Condensation - could it be?

[KellyLyon]

Apologies for the long post but we have a real head scratcher.  So we have a 93’ harboro boat.  We have done a series of modifications including fitting a Victron multiplus 2 with 7 batteries and a new calorifier (75lt) with a 1kw immersion.  We have also removed a very light bench style sofa and replaced with a sofa bed barn sofa all of this fitted to the port side of the boat.  We noticed a slight list and so planned to remove a small amount of ballast. On the weekend we noticed that the bilge pump was kicking in and when we investigated it the engine bilge did have sufficient water around the sides of the engine (not under the engine pan). At first we thought that the calorifier had leaked as the pipes leading from the engine to the calorifier were empty - we called RCR who we paid to swap the calorifier and the engineer thought the water in the engine bay (was yellow) was coolant but he couldn’t locate a leak and opted to send another engineer at a different time.  The second engineer came and checked the pressure on the water system which remained at 6bar although we couldn’t see any water in the header tank (we could still see water in the header tank when the first engineer came and we haven’t run the engine)

 

anyway the second engineer cleared the water system and said that the water was sitting on the port side swim (uxter) and running down into the bilge and that he felt it was a slight leak on a weld or rust letting water through the uxter plate or through the side.

 

we had the boat out of the water in May and blacked it and we didn’t see anything worrying.  We replaced all of the stern gear and had to cut a sufficient amount of steel from the back and this was noticeably thick and well

preserved  much to the shock of our welder who thought it would be thinner.  We have booked to get out of the water to investigate but I suddenly thought of something else.  When we run the immersion heater and the victron is running the temp is c32 degrees and higher in the heat that we have had the last few days.  Could we be creating crazy amounts of condensation in the bilge (all the heat stays in that area) the cooling tanks are directly located in the same area on each side of the boat

 

Some additional points

 

we do get rain in the bay as the gutters are poorly designed could this increase the amount of condensation?

 

we also painted the bilges and cleaned everything in April again didn’t notice anything untoward, the boat had a survey a couple of years ago and the chines were worn so the previous owner paid to have a full over plate of the base in 6mm steel this was pressure tested and we have the receipts and could see the work when we had the boat out of the water in May

 

we have removed the ballast and no longer list slightly but still creating very small amounts of water from the same place the temp is currently 26 degrees according to the victron and the outside temp is 18

[rusty69]

I would get in there, dry everything out meticulously and then watch what is happening, in the dry weather and when its raining.

 

It could be more than one thing. Leaks are either plumbing, windows, skin tanks, stern gland or hull in my experrience.

 

 

Start with the obvious things like calorifier PRV (where does it exit) etc.

 

I doubt it will be condensation this time of year. AN easy way to check i suppose is to turn the immersion off, and see what happens.

 

Welcome to the forum

 

ETA. Do you have a free running bilge, that is to say can water run from the front of the boat to the back ?

Edited July 28, 2022 by rusty69

[KellyLyon]

Thanks for replying

 

The bulk head is sealed so water from the front can’t access the rear/engine bay.

 

we have an inspection hatch immediately in front of the engine bay and that is fine so we don’t believe it to be coming from any other location

 

we have watched and we did fully dry it out and for hours we had nothing but overnight the swim was wet to touch but it had also rained and we did have some water in the bilge as we would normally 

 

Thanks

[Tony Brooks]

I am probably wrong but as it can't be 93ft long the OP probably means a 1993 build. This seems a bit new for a Harborough.

 

If it is an all-in-one bilge it could easily be water still draining back through the ballast, it can take weeks, but still check for leaks.

 

Seems some confusion between the cooling system and domestic water system. Domestic water systems do not typically have header tanks although a wet central heating system might, but that is normally separate from the domestic system. Domestic systems typically run at around 3 to 4 bar and no way would I pressure test at twice that, in any case it would almost certainly blow the PRV open. Cooling systems typically run at between 0.5 and 1 bar so what this 6 bar is about I can't think.

[Chewbacka]

4 minutes ago, Tony Brooks said:

I am probably wrong but as it can't be 93ft long the OP probably means a 1993 build. This seems a bit new for a Harborough.

 

If it is an all-in-one bilge it could easily be water still draining back through the ballast, it can take weeks, but still check for leaks.

 

Seems some confusion between the cooling system and domestic water system. Domestic water systems do not typically have header tanks although a wet central heating system might, but that is normally separate from the domestic system. Domestic systems typically run at around 3 to 4 bar and no way would I pressure test at twice that, in any case it would almost certainly blow the PRV open. Cooling systems typically run at between 0.5 and 1 bar so what this 6 bar is about I can't think.

I wonder if RCR pressure tested the engine coolant system at 0.6bar?

[Tony Brooks]

3 minutes ago, KellyLyon said:

Thanks for replying

 

The bulk head is sealed so water from the front can’t access the rear/engine bay.

 

we have an inspection hatch immediately in front of the engine bay and that is fine so we don’t believe it to be coming from any other location

 

we have watched and we did fully dry it out and for hours we had nothing but overnight the swim was wet to touch but it had also rained and we did have some water in the bilge as we would normally 

 

Thanks

 

Even at this time of year I found you can get a lot of dew (condensation) on the outside of the boat around dawn and that has normally dried by getting up time.  Staring the night before with a nice warm engine bay I could well image that the engine bay inner surfaces above the waterline might get cold enough for condensation to form.

 

Is there any chance that you are overfilling the cooling system so it is venting excess water. You may have a drain hose on the filler that leads outside the engine drip tray. However, that would vet coolant during the warm up, not the cool down.

[KellyLyon]

Thank you, yes this is a 1993 not 93ft, it’s only 50ft.

 

 I am not technical (although you have guessed that already) so the information was what was advised at the time the engineers came out.

 

the calorifier is connected to the engine to heat water and we have the additional immersion when on shoreline

 

the first engineer looked in the header and said we had lost around 4ltr which we thought odd as we haven’t ran the engine but that’s what he said.  He pressed the pipes leading from the engine to the calorifier and said they were empty so it could have drained and that could be what’s in the bilge but he couldn’t locate any leak (he said this could be because they have drained)

 

The second engineer said this wasn’t correct and the pipes would only have water when the engine is running and circulating the water.  we haven’t ran the engine at this point.

 

the header tank is on the engine as normal but it was just interesting to note that we had seen a drop in the level from Friday to Monday (engineer visit 1 and 2)

 

I could be wrong about bar maybe it could have been psi? The device looked like a bike pump attached to the header tank and this was on the system for around 15min but didn’t lose any pressure in that time.

 

 

 

 

[Tony Brooks]

1 minute ago, Chewbacka said:

I wonder if RCR pressure tested the engine coolant system at 0.6bar?

 

Could be but unless it is a 6psi pressure cap that is not enough to my mind.

[KellyLyon]

Could have been 0.6 too I guess

Thanks for all the replies just to answer a couple of points raised we haven’t filled the hearing system this was done when the engineer fitted hit he did explain  that the vent hose was vented to the cabin bilge (the calorifier is the cabin side of the engine bay) this was empty so we did rule that out 

[MtB]

The answer to the question in your thread title is, in my opinion, no.

 

It has to be a qualified no though as you don't actually say over what period the 'yellow water' in the engine bilge accumulated. I can't imagine any more than perhaps a teacupful of water accumulating in the engine bilge each night from condensation in extreme circumstances. In normal circumstances condensation would be more like a thimbleful, or non at all I'd say.

 

So if it had been say six months since you last looked in the engine bilge then yes it *could* be condensation, still probably isn't. But if enough water accumulated overnight (as I infer from the way you wrote) to make the boat list, then I'd say no, no chance at all of that much water being condensation. 

 

So as others have said, this leaves a plumbing leak, windows leaking, stern gland, engine cooling system or a hull problem. Given the problem seems to coincide immediately with you replacing the calorifier, Occam's Razor suggests this the problem lies there, so it must be either the engine cooling system (assuming the engine heats the domestic hot water), or the domestic plumbing. 

 

Are you SURE it is the bilge pump you hear kicking in from time to time, and not the domestic water pump?

 

 

Edited July 28, 2022 by MtB
Add a bit.

[Scholar Gypsy]

I had a very small leak in my coolant system, but only when the engine was running. When it was cold, and pumped up to 15 psi with the pressure tester, the pressure held absolutely constant for four hours.  But as I say when the engine was warm I got a small leak from one of the joints, now fixed. 

What colour is your coolant? 

[KellyLyon]

Hi

 

The water didn’t cause the boat to list the change in weight made the boat list at this point there was nothing to suggest water ingress other than rain water.

 

the water accumulated over the course of a week and we hoovered out about 10-20ltrs since hoovering that out we hoovered 8 litres but it had rained heavily

 

 

Apologies just checked the hoover specs and it has a 20l drum so took out 15 litres on the second removal after heavy rain which is about normal for us after similar levels of rain

[Alan de Enfield]

7 minutes ago, KellyLyon said:

Apologies just checked the hoover specs and it has a 20l drum so took out 15 litres on the second removal after heavy rain which is about normal for us after similar levels of rain

 

That is an inordinate and unacceptable amount of water to be pumping out after it raining.

I really doubt that that is rain water and that the problem lies elsewhere - during the last few days / weeks of dry weather has you had any water in the bilge ?

Edited July 28, 2022 by Alan de Enfield

[KellyLyon]

Hi

 

nothing that we noticed although with the dry weather we hadn’t checked as we only get it when it rains but it’s very unusual to ever here the bilge pump which is why we looked.  We replaced all of the stern gear because we had a worn prop shaft and that’s now sealed (moved away from the traditional type) to a water cooled version and where the water appears to be coming in is the port side swim play running down then into the engine bay - it’s all odd but just thought as all of the heat generating equipment is on that side it may be linked think we will just have to get it out and triple check just to be sure.

 

we have an engineer booked so hoping it’s nothing too serious  

 

 

 

 

 

[MtB]

2 hours ago, KellyLyon said:

On the weekend we noticed that the bilge pump was kicking in

 

^^^This^^^

 

Needs much closer examination. Why are you needing to hoover water out of the bilge if you have a bilge pump for this? 

 

It's a rhetorical question as I think you are hearing your domestic water pump, pumping water out through a plumbing pipework or calorifier leak you haven't found yet.

 

Where is this 'bilge pump' you are hearing? Can you post a photo of it please? Or details from the data label?

 

 

[KellyLyon]

Hi it’s definitely the bilge pump the water pump is at the front of the boat and the two sound very different we can also see the water leaving the boat from the bilge exit point so it is definitely that.

 

we hoover it out because the bilge pump doesn’t fully empty it (sea flow 750gph with automatic float switch) we can also manually activate from a switch in the cabin

 

so it is definitely not the water pump and the plumbing doesn’t have access (with the exception of the calorifier engine pipes) have access to the same area as our bulk head is sealed and all cabin inspection points are dry

 

 

The bilge hasn’t had to kick in for a week or so 

[Tony Brooks]

13 minutes ago, KellyLyon said:

the plumbing doesn’t have access (with the exception of the calorifier engine pipes) have access to the same area as our bulk head is sealed and all cabin inspection points are dry

 

I think that you need to revisit that statement. All calorifier systems should have a pressure relief valve fitted that can vent  when the system heats up. Sometimes the PRV outlet is connected to a skin fitting but I suspect more often than not it vents into the engine bilge. It is liable to vent whenever the calorifier heats up, especially if the system is not fitted with an expansion vessel. It occurs to me that if you are using the immersion heater and draw hot water in the evenings and before you look at the bilge in the morning the PRV is likely to have vented a small amount of water.

 

Find the PRV and see where the pipes on it run to. Two pipes, one from the hot outlet on the calorifier and the other may just be a hole in the valve or have a hose on it that runs to goodness knows where. It normally has  a plastic cap on it that is often red or black that clicks when you twist it, that causes it to vent water.

[David Mack]

46 minutes ago, KellyLyon said:

we hoover it out because the bilge pump doesn’t fully empty it (sea flow 750gph with automatic float switch) we can also manually activate from a switch in the cabin

So if the automatic bilge pump is pumping out an unknown quantity of water and you then hoover out 15-20 litres, there is potentially much more water involved. If that was still happening in the recent dry weather then I think it very likely you have a hull leak somewhere.

If your recent internal rearrangement has resulted in a list to port, and the water now seems to be coming from the port side, you may have a leak which was just above the water line, and is now below it.

[MtB]

I agree with David. If it really IS your bilge pump running periodically, quite large volumes of water could be getting into the bilge and being pumped out automatically. Thats a BIG bilge pump you have there - its 50 litres a minute! - to be running regularly. Make sure you keep your batteries charged and don't leave the boat unattended for long periods (days at a time) until this is resolved. 

 

How often do you hear the bilge pump run? Can you take some notes and measure the approximate period it runs for, and how many times per hour it runs? Or per day?

 

 

 

[Alan de Enfield]

15 minutes ago, MtB said:

Thats a BIG bilge pump you have there - its 50 litres a minute! - to be running regularly.

 

That is enormous (actually nearer 60 litres per minute)

 

My bilge pump is 40 litres per minute and draws 10 amps.

 

I wonder if the OP is getting confused with model numbers and GPH ?

 

Edit to add : No, it'claims' 700 GPH but says a bit less in the details. I dont believe the figures, mine is 40 litres per minute and has a 1" outlet, weighs 3kg+whilst this is allegedly 676 GPH on a 3/4" outlet and only draws 5 amps, AND, weighs in at 500g. :

 

I feel it is a bit of Chinese marketing !

 

SEAFLO 06 Series 750GPH Automatic Bilge Pump : Amazon.co.uk: Sports & Outdoors

 

PERFORMANCE

• Flow Rate:676 GPH
• Voltage:12 V
• Max Draw:5.0 A
• Fuse Amps:5.0 A
• Head:8.2' (2.5 m)
• Wire Lead:3' (1 m)
• Outlet Dia:3/4"
• N.W. / G.W.:0.47/0.52 kg
• Wire gauge:18 AWG
• Connections:19mm (3/4") hose barb

Edited July 28, 2022 by Alan de Enfield

[Tony Brooks]

I would be interested in how the cockpit floor drains. Some have fixed bearers made from upturned U section that drain down steel tubes to holes in the uxter plate. Those tubes do rust through causing hard to find leaks and they also block allowing more rain than they might to get into the bilge. This won't apply if the support drains go straight through the side of the hull.

[rusty69]

2 minutes ago, Tony Brooks said:

I would be interested in how the cockpit floor drains. Some have fixed bearers made from upturned U section that drain down steel tubes to holes in the uxter plate. Those tubes do rust through causing hard to find leaks and they also block allowing more rain than they might to get into the bilge. This won't apply if the support drains go straight through the side of the hull.

 

To add to this, one of our boats had a drain in one corner only (stbd) of the drainage channel. As the boat listed very slightly to port, the water collected in the channel without a drain and eventually rusted the steel through so it leaked into the boat. A second drain was fitted, and the boat levelled out a bit and it has been fine since.(after repairing the channel, obviously)

 

The drainage hole went to a skin fitting, which would also need clearing on a regular basis.

 

I think if I was the OP, I would want to determine how much of the problem is rainwater. Fix the drainage problem, or temporarily put a tarp over the deck. 

[MtB]

19 minutes ago, Alan de Enfield said:

 

That is enormous (actually nearer 60 litres per minute)

 

My bilge pump is 40 litres per minute and draws 10 amps.

 

I wonder if the OP is getting confused with model numbers and GPH ?

 

Edit to add : No, it'claims' 700 GPH but says a bit less in the details. I dont believe the figures, mine is 40 litres per minute and has a 1" outlet, weighs 3kg+whilst this is allegedly 676 GPH on a 3/4" outlet and only draws 5 amps, AND, weighs in at 500g. :

 

I feel it is a bit of Chinese marketing !

 

SEAFLO 06 Series 750GPH Automatic Bilge Pump : Amazon.co.uk: Sports & Outdoors

 

PERFORMANCE

• Flow Rate:676 GPH
• Voltage:12 V
• Max Draw:5.0 A
• Fuse Amps:5.0 A
• Head:8.2' (2.5 m)
• Wire Lead:3' (1 m)
• Outlet Dia:3/4"
• N.W. / G.W.:0.47/0.52 kg
• Wire gauge:18 AWG
• Connections:19mm (3/4") hose barb

 

 

Even so, if it runs for a minute say three times a day at half that 676 GPH, that still tells us the boat is taking on (and pumping out) 17 gallons of water a day. That's WAY too much to ignore.

 

 

[KellyLyon]

Hi all

 

the bilge pump has only ran twice (we are hot on checking any unusual noise and I am on the boat 24/7).  The bilge isn’t pumping out water now but we are still seeing it pool in the bilge but we are having heavy rain overnight and our engine is exposed (the draining system is quite poor)

 

regarding the PRV this is vented into the cabin bilge (this was confirmed at the time of fitting) the cabin bilge is totally sealed from the engine and all inspection points are dry within the living areas so it’s unlikely to be the prv as we would see water in the inspection point right next to the calorifier

 

we have dried and sorted the list so would agree that either there is a leak on the port side that was more under water although as mentioned previously the hull has been inspected a year ago and was visually fine when out of the water in May for blacking.  My thought was that it is consistently warm in the engine bay and cupboards where the calorifier is and wondered if that could be a factor.  We are out the water on the 8th so will let the surveyor take a look and report back

[Tracy D'arth]

16 minutes ago, KellyLyon said:

Hi all

 

t

 

regarding the PRV this is vented into the cabin bilge (this was confirmed at the time of fitting) the cabin bilge is totally sealed from the engine and all inspection points are dry within the living areas so it’s unlikely to be the prv as we would see water in the inspection point right next to the calorifier

 

 

That is so very wrong, needs to vent overboard or as least into the stern bilge where you can see it.