How to detect where boat is leaking

[WalleyeWarrior]

My brother-in-law bought a boat package that was a good deal, however the boat leaks enough for me to call it the SS Colander (still a good deal even with the leaking). We are looking to fix the leaks, but don't know where to start. He wants to pull up the floor, however it is riveted and would be a huge job. Any easier ways to determine which rivets are bad? Any advice/help would be greatly appreciated. Thanks in advance.

[Todd S.]

Fill it up with a garden hose and watch for leaks from the underside, circle the leaks with a sharpe. I would run enough water in the boat to fill the hull on a flat surface.

[SkunkedAgain]

+1

Don't be afraid to put a lot of water in there. As long as you aren't soaking any electrical components you'll be fine. Just to be sure though, I'd let everything dry out for a day or two in the sun before running my electronics if I had even the notion that stuff got wet. It's all worth it to find the leaks though

[Surface Tension]

Check all the thruhull fittings.

Then check all the hoses to livewells or plug the fittings next time on the water. Don't forget to remove the plugs after you pull the boat out of the water.

[Tom7227]

Filling it with water makes sense. But if you are on any incline at all be sure to chock the tires so it doesn't take off on you.

[B-man715]

I would be very cautious about filling the boat all the way with water on the trailer..... water is heavy!!!

For very rough numbers, lets say your boat is 8 feet wide and 16 feet long, and a perfect half pipe shape.

A 96" pipe by 8' long (16' long with a 4' half pipe radius), will hold 3,000 gallons of water. That equates to over 25,000 pounds!!!!!

If I were you I would block the trailer up in a few spots and not put the weight on the springs and tounge jack.

[delcecchi]

I would put like 6 inches of water in, after checking all the hoses to live wells and bilge pumps.

[Gus]

If you do fill, block up the trailer and or boat! Flattened the springs doing this myself before I figured out where the leak was. Seemed to come back ok after the water was dumped. Next road trip... sitting on the side of the road with a broken spring.

I never did find my leaker. I'm waiting until I pull the floor for remodel. Then I plan to put it in the water and see where it's coming in.

[Deitz Dittrich]

as surface tension stated, check hoses.. many times that is the culprit.

[PerchJerker]

I want to re-emphasize what Frank and Deitz said. Hoses and especially thru-hull fittings are likely culprits when it comes to letting a lot of water in the boat. Thru-hull fittings on older boats, where the silicon could have dried and cracked, are a great place to start looking. Good luck.

[SkunkedAgain]

I should clarify that I wasn't advocating filling up the entire boat with water, or anywhere close to that. As others stated, that's a lot of stress put on the trailer and wasted water.

Step 1: Check all fittings and gaskets

Step 2: Fill with some water to check rivets or seems along the very bottom of the boat

Step 3: Tilt the boat (fully secured to trailer & trailer wheels blocked) so that the water goes towards the back where most of the fittings reside.

You shouldn't need to put a ton of water in there

[Tom7227]

You shouldn't have to put more water in the boat than the amount of the boat that is under water when you have it in the lake. So 6-8 inches should be about enough shouldn't it?

[tazimna]

I dealt with same issue on my boat for a number of years, and could never find leak. Filled bottom of boat with water numerous times, and still no "output" from leak. Finally narrowed it down to livewell hose. Easy fix was to take a garden hose, smother with dish soap and just ran it inside the existing hose and this solved the problem. The culprit was the bouncing of boat on water/trailor, caused the hose to rub against one of the metal compartment cutouts(where hose runs thru). I've done this on 6 different friends boats in last several years. Good luck. Taz

[Capt. H (Ret.)]

"Leaks like a colander" but it's still a good deal???? HUUH???

[Surface Tension]

Before storing the boat for winter I blow the livewell line out.

Water trapped in a sag will freeze, it might not burst the hose the first few years but eventually it will.

[Pherris]

Looks like the common culprits have been covered. One thing I might do before trying the suggestions mentioned is call the seller and let them know you are happy with the boat (I am assuming the happy part) And ask them if they have any ideas? Just a thought.

Good Floating!

[WalleyeWarrior]

Thanks to everyone for all the tips. This week we plan on trying all or most of the above mentioned until we get to the bottom of the leaks. These forums are a great venue to ask questions as pretty much every problem out there has been experienced by somebody on here at one time or another.

Capt H: The boat was still a good deal as the 40HP Merc, trolling motor, gas cans, batteries, trailer, etc. that came with it were worth what he paid for the entire package even if the boat is a problem.

[Orlip]

I had this problem with my boat as well. I had to fill the boat with water mark the leaks and then drained the boat. Then I drilled out the old rivets and replaced with blind rivets however I used a spot of 3M 5200 around the hole before inserting the rivet. IMO that 5200 is hands down the best for below water sealants. This was 2 seasons ago and is dry every time I pull plug to date.

One other note is to make sure you get the aluminum rivet with aluminum mandrel. No rust.