Risk of frost damage for boat out of water for the winter?

[Mikexx]

As per subject title.

 

For convenience / cost and survey etc, I have arranged for the boat to be out of the water over the winter.

 

My principle concern is frost damage, the 1.5 BMC engine is keel cooled with an engine heated calorifier.

 

Because the boat doesn't have power I don't know how much is in the water tank which is a smaller plastic affair. There is also the boiler and hot water side. I will endeavour to empty this as best I can.

 

Any suggestions where I should reasonably expect air temperatures to get down for -5C for a week or so?

 

I'm conscious I won't be able to fully empty either the bilge, the engine and keel water tanks without a whole load of hassle and even then it may not be entirely effective.

 

Obviously I'm reluctant to use antifreeze/ethylene glycol as I would never know if it had entered the hot tap water system. I was therefore toying with denatured meths (which would become obvious) or propylene glycol which is non-toxic. I feel I only need enough to stop solid ice, whereas even a weak mixture of water/antifreeze results in slush.

 

Is my thinking flawed? Would be grateful for advice.

[Geo]

Out of the water a boat will come down to the air temperature therefore you either need to use antifreeze or drain. The engine and the keel cooling should have antifreeze in them so should the central heating.

 

I would suggest that the cold and hot water sides need draining down. You do not say what heats the hot water a calorifier or something like a morco gas heater. If a morco style water heater that needs draining fully, as does the water pump. If it is a calorifier get as much of the water out as you can.

 

I would use a hydrometer to check the antifreeze in the engine etc

 

Someone will be alone to add bits I have missed

[Arthur Brown]

Do you have access to shore electricity?If the vessel is draught tight then having a moderate electric heater on a frost stat should be a great help.

[blackrose]

Do you have access to shore electricity?If the vessel is draught tight then having a moderate electric heater on a frost stat should be a great help.

Draught tight? With all the fixed vents? The roof vents will all have to be stuffed with rags and the door or low level vents taped over with duct tape. That's ok assuming nobody's sleeping on board at any time.

[Slim]

A crude way of checking the antifreeze in the engine or c/h system is to dip a piece of tissue or kitchen roll in the water (down filler cap or from rad vent ) CAREFULLY place in a double layer of plastic bags and pop in the freezer for 24 hours. (appropriate warnings to family etc)

 

I know one or two will inevitably come back with dire Health & Safety warnings but hey, clambering around a lock is not without risk

[ditchcrawler]

If you don't have power you wont be able to get a food grade antifreeze though out the fresh water system. I would strongly advise you to drain all fresh water including the contents of the calorifier, this may or may not be easy depending on the plumbing arrangements.

 

A good opportunity to install suitable drain points if they don't exist.

[Mikexx]

Do you have access to shore electricity?If the vessel is draught tight then having a moderate electric heater on a frost stat should be a great help.

 

I do, but it's not a cheap option. I might need a few kW if the temperature gets a few degrees below. The boat's insulation is poor.

If you don't have power you wont be able to get a food grade antifreeze though out the fresh water system. I would strongly advise you to drain all fresh water including the contents of the calorifier, this may or may not be easy depending on the plumbing arrangements.

 

A good opportunity to install suitable drain points if they don't exist.

 

I first need to sort out a water leak engine side but I am thinking of adding antifreeze. It also means I can upgrade some aspects of onboard power and have the engine running.

 

That's a good point about drain points. I'm wondering if I can open taps etc and used compressed air to assist clearing the pipes.

[Mitchellmoxo]

I had my boat out the water from Dec- march last year, there was no interior at the time so so water in the cabin to worry about but I didn't touch the water in the engine cooling or calorifier and all was ok for me. I also have a bmc 1.5

Edited November 27, 2016 by Mitchellmoxo

[Mikexx]

Out of the water a boat will come down to the air temperature therefore you either need to use antifreeze or drain. The engine and the keel cooling should have antifreeze in them so should the central heating.

 

I would suggest that the cold and hot water sides need draining down. You do not say what heats the hot water a calorifier or something like a morco gas heater. If a morco style water heater that needs draining fully, as does the water pump. If it is a calorifier get as much of the water out as you can.

 

I would use a hydrometer to check the antifreeze in the engine etc

 

Someone will be alone to add bits I have missed

 

I have no idea the make of the gas heater. There are 3 radiators as well. To be honest I need to familiarise myself with the heating system and this seems the ideal time!!

 

I assumed I could estimate the quantity of antifreeze I would need from the engine spec and the size of the keel cooling radiators. I'm less worried about the exact quantity of antifreeze though a hydrometer would take out some of the guesswork.

[ditchcrawler]

 

 

That's a good point about drain points. I'm wondering if I can open taps etc and used compressed air to assist clearing the pipes.

That will not empty your calorifier, you have to drain it from the bottom

[Mikexx]

That will not empty your calorifier, you have to drain it from the bottom

 

OK - thanks.

 

Will the calorifier have a primary circuit?

 

Without the pulling away of panels I don't know how the engine circuit and the gas boiler fit with what I assume I have is a hot water tank.

[ditchcrawler]

 

OK - thanks.

 

Will the calorifier have a primary circuit?

 

Without the pulling away of panels I don't know how the engine circuit and the gas boiler fit with what I assume I have is a hot water tank.

The primary coil/s of the calorifier normally have antifreeze in them being fed from the engine cooling and central heating so can normally be left. I cant guarantee that is true of your system. The main body of the calorifier will contain fresh water and it is this that need draining, this can't be done by opening hot taps as the hot should be drawn off the top of the cylinder so requires a drain on one of the bottom connections.

[Mikexx]

The primary coil/s of the calorifier normally have antifreeze in them being fed from the engine cooling and central heating so can normally be left. I cant guarantee that is true of your system. The main body of the calorifier will contain fresh water and it is this that need draining, this can't be done by opening hot taps as the hot should be drawn off the top of the cylinder so requires a drain on one of the bottom connections.

 

Many thanks. I understand the principle, much like an indirect cylinder for domestic hot water.

 

However there is a boiler, am I correct in assuming assuming this would also be supplying heat through the same primary?

[WotEver]

 

Many thanks. I understand the principle, much like an indirect cylinder for domestic hot water.

 

However there is a boiler, am I correct in assuming assuming this would also be supplying heat through the same primary?

Probably not. Many calorifiers are twin coil. Some are triple coil.

[Naughty Cal]

 

I do, but it's not a cheap option. I might need a few kW if the temperature gets a few degrees below. The boat's insulation is poor.

We run a series of greenhouse tube heaters in our boat over the winter. They don't cost a lot to run and they do keep the temperature well above freezing.

 

Our engine is raw water cooled so we have several raw water coolers and heat exchangers to protect and one heater in the engine bay has been fine so far. We also have a small tube heater in the shower room and a small oil filled rad in the main cabin.

 

Some people put them on thermostats so that they only come on when needed we prefer to keep them on 24/7 which uses a bit more power.

[David Mack]

We run a series of greenhouse tube heaters in our boat over the winter. They don't cost a lot to run and they do keep the temperature well above freezing.

 

Our engine is raw water cooled so we have several raw water coolers and heat exchangers to protect and one heater in the engine bay has been fine so far. We also have a small tube heater in the shower room and a small oil filled rad in the main cabin.

 

Some people put them on thermostats so that they only come on when needed we prefer to keep them on 24/7 which uses a bit more power.

Which requires you to have mains electricity at the mooring, and leaves you vulnerable if the power should fail or be disconnected.