two small holes in bilge...

rusty swivel

New Member
I'm wondering if anyone can identify what these are. I recently purchased an older but decent condition Sangstercraft 15.5'. One day as I went out to it to clear out water from recent rains, I notice its bilge wouldn't stop continuing to fill back up after pumping it out completely. (the bilge appears to be a small 25x30x10cm recess) It would take me quite a bit of time to pump, wait for it to slowly fill up again, pump, etc. When it finally stopped filling back up, I'd peer my head inside to see 2 small, maybe 1cm holes, on the side of the recess, one being maybe 2-3cm above the hull surface, and another maybe 2-3cm below the floor height. It seems rainwater flowed back into the sump and went into the void between the floor and hull. If these are OEM hull drainage holes, it just doesn't make sense that the bottom hole isn't larger and flush against the hull so ALL the water would flow into the bilge. Instead these holes seem to trap water.

Anyone familiar with what these may be and if they're not supposed to be there?

Thanks

video of it:
 
Looks like those holes are meant to drain any water that gets between stringers and forward bilge.Because they are 1" or so off the bottom of hull the water builds up forward of the holes.Tilt your motors and lift the front of the boat as high as possible to drain as much water as possible.Sangster boats are at least 40 years old now,water could be in stringers also.Hope not.
 
Looks like those holes are meant to drain any water that gets between stringers and forward bilge.Because they are 1" or so off the bottom of hull the water builds up forward of the holes.Tilt your motors and lift the front of the boat as high as possible to drain as much water as possible.Sangster boats are at least 40 years old now,water could be in stringers also.Hope not.
Thanks, rot is what I'm worried about. Seems though, the water is clear and doesn't smell, and the floor feels solid at least. Could enlarging them and extending them to the hulls inner surface as well as adding them to all sides of the sump be a solution to really drying the floor out? I still don't understand why the boat was designed this way.
 
get the boat tilted as much as you can when sitting on the trailer. or atleast enough angle so those do not back fill. pull the plug. they are there for draining all the forward holds. my dad had the same hull. we used to put buckets of water in the stern when it was at the dock to keep the battery from dying. exact problem you are explaining. do you have a manual switch for the pump? get the nose up and run the pump. bring it back down and the pump should stop doing the constant on and off. PITA
 
get the boat tilted as much as you can when sitting on the trailer. or atleast enough angle so those do not back fill. pull the plug. they are there for draining all the forward holds. my dad had the same hull. we used to put buckets of water in the stern when it was at the dock to keep the battery from dying. exact problem you are explaining. do you have a manual switch for the pump? get the nose up and run the pump. bring it back down and the pump should stop doing the constant on and off. PITA
Ok, I'll get this done and keep it covered from now on. Do you recall if the forward storage compartment is open to the stringers? I might run a small fan in there while I have the boat tilted up. The pump is on a manual switch, that float switch is a dud. Fun times, jumping right into it after my first used boat purchase, yay!
 
Looks like those holes are meant to drain any water that gets between stringers and forward bilge.Because they are 1" or so off the bottom of hull the water builds up forward of the holes.Tilt your motors and lift the front of the boat as high as possible to drain as much water as possible.Sangster boats are at least 40 years old now,water could be in stringers also.Hope not.
The design of stringers are they sealed from the transom or do they go into the transom? I have composite stringers and am curious if water got into one of them as there are holes in the forward bilge. The idiot that owned the boat before me screwed the bilge directly into the stringer! I pulled it immediately and filled the holes.
 
another thing you can do is dry it out and for right now get rubber plugs. plug them up. now get an 1/8 npt tap drill the hole and put in a compression fitting. go to a refrigeration supply store buy some 1/4 hose that fits the fitting and a vacuum pump. Get 3 or 4 halogen lights and point them up at the hull. Run the hose to a pot (air oil and water seperater so water doesnt make it to the pump). Run the vacuum pump it will literally suck all the water out of the cavity and through a peroid of days draw out any moisture from the stringer. then when youre done plug the hoses. Then you can do it each season a dry cycle. Its really not a lot of work. Change the vacuum pump oil when it gets contaminated.
 
another thing you can do is dry it out and for right now get rubber plugs. plug them up. now get an 1/8 npt tap drill the hole and put in a compression fitting. go to a refrigeration supply store buy some 1/4 hose that fits the fitting and a vacuum pump. Get 3 or 4 halogen lights and point them up at the hull. Run the hose to a pot (air oil and water seperater so water doesnt make it to the pump). Run the vacuum pump it will literally suck all the water out of the cavity and through a peroid of days draw out any moisture from the stringer. then when youre done plug the hoses. Then you can do it each season a dry cycle. Its really not a lot of work. Change the vacuum pump oil when it gets contaminated.
The hole for the compression fitting- should I drill it on the sidewall of the recess as close to the bottom as possible? excellent idea with the halogen lights as well. Definitely will be buying the rubber plugs. Thanks
 

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I drilled mine halfway between the bottom of the transom and the lower motor mount. I had to pull the drain tube out and dry it out. the drain is meant to be fiberglassed in but mine wasnt. the drain tube is compression fit normally with a bolt and die (flared shut). Since I dont have fiberglassing there I got a machineshop to compression fit a 1" brass tube in the garboard on the outside of the hull. 4200 sealed everything in place. even though its green board xl plywood I wanted to properly reseal it. I would drill it 1/2 way possibly lower but dont want it submerged for too long so long as you keep the bilge dry. then when you insert the fitting use 3m 4200.
 
Some older boats have compartmentalized bilge compartments which makes the hull extremely strong and especially along the keel line have factory installed drains that are there for a reason. You may want to do a little more research on your particular boat. On our boat there are drain holes between compartments from the forward area into the keel line main gas tank compartment and then into what use to be the motor compartment before the boat was poded. This insures that water that gets into those compartments moves aft and is then pumped out of the boat by your bilge pumps and to some small degree allows air to circulate. Even if you manage to get all those compartments and your wood stringers (assuming they are wood) bone dry, how long are they going to stay that way, especially if your boat spends its life in a marina and outside land storage in the rain. If water gets into those compartments by various means including condensation after you have plugged the drains, things may get worse not better. Rather than plugging those drains, you may way want to make sure they are all clean and draining well. If you do plug them, you may want to pull the plugs from time to time and make sure it is staying dry. On ours, we cleaned out the forward compartment drains when we changed out the fuel tank. I am wondering why your drains are draining so slowly. I sometimes turn on my main pump which drains to a lower lever than the auto rain water pump, and take the boat up on plane a little slower than normal, with the motor trimmed, so that the bow is up while the pumps are running. Our boat is coming up on 40 years old and is very solid. We are, however, fortunate that the manufacturer was an early adopter of glass stringers.
 
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Yes you want to leave plugs in just to get an idea if water is getting in. Im going to do the vacuum pump on my transom and front bilge stringer this year. Leave hoses and compression fittings in plugged. then you can check it once a year no biggie.
 
Some older boats have compartmentalized bilge compartments which makes the hull extremely strong and especially along the keel line have factory installed drains that are there for a reason. You may want to do a little more research on your particular boat. On our boat there are drain holes between compartments from the forward area into the keel line main gas tank compartment and then into what use to be the motor compartment before the boat was poded. This insures that water that gets into those compartments moves aft and is then pumped out of the boat by your bilge pumps and to some small degree allows air to circulate. Even if you manage to get all those compartments and your wood stringers (assuming they are wood) bone dry, how long are they going to stay that way, especially if your boat spends its life in a marina and outside land storage in the rain. If water gets into those compartments by various means including condensation after you have plugged the drains, things may get worse not better. Rather than plugging those drains, you may way want to make sure they are all clean and draining well. If you do plug them, you may want to pull the plugs from time to time and make sure it is staying dry. On ours, we cleaned out the forward compartment drains when we changed out the fuel tank. I am wondering why your drains are draining so slowly. I sometimes turn on my main pump which drains to a lower lever than the auto rain water pump, and take the boat up on plane a little slower than normal, with the motor trimmed, so that the bow is up while the pumps are running. Our boat is coming up on 40 years old and is very solid. We are, however, fortunate that the manufacturer was an early adopter of all glass stringers.

They're draining slowly simply because the holes are tiny. Also, the bottom drain hole looks to be an inch above the hull on the side of the floor sump, so how the water below it would drain I have no idea. As far as finding information on this Sangstercraft 1560, I'm having a hard time but there are a few of them out there I've noticed on marketplace. So there is info out there, I'm assuming. Its just not on the internet, lol.
 
The higher one is the vent so the lower one can drain, Get a small coat hanger to poke though holes in case there stuff blocking hole. if the deck is not sealed underneath it can rot fall of and block the holes.
 
Some water penetration will always happen. you have 3 years. you have to reseal your outboard trim tabs transducers. its a lot of work. boats are a lot of work. Vacuum pump is 300$ at most. protecting a 40k investment? pennies. reseal that **** 3 years.
 
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