea cock.

 

Nick

[GLYN FORSTER]

Am I being foolish to prefer a screw fitting? It seems rather more secure on a sea cock.

 

Nick

Obviously a screw fitting is preferable but not always easy to achieve as i can imagine its a pain to get at, 27.5mm is the right sive for a 3/4" bsp thread but the tool to make the thread is going to be too big to get in, if it were me i would fit the compression type for the time being, and next time you go on the dock for blacking have a threaded fitting welded in.

[DHutch]

... if it were me i would fit the compression type for the time being, and next time you go on the dock for blacking have a threaded fitting welded in.

Yeah, sounds about right.

- And if your going to wait till your in dry dock anyway, it should be a peice of cake to weld in a bit of threaded pipe. (even i could do it...)

 

 

Daniel

[Theo]

Is there any problem with mixing brass and iron in the system?

 

The pipe that comes from the mud box is iron. Can I add brass fittings without corrosion problems?

 

Nick

[Theo]

It's now all sorted!

 

I hired a pipe threader from Speedyhire and took the flexible hose off the end. To my surprise no water flowed out. It was only when SWMBO and I were on the same side of the boat that there was a dribble. Now I know why the pipe angles down into the water in the mud box.

 

Much to my relief the pipe was already threaded but I thought that I would clean the threads with the pipe threader. It was then that I found it would not work. I fitted the sea cock, the T and the antifreeze injection port, put the flex hose on and the job was done. I am pleased that I won't find mysel going down to Raynesway every frosty evening!

 

Nick

Edited February 25, 2007 by Theo

[DHutch]

Sounds like a good days work, good job.

 

 

Daniel

[Theo]

Sounds like a good days work, good job.

Daniel

I forgot to say that I go the money back for the hire of the threader.

 

It didn't take the day. Only half the morning!

 

Nick