Another possibly dumb question

[metalwizard]

I have an older arrowglass (73 omc stringer) I have the motor out doing some repairs.
In the bilge area, back near the transom, very low there are two holes. one on the port one starboard they both seem to go through the stringers.

One has a "stopper" in it (with a really small hole trough it) the other has nothing. My guess is they let the stringer area drain if need be.

Question is, Is there supposed to be 2 plugs? and when should they be in or out?

Thanks a bunch

 

[superbenk]

Re: Another possibly dumb question

Pictures might help.

 

[metalwizard]

Re: Another possibly dumb question

Pictures might help.

Yeah it's dark and raining. I'll trt in the morning.

they are about 1" daim. and are at the very back of the boat. in the bilge under the motor. they do go through the stringers. good think is the wood seems pretty solid.

 

[superbenk]

Re: Another possibly dumb question

Sounds like drainage to me, but I don't understand why they'd be plugged. I've also noticed holes in my stringers further up, but they look more like holes where floatation foam was pumped under the deck. That far back (as you describe) I'd expect drainage, though.

 

[metalwizard]

Re: Another possibly dumb question

Thats what I figured. I just did not know if the plug was supposed to be in there. so I need to get another one. or if they are NOT supposed to be in there,

I figure they should be in there. I don't see that you would want water to be able to go Out of the bilge and into the area under the floor.

Maybe I need to get some of those one way valves? that would let water out of under the floor and into the bilge, but not the other way?

I do have a small hole in my hull up front (mentioned in another thread) I am working on the repair right now. it was about the size of my pinkey, but it was were water pressure would be high when the boat is moving. so maybe someone drilled them to drain that.

anyways check out the pictures. I am thinking one way valves might be the way to go. what do they call them things?

THese pictures are taken from the back of the tansom looking in through the tansom hole. I stuck my hand in one to give an idea of size. the other picture note it's a black rubber plug with a hole through the middle.

Thanks again for any input

 

[Beefer]

Re: Another possibly dumb question

I'm pretty sure I don't know what they're for, but do I understand correctly that they are not thru-hulls? Because of the grommet/plug with the hole in the middle, I was thinking they were for wiring (tach/volt/etc.), or if they go thru the hull, for a transducer/speedo/etc. They don't look like they're there for drainage IMO.

 

[metalwizard]

Re: Another possibly dumb question

I'm pretty sure I don't know what they're for, but do I understand correctly that they are not thru-hulls? Because of the grommet/plug with the hole in the middle, I was thinking they were for wiring (tach/volt/etc.), or if they go thru the hull, for a transducer/speedo/etc. They don't look like they're there for drainage IMO.

They don't SEEM to go out the hull anywhere. But I had never thought about Speedo. the hole in the rubber stopper looking one might be the right size for that. My speedo was not hooked to anything, so I bought a speedo Pitot and drilled a hole through the transom and hooked it up and sealed it..

I am thinking I should get two stoppers and plug them off for now. after I take it out next time, I'll drain anything out of the bilge area, then pull those plugs and see if water comes out.

 

[NYBo]

Re: Another possibly dumb question

Are you sure there aren't compartments that use these to drain?

 

[JimS123]

Re: Another possibly dumb question

Many boats of that vintage did not have under-floor flotation foam, so the cavities were empty. Naturally, condensation could form in these open spaces, or maybe even a leak from cracks in floor seams or if you punch a hole in the bottom by hitting something.

So, the cavities need a way to be drained. But, you don't want openings that will deliberately allow water to get in. The plugs should be kept in the holes at all times when the boat is in the water. When you get home, tip the boat up, pull the plugs and also pull the transom drain so that the bilge AND cavities will drain. When you put the boat up in the garage for winter, pull the plugs so that the cavities will vent all winter long.

My 1971 boat was built just like that and the procedures I just detailed are what the owner's manual said to do. After 39 years that boat's floor still hasn't shown any signs of rot.

 

[metalwizard]

Re: Another possibly dumb question

Are you sure there aren't compartments that use these to drain?

Ni I am not. I don't have a clue what they are for.. just my best guess?

Many boats of that vintage did not have under-floor flotation foam, so the cavities were empty. Naturally, condensation could form in these open spaces, or maybe even a leak from cracks in floor seams or if you punch a hole in the bottom by hitting something.

So, the cavities need a way to be drained. But, you don't want openings that will deliberately allow water to get in. The plugs should be kept in the holes at all times when the boat is in the water. When you get home, tip the boat up, pull the plugs and also pull the transom drain so that the bilge AND cavities will drain. When you put the boat up in the garage for winter, pull the plugs so that the cavities will vent all winter long.

My 1971 boat was built just like that and the procedures I just detailed are what the owner's manual said to do. After 39 years that boat's floor still hasn't shown any signs of rot.

Now that sounds reasonable. I am totally going to go with that.. Now I just need to find a plug that fits.. should be pretty easy.

 

[sasto]

Re: Another possibly dumb question

Sounds like a weep (or limber) hole for drainage. I am curious too.

 

[rodbolt]

Re: Another possibly dumb question

they are limber holes. they are there to insure the water outboard the stringers can drain DO NOT plug them.
most all boats with stringers and decks have them.
most times they are plugged with debris but they are there.

 

[metalwizard]

Re: Another possibly dumb question

Sounds like a weep (or limber) hole for drainage. I am curious too.

they are limber holes. they are there to insure the water outboard the stringers can drain DO NOT plug them.
most all boats with stringers and decks have them.
most times they are plugged with debris but they are there.

Ok, that sounds good, but Why does one have a plug? and what keeps water from going INTO the area outboard the stringers?

sorry just trying to make sense of it.

 

[sasto]

Re: Another possibly dumb question

I assume your speaking of a V hull....wizzard.....if you are...the answer would be gravity..water may lay outboard of the stringers with nowhere to go. Every boat we built had limber holes in every srtinger/bulkhead compartment......usually aft....to insure no water lays in the boat and eventually drains to the bilge compartments lowest point where the bilge pump is located.

On an inboard the area under the engine must (now days) contain any oil or other contaniments and therefore not allowing this compartment to drain into any area that has a bilge pump. Many builders have installed a limber hole with pipe to allow it be plugged. After cleaning this compartment of contaniments, then it can easily be washed down and cleaned further... and drained by removing the plug.

Thats the way we did it......don't know about others.

 

[metalwizard]

Re: Another possibly dumb question

I assume your speaking of a V hull....wizzard.....if you are...the answer would be gravity..water may lay outboard of the stringers with nowhere to go. Every boat we built had limber holes in every srtinger/bulkhead compartment......usually aft....to insure no water lays in the boat and eventually drains to the bilge compartments lowest point where the bilge pump is located.

On an inboard the area under the engine must (now days) contain any oil or other contaniments and therefore not allowing this compartment to drain into any area that has a bilge pump. Many builders have installed a limber hole with pipe to allow it be plugged. After cleaning this compartment of contaniments, then it can easily be washed down and cleaned further... and drained by removing the plug.

Thats the way we did it......don't know about others.

OK thats starting to make more sense. Although it is a trihull. but I think the principle is the same.

thanks for all the input. YOu learn something new every day.