plastic wood boards for worm shoe

[sdowney717]

been thinking of this for a while
http://american-plasticlumber.com/faqs.html
I plan on nailing them into the keel using ring shank monel nails.
Generally they dont absorb water and worms wont ever eat them. So they wont wear out.
Does anyone know of any legitimate reason not to use them (please dont suggest it just isnt done that way, tradition, the boat will sink, resale value will be destroyed, anyother nonthink response, etc...) for such a purpose?

[Thad Van Gilder]

where can one still buy ring shank monel nails? I thought they stopped making them!

-Thad

Oh yeah, your boat is covered in plastic... what do you need a worm shoe for, anyway?

[ 11-09-2005, 11:10 AM: Message edited by: Thad Van Gilder ]

[Rick Tyler]

Have you asked the manufacturer if they recommend their product for continuous immersion on your boat?

[Gary E]

Originally posted by sdowney717:
been thinking of this for a while
http://american-plasticlumber.com/faqs.html
I plan on nailing them into the keel using ring shank monel nails.
Generally they dont absorb water and worms wont ever eat them. So they wont wear out.
Does anyone know of any legitimate reason not to use them (please dont suggest it just isnt done that way, tradition, the boat will sink, resale value will be destroyed, anyother nonthink response, etc...) for such a purpose?Worm shoes are intended to provide Breakfast, Lunch, and Dinner for the worms, it is the nearest thing to the mud where they come from and if you make it from something they cant eat, they will go to where they can eat...your hull, your choise where and what you want to feed them.

Make the worm shoe from ANY wood, the cheaper the better then Nail it on with some tarpaper between it and the keel and you will be fine.

[Bruce Hooke]

I'm a small boat man, so I haven't dealt much with worm shoes, but what Gary just posted does not make sense to me. My understanding of a worm shoe was not so much that it was supposed to provide something attractive to the worms so that wouldn't go elsewhere (what we might call a "bait"), but rather that it was simply supposed to be a low-cost, sacraficial element with a barrier between it and the rest of the boat (more like a "bumper"). In the days when wood was the only viable option the only choice was to assume that any barrier coating on the worm shoe would get rubbed off and that the worms would therefore get into it, but I don't think acting as bait was the essential idea. As I understand it the idea was simply that it is very hard to keep an unbroken coating on the bottom of the keel since it gets rubbed off if you go aground and thus worms can get in, so the best option was to put a sacraficial piece of wood that the paint could get rubbed off of, and that worms could get into, but then not be able to get to the rest of the hull from there.

The only issue that comes to my mind with the proposed plan is, as Rick asked, how the plastic in question will handle continuous immersion. But, as I said, I am a small boat man, so don't put too much stock in my not being able to come up with any reasons not to do what you are proposing!

[nedL]

I see no problems with the idea. As Rick & Bruce mentioned, check to make sure it can take full time immersion (that it won't crumble away over time). As Bruce said, a worm shoe is supposed to be something cheap & replacable IF the keel gets scuffed & scraped and woms settle in, not as a bait to attract them.

[Gary E]

Just whut kinda worms do youse guys that like a plastic worm shoe have in your waters?

THE INTENT OF A WORM SHOE IS FOOD !!!!!!!

[Ron Williamson]

If the worm shoe is food,then why don't people just hang old lumber over the side when they are moored?
Maleo,FIL's Chesapeake Bay boat,has a copper skin on the keel,instead of a sacrificial worm shoe.
R

[Gary E]

Originally posted by Ron Williamson:
If the worm shoe is food,then why don't people just hang old lumber over the side when they are moored?
Maleo,FIL's Chesapeake Bay boat,has a copper skin on the keel,instead of a sacrificial worm shoe.
RBecause the FIRST and NEAREST WOOD is the FOOD... hanging lumber over the side is NOT the bottom of the keel...and what fool would actually do that :D

Yes, the copper will also prevent the keel from being lunch, but what about the next nearest plank? was it also covered with copper? If it was, good, if it's not...IT's FOOD !!!

[Bruce Hooke]

I believe shipworms are "free-floating" in the water when they are looking for wood to eat. As such they are not necessarily any closer to one part of the boat than the other.

[Gary E]

Originally posted by Bruce Hooke:
I believe shipworms are "free-floating" in the water when they are looking for wood to eat. As such they are not necessarily any closer to one part of the boat than the other.You think so huh,,,

If that were true the boats in very deep slips would still get "worms" and they would be in all parts of the hull not only the keel. Fact is that they come from the bottom, your choise on what to feed them. By the way, they dont eat plastic.. so GLASS THE BOAT !!!!

[mmd]

"Worm shoes are intended to provide Breakfast, Lunch, and Dinner for the worms..." - Gary E It is also termed the "sacrificial keel" and the "grounding shoe". Presumably these are different from worm shoes and are used in religious sacrifice ceremonies to appease the Sea Gods and for completing on-board electrical circuits, respectively. ;)

Gary, the reason that the worm shoe is more prone to borer attack is because it is more likely to have exposed raw wood than the surrounding planks, not because it is closer to the bottom. Shipworms (teredos) do not eminate from the mud bottom, but are present in larval form in the entire water column. See one reference here. (http://www.chesapeakebay.net/shipworm.htm)

For info on another nasty little eater of wooden boats, check out gribble. (http://news.nationalgeographic.com/news/2004/04/0423_040423_gribbles.html)

[Thad Van Gilder]

You guys are all close...

First, boats in deep slips DO get worms.

Also, boats do get worms all over. I just gave a once over to a 94 footer in Greenwich for a guy in Africa, and every plank below the waterline was eaten.

Bottom paint protects boats from worms. Bottom paint often scrapes off the bottom of a keel, allowing a place for worms to get in. That's what the worm shoe is for.

-Thad

[Thorne]

Interesting article. One thing that is still unclear to me is the basic assumptions behind use of a worm shoe.

A worm shoe would seem justified IF:

IF the boat is annually "dewormed" by hauling, mooring in fresh water, freezing in place (like the Dutch boats in the 16th and 17th C), etc.

IF the boat's hull is wood unprotected by nothing but paint.

Otherwise, it seems sort of strange to use one.

The logic behind the shoe seems to be, "There are x number of worms in y amount of water that will contact the hull, with z number actually infesting the shoe. So providing these worms with a sacrificial keel will keep them out of the rest of the hull."

But if the worms (really small clams) reproduce in place (and since they don't travel, they gotta), then any sort of gain can be lost once they start producing clouds of new hungry-all-the-time teenage worms right next to the hull of your boat.

The logic then fails with, "The x number of worms results in z number of worms actually eating their way into the worm shoe. There they produce zillions of baby worms who are located in and around the shoe and hull, vastly increasing the chances of worm infestation of other hull/boat parts."

Am I wrong?

Here's what the article says (and doesn't say) about the infestation issue:

"...once the shipworm has infiltrated a ship's structural member or an untreated dock piling, it's a matter of time before the entire structure will become infested, weaken and collapse.

Despite its tolerance of low salinities, Bankia often die off in years when there is a strong freshet, or when the "host" ship moves upstream into fresher waters. Shipworms also perish when their wooden habitat freezes, becomes too hot, or if the hull is hauled from the water."

..." Shipworms release planktonic veliger larvae (larvae that have developed swimming membranes or velum). The larvae exist in the water column for two or three weeks before settling, if they're fortunate, on untreated wood.

The larvae have a small foot that enables them to travel over the surface of the wood. They eventually attach by means of a secreted thread. Larval shells develop into minute versions of the shells that they use to bore through the wood, where they develop further into adult shipworms."

[ 11-09-2005, 03:43 PM: Message edited by: Thorne ]

[mmd]

"am I wrong?"

Yeah, well, sorta...

The logic goes something like this:

Postulation No. 1:

1.) Boring worms are defeated by anti-fouling paint.
2.) The sharp edges of keels are most likely to be scraped of paint and damaged by collisions with floating objects and the sea bottom.
3.) Ergo, the most likely place for boring worms to gain a foothold on a boat is in the keel wher the anti-fouling paint has been compromised.

Postulation No. 2:

1.)When worms are discovered in a piece of the boat's structure, the only sure cure is to replace the piece of structure.
2.) Keels are terribly expensive and difficult pieces of structure to replace.
3.) Ergo, a removeable piece of the keel, located in the area of highest possibility of damage, is fitted to the permanent keel to allow effective repairs easily and inexpensively.

[Gary E]

I dont know about other area... I do know about the New Jersey area...

I have kept my boat in several diferent marinas starting in 1968...

Sommers Point with the very shallow water was where the worms were active and ate the shoe which was elCheapo wood, dont ask what kind, I dont know..The rest of the boat was not harmed, the boat was kept in the water all year and it froze in place most every year. I NEVER RUN AGROUND..It was painted every other year. This happened to all of the boats in that shalow marina, it is where I learned about this "Worm Shoe" from the old timers.

Move to Beach Haven an area where I did touch bottom in the shalow bay and it could of been mud or sand. Again same paint schedule and the boat stayed in the water. Since the slip was deeper, no worms ever in any other part of the boat.;

Move to Cape May, MUCH deeper slip, 6 or 7 ft below the keel at extreem low tide... NEVER had to replace the shoe.

Could it be that the paint kept them away?..possible, but why did the shoe not get eaten by as much as ONE LITTLE HUNGRY MUNCHKIN in Cape May??? The only diference is the deeper slip. So is deeper water a cure?.. Dont know..are the worms in all water?..dont know and dont care...

And as for that 94 ft eatin alive boat.. you dont have a clue where it was or for how long it was not taken care of.

One last thing....
Make sure the worms in your area like the taste of plastic wood before using it for a "Worm Shoe"
Wont matter what the nails are... I used galvanized..

[ 11-09-2005, 04:22 PM: Message edited by: Gary E ]

[PeterSibley]

Should you find yourself in Australia, North of Brisbane be aware that worms are very ,very nasty little creatures.When I was a boy and mucking a round with boats we would sometimes wire a length of hardwood ( thats Australian Hardwood...the Real thing) to the leg of our steel pipe jetty.In 6 weeks you could usually break it up with yur fingers :eek: :eek: :eek: Should you venture South take worms very seriously.

On my boat I have a wormshoe then a layer of 1/8" lead sheet ....easier to shape than copper,then the keel timber.

In respnose to the question,if the plastic wood will last underwater I'd be happy to use it.Cheers.

[ 11-09-2005, 04:28 PM: Message edited by: PeterSibley ]

[Doug Wood]

I NEVER RUN AGROUND.Well, you will now. ;)

[Thorne]

I'm still not convinced that the logic is correct, but it all depends on the reproductive cycle, how consistent the production of new worms is, and how far they might drift in the two weeks before they attach and attack.

A comparison might be with a sheep farmer plagued by wolves. If he had a large supply of meat from some other source, he might consider piling it near the sheep pasture in hopes that the wolves would just eat the meat, not the sheep.

But once they started reproducing, it sure seems that the young wolves might start going for lambchops occasionally.

In other words, if you provide a home for a colony of worms which breeds rapidly, and the little ones drift about in the water before settling down again, isn't the overall level of worms in the nearby water gonna be MUCH higher than elsewhere?

Doesn't this higher level of nearby "worms per cubic gallon" increase the possibility of worm damage to other parts of the hull?

[ 11-09-2005, 07:45 PM: Message edited by: Thorne ]

[Bruce Hooke]

Thorne,

I think the key thing is that if other parts of the hull are vulnerable to worms (i.e., there is a break in the paint) then worms will find that spot fairly quickly in areas where worms are a problem, whether or not there is an immediate nearby source of worms (i.e., the infested worm shoe). Furthermore, aside from a plastic worm shoe (or coppering or glassing the hull), worms are likely to get into the area around the bottom of the keel whether you have a worm shoe or not, so better to have one and at least only loose the shoe and not the keel.

[Bruce Hooke]

Gary,

Two points:

1. You don't have to run aground for the paint to get rubbed off the area around the keel. As mmd noted, all you have to do is run into occassional floating debris that will rub along the keel area. Even the process of launching a boat can rub the corners of the keel...

2. There are lots of other potential differences between the various marinas you were in that you may not have consider and that could account for the differences in worm problems. One fairly obvious one is that I understand worms are fairly sensative to pollution, so if the marinas where you had fewer problems were in more poluted areas that might be the issue. Many other factors related to the biology and hydrology of each area could determine how many worms there are in a given location. Worms float in the water column so depth just does not make sense as a factor.

[sdowney717]

Yes, the worms are opportunistic and eat wood anywhere they can find it.
Paint helps as long as it is intact but all it takes is a small crack or opening and if they find it they set up housekeeping.

This picture is not the greatest.
On the left is a round plug out of pressure treated pine eaten by worms. They got in past the paint. I had moved a thru hull and had epoxied in a plug. This damage happened after only 5 years and it is riddled with tunnels.

The worm shoe pieces show how devasted it is.
The right picture has a channel 1/2" in width.

And a few worms had gotten thru the tar paper and into the white oak keel.
http://static.flickr.com/27/61745911_3edd105d84.jpg?v=0

[sdowney717]

Thad,
I am reusing the nails that held the original worm shoe. They look like white metal and many held up and look almost perfect. (80% or so). They dont look or corrode like the SS I have seen, there is no crevice corrosion on them, just light surface corrosion. And they look like a monel nut I have so I think they are monel nails. Some are a discolored brownish color. I also think they are original, they match the nails used to secure the lower frame ends where they were notched into the keelson. Those nails were mostly destroyed by corrosion.

I plan on painting the permaflex on the bottom of the keel and then nail the worm shoe on.

[JimConlin]

What about polyestermites? They were reputed to LOVE plastic.

[L.W. Baxter]

Downey, yer doin' a heck of a job.

[AngWood]

I got news for you, gents. Worms don't have feet! So there's no need for a worm shoe of any kind. I don't even need to read this whole thread to tell you that. Sheesh.

[Thad Van Gilder]

ahh, pollution... Cape may Harbor is much more polluted than Somer's Pt... That could be an answer!!!!

Downey, Yup, is you got silver ringnails that are more than a few years old and still good, they must be monel. Lucky bastard!!!! monel's nice!

-Thad

[Thad Van Gilder]

ahh, pollution... Cape may Harbor is much more polluted than Somer's Pt... That could be an answer!!!!

Downey, Yup, is you got silver ringnails that are more than a few years old and still good, they must be monel. Lucky bastard!!!! monel's nice!

-Thad

[Thorne]

Actually these are beensie little clams, and they each have a foot -- seriously! But they can sure get a lot of feet into one worm shoe...

;- )

Pollution benefiting wooden boats -- what a reversal. Was it the latest edition of WB that had the article about the Wasa, and how the timbers were preserved in the water partially due to the pollution near Stockholm?

[neptoon]

I could be wrong but I thought the idea behind the shoe was to give the worms a place to eat and give you an easy replaceable item....working like a zinc...for errant current.....these raging worms might make the effort to eat above the shoe

[sdowney717]

As an update they told me you can use this plastic lumber underwater and it will not swell or fall apart. And it will support the weight on the hard.
But they dont sell it unless you order $500 worth or more.
So I gave up and bought some 1 by 4 knot free clear treated pine and will cover the outside with 20 oz FG cloth. I will glue the cloth on with the permaflex.

Yes, a worm shoe is a sacrificial part meant to be easily replaced and act as part of a worm barrier to try and keep worms out of the keel. Because, when the boat is in the water, bottom paint will scrape off the bottom of the keel, exposing the wood and give worms a place to start. But this wood is not any more tasty to worms than any other wood.

[seo]

The sailboat I have now has copper (maybe bronze) sheathing on the keel foreward and aft of the ballast casting. It's nicely shaped around the keel, and the rudder is sheathed too.
She was built in '56 by Nevins and spent many years in the Chesapeake, Florida, and the Carib. No worms.
The sheathing looks to be 11 gauge (1/8") thick.
On other boats I used pressure treated pine (probably shortleaf southern pine) over tar paper. My theory was that the shoe was there to protect the paint on the keel bottom and the tarpaper membrane.
Now I don't use tarpaper much. Bituthene is more effective, and lots more fun to use. I've been told that an effective emergency-duty condom can be made out of bituthene, but can't testify to that...
seo