Leaky boat

Posted By: Greg/Debra

Leaky boat - 04/11/15 08:44 AM

Since we came back from Bendigo, Atreus 1727 has been taking water, and it is getting worse. Today after about an hour's sail in fairly calm conditions there were about four litres in each hull. Before Bendigo, Atreus was mostly dry.

Atreus once had bungs in the transoms; at Speers Point Warwick commented that all of his boats have bungs. Somewhere along the way the bungs have been removed and the holes filled in with plugs which have been glued in.

I know that Atreus is leaking at the filled bung holes because this afternoon I saw water dripping from there.

I was wondering if anyone has suggestions as to the best way to go about this? Should I drill the plugs out, make new ones and glue them in? Any advice would be much appreciated.
Posted By: Matt_Stone

Re: Leaky boat - 04/11/15 09:47 PM

Drill out and fill with epoxy filler and finish with gelcoat or paint.

Have a backing plate behind the hole so the "bog" won't go everywhere in the hull. Counter sink or bevel an angle on the hole so the bog has some grip.

Posted By: Pirate

Re: Leaky boat - 04/12/15 12:06 AM

mmmmmmm confused

seems rather odd that both hulls suddenly start doing this at the same time.... something has caused the failure or its related to another issue not yet discovered

Have you checked the rudder case pintels where they attach through the transom ?

I know through lots of experience that the lower pintel is under a lot of sideways load compared to the upper pintel, I've actually had the mounting bolts sheer on a couple of occasions and as a result the holes that they passed through became oval in shape and allowed water in.... certainly pay to check that area

I solved my issue by going to larger bolts in the lower pintel but left the upper pintels as they were..... the uppers are 3/16 while the lowers are now 1/4, since that change I've had no further issues.

A simple way of testing is to.....

fit a push-bike tyre valve to a hatch cover (use a spare cover for this)

use a push-bike pump to add some air pressure to the hull, don't use an aircompressor and a car valve, you could induce a rush of air that could in theory split the seams on the boat.
To give you an idea, 3pound of pressure will be enough to rupture the hull
A push-bike pump wont supply a rush of air and you wont get the pressure needed to do damage

get the chief cook n bottle washer (or who ever is around) to run a tea-towel that's been soaked in soapy water over all the possible places you think a leak is coming from.

You'll soon see a mass of bubbles in the soap-foam where the air is escaping from, if needed use a pastry brush and a cup of soapy water to 'fine tune' the exact spot the air is coming from

I find it odd that both hulls fail and water is entering via a repair, I tend to think its the pintels and its an easy overlook, the riggors of racing and a few hard turns or reefing on the tiller will load up the lower pintels. to a point where they can become loose or in my case, actually sheer the bolt...

good luck with the hunt

Posted By: Tim_Mozzie

Re: Leaky boat - 04/12/15 05:00 AM

Pirate is right - find the leaks before you start doing anything else.

When the hulls are leaking that much, you will only need a bit of air pressure inside and you will hear the air rushing out through the leak(s).
For finding the smaller leaks, an alternative to a tea-towel is one of those little hand spray bottles with washing-up liquid and water in it.

I don't use a bike pump. I fitted a pop-top off a drink bottle onto a spare hatch cover. It only takes 3 -4 breaths to get enough pressure in the hull. Then you push the pop-top closed and go hunting for leaks.

Like I say, with such a big leak you wont have to look for long.
Posted By: Greg/Debra

Re: Leaky boat - 04/12/15 08:52 AM

Many thanks to Matt, Kingy and Tim.

I decided to take Kingy's advice and pump the hulls up with air. The bike pump idea didn't work so used an air compressor - very carefully. The centreboard cases on Boyer boats are very thin and flexible, so I was able to look down the slot while inflating and watch the sides of the cases bulge inwards as the air pressure increased.

The port hull would only hold pressure for about 20 seconds but the starboard hull would hold for about two minutes. So it would seem that the starboard hull only has a minor leak, which I find perplexing seeing as it had about four litres of water in it yesterday.

We did the soapy water test on the pintles, and found the port top pintle was leaking, but nothing on the other three. A leaky top pintle would explain why the hull wouldn't hold pressure for long, but it doesn't explain how four litres of water got in there yesterday in calm conditions.

We removed all four pintles and re-siliconed them, but I am not at all confident that we have fixed the leaks. It would appear that the leaks are one way; from out-to-in but not from in-to-out. Both of the bottom pintles' bolts were tight and the pintles weren't moving at all so I think it is unlikely that they were leaking.
Posted By: Anonymous

Re: Leaky boat - 04/12/15 09:53 AM

Hi Greg,

other likely leakage points from my experience are, hatch covers and hatch ring to hull, bridle tang points on hull, centreboard cases and trampoline tracks.
Posted By: Pirate

Re: Leaky boat - 04/12/15 10:55 AM

Originally Posted by Greg/Debra
.....The port hull would only hold pressure for about 20 seconds but the starboard hull would hold for about two minutes.....

As Gary suggested, hatch covers would be my next bet....
only takes a fine grain of sand or grit to break the 'seal' to a point where a decent volume of water can enter even tho you've tightened them up as per usual.
One old trick I learnt years ago was to coat the threads in car polish and then buff them off like one would a 1/4 panel, the polish free ups the threads to better than new and unlike silicon sprays etc it doesn't act like a glue and hold the grit in the thread

I'd still be inclined to do the soapy water trick again, only this time I'd do the areas Gary said to check...
hatch covers and hatch ring to hull, bridle tang points on hull, centreboard cases and trampoline tracks.

& seeing you've done a few miles of towing of late I would add to that list the actual beams, jiggling around on the trailer may have loosened them off a tad, enough to break the seal... well that's anyones guess, but armed with a bucket of soapy water you may aswell check it all over

Posted By: Anonymous

Re: Leaky boat - 04/12/15 10:01 PM

Keep doing the soap thing until it stops leaking. One thing to remember is that when you put air into the hull that flex you're seeing in things like the centre cases may actually be closing holes. This is one of the reasons (aside from damaging the hulls) why you don't want too much pressure.

If you do fix this "plugs" in the transom:

1. Remove existing plugs.
2. Fill holes with plasticine
3. though inspection ports apply glass to inside.
4. dig out plasticine and clean well with acetone or similar.
5. Fill hole with bog.
6. Fair and paint.
Posted By: Greg/Debra

Re: Leaky boat - 04/18/15 08:32 AM

Went back to Grafton today and had another go. This time I used water instead of air; about eight litres in each hull. I lifted the front of the boat and straight away water started dripping from the transoms onto the concrete floor of the shed.

The water is definitely leaking from the filled bung holes. Funny how we couldn't get any soap bubbles there last week. I will start the repairs next week.

Thanks to everyone for their advise.
Posted By: Greg/Debra

Re: Leaky boat - 04/25/15 08:10 AM

I drilled out the plugs today - they were timber dowels. I don't know what they had been glued in with... whatever it was had dried hard and white, but evidently didn't bond very well to timber.

I took Scarecrow's advice put some fibreglass with epoxy on the insides, then filled the holes with epoxy mixed with micro balloons.

Next week I will go back and sand off. I might also put a little bit of glass over the filled holes on the outside, for good measure.
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