Rusted-out Drain Plug!!!

[Brentathon]

I just hauled my boat out (salt water) for the season, went to remove drain plug....and it practically fell out with almost no pulling
The brass plate on the inboard side corroded, and the threads were corroded/stripped. I've had the inboard plate of stainless steel drain plugs corrode, too...so that's why I tried brass.
As you may guess, I always have salt water in bilge, as I have been dealing with a leaking Upper Swivel Shaft Seal........but this drain plug issue is scary
I hope/plan to fix the seal leak this fall/spring, but are there better drain plugs out there? Perhaps with an inner plate that's thicker? More material? Better threads? etc. etc.

 

[Lyle29464]

Re: Rusted-out Drain Plug!!!

Check to see if you have some wires that are under water near it. Maybe the pump wires are bad or the pump.

 

[sasto]

Re: Rusted-out Drain Plug!!!

Make sure the brass drain fitting (not the plug) is wired into the bonding system. I would think not.....Good Luck

 

[109jb]

Re: Rusted-out Drain Plug!!!

Plastic??

http://www.pleasureboatmarine.com/sdg5200501.html

 

[Chris1956]

Re: Rusted-out Drain Plug!!!

Brent, If that is a standard brass plug, it should not happen. Not even close. I have run the same garboard plug for decades w/o an issue.

I would look for a significant current leakage into the saltwater in the bilge. Your running gear should also be subjected to that corrosion as well, so check out prop, outdrive etc. Make sure the zinc anodes are intact as well.

 

[Brentathon]

Re: Rusted-out Drain Plug!!!

It's not a garboard type, it's the T-handle screw-type with the rubber section, that expands radially when you tighten it.
My boat simply has a metal-lined (bronze or brass?) thru-hole, where this T-handle type plug goes.
-I have shore power with a galvanic isolator
-I don't notice any abnormal corrosion on anything else
-The metal in the transom thru-hole is not bonded to anything, nor is the T-handle drain plug, since the rubber is the only think that touches the metal inside diameter of the thru-hole.

 

[Home Cookin']

Re: Rusted-out Drain Plug!!!

I'm confused about a rubber plug corroding and its threads corroding as well. Perhaps it rotted, but it shouldn't have.
Any chemicals in there?
All boats have salt water on the outside and almost all retain a little water against the drain plug, which is probably right salty, but I'm not tasting it.
So the issue is not the exposure to water. It's either cheap parts or a power issue as suggested.

 

[Beefer]

Re: Rusted-out Drain Plug!!!

I would ditch the rubber plug type, and go to the tried & true screw in brass plug. Those expanding rubber kinds are cheap, and IMO, cheaply made. They're good for livewells, coolers, etc., but I wouldn't use them as insurance against my boat sinking.

 

[rwidman]

Re: Rusted-out Drain Plug!!!

Brass plug, brass fitting, salt water - bound to happen. It's called "dezincification" and it's the leaching out of metal in the brass alloy.

You need bronze, not brass for thes plugs and garboard drains.

Buy them at your favorite marine center, not Walmart, and specify bronze.

This article is written about plumbing fittings but it applies to any underwater metal on a boat as well:

http://www.westmarine.com/webapp/wc...51&catalogId=10001&page=Bronze-Brass-Fittings

 

[Beefer]

Re: Rusted-out Drain Plug!!!

Opps... I meant bronze. :redface:

 

[Brentathon]

Re: Rusted-out Drain Plug!!!

I know I'm not the only one with a non-garboard type drain plug.......so, the design doesn't signify an inherent issue.
I don?t believe they make bronze T-handle type drain plugs; if they do, I would definitely buy one.
I think Beefer hit on a one of the issues???cheaply made?; the inside washer that compresses the rubber is fairly thin AND threaded?.setting itself up for an issue with the very few threads that are there.
I?m not sure if I could easily install a garboard type, as my thru-hole is quite close to the keel, and the garboards have a rather large mounting flange.
A ?stray current? issue I guess is possible, but the metal (brass) of the drain plug is not touching any other metal component; unless it acts as a conductor to connect the bilge water with the outside water?

 

[rwidman]

Re: Rusted-out Drain Plug!!!

If you keep the boat in the water and the boat has shore power, every piece of underwater metal must be bonded together. This keeps them at the same electrical potential. Unbonded metal will act like the plates of a battery when in salt water and it will be disolved away.

It's hard for me to imagine a manufacturer building a boat with shore power and an isolator and forgetting to bond the garboard drain. It's also hard for me to imagine a manufacturer building a boat that might be left in the water and installing an expanding rubber plug.

Want to do it right so your boat doesn't sink at the dock? - Install a proper bronze garboard drain and plug and bond them to the boat's bonding system.

 

[Brentathon]

Re: Rusted-out Drain Plug!!!

I have to disagree with you, Ron; thru-hull fittings should NOT be bonded, if they are isolated from all other metal components.
?Do not bond any thru-hulls or other immersed metal that can be electrically isolated. Specifically, keep your metal keel/ballast, your metal rudder shaft, your engine/prop, and all thru-hulls electrically isolated, from each other, and from the engine.?
http://www.westmarine.com/webapp/wc...catalogId=10001&page=Marine-Grounding-Systems

 

[Chris1956]

Re: Rusted-out Drain Plug!!!

Brent, Those lever "flippy plugs" are poorly made. They do rot out, because of the crummy brass they use.

They probably still make the Tee handle plugs, which are much heavier and will work better. They are a PIA to remove, which is why the lever type are popular.

I would search around for the T-handle type and check it each season....

 

[109jb]

Re: Rusted-out Drain Plug!!!

I still say --- plastic.

http://www.basspro.com/Floating-Drain-Plug/product/39744/-900959

I have used the plastic plugs in the link on my old Starcraft, and I now use one on my Sea Ray and it has a Garboard drain. Never a problem, never a leak. I replace them about every 2 years. On the Sea Ray, I just put the plug (different size that the typical 1") into the threaded Garboard drain and lock it down. I have always preferred the expanding rubber plugs for their ease of use and no tools required.

 

[Home Cookin']

Re: Rusted-out Drain Plug!!!

what kind of boat is it, made with the rubber plug? If it's the one in the photo, it's way too big.
The rubber plug is best suited for boats where you will frequently remove the plug, especially those you drain while running them rather than using a pump. Anything that is to stay in except for occasional haulings out, or which is inconvenient and unneccssary to remove while in the water, should be threaded.

 

[Beefer]

Re: Rusted-out Drain Plug!!!

Not that I'm condoning the use of these, but WalMart has the T-handle ones for like $3.79. I know this cause it's what I use for my livewell drain. I would not use it for my garboard.

 

[Chris1956]

Re: Rusted-out Drain Plug!!!

Hey Home, My neighbor has a 27' Boston Whaler Outrage. It came with a flippy-type plug, that must be installed from the outside, since you cannot get to the inside of the bilge. I recommended he install a garboard drain and plug... but he didn't think it necessary.

I fully expect to hear that he hit a stick while underway, which pulled the plug off and the boat sunk.....alas it is only a $90+K boat

 

[Treager]

Re: Rusted-out Drain Plug!!!

You have to be careful with the T-Handle and Flip Handle Drain plugs, especially the brass and aluminum varieties. I would suspect that the Asian vendors that supply these plugs could change the alloy used for the brass/AL and the accessory companies wouldn't know the difference.
There are also some things to be concerned with in terms of the physical designs as well. As indicated above, the washer at either end of the plug is thin and tends to weep, no matter how tight you make it to expand in the tube and are prone to deformation with even moderate torque. Another issue is the size of the threaded shaft diameter and the diameter of the hole in the rubber, which also contributes to water weeping through the center of the plug.
I would also be wary of some of the types of rubber that are used, I've seen some of the compounds start to degrade in less than a year.

One of the best garboard plugs I've tested is http://boatwize.com/Home_Page.html
It doesn't leak water and is easy to clean.

 

[109jb]

Re: Rusted-out Drain Plug!!!

I've never in 30+ years of boating ever had a rubber flip plug get knocked off by hitting anything, plastic or metal. I always install from the outside with the handle flipped up and out of the way. I have also never had one leak. I do trailer my boat most of the time, but a couple times a year go on fishing trips where the boat sits in the water for a week and still never had a problem or ever had a drop of water in the boat from the plug. I personally would not worry about it.