Aluminum boat leaking

[iggyw1]

I have an aluminum boat that has a small leak in the rear end somewhere, but I cannot find the leak. I know it is somewhere behind the read bench seat, as I have a flat floor in the boat with some inspection plates I can unscrew and look down to see dry bottom of boat. No floor behind the back seat between this seat and stern, but when I am in the boat fishing, I need to use the bilge pump after about three hours on the water. I filled the boat with water in my driveway to see where water drips out under the boat while on the trailer, and no water comes out. I can leave the boat in the water overnight and no water enters, but when I get in the boat and sit on the rear seat, water comes in at a very slow rate. (When my weight is added). How can I find the leak?? TY

 

[racerone]

Must be a leak near the waterline.-----Any pictures of transom.-----Livewell leaking ?

 

[Scott Danforth]

On an aluminum boat, the leak could be at the front of the keel strip and enter the boat at the stern

If you have livewells, the plumbing could be leaking, especially if the plastic fittings are 15 years old or older

 

[83bluefin]

I’d leave the boat strapped to the trailer and dunk the boat at the nearest launch. Let the weight of the trailer pull the transom down. Then check to see where it is coming in.

If it’s not found, is it possible the splashwell or drains are letting water in? Or possibly a loose rivet hidden by trailer rollers/guides…

 

[airshot]

Not going to be easy, so get ready to get down inside with a flashlight when you are in the water. Going to take some time and hard looking, but you will find it with enough patience. Make sure the boat inside is good and dry before you start. Finding leaks from the outside are more of a challenge as the capillary action of the water can make a leak appear where there is no leak. Filling your boat with water on a trailer is dangerous ! Removing the floor and getting on your hands and knees will be better. Get some pics for us to help give you more ideas where to look.

 

[Scott Danforth]

Never fill the boat with water. That's an easy way to collapse the trailer and dent the boat by adding many thousands of pounds of water

 

[Mc Tool]

Never fill the boat with water. That's an easy way to collapse the trailer and dent the boat by adding many thousands of pounds of water

Yep , deadly for glass over ply boats that fill up with rain water too.

 

[redneck joe]

Is it welded or riveted?

 

[Ifishmuskie2]

I find the transducer screws leak. It seems people don’t put sealant on them. Sometimes it’s the drain plug. It seems like every old aluminum boat has a few loose rivets.
I take on a gal or two in a day and I don’t worry about it as I get water in my boats when I’m fishing and it rains.