Pesky Water Leak

[AguaSki]

I have an 18 foot Glastron with a 140 hp Johnson outboard. When the plug is pulled after 2-3 hours on the lake, a gallon or two of water drains. I know that wet people entering the boat can be the source of some water, but it seems reasonable that a well sealed fiberglass boat should have a limited amount of water draining when the plug is pulled. The boat has a thru-hull on the starboard side of the bow that is intended to drain water that enters the open bow. It seems that when in rough water, some water is entering from the outside of the thru-hull and coming into the boat via the drain hose attached to the thru-hull. On several occasions I have bailed several cups of water out of the storage space under the bow seat cushion. I can also see water starting to puddle at the foot drain. This water is noticeable without taking on water across the bow. Is it possible that some of this water at the bow is eventually working its way to the rear drain plug? Is there a way to plug the thru-hull or attach a valve that can be opened/closed as needed? With a valve or plug I could keep the thru-hull closed while underway, but open during storage or if a large amount of water entered the bow.<br /><br /><br />I would like to fix the bow leak, but if this is not the primary source of the water I see when I pull the drain plug, I am interested in additional suggestions.

 

[Solittle]

Re: Pesky Water Leak

A big welcome to you Kapoof (interesting name) -<br /><br />A couple of things - All (and that is a big ALL) well made boats will have a drain hole in the frame below the deck to allow water to drain from the bow down to the transom.<br /><br />Another big ALL is that all well made boats will have a marine bronze (no plastic or nylon) valve on each and every thru hull opening (pick-up or drain). They are easy to add just make sure that you use a bedding compound like 3M 4200 to seal the hull opening.

 

[fishingdan]

Re: Pesky Water Leak

It really doesn't take much spray or kids jumping in and out of the boat to have noticeable water in the bilge. I have often been surprised at the amount of water in my boat from spray after running across a rough bay. <br /><br />Another and more rare cause could be a stress crack in the hull. These can allow water to enter the boat when there is sufficient water pressure to open the crack slightly (ex: going from a stop to getting on plane). When the boat in on the trailer, take a good close look at the hull bottom. If these occur, they are often in the front third of the boat near the centerline.

 

[Osprey]

Re: Pesky Water Leak

Kapoof,<br /><br />If your thru-hull fitting is plastic it may have an internal crack which is allowing water into the hull. From outside the boat, use a flashlight and inspect inside the fitting. Look for an signs of cracking. It could also help to have someone in the boat flex the fitting back and forth while your looking inside the fitting for any crack to open up.<br /><br />If you have plastic thru-hulls and the boat is more than say three years old I would replace all with stainless steel or chrome over bronze. The plastic ones will become brittle and fail with age, its just a matter of when. Adding a second stainless hose clamp on both ends of the drain hose is also a good idea.<br /><br />To add a valve you would need to replace the current thru-hull that has a hose fitting end with one that is threaded to accept the valve.<br /><br />I have experience with Grady Whites, Boston Whalers and Parkers. All of these would be considered well made boats. Non of them have valves on deck drains and other thru-hulls that exit the hull at or above the waterline.<br /><br />I could see the argument for adding the valve. But if you took a lot of water over the bow, do you really want to be scrambling to get it open?

 

[cuzner]

Re: Pesky Water Leak

Check your hoses.thru hulls are supposed have a a loop in them(called an anti siphon riser)to prevent water from coming in. If it doesn't have this replace the hose with enough to add the riser, and keep the twist with a cable tie.<br /><br /><br /> Jim

 

[prockvoan]

Re: Pesky Water Leak

All ya'll are looking at one thing,thru hull drains,great but there is another way that water will get in.That is,the rub rail.Alot of times,the silicon that is placed under and at the bottom of a rub rail breaks down in time.Water splashing up,it will get in from under the rub rail,then thru the hull and cap(deck).I had seen it manny times and it is one of those things that are over looked most often.<br />Anti siphon loops are NOT used for floor drains and isolation valves are not need for thru hulls that are above the water line.