Sea Worms!

I have read and re-read all about these critters!

My question is:

Assuming a NEW bottom paint on a WOOD hull boat, in the tropic's.
How easy is it too SEE the worms if there is a problem (on the hull).
If diving around the hull, can you see little holes into the hull
if there is a problem?
Also if you were too keep your bottom coat good, and
cleaned the hull with a soft brush (under waterline)
say every week, how far would this go in helping
keep the critters at bay? Thanks all, GREAT site!

 

The larval stage is minute and you won't see any entry holes. The problem with planked wooden boats is that they 'work' . The resulting cracks are a breach in the coating. Thats why sheathing works to keep the worms out. If it is a ply-layered construction then a good thick layer of paint will keep them out, but if the paint is damaged the borer will enter.

 

Its illlegal in the US but if you add a bit of copper sulfate to your bottem paint you should never see one of these worms.

K9

 

I have seen at Sydney Tech a sample of a fibreglass bottom that was eaten by teredo worms, it was full of holes just like a wooden boat, so beware, the little suckers can sure chew. As previously stated, keep the antifouling always there, and certainly diving on it weekly will assist. We used to squirt acetone up the holes with a plastic syringe when the boats were out of the water in Sydney, I cannot confrim any dead, but it sure would have hurt their eyes.

 

Mike is correct ,--the tinyest of holes will let them in. The entire surface should not have one speck of unpainted or crack in the surface. They cant and dont eat antifouling.

 

Thanks for the suggestions!

My next question then should be, if some of these beasts get into
a area (small crack) How long will it take too see MAJOR
damage?

My thinking is this:

I'm in the tropics, I want too prevent damage from these critters,
So lets assume a plank moves and creates a super small void.
If i were too dry dock the boat say every 3weeks, for 2-3 days.
Should this kill them off? How much damage
can they cause in a 3-5 week time frame?

BTW: I have too say, the hang a board over the side and attract
them away from the hull sounds like the talk of someone drinking
too much rum! (and i hope too find them soon!)
But, i am still thinking over how too mix in hot peppers too my
bottom paint!

 

The traditional technique is to motor up a freshwater creek for a few days. I suppose you could get one of those floating "swimming pools" plastic membranes they float around yachts to stop fouling, and pump a fair bit of freshwater into it.
The obvious thing would be to glassfibre and epoxy to the waterline on a wooden boat perhaps?

 

Man, now I've heard everything - fiberglass-eating sea worms. What do they do to people?

 

rwatson is correct ,,go up a fresh water river for a few days,,,,I can tell tinhorn aint been around boats too long,,,,longliner

 

I think tinhorn was reffering to landlubbers story of a fibreglass hull being eaten by worms -
I would have to assume the fibreglass was coating some type of timber in that situation - because like tinhorn, I dont believe Toredo worms eat pure fibreglass.
That would make headlines in most cruising magazines if that were the case.

 

its ok me and tinhorn will get along just fine ,,hes gonna be lots of fun,landlubbers story aint too far fetched,,fiberglass acts like wood ,just takes more time ,,it rots and weakens,,,,,,tinnys ok with me ,,the question is ,,am I ok with him ,,longliner

 

Well, I sure hope so. I come in peace.

Yup, I'm a landlubber alright, but I've always thought boats were beautiful. Since I anticipate moving to an area surrounded by ponds and rivers, I figure it's time to start learning about basic design stuff. Had no idea they were so complicated.

And now I also have to worry about cooties in the water!

 

oh yea ,,the water is full of em ,,in fresh water you got mussels ,,,grass and some stuff I cant name,,in salt water you got barnicals ,worms and grass and it all starts so small that any creavis or gap will let them in ,,,,in your engine intake ,,in your head(toilet) but you have a good location,,you can keep your boat in salt water ,,and then go to a river to (detox) or you can keep your boat in freash water and go to the salt to (detox),,dont forget electrallisis,,,,,use zink,,,,,,,yes ,much to learn ,,but when you stop learning ,is when your trouble will start,,,good luck ,,and send pics of your boat,,longliner

 

The fact is, they aren't worms at all, they are bivalves (molluscs, little clams) that use their tiny sharp-edged shells to do the boring. My neighbor has a boat sitting upside down on the beach that has literally hundreds of tunnels bored into the keel log by these critters. The tunnels are not tiny either, they are 1/8 to 1/4 inch in diameter (some may be even bigger) and some of the tunnels are at least foot long if not several feet long.

I think the "small void" theory is incorrect. In fact I don't think they need any voids at all to bore into a wooden boat.

I don't think they bore into fiberglass either, unless they can smell or taste wood on the other side. Molluscs like these can bore through almost any soft material, but I think an epoxy and glass sheathing layer prevents them. Epoxy is far more waterproof than polyester so it probably prevents the 'flavor' of the wood from getting into the water, thus the worms might not try so hard to get in when the bottom is properly sheathed to prevent them.

By the way, the idea of putting a tasty unprotected board in the water is exactly what was done traditionally to deal with these pests. The keel had a "worm shoe" attached, and the molluscs would bore into and eat that wood, leaving the keel untouched. Then the ship owner would periodically replace the worm shoe when too much of it was already gone.

 

Ken,

Interesting, your comments.
I have always known the piece of wood on the bottom of the keel as a docking plank, attached to provide protection for the keel itself from being damaged during docking, as such.
That is not to say that it had either a dual purpose, or I have missinterrpreted the actual job of the plank. I certainly have had to replace them for customers, and yes they would be eaten, but we always painted and tried to protect the docking strip just the same as any other piece of wood in the boat.
You are writing from the Phillipines, maybe we have different sea creatures to you, but certainly with the same result. They eat wood!

My comment previously about the teredo worms eating glass, the piece for the sample, I am sure would still be there at the Tech, it was rare, but was there to show that it could still happen and to be aware of it. I have seen myself on boats that I slipped on Sydney Harbour, evidence of small holes that were obviously from something in the water, but these were only through the surface, nothing like the Tech sample, it was eaten up like an old piece of wood. I do not think we were told where the boat operated.

I was the Shippy for the Aus Maritime Museum too about 18 years ago, they purchased a Vietnamese boat from Darwin for the museum at that time, it was totally destroyed by worms. It lived up a creek in Darwin, so all the locals had free dinner on board till it was moved to Sydney. It had serious problems just getting down to Sydney it had become so rotten.

Please take these worms seriously, they are real little devils.