Drain Plug for Aluminum Houseboat?

[iflyboeing]

There is simply a 1/2" hole, not threaded, as the drain for my aluminum houseboat. Previously there was a 1/2"bolt which was inserted from the outside, and a nut on the inside. There were washers with silicone for isolation. The assembly was corroded so I removed it during dry layup. What should I replace it with?

 

[robert graham]

Re: Drain Plug for Aluminum Houseboat?

Ace Hardware has rubber pipe plugs that will work, that's what's on my aluminum jon boat and it works fine. Some of the plugs have a little lever or screw on them that allows them to expand inside the hole for a tight fit. Good Luck!