anyone convert their drain plug to threaded plug

[elkhunter338]

A common problem that is surfacing with alum. boat moored in salt water is the cheap china plugs go bad. There is not much threads, most are brass of some sort and the brass dissolves over time thus the plug fails and the boat sinks.

North River Sinks Due to Corroded Plug - www.ifish.net

My buddy installed a new plug this summer and within 2 months the plug went bad and started leaking, luckily he notices his bilge running more often and got he boat on the trailer to find his quote new plug the threads were gone.

So has anyone converted their boat to a pipe threaded plug? All you need an alum. pipe plug.

It appears you could tap the hole for a 3/4 pipe plug but I am not sure the wall thickness on the plug hole is adequate after being threaded. I measured the hole and 3/4 pipe plug and It measured the wall thickness would be 0.15 which seems too thin.
I do not want to weld on the boat and heat up the seam and cause a leaking issue. You could weld the hold closed with an alum. slug, then tap it for 1/2 pipe plug.

 

[Gibbles]

Re: anyone convert their drain plug to threaded plug

to much work.

Get a stainless plug
Boat Drain Plug Neoprene Stainless Steel 1" Snap 7 0563 | eBay

 

[astor]

Re: anyone convert their drain plug to threaded plug

need to use a similar metal or a stainless steel plug like Gibbles suggested, or you will have corrosion.

Aluminum drain plugs are available.

New Seasense Aluminum 1" Snap Boat Drain Plug 50032288 | eBay

 

[classiccat]

Re: anyone convert their drain plug to threaded plug

Very informative link/thread elk!

After reading,^^^ +1 on the aluminum plugs.

from post #93:
"The beauty about Stainless steel is it can act like two dissimiliar metals. The portion exposed to seawater is passivated and has one electrical potential, the portions protected from oxygen by the rubber is active at a different potential. Since the potentials are different you have a current generated, with the active portions acting as a anode and wasteing away material.


Another issue with stainless steel in boat plugs is rubber, or more specifically the carbon black in black rubber. Carbon black is graphite, which is the only common material that is more noble than platinum and gold in the galvanic series. So if you have SS against black rubber, like in a boat plug, the rubber acts as a cathode, the metal acts as an anode, and goes away. I've seen this happen pretty aggressively with aluminum boats with black rubber rub rails.
This is a huge problem for any ship or boat with stainless piping, ask the Washington ferry people if you don't believe me. Works on boat plug too.

I have had 20-30-40-50 year old brassy bronze plugs that still work fine in wood and plastic boats.

Don't use stainless steel below the waterline if it affects water tight integrity.

If North river supplied the plug it is one of their products that they need to stand behind it if they are worth anything. "

 

[astor]

Re: anyone convert their drain plug to threaded plug

Should have read further in the attached link regarding stainless steel. I also had corrosion from the rubber fuel lines on my aluminum fuel tank. I patched the holes from corrosion and painted the tank, so hopefully that will protect the tank from the new fuel lines.

my 87 Starcraft had a chain that attached the drain plug to the knee brace and would have "grounded" the plug to the hull, and the zincs. May have to get the aluminum plug and attach it as it was originally.

 

[elkhunter338]

Re: anyone convert their drain plug to threaded plug

So does anyone have a good place to buy 1/4" alum. bolts.
The thru bolt on these plugs is 1/4", I could replace the bolts with an alum. bolt and make a thick threaded washer out of a piece of solid alum. rod.
I don't have a way to weld alum. If I did I could buy some alum rod, weld a thick washer on one end and thread the other to make my own.
Interesting about the stainless and rubber issue. The outdirve has lots of stainless touching rubber, bellow clamps, through bolt on the rams. Using a stainless plug is probably better. I am not sold on the flip lock plugs.

 

[Gibbles]

Re: anyone convert their drain plug to threaded plug

Boat Drain Plug Neoprene Stainless STEEL1" Twist | eBay

:watermelon:
Search term for all things drain plug on ebay you may ask your self; "Stainless drain plug" from the section
"eBay Motors>
Parts & Accessories>
Boat Parts>
Plumbing & Ventilation"

From the root of the site, add the word "boat" to the above search query

 

[Gibbles]

Re: anyone convert their drain plug to threaded plug

Oh wait it does not end there!!!

New Seasense Aluminum 1" Twist Boat Drain Plug 50032286 | eBay

!

 

[N1265]

Re: anyone convert their drain plug to threaded plug

" I am not sold on the flip lock plugs "

Years ago, That's all I used, the design itself is proven.

But that rivit in these newer ones looks kinda small to me, Not sure I would trust the newer Sea Sense flip lock plugs that they have out today. I would like to see one of the Alum. twist lock plugs to see how well they are made.

 

[Gibbles]

Re: anyone convert their drain plug to threaded plug

Flip lock to me looks like something could get stuck on it and pull it down, mostly I use the twist lock because of that thought...
I have never heard of anyone having an issue with the flip lock tho

 

[barato2]

Re: anyone convert their drain plug to threaded plug

i think the big issue with the threaded alum plugs might be galling of the threads. keep em slathered in antiseize (or silicone grease if there might be an issue with the antiseize eating plug rubber).