View Full Version : Keeping the water out: choice for old boat.

Denny S. Anspach, MD
09-04-2005, 10:54 AM
For some 20 years I have been episodically rebuilding/restoring a very much complete incredibly-graceful 16' Truscott fantail launch c. 1896-1910. The original basic construction was clench-nailed carvel-planked and caulked cypress on bent oak ribs. However, the nails were driven "hot" (no pre-drilling), and over time, virtually each and every rib failed at the nail sites. I have replaced ALL of these ribs, and changed the fastening mode to predrilled copper rivets and roves.

The big hangup is how to proceed from this point. To be useable, the boat has to be able to be day-sailed, a very difficult proposition with this type of construction- with respect to keeping dry, keeping hull shape, and maintaining a fair appearance.

The seams are very wide, apparently a reflection of cypress's reputation of being remarkably hydroscopic. Many years ago, I corresponded with John Gardner on this issue (a privilege I earned as a one-time student of his at a Mystic small boat-building course). His advice was to drench everything is hot linseed oil, and then conventionally caulk the seams. Well, with the highest respect, I believed then, and am convinced now that this simply would not work for very long, especially in this climate.

I have then contemplated wedging the seams with cedar. This allows a potentially fair and tight dry hull that will maintain its shape both in and out of the water. This is still a viable idea, but I am very much concerned that with seams this tight, any significant swelling of planks might well pull the ribs apart.

I have also considered some various combinations of the above, coupled to the use of two part polysulphide- a truly wonderful substance- and epoxy "encapsulation" of planks to limit moisture-driven wood movement (I have a relatively broad experience with these substances dating back to late '70s).

I am very much interested in comments or ideas. Creating a tight fair hull that will remain so in and out of the water is a goal. A secondary philosophical goal, of course, is how far I am comforatably going in this process making irreversible changes in basic historical construction- in the interests of modern use and requirements.

BTW, the boat described is a more complete and original direct sister of a lovely launch that resides in the center of the floor main marine gallery of the Deutche Museum in Munich. It is also a sister of launches that were purchased for public use in the lagoons of the St. Louis Exposition (1904?).

I welcome any and all comments!

Thank you.

Denny S. Anspach, MD

Bob Cleek
09-04-2005, 11:45 AM
Oh, gosh, you really have considered all the variables here. I am afraid I agree with all of your conclusions. Others may have all sorts of suggestions, such as slathering epoxy and glass all over her, but I have to say that it seems to me this is a boat that is intended to remain in the water, particularly with cypress planking, and there really isn't a solution that would allow her to be turned into a trailered boat while maintaining her historical (let alone watertight) integrity. I'd be looking for a covered berth somewhere in the Delta. She'd be happier there.

09-04-2005, 12:03 PM
Dr. Anspach,

I do runabout restoration here in Seattle; I believe I recognize your name from the Tahoe festivities.

I'm leaving shortly; I must be brief. You've demonstrated that you have a very nice even historic boat. The best advice I can give you is one that you heard many years ago: do no harm. Wedging the seams or slathering the hull with goo is not going to win you thanks from the next guy that will own your boat.

I would try to find a solution that is minimally invasive. The best would be to keep the boat in the water and trailering the boat. When trailering the boat, be sure to have a cover which will protect the hull from the withering 60 mph wind it will experience when travelling.

Second choice: Swell the boat by being in the water a week. I have had good luck raising/stabilizing the moisture content of wood by getting planer shavings, putting them in a garbage can and filling with water. Then the shavings are distributed under the boat in a layer a few inches thick. This will stay moist for weeks and provide an island of humidity. A few inches of water is maintained inside the boat.

At this point don't simply throw plastic sheeting over the boat. This can lead to imbalances in moisture content inside versus outside planking. There are plastic temporary garages for sale for about $150 (thank you chinese slave labor) These are just dandy for such a use.

Of your suggested remedies, polysulphide might be my choice. Perhaps it could be combined with the above suggestions.

Best of luck!!!
Pat Ford

09-04-2005, 12:25 PM
Seems like with the lack of humidity there you dont have much choice other than to close the gaps with the wedges.Have you tried soaking the hull yet to see if they close up?Other than that with a historical valued launch like that it would seem it would have to be stored in a climate controlled space with a humidifier or something.There was an old man here about 10-12 yrs ago that had an old sail boat he was restoring over the course of about 4 years and towards the end of the project,he had irrigation misting sprinklers on a clock that would give the hull a dose of moisture 2x a day.From there it had a catch drain at the rear of the boat that enabled the water to run out into his garden bed.That sounds extreme but people do some funny things sometimes.It was actually pretty clever if you think about it.The only problem he said was that with his oncoming senility,he would forget that it was on and while he was working in the boat he or his tools would get spritzed by surprise.When he first installed it,the hull leaked alot from everywhere. After 2 days it had stopped completely allowing him to regulate the sprinkler clock to less days.

Paul Pless
09-04-2005, 12:28 PM
wow, i can offer no advice, but request that you post a few pictures of what sounds like a cherished boat

[ 09-04-2005, 01:29 PM: Message edited by: Paul Pless ]

09-04-2005, 03:00 PM
I once had a 15 foot lapstrake boat that did a wonderful imitation of a wooden collander for the first week it was in the water. I also had an old (and fairly worthless) 17 foot fiberglass runabout. I figured with a couple of cheap engine hoists (I got one at an outlet store for $99) I could just fill the hulk with water (adding some salt to inhibit rot) and drop the lapstrake in when she wasn't in use. Then I could pull her out and drop her on the trailer.

However, I sold the boat and undertook other projects before I tested out my solution. Heck, I even sold the fiberglass hulk.

Good luck

[ 09-04-2005, 04:01 PM: Message edited by: nutmeg2go ]

Ken Hutchins
09-04-2005, 03:04 PM
Heck, I even sold the fiberglass hulk Somebody bought it???? :D

Denny S. Anspach, MD
09-05-2005, 09:33 PM
Thank you all for your thoughtful replies, which touch on a lot of relevant issues. My doubts and concerns are the same as yours.

Keeping this boat in the water is simply not in the cards. Its destiny is to be kept dry and under cover, with seasonal short periods of use. During the season, however, it eventually may be suspended over the water rather than being kept on a trailer/cradle. I have spent many early years with boats (plural!) that had to be soaked for days before floating, and this cannot be one of them. Times have changed.

Some of you have spoken to the moral issue- that this boat could be perceived as "historic". I am aware of this and it is a factor that ticks my conscience. On the other hand, the boat is not is not intended to be a museum piece. If it was, the boat should probably have been left as it was (intact, although "losing support"), or, I should be restoring it with the freedom knowing that it will never again have to go into the water.

The boat is already increasingly not original. I have spoken of all the new bent ribs, and the substitution of copper rivets for galvanized steel clench nails. There are all new floors (oak instead of cedar) fastened with beeswax-coated silicon bronze screws instead of galvanized nails. There is a new oak keel and gripe.

The hood ends of the planks are bedded with two part polysulphide into a rebuilt but largely-original stem piece. Of the basic hull structure, only the planks, most of the stem and deadwood are original- and of the planks, all but one sheer plank is near-perfect (the sheer planks are white oak).

I am preparing to make a detailed assessment of seam widths so I can have some idea of what has to be be expected to close them. The worst, and the one I am most concerned with are the garboard seams, parts of which appear to be about 5/16th" . Inasmuch as based on relative sizess alone, the keel has the potential to move much more (or less) than the adjacent planks, so how to make such a broad flexible closed seam (that will stay closed) is a major preoccupation.

I feel that I probably will likely be treating the garboard seams differently than the rest.

Wedging seams with cedar is a time-honored method, historically largely done in Scotland on larger boats. However, I have talked with no one who has attempted it on a small boat of this size. The advantage of course is that the hull can be made completely fair, both in and out of the water. Whether the wedges would be glued (epoxy). or simply held in by friction, varnish or paint, or a "water-resistant" white glue, I do not yet know, as well.

I do not rule out epoxy encapsulation to stabilize the wood. I am very much aware of cautions, and that if done it is a one way trip- so it had better be well thought out ( not yet reached !).

This hull was basically inexpensively constructed to a price (but also with remarkably graceful lines, with a high level of fancy detail and joinery) ; and for a useful life perhaps of ten years or less.

I have always believed believed that there is no particular credit to reconstruct/restore a boat in a way to just fail again, or to just to provide another short useful life. In this way, I am not at all afraid to apply any useful method of modern technology in the restoration process- providing that the technology does what you actually want it to do.

Yes, I was at Lake Tahoe for many years, serving as Chief Judge at the Concours d'Elegance for four years prior to retiring "forever" in 1991. Your memory is good!

If I could find someway to post photos on this forum (I don't believe it is possible), I would scan some slides of the boat so that you might see for yourself the sheer grace of this small motor boat.

Denny S. Anspach, MD

09-05-2005, 11:47 PM
I have a similar dilema with a Kettenburg that I working to restore to sailing condition. Restore in the sense of restore to functionality - not restore to original (especially as it is almost impossible to determine what original means from nearly 60 years distance).

Anyway, my question is, have you considered using redwood as a seam (wedge) material? I've been considering the idea, since redwood is pretty rot resistant, and pretty soft. It is my idea that redwood will compress much easier than other woods. Am I missing something important, or is this an idea worth considering?

Dan McCosh
09-06-2005, 05:16 AM
Polysulfide itself is not going to allow sufficient expansion/contraction to allow drysailing a cypress-planked hull. I've only seen one of these, and the seams indeed were very wide. It's an unusual wood in that it is both fairly hard and swells a lot when it soaks up. It's probably the worst wood to contemplate dry-sailing, while being a rot-resistant and good planking material for a boat that stays in the water. I don't think there is an answer other than using it as it was intended.

[ 09-06-2005, 09:46 AM: Message edited by: Dan McCosh ]

09-06-2005, 08:43 AM
The solution is simple. Send the boat to me. :D Then hire me to build you a different boat that can be trailered without worrying about taking up.... Simple! ;)

Dale R. Hamilton
09-06-2005, 09:49 AM
Historical significance be damned- the first task of a boat is to keep the water out- and when you complicate the issue by keeping the boat dry much of the time- you must resort to novel solutions. I'd wedge the hull, fair it smooth, then glass it with 2 layers of 8 ounce cloth. Fair it again, paint, and you have a hull that is both beautiful and will endure the conditions.

Dave Carnell
09-06-2005, 09:51 AM
Back around 1980 a 26' reproduction surfboat at New Hanover County Museum was taken out of the water and put in dry inside storage. Within two months all of the lapstrake planking joints had opened, as shown by the broken paint film on the outside. The curator agreed to my suggestion that I treat it with antifreeze. The boat had an oil finish inside and oil-based enamel outside. I loaded a garden sprayer with antifreeze and wet down the inside. Every plank joint dripped on the floor. After three more treatments 1-2 weeks apart, not a joint leaked and all of the breaks in the outside paint had disappeared as the juniper boards swelled back together. I was surprised that less than two gallons of antifreeze were needed for the successful treatment. The boat stayed tight for over ten years in shaded outdoor storage. After I reported this at the Small Craft Curators Conference in 1986, George Surgent at Calvert Maritime Museum reported that he, too, had used antifreeze to swell hull planking. You can minimize the leakage through the seams while treating by lining the hull with something absorbent such as old newspapers. In addition to swelling the wood, you will kill all rot organisms and protect against future attack.

09-06-2005, 10:11 AM
Dr. Anspach,

Wedging the hull creates one plank from garboard to sheer. It's fair to say that wedging had a popularity around Seattle in the 60s and early 70s. Works fine for a hull that will stay absolutely stable. You are creating a plank whose width goes from the garboard seam. If there is any movement whatsoever in the wood, you will have a split wedged seam. Does not look good. Cypress is a fairly rare wood around Seattle. (Though Fertello Woodworking is doing an entire house interior with the stuff!!!!) I assume the others comments that it is not particularly stable is true.

Many runabouts are dry moored around here. They are soaked up in the spring using Slick Seam and then used occasionly. If stored in an appropriate place this is the best solution in my humble opinion.

I think that a reasonable solution is to replicate the hull in cold molded construction. 'Course, like the other fellow, I would love to help with this.

Denny S. Anspach, MD
09-06-2005, 02:07 PM
I am not adverse to thinking very selectively about the use of expoxied cloth. If so, I would probably still favor polypropylene cloth (if it is still available) over fiberglass because of its superior drape over compound curves.

I successfully did exactly this it before on a cedar-strip bent-rib runabout 26 years ago (it subsequently won 98/100 points at the New England boat show on L. Winnepesaukee!). No one (no one) yet picks out that the hull is cloth covered, and when I last looked at the hull about three weeks ago, it was still tight as a drum, and the individual seams show through the filled cloth only to the extent that you still know the boat is planked.

The only significant error that I made on that application was to stop short of the garboard seams (feeling then, and still questioning now whether or not the cloth could withstand any mass movement of the keel; -of course, if the keel is covered, how much would it then really actually move?). These seams have been sources of leaks ever since (manageable, however).

The ideas on "pre-swelling" the planks are very welcome, and I am paying close attention. This offers so many advantages to the dealing with hull issues. When Dick Clarke at Sierra Boat Co. at Tahoe was applying his distinctive structural fibreglass bottoms to runabouts and cruisers in the '70s and 80's, the planked bottoms underwent days of wetting down by a lawn sprinkler perched in the center of the overturned hull. Before applying the fibreglass he would "dry" the planks with acetone (I am not sure how that works). Two boats so treated (1976, 1982) are still in our family, and again, both boats still serve daily in season without any visual or other indication that the bottoms are anyting but original.

09-06-2005, 04:29 PM
How about this.
Fill your seams with polysulfide caulk.

Use Dynel Cloth with Sanitred Permaflex to coat the hull.

www.sanitred.com (http://www.sanitred.com)

The Dynel will stretch and so will the permaflex. So if the wood wants to move around, it can without breaking the seams.

Simply coat the hull with permaflex, lay on the cloth, then coat more permaglex on top.

Roger Cumming
09-06-2005, 10:58 PM
I am with Cleek on this one, having tried valiantly (and somewhat ignorantly) many years ago to to treat a Scandinavian-built tight-seamed sloop as if she were conventionally built. We hauled her every winter, kept her covered up into the spring and sometimes summer while the heat built up inside her black-painted hull. We watched her seams open up and then leak badly when she finally went overboard, usually spending the night in the slings of the travelift. After 5 years of this treatment she needed refastening. The boat needed to remain in the water year round or, at the very minimum, to be hauled late and launched early, be stored outside but under cover out of the wind and sun, and have some linseed oil treatment at least once during the winter. And probably be painted white. The worst effect of the annual haulout is the shrinkage of the planking and the consequent stress on the plank fastenings. This is especially true if the hull is planked with a wood that "comes and goes" a lot.

09-07-2005, 07:59 AM
All you have to do is preswell the planking.. although having a boat that is designed to be drysailed would be better.

If you really want to be efficient, you can make up a preswell setup you can use before you take her out.

Get a decent continuous duty water pump and 4 (or more) water saver shower heads. Make up a simple setup that would fit under the boat, made of inexpensive home depot plumbing parts. The shower heads should be pointed at the bottom of the boat and be on wide spray. Get some pond liner and make a frame out of 2x6 stock that surrounds the boat. Get a tarp or tent that can be reasonably closed around the boat to prevent too much evaporation.

Ok.. dump a bunch of water into the pond liner + frame and turn on the pump. The spray heads send out a fine mist, which then drips back into the trough. After awhile the planking should swell. Check the water level each day and make sure it stays topped off. I really don't have any intuitive sense of how powerful the pump should be to power this setup.. you'll probably have to ask a plumber some questions.

When done, you can just turn a valve and send the water into a ditch or drain, and get the framework put away in less than 30 minutes, I am guessing. This is more expensive than the garden sprinkler version, but saves a LOT of water and can be reused over and over. The water saver shower heads are easily found and inexpensive. The most pricey part of this setup will probably be the pump, but I imagine you could give it double duty as an emergency sump pump for your house. If you wanted to get fancy, you could rig a float valve that automatically topped off the water level.

Get creative! :) And please let us see photos of your beautiful boat.

[ 09-07-2005, 09:02 AM: Message edited by: TimothyB ]

09-07-2005, 11:29 AM
Iīm a little surprised that Dave Carnellīs post was not considered worth a single comment! If "antifreeze" doesnīt seem convincing, Ethylene Glycol might sound better. :D

I havenīt tried it myself, but I have heard of several succesful cases. And it sounds quite logical. It would be easy to test it with a piece of cypress and some good measuring instruments.

I almost got the impression here that everybody already knew itīs not going to work :confused: .

Anyway, if glycol is feasible, it would be in line with John Gardnerīs comment: The Logical way is to impregnate the wood with something. He mentioned linseed oil. Surely there can be other stuff. Methinks glycol is a good candidate, or is there some research indicating that it isnīt? smile.gif

09-07-2005, 01:47 PM
Yes it would work to swell the planks and they would not dry out like when plain water is used. I think some people dont like the thought of using ethylene glycol car antifreeze because it is poisonous or perhaps they think it may affect future gluing properties of the wood. One advantage is it will kill rot.
I have often wondered if the weight of water soaked wood is ever a consideration as opposed to glooping on fiberglass cloth and some sealer. Is a dry sailed boat if sealed from the water generally lighter than one where the planks are saturated?

Dan McCosh
09-07-2005, 02:03 PM

Gary E
09-07-2005, 02:11 PM
I loaded a garden sprayer with antifreeze and wet down the inside. Sounds interesting...was it straight or was it cut with water? what ratio?

Is he claiming that it never evaporates?.. it does, but not as fast as water.

Since this was done to a boat that never went back into the water, would it work on one that did?

As for the rot preventing properties, ok, any proof of that, or is that an old salts tale?

Denny S. Anspach, MD
09-07-2005, 04:35 PM
Well, I am convinced that in order to make reasonable decisions, I must soak the boat to see how the seams behave. I will probably use a soaker and a lot of burlap to conserve water (the California water vigilantes look askance at water pouring out of the drive into the gutter).

Storing/moving/operated a boat with dry seams is how so many small wood boats fail. The fastenings are doing all of the work, and as more and more of them fail, the ones that are left collapse under the load.

Dynel: tell me more about this unfamiliar cloth (unfamiliar to me). I would presume from comments that it could and would drape in one piece over a round half-hull?

Sanitred: this is also completely new to me. What is its history, and longevity in situations like this? Is it sufficient enough adhesive that separation is not/will not be an issue, and that it can and will contribute as a structural skin that will substantially support the hull?

There are other thorny issues with this boat for which I will be seeking guidance, but one thing at a time!

I will scan some slides in the next week or so, and I would be happy to send them to a reasonable number of listers privately off-line.


09-07-2005, 04:57 PM
Denny -

If you ever make it over to SF Bay, check out Smith and Co. right off the 580 Freeway in Richmond. They have a rather home-grown perspective on wood-preservation products, and might be able to answer your technical questions.

Some of the interesting products they sell migrate along the grain of the wood like water, then seal it all against water penetration along the grain.


Best of luck! I know how bad the sunlight and low moisture are out here, having lost the battle on a few small wooden boats myself -- and am building the next one from marine ply and sealing it well.

[ 09-07-2005, 05:58 PM: Message edited by: Thorne ]

Stephen Hutchins
09-07-2005, 05:21 PM
What about elastomeric caulking? I have no experience with it but it might be worth checking out for yourself.

09-07-2005, 09:12 PM
The sanitred is a very good adhesive elastic type of material all by itself. However since the planks will likley move around, it may need something extra, the Dynel is somewhat elastic unlike fiberglass which will simply crack under the pressure.
A nylon or polypropylene fabtic wil also give stretch under pressure and you need something here that will have some give to it as the planks change dimensionally with moisture changes.
I have used quite a lot of sanitred permaflex and actually it is a very good glue for laminations. It forms a hard rubbery shiny surface on whatever you paint it on. It will soak into cracks and small holes, And it soaks into endgrain just like water. It looks like a thick paint. If the surface has any oil or the wood is oily you wont get it to adhere. Oil and polyurethanes dont stick to each other.

09-07-2005, 09:23 PM
http://groups.google.com/group/rec.boats.building/browse_frm/thread/fca3443b459fb20c/202090c1f26c112f?lnk=st&q=dynel+clo th&rnum=4&hl=en#202090c1f26c112f

If this thread works you can read about others experience using Dynel

09-07-2005, 09:26 PM
guess you have to copy and paste the whole link into the browser.
I would totally agree with his observations about Dynel written right here.

4. Ken and Clara Jun 13 2000, 3:00 am show options
Newsgroups: rec.boats.building

I have used Dynel cloth in some areas on a 28' cat I built 15 years ago. It
is harder to work with than fg. It doesn't 't cut as smoothly, it floats in
the resin therefore you apply it to a thin coat of epoxy and as the resin
gets stiff you roll on additional resin. It has some great qualities that
make it worth the extra trouble. It stretches and lays smooth over compound
curves, it does not cause the itch when sanded (it is hard to sand though,
the sand paper wants to skid
off it) it resists being scratched and scuffed which makes it great for a
boat bottom. It is difficult to get smooth feathered edge when sanding. As
to using the prepreg vs glass mat over plywood I assume you mean using
polyester resin and mat. I would choose epoxy over polyester any day, the
extra expense does not amount to spit over the total cost of the completed