Is this a daft idea?

[peter2407]

Under cushion (sp?) heating. So, this is for the forepeak that previous owner managed to soak sea water into the cushions which will never dry out, added to which the steel fresh water tank is under the berth. There is a spare battery stored in a locker at the front of the v berth. Idea - using a walkable on solar panel, fit it to the hatch, run a cable to the spare battery and have a timer driving 12v under mattress heater to both heat the v berth in winter and keep it dry in summer. If such wonders are available (thinking of the caravan market, rather than marine) and it works I get a. The battery topped up, b. Warm berth in winter and c. Dry berth in summer. Kick it to death please as i am sure there is/are a/many fundamental flaw(s).

 

[Rum Run]

It would depend on the size of the PV panel, but even assuming a 90w semi flexible, which is about 3'x2', it would give you an old-school lightbulb's worth of heat during some of the day in the summer and practically buggrall the rest of the time. If your boat is in sunnier climes this would be different of course.
Is it not possible to launder the cushions and put thin insulation on the tank top?
I'm a fan of PV panels but on a normal sailing boat in the UK I'd say it wasn't a goer

 

[VicMallows]

With salt in the cushions they will always attract moisture and be damp. Solution is easy but slow. Take the covers off (and wash them). REALLY thoroughly wash/rinse the foam. (You can tread them in several changes of water in a bath). They will take many days -in good drying weather- to properly dry, but you will get there in the end

 

[jac]

Not sure which is the problem you're trying to fix.

If it's the damp cushions then wash as Vic suggests. Just make sure you fix the root cause of the salt water ingress.

If it's a cold bed in the winter then insulation and some other form of heat. If winter sailing is mainly marina bound then electric blanket and shore power (or generator for short while before turning in) otherwise a good hot water bottle and space heating.

 

[Allan]

I agree with everything said above. Heating requires much too much power for PV panels to cope with.
Another factor I've found is the angle of the PV panel. I have two on my boat, one fixed on the coachroof and a plugin one which I can put in the cockpit and "point" at the sun. I get much more power from the plugin panel.
Allan

 

[JumbleDuck]

With salt in the cushions they will always attract moisture and be damp. Solution is easy but slow. Take the covers off (and wash them). REALLY thoroughly wash/rinse the foam. (You can tread them in several changes of water in a bath). They will take many days -in good drying weather- to properly dry, but you will get there in the end

I have had success pressure washing cushions.

 

[skyflyer]

I reckon the biggest cause of cooling and condensation in the forepeak is from the cabin walls (bows) beneath the waterline.