Find that deck leak!

[alex23299]

In desperation, I'm now thinking of sealing the cabin and letting go a smoke flare (I will pop outside and watch...) - any better ideas to find the persistent leak from somewhere on the side deck and/or coach house roof? I've had the headlining down, and all...?
Thanks

 

[KellysEye]

We had a two charter boats that had a leak and the water wasn't appearing where the leak was it was running along the headlining. Both leaks were stanchions not bedded properly. However as you have had the headlining down and I assume you didn't find any damp patches it indicates it isn't the stanchions. It could be a leaking hatch or window or deck, I think the best solution is to wait for a dry day then take a hose and water small sections of the deck, coach roof, and one at a time hatches and windows, then go below and wait for 5 minutes each time to see where the water is coming in, you may need to trace it back to where the leak is. As the deck is normally higher at the bows start there. Definitely don't use a smoke flare inside the boat.

 

[Spirit of Glenans]

In desperation, I'm now thinking of sealing the cabin and letting go a smoke flare (I will pop outside and watch...) - any better ideas to find the persistent leak from somewhere on the side deck and/or coach house roof? I've had the headlining down, and all...?
Thanks

Get a bottle of red food dye and make up a weak mixture. In the area where the leak is evident you should test your mixture on an unobtrusive piece of whatever interior finish is being affected. Use Plasticene to create a coffer-dam around each deck fitting in turn. Pour in some of the coloured water and wait for it to show up inside. By this method you can quickly isolate the leaky fitting and confirm which ones are sound. After you have gone through all the fittings and have still found no leaks, the windows and hatches can be tested with a hose, making sure that you start at the lowest point first. It can be surprising how far from their original source some leaks will emerge.

 

[ksutton]

In desperation, I'm now thinking of sealing the cabin and letting go a smoke flare (I will pop outside and watch...) - any better ideas to find the persistent leak from somewhere on the side deck and/or coach house roof? I've had the headlining down, and all...?
Thanks

Usually leaks will revolve from common build or design problems and would have most likely been experienced by someone before. Although its still a long shot why not change your post subject to (Boat and model manufacture), someone who has that model of boat are sure to open your post. Then ask about leaks, approx location etc etc, has anyone experienced similar and successfully sorted it, could just work out for you.

 

[Highndry]

Seal the cabin/companionway (gorilla tape, plastic sheeting, etc) save for an inlet for either a leaf blower or an industrial vac on blow. Cover the top sides with soapy water and turn on the blower. Watch for bubbling where the air escapes. That's your leak.

 

[David2452]

Leaks on cars are often diagnosed using a smoke generator and I believe they can be hired.

 

[Angele]

Get a bottle of red food dye and make up a weak mixture. In the area where the leak is evident you should test your mixture on an unobtrusive piece of whatever interior finish is being affected. Use Plasticene to create a coffer-dam around each deck fitting in turn. Pour in some of the coloured water and wait for it to show up inside. By this method you can quickly isolate the leaky fitting and confirm which ones are sound.

I like this one. :encouragement:

If you have some young crew (under 10s probably) they would love to help with the clay modelling and, if you bought variously coloured food dyes, you could have a little game guessing what colour it was that would show up in the cabin.

... something for the next edition of "Kids in the Cockpit" perhaps?

 

[PabloPicasso]

Be careful food dyes can be very difficult to get off and may stain. Use water based ink instead

 

[Talulah]

In desperation, I'm now thinking of sealing the cabin and letting go a smoke flare (I will pop outside and watch...) - any better ideas to find the persistent leak from somewhere on the side deck and/or coach house roof? I've had the headlining down, and all...?
Thanks

What make/model/year?
May be a common fault.

 

[tawhiri]

It took me two years to find a leak from the anchor locker. The water only came insde when the water was directed horizotally. I used talcum powder to narrow the leak down.

 

[simonfraser]

Check all the through bolted / screwed items, that's where mine have been.

Rubbing strake fitting ?

Some one outside with a decent hose pipe ? pressure washer should help.

 

[PhillM]

I am in the process of tracing a couple of leaks. Next step is to put a line of masking tape in the areas affected and then hose down. Then look on the tape for damp spots.

Have been waiting to use this on a few leaks but so far actually inspecting affected areas has led to an obvious fault. Its only now that all the obvious ones are sorted will this come into its own.

 

[alex23299]

What make/model/year?
May be a common fault.

Yes - she's an Ohlson 38 from the mid-Seventies. "Very wet boat" said Clare Francis, who made them famous with Robertson's Golly.

 

[pcatterall]

How soon do you get drips following rain. if quite soon then I second the idea of running water over discrete sections where ingress seems possible. Eventually you should find it.

 

[Neil_Y]

Can't help with any new ideas on how to find one but my long term leak on last boat was where cabling ran through bulkhead from outside locker to the inside, with cabling from anchor winch and deck lights, even though the wires were at the top of the locker rain would seep through the hatch surround onto cables that had a slight downhill run to the place where they entered the boat, it looked well sealed with silicon but it had separated from the grp. Inside the water started near a stanchion to confuse me.

 

[Lakesailor]

What make/model/year?
May be a common fault.

Exactly. Asking an open question like that generates loads of answers which may not be relevant. Same as outboard motor questions.
Details, details.

Edit: Sorry, See the added detail now that I am fully awake.

 

[Blueboatman]

Weren't Ohlsons a Tyler moulding then diy fitted out, which may make em individually different?

IIRC Francis' s boat leaked on every single ally toerail bolt

 

[Spirit of Glenans]

Can't help with any new ideas on how to find one but my long term leak on last boat was where cabling ran through bulkhead from outside locker to the inside, with cabling from anchor winch and deck lights, even though the wires were at the top of the locker rain would seep through the hatch surround onto cables that had a slight downhill run to the place where they entered the boat, it looked well sealed with silicon but it had separated from the grp. Inside the water started near a stanchion to confuse me.

Wires should dip and then rise before entering a bulkhead to shed warer off the bottom of the dip.

 

[Avocet]

Can be a real nightmare. Is it double-skinned on top of the coach roof? If so, the hole could be some distance from where the water is emerging. I'd agree with the talcum powder suggestion on the inside of the affected surfaces and look for the trails.

 

[thalassa]

Be careful food dyes can be very difficult to get off and may stain. Use water based ink instead

You can get U.V. dye. Some colours can be diluted to nearly colourless in visible light, but still light up with a cheap UV LED lamp.
http://www.ebay.co.uk/itm/Leak-Detection-UV-Dye-Water-Ingress-Window-Seal-Leaks-1-X-25ml-Bottle-RLD3-/260889559757?pt=UK_Diagnostic_Tools_Equipment&hash=item3cbe3ac2cd