Water in hull, why/where?!

[Spartanfalcon]

I have a 1979 SS170 Sea Nymph. It WAS powered by a 55hp Chrysler. I just repowered it with a 60hp Mercury ELPTO. When I would be out on the water, the ONLY time I'd get water of ANY amount was if the plug was loose or forgotten all together (only once, so far). Now on the first two times out with the new outboard attached i'm getting gallons of water coming out the plug hole AND the bilge.

So, where is it coming from? The old holes and the new holes for the outboard looks fine and nothing looks like it's even seeping when running and floating. Where else should I look? Yes, there is a livewell pump but that has never leaked and didnt appear to be.

What should I do next? What products should I use when I find the water's point of entry? Any and all help would be GREATLY appreciated!

 

[jbcurt00]

Re: Water in hull, why/where?!

You'll probably need to post some pix of your transom, bilge & bilge plug areas. Is the new Merc (still a 2cyl not a 4cyl, correct?) much heavier then the old 55hp Chrysler? And your positive that the thru bolts on the old motor are either filled & sealed around the new motors thru bolts? Or at least well sealed? 3M 5200 would be a significantly better choice then any other type of caulking or silicone.

Transom thru bolts would be my first thought. Esp the lower (if there's 4) which are below the splashwell aren't sealed. The different motor may have exposed previous damage from the other motor's mounting.....

Pix would help.

 

[Pmccraney]

Re: Water in hull, why/where?!

Agree with above, and also, look for metal cracks (even hairline) in your transom... I just removed my Johnson 85 of my Sean Nymph because of a weak transom. When cleaning it up, I noticed for the first time that it had a hairline crack right where the bottom starboard side bolt was -- due to stress. If you have a weak transom (possible on a boat of that age) or put some stress on the transome when doing the swap you might have a crack in that area that's hard to see...

Its also possible that you could just have developed a leak coincidentally somewhere else... which is tough to find and pinpoint without removing your structure and doing a leak test... Look on the bottom of the hull for loose or removed rivets and gaps in seams, etc...

 

[GT1000000]

Re: Water in hull, why/where?!

As a last resort, if you can't visually find where the water is getting in...you could put all the plugs in, and fill the hull partially with water...tilt the boat on the trailer, all the way forward, then all the way back, and look for water coming out...

Once you find the leak, drain, dry and seal as required...then retest...

Good luck

 

[Spartanfalcon]

Re: Water in hull, why/where?!

Thanks for the replies! I am worried too about the thru bolts, EXCEPT, that the work was done by a very good local marina. I will be double checking all of their work regardless. But, if the water came in that way wouldnt it also be able to leak out that way? They did use plenty of sealant! A few additional questions/concerns. Is it possible that the transducer could be bringing in that much water? I believe it was disconnected along the way. Also, I've heard negative things about a water test by filling it with water.

 

[jbcurt00]

Re: Water in hull, why/where?!

Thanks for the replies! I am worried too about the thru bolts, EXCEPT, that the work was done by a very good local marina. I will be double checking all of their work regardless. But, if the water came in that way wouldnt it also be able to leak out that way? They did use plenty of sealant! A few additional questions/concerns. Is it possible that the transducer could be bringing in that much water? I believe it was disconnected along the way. Also, I've heard negative things about a water test by filling it with water.

If the weight of the motor & the boat being IN the water, lower the transom thru holes below the water level, water could get into the boat. But until the boat has 6-10" of water in it (that'd be a lot, close to swamping the boat) there would be no way for the water to get back out thru those same holes. And when running, those holes would probably be above the water, it'd only be coming in while at idle or stopped.

Even reputable shops occasionally have something get by them, esp if multiple people are all working on the same portion of the project. If they removed the transducer wire, and it was routed in a thru transom hole, and the hole wasn't well sealed, yeah water could easily be coming in that hole. I'd never seen it before, but recently someone posted a pix of their transducer, it was a fairly large hole cut thru the bottom of the hull, and covered (from the inside) w/ an old style inner tube looking 'patch' covering the thru hole. That type of a transducer installation, if breached, could easily let LOTS of water into the hull. And it'd be taking on water as long as it was submerged, even while on plane, not just at idle or rest.

Tin boat right?

 

[jigandgrub]

Re: Water in hull, why/where?!

Thanks for the replies! I am worried too about the thru bolts, EXCEPT, that the work was done by a very good local marina. I will be double checking all of their work regardless. But, if the water came in that way wouldnt it also be able to leak out that way? They did use plenty of sealant! A few additional questions/concerns. Is it possible that the transducer could be bringing in that much water? I believe it was disconnected along the way. Also, I've heard negative things about a water test by filling it with water.

You might be amazed at the amount of water that can enter a boat in a very short time through just a 1/8" screw hole.

A lot of people have used the dry land water test by filling the bilge with water or partially with water and have never heard of anyone having any problems with it, I have heard a lot of people say that is how they found and fixed their leak though. What part of the on land water test has you worried?

 

[Spartanfalcon]

Re: Water in hull, why/where?!

After some more close inspection and finally getting to see the thrubolts both on the inside and outside, I'm confident the bolts are not leaking. I have, however, noticed that the seams of the splashwell area (the area where water collects after coming thru the thruholes) had very worn out sealant. I have since put two layers of 4200 on it and though it's no where near professional I'm hoping that will do the trick. Plus, a new toggle styled plug just to make sure and we'll find out if its back to water tight this week. If this doesnt fix it I will be doing the on-land water test. Thanks everyone!

 

[Georgesalmon]

Re: Water in hull, why/where?!

The only thing about filling the boat with water is the weight. Remember that if your boat weighs 2000 lbs, it will displace 2000lbs of water when floating. Putting water in the boat just to equal the waterline will be 2000lbs of water. Much more weight than your trailer was probably designed for. Just say'n

 

[Spartanfalcon]

Re: Water in hull, why/where?!

Just an update... A new plug and resealing the splashwell fixed the problem. Not a drop to be found! Also, thanks to a leaking boat cover and a HEAVY downpour I was able to test the hull without even trying! I had left the new plug in and the water held in the hull just fine! No leaks on hull anywhere. The isue was all a combonation of choppy seas, bad plug, and poor seal on splashwell.

Boat ON!