Condensation in engine bay

[Broughton 2]

Shall be grateful for suggestions for hull lining materials to counter condensation in an engine bay. Must be reasonably durable against knocks and bruises and also fireproof.

 

Cork has been suggested but I'n not sure whether or not it can be made fireproof to suit safety needs.

[wonderdust]

I know there are fireproof insulation/foams out there, we have some to deaden the engine sound on the engine covers but don't know the name of it. How where you thinking of fixing it to the walls?

[Broughton 2]

I know there are fireproof insulation/foams out there, we have some to deaden the engine sound on the engine covers but don't know the name of it. How where you thinking of fixing it to the walls?

 

 

Open to suggestions as to fixing. Possibly glue or maybe the sides could be painted with engine bay/bilge paint and the insulation material then applied before the paint dries?

[stuart]

What sort of stern is it?

[blackrose]

Condensation should only form where warm air meets a cold surface. An uninsulated engine space clearly has plenty of cold surfaces, but if it's properly ventilated the inside should be more or less the same temperature as outside. So do you have something in the engine bay that's generating heat (apart from the engine of course!) that's causing the condensation? A calorifier, pipework, even a battery charger / inverter perhaps?

 

I'm just thinking that it might be possible - in the case of hot pipes from the calorifier for example - to insulate these instead of trying to do the whole engine bay, even if that's temporary pipe insulation whih you could remove when you cruise. Obviously you can't insulate electrical items like battery chargers beause they need ventilation, but they won't like being in a damp environment much anyway, so in your case the engine bay is not the best place for them.

 

If you do have to insulate the engine bay, what about using 1" thick Kingspan with some 9mm marine ply on top? (Not sure what thickness the ply comes in?) Anyway, once you've offered it up to the area being insulated and made sure it's the right size you could stick the ply to the Kingspan with a PU adhesive/sealant like Marineflex or Sikaflex (you wouldn't need much, just a few splodges at the corners and the middle), let it go off and then stick the whole lot to the metal with the same stuff.

 

Edit: I know marine ply isn't fireproof but I think plenty of people have wood in their engine space don't they?

Edited February 24, 2008 by blackrose

[Broughton 2]

What sort of stern is it?

 

 

Semi-trad.

[Broughton 2]

Condensation should only form where warm air meets a cold surface. An uninsulated engine space clearly has plenty of cold surfaces, but if it's properly ventilated the inside should be more or less the same temperature as outside. So do you have something in the engine bay that's generating heat (apart from the engine of course!) that's causing the condensation? A calorifier, pipework, even a battery charger / inverter perhaps?

 

I'm just thinking that it might be possible - in the case of hot pipes from the calorifier for example - to insulate these instead of trying to do the whole engine bay, even if that's temporary pipe insulation whih you could remove when you cruise. Obviously you can't insulate electrical items like battery chargers beause they need ventilation, but they won't like being in a damp environment much anyway, so in your case the engine bay is not the best place for them.

 

If you do have to insulate the engine bay, what about using 1" thick Kingspan with some 9mm marine ply on top? (Not sure what thickness the ply comes in?) Anyway, once you've offered it up to the area being insulated and made sure it's the right size you could stick the ply to the Kingspan with a PU adhesive/sealant like Marineflex or Sikaflex (you wouldn't need much, just a few splodges at the corners and the middle), let it go off and then stick the whole lot to the metal with the same stuff.

 

Edit: I know marine ply isn't fireproof but I think plenty of people have wood in their engine space don't they?

 

 

Condensation in summer isn't a problem but in winter, when water is cold, it appears even when engine hasn't run for days! Engine bay ventilation is typical (two good sized vents). I suspect the semi-trad stern with it's canopy may be retaining heat in the engine bay (even in winter the dark green steel hull can get quite warm when the sun does shine).

 

Don't other folks have same problem, is it just me?

 

Thanks for the idea of Kingspan with ply, sounds OK.

[blackrose]

Don't other folks have same problem, is it just me?

 

Thanks for the idea of Kingspan with ply, sounds OK.

 

I've only ever once seen a trickle of condensation on the floor in my engine bay (cruiser stern). Most of the time it's bone dry.

 

What about trying to increase ventilation instead?

 

Personally I think any insulation method you use shouldn't be too permanent - you might want to take it out in summer to see what's happening behind, so a few blobs of Marineflex would be probably ok. If you used Kingspan/ply you'd have to think of a method of sealing the gaps where different panels join, otherwise you might get condensation & rust forming at these points.

Edited February 24, 2008 by blackrose

[jactomtroub]

We have a traditional engine room with our engine sitting smack in the middle. The walls below the gunnels are not lined but are painted. They form condensation especially if it is cold outside and warm in. Ventilation can't be a problem as we have two sets of sidedoors and the boat is well aired. We get no condensation elsewhere. For us its not really a problem as it runs off into a tray. There is no rust but we do keep it well painted. Jac

[blackrose]

We have a traditional engine room with our engine sitting smack in the middle. The walls below the gunnels are not lined but are painted. They form condensation especially if it is cold outside and warm in. Ventilation can't be a problem as we have two sets of sidedoors and the boat is well aired. We get no condensation elsewhere. For us its not really a problem as it runs off into a tray. There is no rust but we do keep it well painted. Jac

 

With a trad stern you're probably getting some heat loss from the cabin into the engine room, thus the condensation.

[jactomtroub]

Sorry I didn't make it clear its a tug with her engine in an engine room. Yep the condensation comes when we have both stoves on. Only is a problem when I am working on the engine and my bum touches the side - get wet pants then!

[RobinJ]

Condensation in summer isn't a problem but in winter, when water is cold, it appears even when engine hasn't run for days! Engine bay ventilation is typical (two good sized vents). I suspect the semi-trad stern with it's canopy may be retaining heat in the engine bay (even in winter the dark green steel hull can get quite warm when the sun does shine).

 

Don't other folks have same problem, is it just me?

In winter I suspect the water might be warmer than the air and condensation might occur above the water line.

It is not helped by the fact vents tend not to allow the warmest air out (which will collect at the top)!

Condensation in mine is generally not a lot, but shows itself by mould growing in the drainage channels!

I don't want the engine compartment to be colder than the water as this could mean worse problems for stopping the engine from freezing.

[dor]

Cork has been suggested but I'n not sure whether or not it can be made fireproof to suit safety needs.

 

Can't comment on the aesthetic qualities, but cork tiles are virtually fireproof. Cork just does not burn very well.