Drain Plug ??

[busted-bayliner]

So last night while having a few beers in the garage with a friend he asked me why i put the plug in the back of the boat instead of puttin the plug in from inside the boat in the bilage. I told him thats what i was taught to do. He states that he was taught to put the plug in the bilage inside the boat i told him he was crazy. i owned a boat before where u could barley get a hand in the bilage to put a plug in

so does any one else do what this friend of mine does? And if so why?

 

[oldjeep]

Re: Drain Plug ??

I've seen people do that with rowboats, but it would be a hell of a trick to get down there in most boats.

 

[BoatDrinksQ5]

Re: Drain Plug ??

I hadn't ever seen a plug go in the outside of a boat until MINE... i grew up with mainly 14-16' alumi cheapies.... plug ALWAYS was put in from the inside on them.

Same with my friends nice alumicraft jon/bass style. hard to get at plug sorta.

 

[shrew]

Re: Drain Plug ??

Boat displacement is going to place water pressure on the garboard plug. Placing it on the outside allows the waster pressure to push the plug in. Placing the plug on the inside, could allow enough water pressure to pop the plug 'out' into the bilge and flood the bilge. On small tinny's it is doubtful you can create alot of water pressure. The larger the boat, the more pressure. How much until the plug can't hodl on anymore.

My vote is to place from the Outside and let all the water pressure hold it in place.

 

[busted-bayliner]

Re: Drain Plug ??

Boat displacement is going to place water pressure on the garboard plug. Placing it on the outside allows the waster pressure to push the plug in. Placing the plug on the inside, could allow enough water pressure to pop the plug 'out' into the bilge and flood the bilge. On small tinny's it is doubtful you can create alot of water pressure. The larger the boat, the more pressure. How much until the plug can't hodl on anymore.

My vote is to place from the Outside and let all the water pressure hold it in place.

this was my reasoning with him last night

 

[JASinIL2006]

Re: Drain Plug ??

I'd need 7' arms with a couple of extra elbows to reach mine from inside!

Jim

 

[81 Checkmate]

Re: Drain Plug ??

Dito as above.........
Could never reach it from the inside!

 

[UncleWillie]

Re: Drain Plug ??

If you have the fancy rubber cork style, the inside could be an option.

A Brass Tapered Pipe Thread Plug is only going to fit from the outside.

 

[Home Cookin']

Re: Drain Plug ??

Bilge.

Like everything with boats, it depends. There is no meaning to the word "boat' and the OP doesn't say what he has. I have 6 boats with plugs and two are outside screw in garboards and four are inside push in rubber plugs. So how could I answer the "question"?

First there's the matter of what you can get to.

Then there's design. Most screw-in bronze garboard plugs go in from the outside and stay there.

Most push-in rubber plugs go in from the inside. Why? because they may fall off if they are outside. More important, with the rubber plugs, they are typically on boats that you pull the plug while you are runnnig to drain the boat. Until you do that, if there's water in the bilge, it puts pressure pushing out--why you don't want the plug on the outside. PLus they sink.

And by the way, there's no water pressure when you are on a plane and very little just sitting there. It's really not a factor in the decision how to rig the boat.

 

[scrit9mm]

Re: Drain Plug ??

Some boats are set up certian ways. Most boats larger than 14' will have a threaded hole on the outside at the bottom of the transom which takes a threaded brass plug. My 14' Duracraft has a hole in the bildge area on the bottom of the boat, I insert a rubber plug from the inside because the bottom of the boat has a plate over the hole that leaves a 1/2" gap between the bottom of the boat and the plate. The plate is open toward the back, I suppose so water can flow out of the bildge if I removed the plug while at speed. I have not nor will do that, dont trust the design that much.

 

[dmccaffrey]

Re: Drain Plug ??

Boat displacement is going to place water pressure on the garboard plug. Placing it on the outside allows the waster pressure to push the plug in. Placing the plug on the inside, could allow enough water pressure to pop the plug 'out' into the bilge and flood the bilge. On small tinny's it is doubtful you can create alot of water pressure. The larger the boat, the more pressure. How much until the plug can't hodl on anymore.

My vote is to place from the Outside and let all the water pressure hold it in place.

Fortunately, physics says this won't happen.

Even with a 4 ft hull draft, the pressure differential will only be 2 psi. That's not enough to move the plug no matter how it's installed. I haven't actually measured it but my guess based on year of tugging on the plugs is that it would take closer to 20-30 pounds of pressure to cause it to pop out. To get pressures that high, you'd be talking about drafts of 30+ feet or what you'd find on freighter not a pleasure boat.

Now, installing it from the outside will make it seal better since the lip of the plug will be pushed tighter into the transom. That could help prevent water from slowly weeping around the plug. But it will never get popped out by the water pressure.

 

[busted-bayliner]

Re: Drain Plug ??

Bilge.

Like everything with boats, it depends. There is no meaning to the word "boat' and the OP doesn't say what he has. I have 6 boats with plugs and two are outside screw in garboards and four are inside push in rubber plugs. So how could I answer the "question"?

First there's the matter of what you can get to.

Then there's design. Most screw-in bronze garboard plugs go in from the outside and stay there.

Most push-in rubber plugs go in from the inside. Why? because they may fall off if they are outside. More important, with the rubber plugs, they are typically on boats that you pull the plug while you are runnnig to drain the boat. Until you do that, if there's water in the bilge, it puts pressure pushing out--why you don't want the plug on the outside. PLus they sink.

And by the way, there's no water pressure when you are on a plane and very little just sitting there. It's really not a factor in the decision how to rig the boat.

well i learned something new. My boat is a title says 18 ft critchfield i measured and from the point of the bow to the stern it measures 17 1/2 ft 1974 V hull. i have no threaded drain tube it was just a brass drain tube. I can access the drain in the bilage easy to plug there just thought is was the way of life to plug from the back

i wont be plugging anything for awhile as the boat is dry docked (driveway) gettin the transom ripped out :facepalm:

 

[jestor68]

Re: Drain Plug ??

Boat displacement is going to place water pressure on the garboard plug. Placing it on the outside allows the waster pressure to push the plug in. Placing the plug on the inside, could allow enough water pressure to pop the plug 'out' into the bilge and flood the bilge. On small tinny's it is doubtful you can create alot of water pressure. The larger the boat, the more pressure. How much until the plug can't hodl on anymore.

My vote is to place from the Outside and let all the water pressure hold it in place.

Since water pressure increases with depth at a rate of 0.43-0.44psi per foot; I doubt seriously if the drain plug can be displaced in 3-4 feet of water(what the average boat displaces at rest).

The only issue is access.

 

[JEBar]

Re: Drain Plug ??

If you have the fancy rubber cork style, the inside could be an option.

A Brass Tapered Pipe Thread Plug is only going to fit from the outside.

this has been my understanding .... on smaller boats I've used a Snap-Tite Boat Bailer Plug inserted from inside the boat .... I used it when needed to drain the boat while underway .... on our last two boats we use a 1/2" NPT Male Square Head Brass Plug which had to be inserted from the outside of the boat

Jim

 

[ondarvr]

Re: Drain Plug ??

There is no right or wrong way for either type of plug, it all depends on the hull, if you can get to it from the inside, and exactly where it is located on the hull. Do it whatever way works for you and your boat, this is another non important preference choice.