Teredo worms (the termites of the sea)

[lustyslogger]

For the first time in all of my sailing ventures I have encountered teredo worms. This is actually the first time I have left my boat in salt water for any length of time and they have had a feast on my mahogany rudder. I have removed the rudder from the stern and just have in lying in the boat right now until I am ready to move it. I am moving it to a fresh water lake once again.

I don't expect there to be a problem with new attacks but I'm a bit worried about the critters that may be lurking in those holes now. And I certainly don't want to put them in fresh water and have them adapt and overrun the lake. Does anyone have any ideas of what I could do to insure the litter buggers are dead dead dead? I am going to plug the holes (its seems like a few hundred!) but if they could drill those holes in just a few months I am not sure if merely plugging them will matter.

HELP

[JacquesR]

Sorry to hear about your problem. Hope someone can provide a solution. I Googled and found many articles about Teredo worms but nothing definite about treatment. Hope you have better luck.

[Michel]

Looks like serious pests to me!
https://en.wikipedia.org/wiki/Teredo_navalis

Do they go trough epoxy? What about glassing the hull and rudder?

[lustyslogger]

Looks like serious pests to me!
https://en.wikipedia.org/wiki/Teredo_navalis

Do they go trough epoxy? What about glassing the hull and rudder?

As far as I know I have no problem with the hull. I will know for sure this week end when I pull the boat out of the water. As far as the rudder is concerned I am going to putty in the edges and revarnish. I don't think I will have a problem in fresh water. I just want to make sure I've got rid of the little critters. In TN someone brought in a few Zebra snails and within a few years some of the lakes are absolutely engulfed with them. I don't want to do the same to Harris Lake.

[Art Haberland]

From Wiki:

Distribution and habitat

Teredo navalis is found in temperate and tropical seas and oceans worldwide. It may have originated in the northeast Atlantic Ocean, but it is difficult to establish where it originally came from because it has spread so efficiently around the world on debris and hulls of ships. It is found in the littoral zone, living inside submerged timber, pilings, driftwood, and in the hulls of wooden boats. It is found in brackish waters as well as the open sea, and tolerates salinities ranging from five to thirty-five parts per thousand. It is also tolerant of a wide range of temperatures. Individuals have survived temperatures as high as 30 °C (86 °F) and as low as 1 °C (34 °F), though growth and reproduction are restricted to the range from 11 °C (52 °F) to 25 °C (77 °F). It can also live without air for about 6 weeks, using up its stored glycogen reserves. Dispersal to new habitats occurs both during the free-living larval stage, by floating timbers carried along by currents, and, historically, from the hulls of wooden vessels. In the Baltic Sea, there were several mass occurrences in the 1930s and 1950s.

[wdscobie]

Florida is thick with wood worms and wooden boatowners must be vigilant.

They can't get through epoxy.

After full drying, so not to trap water inside the wood, I'd repair the rudder with thickened epoxy to fill the holes. Cover the entire thing with a few coats of epoxy after fairing. (See note below about rubber mallet).

Antifouling paint can keep them away (usually). A skip or thin spot will just give them an entry point. If your boat's hull was protected by only antifouling paint inspect it carefully!

I'd use rubber mallet on all locations. Whack the boat and rudder hard (and all other underwater wood) to ensure it is still structurally sound. The external holes are only a small representation of what they do inside the wood. Be sure the entire boat is still sound!!

[JacquesR]

On the Web, it was suggested to insert a glowing wire into the holes to kill the worms before filling them. Hope this helps. Good luck.

[wdscobie]

Found this -

http://depts.washington.edu/oldenlab/wo ... s_Elam.pdf

(Downloads a PDF)

Within it talks of putting a wood boat in fresh water for extended period to kill the critters. This is water with salinity below 5ppt.

[lustyslogger]

I am fortunate, the only part of my boat below the water line that is wood is the rudder and unfortunately the centerboard. I used to keep it in the down position when I had a lot of water under me. Here in Crystal River I only have between 1 and 3 feet of water so I keep the board in the trunk. I don't think any part of it extends below the water line when its raised but I will check it.

I kept the rubber in the up position with only about 2 inches actually in the water. It is those two inches that have been affected and in a very short period of time. I put the boat in Crystal River in May so in about 10 weeks they have have bored a hundred holes in my rudder!

I took the rudder off the boat because it was getting a lot of growth on it and I wanted to clean it off. I put it in the cockpit, which filled with water from the rain. I have noticed several things floating in the water that looked by a crinkled up rubber band. Perhaps the rain water's lack of salt is killing them since there is a photo of one on one of the websites that looks exactly like what I saw.

Thanks for everyone's help. Every now and then I get this urge to buy a wooden boat for the romance of it all and then something like this happens and smacks me upside the head with reality

[wdscobie]

Every now and then I get this urge to buy a wooden boat for the romance of it all and then something like this happens and smacks me upside the head with reality

Like all things boats each type has + and -.

SWALLOW is cold molded so her cedar hull is wrapped in epoxy and fiberglass. There are worms in the Salish Sea -- slower growing than yours as the water is only 50-degrees.