Is it normal to have a damp hull in the winter months?

[charliemcsnarly]

Hi all

 

I examined the hull in a few places in the summer by lifting floorboards - bone dry, healthy looking metal. Done it again recently, everywhere I look is damp/wet, some rust flakes.

 

Presumably, if it is like this every winter, the hull will eventually thin until leaks appear? I presume this dampness is due to consensation? Our insulation is good in general, but there are gaps here and there like holes in the floor boards under sink, bed etc for access.

 

Is this something to be worried about? I understand it is possible to treat the metal with vactan and other various products, but that would involve taking practically everything out of the boat, including fixed furniture, dividing walls etc. Also, that would have to be a job for the spring/summer for the paint to dry right?

 

Our hull still seems very solid everywhere I have looked, and it has lasted over 20 years. I just wondered how much of an issue this is so I can take necessary action. Surely other boats have the same problem?

 

Thanks

[Guest]

Hi all

 

I examined the hull in a few places in the summer by lifting floorboards - bone dry, healthy looking metal. Done it again recently, everywhere I look is damp/wet, some rust flakes.

 

Presumably, if it is like this every winter, the hull will eventually thin until leaks appear? I presume this dampness is due to consensation? Our insulation is good in general, but there are gaps here and there like holes in the floor boards under sink, bed etc for access.

 

Is this something to be worried about? I understand it is possible to treat the metal with vactan and other various products, but that would involve taking practically everything out of the boat, including fixed furniture, dividing walls etc. Also, that would have to be a job for the spring/summer for the paint to dry right?

 

Our hull still seems very solid everywhere I have looked, and it has lasted over 20 years. I just wondered how much of an issue this is so I can take necessary action. Surely other boats have the same problem?

 

Thanks

Some people apply Waxoyl inside for this very reason when fitting out. My previous boat had been as you describe for many years, but had lost virtually no metal, having lost most of the red oxide paint. I don't think that it is at all uncommon.

[andy the hammer]

I spent a lot of time and effort pumping water and checking for leaks last winter only to find when the weather warmed up the problem disappeared.

The only cause I could come up with was condensation on the base plate and condensation on the stainless steel water tank and I have the same problem as last year.

 

Regards

 

Andy

[charliemcsnarly]

Well that definetely puts my mind at rest, for now. Thanks

[alan_fincher]

I spent a lot of time and effort pumping water and checking for leaks last winter only to find when the weather warmed up the problem disappeared.

The only cause I could come up with was condensation on the base plate and condensation on the stainless steel water tank and I have the same problem as last year.

 

Regards

 

Andy

I can only assume this is a consequence of being on board, and having the boat well heated ?

 

Our boat (unfortunately!) sees little occupancy in the depths of winter. But the baseplate usually stays completely dry - or, at least, it does at the back, where I can really check it.

[sociable_hermit]

Leave windows open to encourage air circulation, if you can. I appreciate that in very cold weather its better to protect the boat though. A bit of condensation is better than burst pipes!

[blackrose]

I live aboard in winter and have never seen any dampness in the bilges. Perhaps it depends on one's floor insulation? I have carpet tiles over foam underlay.

[andy the hammer]

I can only assume this is a consequence of being on board, and having the boat well heated ?

 

 

That is exactly the problem, the water tank runs constantly and am planning to try and insulate in some way.

 

Regards

 

Andy

[blackrose]

That is exactly the problem, the water tank runs constantly and am planning to try and insulate in some way.

 

Regards

 

Andy

 

Remember that you do not necessarily need to insulate the water tank itself. Any thermal barrier between the heat source and the tank will work just as well. Think bulkheads & hatches - it might be easier.

Edited January 17, 2011 by blackrose

[NB Alnwick]

The last few weeks have been particularly unusual. We saw the temperature on the towpath at Cropredy change from an average of minus ten degrees over two weeks to plus fifteen in the last few days. Added to which we now have an unusually high level of humidity in the atmosphere. Under these circumstances, most large exposed metal objects will be dripping with condensation as they start to warm up. You should see our church bells they are soaking wet despite being well protected.

 

Unusually, we have even witnessed some condensation aboard 'Alnwick' although not on the baseplate - which is deeper in the water than most!

[alan_fincher]

The last few weeks have been particularly unusual. We saw the temperature on the towpath at Cropredy change from an average of minus ten degrees over two weeks to plus fifteen in the last few days. Added to which we now have an unusually high level of humidity in the atmosphere. Under these circumstances, most large exposed metal objects will be dripping with condensation as they start to warm up. You should see our church bells they are soaking wet despite being well protected.

 

Unusually, we have even witnessed some condensation aboard 'Alnwick' although not on the baseplate - which is deeper in the water than most!

In that I agree with you!

 

Because of my Mum's death, we have got to the boat far less than we would have liked, but it has been left ventilated, and cleared of snow as soon as possible.

 

I have certainly recorded some of the lowest temperatures aboard before it got much warmer.

 

Unusually the other day I found.....

 

1) The engine dripping with condensation.

2) Condensation running down the stove chimney in huge amounts, and the stove starting to rust.

3) The bathroom mirror literally running with condensation.

4) Even some condensation on the veneered ply panelling - never seen that before.

 

There are no obvious plumbing leaks, and no evidence of "weather" getting in from outside. It all seems to be to do with it having got very cold, then warmed up again.

 

Fortunately, having run fire and engine for a few hours at the weekend, all is now returned to normal.

 

The base-plate was still dry, though!

 

Yet to refill hot water system, and see if anything failed there, before we were able to get it drained down, though.

[FORTUNATA]

I blame boatbuilders in general because I've always believed steel should be protected inside and outside. That means painted bilges and all internal base plates.

The simplest solution I can think of getting oil into the bilge and I sometimes tip a little oil in that area. I never have enough bilge water for the pump to eject it so there's no pollution problem.

[charliemcsnarly]

I can only assume this is a consequence of being on board, and having the boat well heated ?

 

 

That's definetely it for us, this winter was so cold we had our little woodburner on constantly. There are places where the warm air can probably reach the hull, all be it only a few small places, but that it seems is all it took to soak the whole thing. If it's 25 degrees inside the boat and -10 outside, what can you do?

 

 

I blame boatbuilders in general because I've always believed steel should be protected inside and outside. That means painted bilges and all internal base plates.

 

This was my thought too. It's probably overlooked in the beginning because of the extra cost.

[charliemcsnarly]

Hyperthetically, if a boat were to get condensation on the base plate every year, and every year it produced 1mm of flaked rust, that would equate to a thinning of approximately 0.1mm of steel every year. Therefore it would take 50 years for the condensation to eat through the (probably) 5mm steel of our springer's base plate.

[Scooby]

Hyperthetically, if a boat were to get condensation on the base plate every year, and every year it produced 1mm of flaked rust, that would equate to a thinning of approximately 0.1mm of steel every year. Therefore it would take 50 years for the condensation to eat through the (probably) 5mm steel of our springer's base plate.

 

 

5mm, ours is 12.5mm...modern things eh..

[blackrose]

The last few weeks have been particularly unusual. We saw the temperature on the towpath at Cropredy change from an average of minus ten degrees over two weeks to plus fifteen in the last few days. Added to which we now have an unusually high level of humidity in the atmosphere. Under these circumstances, most large exposed metal objects will be dripping with condensation as they start to warm up. You should see our church bells they are soaking wet despite being well protected.

 

Unusually, we have even witnessed some condensation aboard 'Alnwick' although not on the baseplate - which is deeper in the water than most!

 

Yes, the big steam boiler (still full of water) on the boat I am working on was "sweating" profusely last week.

 

Hyperthetically, if a boat were to get condensation on the base plate every year, and every year it produced 1mm of flaked rust, that would equate to a thinning of approximately 0.1mm of steel every year. Therefore it would take 50 years for the condensation to eat through the (probably) 5mm steel of our springer's base plate.

 

Well, you don't wait for corrosion to eat through your hull. Anyway, you're only talking about internal corrosion and that doesn't account for external corrosion and wear. Even so, just with internal corrosion, you actually only have 10 years before most insurers would want you to do some work on the hull. With wear and external corrosion you might even halve that figure because you're not sure if it's 5mm minimum thickness as it is.

Edited January 18, 2011 by blackrose