Drain plug for aluminum hulls?

I am about to start refurbishing my grandfathers Lone Star boat, and will be using it as our dinghy/get around the lake boat. It will be stored in our slip, and in the water 24/7.

It is missing the drain plug assembly, and I need to reinstall a new one. There is only a bare hole in the aluminum. I'm concerned about putting dissimilar metals together, as I'm not well versed on the topic of galvanic corrosion. There will not be any electronics on board, however I will eventually install running lights and a battery.

Should I use a metal plug assembly, or go with something like a plastic fitting made for inflatable ribs?

Variations on the rubber plug, should be fine if the brass doesnt touch the aluminum...if in the water all year, then I would switch to the all pkastic unit.

Available almost everywhere.

Can bronze and aluminum coexist?

I have used the rubber style (posted above), that is twisted to tighten them up, for decades. They work wonderfully. I'm not sure what size you have on your boat. Usually 1 inch. Sometimes 3/4.



I use these snap style inside the hull. Make sure your through hull is one inch and not 3/4.
https://www.amazon.com/dp/B000MT95N...6027fe3b507d5efd7600e5a586b3f6&language=en_US

I really want to try and get a screw in type instead of these rubber expanding plugs. I wouldn't trust leaving my boat in the water with these snap in plugs.

toocoys said:

I really want to try and get a screw in type instead of these rubber expanding plugs. I wouldn't trust leaving my boat in the water with these snap in plugs.

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For what it's worth we used an expandy plug for 16 years on our 19' Mako. No problems. Also used one on various other boats over the years. All were kept in the water the entire season.

Rob

On a plane you can pull the plug and drain the boat. Easy out is the way to go. Get a couple spares.

If you leave it in the water you have to watch it all of the time. Tie it at both ends so you can pull it up when it sinks.

I'm with datenight. I used one in Pond Scum for 10 years. I kept an eye on it. Checked it when it was out of the water. Replaced it if I saw any cracking. I think I replaced it twice and one of those may have been a spare I bought and zip tied to the transom. Remeber this, if one some how comes out, keep moving on plane, and beach the boat. If you have a spare get on plane and then pop it in. It will keep the water from coming in. When we would fill our J boats with water from fishing, we would get on plane, pull the plug(s) out, and allow water in the hull to drain out of the back. Then pop the plug back in. I tried to find a video on this but no luck. I thought one of the rednecks in the south would have posted a few dozen.



I assume if the boat is in the water, it won't be left unattended for long periods of time. If it leaks, it shouldn't leak much. Mine only leaked in about a quart per day until I changed it. That was a big leak for a 10-foot boat though, with a 320lb capacity. It had flotation in strategic areas to keep it from sinking.

I've had a boat with those kinds of plugs before. A 19' center console fishing boat, and I've had to do the "pull the plug and floor it" bit after nearly being swamped by a large wake.

My concern is that the hole in the boat is in the thinnest part of the aluminum. It's only aluminum panel. Wouldn't that cut the rubber quite easily?

ben2go said:

It had flotation in strategic areas to keep it from sinking.

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This little lone star has three sealed air tanks under each seat for flotation. I could care less about the hull sinking, that's easy enough to pull up. I'm more worried about the outboard sinking with it!

Toocoys dinghy no.3? That opening could take a simple rubber bung. You may not feel it`s secure,but I had an old aluminum 10ft dinghy kept on the shore or the mooring,only bung issue was forgetting to insert it. I think you are onto something with the plastic inflatable dinghy type but you might have to find some monel screws to attach the body. Plug is usually captive on a cord.

BruceK said:

Toocoys dinghy no.3?

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Just two! :lol:

I couldn't stand the Caribe inflatable RIB. I have a feeling this is going to be much more satisfactory for me.

toocoys said:

I've had a boat with those kinds of plugs before. A 19' center console fishing boat, and I've had to do the "pull the plug and floor it" bit after nearly being swamped by a large wake.

My concern is that the hole in the boat is in the thinnest part of the aluminum. It's only aluminum panel. Wouldn't that cut the rubber quite easily?

Click to expand...

There should be a through hull tube there. Some are rolled in or stamped in when the transom is made.

toocoys said:

I've had a boat with those kinds of plugs before. A 19' center console fishing boat, and I've had to do the "pull the plug and floor it" bit after nearly being swamped by a large wake.

My concern is that the hole in the boat is in the thinnest part of the aluminum. It's only aluminum panel. Wouldn't that cut the rubber quite easily?

Click to expand...

I quit using my J boats here because people intentionally try to sink them, especially kids on jet skis.

The cork closure from a good single malt is a perfect fit in the hole in my Laser. You also get the added benefit of drinking the contents of the bottle first.
No dissimilar metal problems either.

Have a 2” aluminum pipe or tube welded into the old hole. With an id for a rubber plug such as on post #3.

If it were mine I would have an aluminum plate welded to the hull and put in a proper treaded plug (plastic) or expandable as described above.
I would want some thickness there.