Topside Leaks: Finding And Fixing

[floydraser]

Aaagh!   I've spend two days removing old sealant, rubbing down, varnishing and resealing part of a cabin roof, only to find it peeing in water as if I'd done nothing! 

We had been over a couple of weeks ago and used a hose to (we thought) pinpoint the major leaks. I managed to stop one over the weekend but the other one is leading me a right dance.

So my question is: does anyone know any shortcuts/tricks/old boat builder's techniques for finding and fixing leaks?

Is there anything available like a liquid sealer? My imagination thinks about dilute pva; something to pour over a suspect area to soak through.

[ChrisB]

I have used this product with mixed results. It really is good on cracks but anything bigger not so good.

Did a terrific job on the old Claytonrite type window seals.

[RumPunch]

Good luck - been trying several years to find mine ! Even built plasterscene dams and used food colouring to dye different areas of test water - and what emerged was clear !

[kpnut]

2 minutes ago, RumPunch said:

Even built plasterscene dams and used food colouring to dye different areas of test water - and what emerged was clear

But what a brilliant idea though. 

[BrundallNavy]

We were plagued with leaks when we first got Papaver. The only way we found was to remove the cant rails completely and plane a small flat onto the back then a bead of sikaflex along the join and bytal rubber beads each side of the cant then screwed it back on and we have had no more leaks. I did a temporary repair with sellotape first which worked to a point. 

[Smoggy]

Finding the leak is always the hard bit, chalkdust is the trick and can be got in colours for the good old fashioned chalk line from a diy shop, it will usually leave a pattern of where it's come from quite nicely.

I usually use a crack testing developer spray that has the same effect of leaving a dusty surface but only because we use it at work.

[floydraser]

Thank you for all the replies so far, I now feel part of a community, like we're all in the same.... like we're in this together. 

Capt Tolleys looks good but as Smoggy says, finding the source of the leak is the hard bit, finding where to squirt the stuff.

The problem is the source and the leak are far apart. The frustrating leak is in a roof which is 3/4 ply which has been topped with another sheet of ply. the water is getting between the two. We'll get it though.

Using chalk dust reminds me of Tom and Jerry. 

[chrisdobson45]

I’ve recently had some success in sealing a persistent leak in a window seal with Captain Tolley’s but it can be a time consuming task. The front screen had a drip after heavy rain when the screen covers were off. Captain Tolley’s needs to be applied when the receiving substrate is dry, and then sparingly. I applied to the entire seal and waited 30 minutes and then applied again. At first it has a milky appearance and dries clear. I was able to see it migrating through to the bottom of the frame where the drip had been. I carried out two further applications, 24 hours apart. It was noticeable that there was less take of the stuff upon the third application and there appears to be no further drips, fingers crossed…

[grendel]

well when you see some paint bubbling, and peel it off to reveal a 2" hole filled with rot, dig the rot out and hit the filler on the back plank, then you know you have some work to do, the leak is behind the steering pulley blocks, and it literally pours in. catch buckets are positioned for these leaks with drains to the bilge. I will see how effective the buckets have been when I head back aboart this weekend.

[floydraser]

3 hours ago, grendel said:

well when you see some paint bubbling, and peel it off to reveal a 2" hole filled with rot, dig the rot out and hit the filler on the back plank, then you know you have some work to do, the leak is behind the steering pulley blocks, and it literally pours in. catch buckets are positioned for these leaks with drains to the bilge. I will see how effective the buckets have been when I head back aboart this weekend.

Ah rot and filler. They have become part of my life since I bought this boat. But thank goodness for modern materials.

[Bikertov]

And it is not just wooden boats that suffer - I had leaking side windows in my tupperware boat, that resulted in rotten internal wood panels that needed replacing along with the frames themselves being refurbished.

I also still need to find the leak from my windscreens.

[BrundallNavy]

Captain Tolleys is only any good for small leaks otherwise you will get a milky puddle on the inside. 

[chrisdobson45]

1 hour ago, BrundallNavy said:

Captain Tolleys is only any good for small leaks otherwise you will get a milky puddle on the inside. 

Indeed it is, that’s why multiple applications are required, over time to allow it to dry before the next campaign of application.

The first time I applied it I was waiting the 30 minutes for the second go and we had a short but heavy shower, resulting in milky drops on the top of the dash. 

The instructions state two applications 30 minutes apart and then repeat 24 hours later. It took me a few days of applications to solve the drip, but I’ve about half the bottle left and lots of time for more applications if needed, just needs to stop raining…

[floydraser]

Mine are not small leaks so I'll wait until I've found the source before I commit to remedial action. I'm liking the plastecine idea and I reckon I'll be visiting a toy shop or Poundland before my next trip to Brundall. 

[Bikertov]

The guy who refurbished my windows stuck down a clear/pink wide sellotape type material over the areas and joints he thought might be leaking, to see if it stopped. That way it would rule in or out an area where a leak might be coming from 

[BrundallNavy]

9 minutes ago, Bikertov said:

The guy who refurbished my windows stuck down a clear/pink wide sellotape type material over the areas and joints he thought might be leaking, to see if it stopped. That way it would rule in or out an area where a leak might be coming from 

This is what I did with 2” clear sellotape. It also gives the area a chance to dry. 

[floydraser]

And the winner is....

Well actually the results aren't truly in yet. Thanks for the heads up about Plasticene Rum Punch, brilliant idea. In the photo I have removed the vent and made a dam around the suspect area. Actually this is the second version having found what I believe to be the culprit, a hole in the filler which I applied! Look close and you can see three small bits of "plasticene", two plugging the screw holes for the vent and one on the suspect hole. This was to test my theory and it cured the main leak - I think! I won't be sure until I visit again after a wet spell of weather. 

The hole was like a blow hole in my filler which I hadn't noticed at the time of application, about 2mm accross. Of course it's a slightly curved roof so the rainwater dams against the cant rail and drains slowly off at the ends, unless I provide a convenient drain hole for it to find it's way inside the boat! After taking the pic I plugged the hole with Sikaflex EBT and refitted the vent and sealing the screw holes. The rail has been cleaned up and had one coat of dilute varnish but I'm not going to repaint the roof until I'm satisfied I've found most of the leaks.

"Plasticene" wasn't the real deal. I got a big pack of 20 strips from The Works for £2.50. I remember Plasticene being quite dry but this stuff feels oily and a bit clammy. Actually better for this application but makes your hands sticky. They probably had to change the chemical formula when someone pointed out that making it from lead paste with asbestos and colouring with arsenic, wasn't such a good idea... Never did me any harm...

But thanks again everyone.

[marshman]

Oh so you are only talking drips!!!!!

Back in the day thats why boatyards asked you to mop the decks every day -  to keep the wood wet!! As it shrunk so it leaked and why boats were frequently festooned with sleeping bags, and other assorted bedding.

Its hardly surprising seals around windows have been giving up the ghost - some sealant will be pretty old by now and when it goes hard, tends to leak - not a new problem and to be honest, not sure if you will get a 20 yr old grp boat without a few drips and runs.

Hope that cheers you all up!!!!!

[grendel]

the rot hole I found was treated with wet rot hardened before I left, and as far as I could see that had stoped the big leak, so the hole was filled with wood filler, and then a coat of paint applied, In addition the outside where the leak originated had been caulked, and now has 6 good coats of varnish to preent any more water ingress.

[floydraser]

2 hours ago, marshman said:

Oh so you are only talking drips!!!!!

I wish! 

The top of the cooker had puddles around the burners and when I went to get the wok from the cupboard, it was full of brown water. There's also plenty of water getting down to the bilge. 

Like Grendel, I am also replacing more rotten wood.

Forgot to add a tip: when testing for leaks, add a tiny amount of washing up liquid to the water to break the surface tension. 

[marshman]

As always - old boats leak nearly as much as old men!!