Keeping the boat ready to go through the winter

[oGaryo]

Hi, sorry if this one's been done to death already.. I keep the boat 20ft from my front door so rather than winterising her I'm thinking of keeping the engine bay warm with a low wattage thermostatically controlled tubular heater so I can take her fishing with me when the elements permit without the need to de-winterise each time

recognising these things can fail with potentially disasterous consequences, I'm intending on using two temperature sensors to ensure the engine bay and engine block are monitored:

one that'll set off an alarm in the house if the temperature drops below a preset value

and a wired battery operated remote temp monitor that I'll have as a means of checking the engine block temperature without having to take the covers off... the sensor will be put on the block with the monitor under the cover of the boat in an accessible place e.g. on the swim platform

what do you reckon.. a workable solution or incredibly flawed thinking

 

[jfm]

Hi, sorry if this one's been done to death already.. I keep the boat 20ft from my front door so rather than winterising her I'm thinking of keeping the engine bay warm with a low wattage thermostatically controlled tubular heater so I can take her fishing with me when the elements permit without the need to de-winterise each time

recognising these things can fail with potentially disasterous consequences, I'm intending on using two temperature sensors to ensure the engine bay and engine block are monitored:

one that'll set off an alarm in the house if the temperature drops below a preset value

and a wired battery operated remote temp monitor that I'll have as a means of checking the engine block temperature without having to take the covers off... the sensor will be put on the block with the monitor under the cover of the boat in an accessible place e.g. on the swim platform

what do you reckon.. a workable solution or incredibly flawed thinking

Seems a good idea to me. The required wattage of the heater will depend on how fast the heat leaks from the engine bay, so you might want to insulate the engine bay (blankets, bubble wrap, draped over the engine hood) to make sure that the temp is kept quite high even with a very low wattage heater? Just a thought. Obviously you can have plenty of antifreeze in the cooling circuit to make sure it can withstand low temps. You can also buy electric heating elements that you screw into the engine cooling jacket and wire up to the mains/battery, to provide direct heating to the cooling water. Some cars have these in cold climates to preheat the car, so the heater works even before you turn the engine on. Probably a bit over the top though!

 

[MapisM]

Obviously you can have plenty of antifreeze in the cooling circuit to make sure it can withstand low temps.

I don't think he has a closed cooling circuit on his boat, J.
What he could consider is fitting a 3-way valve on the raw water circuit, connecting a hose to fill it with fresh water plus antifreeze after each usage. This has the side advantage of not leaving salt water around (and I'd do it for this reason alone, regardless of antifreeze, also in summertime), but depending on how frequently he's using the boat in winter, the antifreeze expense might go over the top...

I agree on your other recommendations. Just another couple of thoughts:
1) if there's a fresh water circuit onboard, e.g. for a transom shower, I'd leave it empty in winter (unlikely to be used anyway!)
2) I'm not sure about the specs of the gear oil used for sterndrive. I guess it can withstand a very low temperature, but worth checking.

 

[lovezoo]

I kept mine round the side of the house under the carport one winter. Covered the engine and leg with blankets and put a small oil filled radiator on the boat. Temperature in the engine compartment never dropped below 2 degrees, but then it wasn't a particularly cold winter.

Another alternative is to put the leg in a dustbin of water/anti-freeze and run the engine up - no worries about freezing weather then.

Or just tow the boat to Spain, some of the best boating weather is in the winter here and hardly anyone about to spill your G&T when at anchor.

 

[MapisM]

put the leg in a dustbin of water/anti-freeze and run the engine up

Careful there, that's not good for your impeller.
When you lift your boat, some of the raw water in the circuit between the leg and the pump leaks from the intake on the leg, thus leaving that part of the circuit half empty. If you afterwards turn your engine on with the boat in the water, there is some pressure on the water intake, 'cause it's well below the water surface.
The dustbin otoh doesn't create any pressure, which means that the pump has to work hard and dry for a while. And those seconds can wear the impeller more than many hours of normal operation.
I know that the dustbin is commonly used, but the valve I previously suggested is a much better solution because (aside from the initial hassle of fitting it) it's not only more effective, but also very convenient:
in summertime, after using the boat, you can just plug a hose and run the engine, job done. The water pressure in the hose assures that the impeller gets wet immediately. If used to fill the block with antifreeze, allows you to use a canister raised well above the engine, thus creating some pressure also in this case.

 

[lovezoo]

You really think it makes that much difference? The impeller is at the bottom of the leg and will be below the level of the water in the dustbin. Where would you fit a valve to allow you to fill the leg with water?

I´ve seen some boats with built in flushing circuits as you mention, but those have been on Bravo legs. The OP will have an Alpha.

 

[MapisM]

I´ve seen some boats with built in flushing circuits as you mention, but those have been on Bravo legs. The OP will have an Alpha.

Whoops, apologies. I had Bravo in mind 'cause that's what I have on my boat, and forgot that Alpha has an internal pump.
Yep, all I said applies only when the pump is engine driven.

 

[lovezoo]

You´re probably right to be careful though. You have to make sure the engine has warmed up fully so that the water/antifreeze mix goes everywhere it needs to.

I suppose it also does depend on how cold you think the weather is going to get. If in doubt drain the block.

 

[oGaryo]

thanks for the advice... I reckon I'll play it safe and drain the mainfold after each trip (flushing the engine first of course) in addition to the measures I've listed in the first post