Taking on water

[Mustang1600]

Good morning gents,

Yesterday I finally took my boat out onto the river, after fixing a lot of things. After 2 hours of motoring around we headed back to the ramp. Once she was out I pulled the bungs out and what came out was a bit of shock.

I would estimate that about 3lts of river water drained out of her, not exactly what I was hoping for on her maiden voyage.

My question to you, how do I go about finding the holes, cracks in the hull?, iv gone over the hull and tried to find any holes with no luck.

Boat is 1980s fiberglass half cab.

Cheers
Mustang

[ShaneC]

3 litres is nothing mate, I wouldn't worry too much about it. Is it possible that the water may have come from the recent rain at all??? Generally these small leaks are through the bungs....

[Rodman]

mate I am not sure if this the go for yyou but I have found that if you fill your boat with water whilst it is still on your trailer and them get underneath and see if you can see where any water is leaking out.


Ken

[netmaker]

gday mate. i would suggest using a bucket under your bungs next few trips and measuring the actual amount of water. it probably looks worse than it is. on your estimate of 3 litres over 2 hours thats 1 and half litres per hour (whilst motoring). it may be worse while under way also. either way, a 10 hour outing would see 15 litres in the hull - no biggy. thats less extra weight than taking the family pooch along. if you dont have an automatic bilge pump fitted it would be a wise investment tho.

cheers
davo

[Fed]

Any water at all is too much get down under the back with a good torch next time you go out.

[Mustang1600]

Thanks for the replys guys, I like the idea of filling the boat up with water, but is it safe to do with a fiberglass boat?, won't it rot the wood?

Davo, I'm having the floor rebuilt over the next few weeks, so a pump sounds like a good idea.. For a 16ft boat what size pump would be adequate ?

Mustang

[Out-Station]

Mustang, just tip i've used in the past. If you put a bit of water in your boat to test your various bung's, skin fits etc, put a bit of regular old washing up detergent in it as well. Acts as a surfactant and gets the water running out through the leaks much quicker and bettera.

Scott

[BM]

Mustang,

The problem with filling up the boat with water is that you may not get it to leak. Whilst it will let water in when sitting in the water, often they won't leak when the hull is filled with water. And not really the best of ideas to fill the subfloor area with water.

By all means give it a go but just be aware it may not work.

I would pop it in the water and have a close look around the boat paying particular attention to the bungs and the engine bolts and any other through hull penetration.

As mentioned minor leaks are often poorly sealed bungs, or laking bung seals. So don't stress. Whilst it's an issue that needs fixing it's not a real drama.

cheers

Edit: after posting I saw Out Stations post and agree completely. The detergent helps break the surface tension and enable the water to come out of leak areas more easily. You could also add some food colouring or die to make identification a bit easier.

[Fed]

Support your trailer if you want to try filling it up.
I once filled a boat and when the water got up near the chines the weight in the back exceeded the weight in the front and the front started to lift.....
The water moved from front to back and WOOSH the back crashed to the ground at a great rate of knots.
This was on a tandem trailer a single axle would be even worse, maybe starting off with the front up might be a safer option but I would stick torch next time you go out.
You will probably find it leaks more at rest than it does while you're moving forward too.
It's well worth tracking down & fixing because 99% of leaks are transom related & you don't want to be replacing that from rot anytime soon.

[marto78]

Don't stress too much if you can't find it mate. It took me 2 years to find the leak in mine and I only found it when someone else was driving and I was sitting down the back and noticed water dribbling out of a weld in the top of the bait tank.

[tunaticer]

First thing I would do is go to Bunnings and buy some nice thick rubber O-rings that will replace the standard seals on your bungs. Bung seals fail pretty quickly from my experience and will let in ample water without you noticing. Put some water in the hull with a quick spurt of dishwashing liquid and some of that blue stuff the women used to put in the laundry washes (don't worry, it will not stain anything). Presuming your gelcoat underneath is white, that blue colour will stand out like dogs balls as soon as it finds an escape route. Pretty hard to see clear water on white gelcoat.

[Jarrah Jack]

Just to reiterate what a few have said. Do the easiest first. That is the bungs and through hull fittings like the engine bolts. Sikaflex all the fittings. I'd even just do the bungs first, before the fittings, put it in the water after each step and see if its fixed. If you do the lot at once and the leak stops you'll never know the source of the leak. Putting vasoline or grease on the bung helps the seal.

Also have a good look around the outside of the hull below the water line for hairline cracks.

[Roughasguts]

Don't stress too much if you can't find it mate. It took me 2 years to find the leak in mine and I only found it when someone else was driving and I was sitting down the back and noticed water dribbling out of a weld in the top of the bait tank.

He He it took me 8 years to find mine did the whole fill with water stuff never leaked from the inside out, found hairline cracks under the chines, wasn't that found a rub under a centre roller wasn't that, wasn't the bungs they where re sealed and I used plumbers tape on the threads. But it was 4 of the transom bait tank pump mounting screws which penetrated the floatation tank up high.

Cheers.

[Mustang1600]

Thanks for the replys,

Well, i filled her up using some dye and could not find a leek point anywhere. i went out and got new bungs and sealed them in tightly and found squat... atm its draining and hopefully it wont fill up again. But ill get a pump anyways..

Ill take it out again tomorrow and see how i go, thats if i can get the bloody outboard to start again.

Mustang..

[Blusta]

I have 3 bungs in my fibreglass boat. Two are sealed finger tight but one needs pliers or shifter(not too tight, just tighter than I can manage with my soft fingers) to tighten to stop water getting in. Either the face or the o-rings are just slightly out of parallel.

[Angla]

Do you have any pickups for live bait well or a deck wash? Check the connections are all tight as the pressure of being under way may cause a pressure leak that cannot be seen when stationary. Bung washers would be my next thought.

Hope you find the problem quickly

Cheers
Chris

[Mustang1600]

Thanks again for the replys, got no bait tanks or anything like that. I took it out yesterday Arvo and this time I took on more water, but now I'm sure that it's the bungs. Water was coming throughout one of the deck bung holes.

Now I only tighten them up with hand so is there a better way of doing it?, should I wrap the tread with tape?

Mustang

[Fed]

I thought I had a bung washer problem & mucked around with replacement washers for a while then finally removed the whole fitting & re-sealed it properly to the transom.
The washers were the hard red plastic ones & I was positive the washers were leaking but they weren't, now I only finger tighten mine.
Makes me think that a lot of 'leaking bung washers' are really just complete fittings that need re-sealing.
Don't be surprised if you have more than one leak I had three and it was like herding cats to find them.

[dreemon]

If you had a bilge pump I thought it might be coming in through the outlet hose or it could be getting water in from the engine well where the cables come out, this will happen to my glass boat when in rougher waters, smooth water nothing comes out out of the bungs, do you have a heavy engine that makes your boat sit low in the rear?

I did the "fill the hull" thing on mine last year ( not full) and found 4-5 leaks, pulled the floor up and re-glassed the hull under the floor up to the water line, repaired the cracks on the bottom and flow coated it. very solid now and rides better but heavier now and less top speed by about 1 -2 kph, Cheers

[Drifty75]

Wouldn't even worry about that much water. I recently plugged a hole in my tinny but before that, would have approx 20 to 30 litres in it after a day's fishing. Still, that's nothing to worry about IMO... A 30s burst with the pump and she's gone.

When it starts lapping your ankles, then be concerned!! Of course I don't go off-shore fishing so if the worst was to happen, it's almost get-out and walk home. lol

:)