Cold Molded Construction -- Why Not?

[Wayne Jeffers]

I've been looking for/at designs for small trailerable cruising sailboats. My first choice would be cold-molded construction in order to achieve a tight rounded hull form and to avoid dependence on plywood as the principal material.

After what I think is a fairly thorough search, I've found no designs in the 18- to 22-foot range designed for cold molded construction. Nada! Zip! There are several designs under 12 feet and plenty over 30 feet (especially catamarans and trimarans), but none in between that I have found.

I'm seriously considering commissioning a design by a respected naval architect in cold-molded construction. This is a step I had not really considered ahead of time (my inquiry about a stock plan started this dialog), but I've received a preliminary sketch that I like a lot. He's quoted a price for full development of the concept that is a lot more than the price of a stock plan, but reasonable given the amount I expect to spend in construction. And besides, I may build only one boat of this size in my lifetime so it may as well be one I really like, eh? :D

Before giving the go-ahead, I'm pausing to decide if I love this idea as much in a few days as I did when I received the sketch a week ago. And I have to decide whether I can handle with only a little help raising a mast the length required by the rig he has suggested. Besides, I'm usually not so impulsive. ;)

I know cold-molded construction requires more labor than sheet ply or lap-ply, but building a boat is the second most fun thing one can do with pants on. :cool: Right? It's hard for me to figure why there aren't at least a few designs this size in cold-molded construction. :confused:

So my question for this august group: Is there something about cold-molded construction that makes it ill-suited for a design this size?

Wayne

[On Vacation]

Wayne I consider myself an expert in cold mould construction as having about 20 years in hands on work in this method. One reason in this type construction is labor intensive for the size in small craft construction. In this length, designers are selling to many novice. The amateur has no knowledge of jig building or fitting. Many care not to put the time involved in this type construction. This is why you don't see a lot out there. Feel free to ask follow up questions.

BTW, this in no way am I saying that I know it all. Just so you understand. This is my read.

[ 08-22-2002, 09:36 PM: Message edited by: oyster ]

[NormMessinger]

Cold molding, that's sort of like making your own plywood, right?

--Norm

[On Vacation]

:D

[Wayne Jeffers]

Thanks, oyster! I can't think of anyone whose opinion I value more on this subject.

Yeah, I know cold molded takes time but I'm gonna be following your example (retirement) in a couple of years and this will be my first retirement project. :D

I know fairing the building form/jig is critical to cold molding and I know there must be many people who might build a boat but would not want to go to that extra work. But don't you think there would be a few cold molded designs out there for folks like me who would like an alternative to plywood for a small trailerable cruising sailboat?

If there's any structural/performance drawback to cold molded construction, I don't know what it may be. Is there something I'm missing?

Norm -- Yeah, making your own plywood. . . but with compound curves!! :cool:

Wayne

[ 08-22-2002, 10:17 PM: Message edited by: Wayne Jeffers ]

[On Vacation]

Cold mould boat building, if done properly with the right materials is as strong a construction in today's building industry as you can get for the dollar spent. It allows more room inside and a cleaner finish to work with , also.

As far as making your own plywood, as Norm states, it makes no smarts to use solid veneers. You end up with a lot more fairing for the work involved and waste. The labor is increased with the before work required. In the long run, maintainance is less, extremely less than any strip planked boat design on the market today.

Posted by Wayne:
"But don't you think there would be a few cold molded designs out there for folks like me who would like an alternative to plywood for a small trailerable cruising sailboat"

Visit some plans board and just read some questions of persons buying plans for 18 to 22 foot sailboats. I have not found any qualified to be on the water to start with reading the questions 101 that is asked much less laying up and building a cold mould vessel.

[ 08-22-2002, 10:36 PM: Message edited by: oyster ]

[CharlieZ]

Functionally, I think it's the best method of building a boat. It has the best properties of 'glas boats (maintainability) and wood (solidity, sound, beauty). It is usually ridiculously strong, too.

We had the Alexandria Boat School (Geoff Kerr - now at Two Sisters - and Joe Youcha) build us a coldmolded '21 daysailor that will outlast me. Joel White helped with the design change to go from carvel to cold. I'd love to have a lobster or bass boat built cold molded, next.

But, I hate working with epoxy and would build a traditional wood method if I were doing it myself.

[John E Hardiman]

Wayne,
E-mail bainbridgeisland. I know he designed and built a couple of MORA boats (Midget Ocean Racing Association, think Moore 24's, Santana 22's) out of San Francisco in the late 70's/early 80's using cold molding. Two of those, CRITICAL MASS and BLOOM COUNTY picked up a few pickle dishes in their time. He may have some insight as I know he has given me a lot of it.

[imported_Steven Bauer]

Don't forget the cold-molded Eun Mara featured in Watercraft magazine.

[Wiley Baggins]

After what I think is a fairly thorough search, I've found no designs in the 18- to 22-foot range designed for cold molded construction. Nada! Zip! There are several designs under 12 feet and plenty over 30 feet (especially catamarans and trimarans), but none in between that I have found.

-Wayne JeffersWayne,

I assume that you mean you have not founda boat in the 18- to 22-foot range that you like. MattM posted a link ( http://www.gartsideboats.com/catsail3.php#weekender ) to a gorgeous (to my eyes) cold molded 22-footer. Also, Tony Dias ( Dias Designs (http://www.diasdesign.com) ) had an attactive, trailerable (but not a trailer-boat) design in WB a couple of years ago (I belive that it was INDIAN HEADER in WB No. 140 ). That design was probably strip planked but I'm sure that he would provide a cold-molded alternative. The design is, unfortunately, not shown on his site. Good luck!

[JimConlin]

Other than a few test panels, I have no experience with cold molding, so take with a grain of salt.

I think that the following have been discovered:
Cedar veneer cold molded boats, while very strong and stiff, needed a glass overlay to get acceptable resistance to dings.
(A glass layer stiff enough to offer much ding resistance is not transparent. That's why we see fewer bright-finished cold molded boats these days.)

If, for practical reasons, there's a glass skin over the soft wood, and the glass serves a structural purpose, so much the better.
If the glass cloth skin offers about the same strength in all directions, why not orient the wood in the direction that he hull shell needs more strength in? In sailboats particularly, that's the longitidinal direction.
If most of the wood is going the same, long, easy-bend way, why bother to slice it up into skinny wobbly slats and goop 'em back together with lots of expensive goo, fairing at every step, when the fattest stick that can be bent over the mold will yield a fair shape with less sawdust, less goo and less fairing?

And that's why strip composite has pretty much replaced 'cold molding' (veneer composite).

Jim

[On Vacation]

http://www.imagestation.com/picture/sraid15/pe7c62894dcfc6b015b3f9e54e8f0031c/fde67f23.jpg
There is a lot of work in the jig before you start the boat.
http://www.imagestation.com/picture/sraid15/p5c5bb5290bd742edd732cf83a82bfe09/fde67f1d.jpg
Sheet plywood will not compound bend in most hull designs that are rounded. That is why you need to strip it to verious widths to do the job.

http://www.imagestation.com/picture/sraid15/p897825cfa61bd5300bbfc4b1b4f7df06/fde67ed8.jpg

If using planking strips longitual, framing inside is key to the construction. The weight issue comes into play at that point. You loose a fair amount of interior space. Your bilge area is not as easily cleaned. There is just a lot of pros for cold mould type construction.

The cost of composite construction runs about 50 percent more per sheet and it requires more glass and more reinforcement done cold moulded.

A trailer stored boat, built cold moulded, can get a lot more years on a trailer without maintainance than a strip glassed boat also.

[ 08-23-2002, 07:06 AM: Message edited by: oyster ]

[Dave Hadfield]

Sure you have to build the hull 3 times with CM, but so what? By the 2nd and 3rd times you'll be pretty quick at it, and 22 ft isn't all that big.

Also, building the hull is only about 1/3 of the work. Finishing and rigging and systems installation take the longest time.

Build what you like.

[Charlie J]

Cold mold isn't all THAT slow either. I planked up my 32 foot amas on a 35 foot trimaran (Cross design) in nine days each. Two weekends and a weeks vacation time for each ama. 3 layers 1/8. I did have my ex helping to wipe down drips and runs.

Spiling was all done by hand with an old #220 Stanley block plane.

[ 08-23-2002, 09:01 AM: Message edited by: Charlie J ]

[Keith Wilson]

Just a thought - If you have a design you really like, converting it to cold-molded construction would be a lot easier and cheaper than starting from scratch. You could enlist the aid of the original designer if he's alive. Otherwise, I'm sure you coud find someone experienced in cold-molded bosts to work out the conversion for you. There are quite a few boats that are built both ways, the Haven 12-1/2 for one. There are some things to work out, of course; cold-molding is lighter for equivalent strength than plank-on-frame, so you may want more ballast, for example. Cold-molding has fewer restrictions on hull shape than any other method of wood construction, so conversion is certainly feasible.

I think that the only reason we don't see more cold-molded boats in that size range is that it's more work: a complex mold, still have to spile planks (several times!), loots of goop, lots of sanding to fair the hull. Norm is right, it's building you own boat-shaped piece of plywood. It's your time, though, and the results would be very nice. From a purely functional point of view, it's the very best type of wood construction for a trailered boat IMHO.

[Buddy Sharpton]

Wayne, you've passed the exam when you said you have fun building boats, as opposed to can't wait to get on the water.

A cold molded hull is more time consuming to build than a plank on frame or panel boat hull ,but the hull is only a bout a third of the work. The rest is just the same as a "regular" boat.

Cold molding done right is as maintenance free as anything I know about. If you're storing on a trailer there none better for keeping the shape.
Stringer and lighter than anything out there.

You've just got to not create voids in the layers by scrimping on the thickened epoxy slathered between the layers. Be prepared not to stretch the
goop in a false sense of economy.

Anything drawn for carvel or strip production can be cold molded without a new plan. If you figure on making a hull as thick as the planked version, you will in fact be better built. You won't have frames to locate your bulkheads and such so you will need to gusset them in or make lands or cleats for them is all.

All in all, you avoid a lot of needs to people work like planking. Great way for one guy, who has to work in time increments anyway, and will gratefully go to bed while the last batch of epoxy cures.

So don't rule out the consruction method because the boat plans you like don't show cold molded. You can see what a similar size/weight cold molded boat uses and get a great idea of the scantlings you should use.

[garland reese]

Hey Wayne,

You should get in touch with Tony Dias. He does a very good job of blending traditional design and modern methods/concepts. He does have some small boats in the 18-23 foot range. For the most part he designs in strip composite or foam core construction, which would translate easily into coldmolding. The 29 footer (Brochman?) in TX is being done in cold molded construction.
The Eu Na Mara can be done that way and has been done that way. WaterCraft did have a multi-issue story on one cold molded 'Mara.

I just got Tony's Book, and a bit more info on "Buck". "Buck has sitting headroom (3" over the bunks). The Vee berth is at seating height and the table can be lowered to fill in. The centerboard trunk rises above the sole but only to the level below the bunk.

Towing weight would be the displacement minus the crew weight and plus the weight of the trailer.

I don't have Tony's design catalog, but he has Galena and Annebelle II, which may be close to your size range and they are very pretty. There is also Trooper. All of these designs were involved in the discussion, and in the final synthesis of the Indian Header 23' that was mentioned in a post above.

Sorry, don't mean to ramble on about Mr. Dias; there are many designers to choose among. I do think that there are exsisting boat designs out there that will meet your requirements, and are designed for, or can easily be modified for your preferred methods of construction. I am starting to see the value in considering the support that you might get from the designer, when choosing a design. Especially if you feel the need to modify methods, or layout, or rigging, or whatever.

If there is a design that you "mostly like" (ever seen Princess Bride............"he's only 'mostly dead.'"), from a designer that is accessible and that you feel you can work with, I'd bet you can work together to come up with a few changes to make something that suits your fancy just fine. And maybe you won't have to start totally from scratch.

Getting serious about your search this early is a wise thing on your part (you said you were a year or so out from starting construction didn't you?). It will give you time, if you need it, to work with someone who can help you get what you want, and you can spread the potential costs of a custom or semi-custom design out over a period of time.

I appologize if I overstep the boundries with my opinions. I am pretty much where you are with my boat dreams, and I find this both intriguing and educational.

Good luck,
Garland

[Garrett Lowell]

Oyster, have you built (or heard of) a cold molded boat that had the final layer running longitudinally, like strip plank, and finished bright?

[On Vacation]

You are real limited with the design and the width of strips in doing so. Sheerlines play a big roll in this as does the amount of flare in a runabout. I am sure that you have seen more sailboats done that way than a custom broken sheerline runabout. Many of the older wooden varnished hulls were done that way.

[paladin]

I built a 24 footer by using a sabre saw, skilsaw, power plane and sander for all the framing.........if you use narrow strips...perhaps 2 1/2 inches to 3 inches wide throughtout, you can build the entire boat with a box knife and a box of blades. Balance your layers and adjust the thickness...for instance on a boat about 20 feet long, divide the the proposed hull thickness by four and use that as a veneer thickness to work with. Put on the first and last layers longitudinally with the inner layers at a 45 degree angle, then final finish with a fore and afte 1/16th inch layer of veneer. Most of this will be sanded away when you sand the hull fair...then Xynole epoxy and paint to finish.....

[On Vacation]

On batten construction, you can't put on the first layer fore and aft. It will have to be framed. Without frames, you have to have the longitual battens and bulkhead along with covering boards or built in seats for strength and to keep from twisting.

[ 08-23-2002, 12:39 PM: Message edited by: oyster ]

[Wayne Jeffers]

Thanks for all the input!

Oyster – If you're posting before 5:00 a.m., I hope it's because you were up to get in some fishing or gardening before the heat of the day sets in. smile.gif

I know various designs can be converted to cold-molded construction and I wouldn't hesitate to do this myself for a small boat. For a 20-footer, I want to build to plan, without deviation (except perhaps for non-structural elements). I know that if I start changing things, I will almost surely overbuild to make sure I don't weaken something important, with the result that the boat will be heavier than it should.

Well, when I posted, I forgot about the few stock plans for cold molded hulls I had seen in this size. (Hey, it was at the end of a long day. :rolleyes: redface.gif ) I had even contacted Mr. Gartside about #106, the 22-foot cold-molded double-ended sloop. He advised that it was trailerable in the sense of moving from one cruising ground to another a couple of times a year or for taking home for the winter, not for living on a trailer as I require. Displacement is 4200 pounds; it's not a lightweight boat.

The layup mentioned for the custom design would involve a first layer of horizontal strip, followed by two diagonal layers of veneer. I haven't yet asked whether this means the jig is basically closely spaced molds, without all the battens that are normal in the setup for a first layer running diagonally. There will be time for those questions later, if I decide to go ahead with the custom plan.

This thread confirms my faith in cold molded construction and ends some nagging doubts as to whether I was missing something that should set off alarms.

Thanks, everyone. I'll let you know what I decide and how it turns out.

Wayne

[NormMessinger]

Speaking of cold molding, the last issue of EpoWorks had an article on a 155' sail boat being built in Wisconson?. Cold molded using WEST epoxy, of course. But the point of the artilce was the test Gougeon bros did to determine how much force it takes to pull a threaded rod bedded in raw epoxy out of a hole. The keel bolts will be 1-1/2" in diameter and bedded, not through bolted, in the keal.

--Norm

[On Vacation]

I would like to comment on the issue of battens and fore and aft first layer. Being built on battens and first layer diagonal creates one less layer for the same strength and easier layup of pieces that have nothing to cover the seams to start. Without scarfs in the intial layup, we find that many highs and lows exist in the multi- curvature hulls.
And yes I was up a 3 A.M. for reasons I care not to speak about. ;)

[Tar Devil]

And yes I was up a 3 A.M. for reasons I care not to speak about. Linda, make him behave!!

Later,

Phil

[Tomcat]

One problem I have with CM is finding the veneer. The strips are easily made, but sawing ones own veneer is another thing. Dean is out of it. Where does one go to get good veneer? Ply does not inspire me. I am not saying I wouldn't do it, but it ads a level of uncertainty and cost for no return whatsoever.

I don't believe CM will last better on a trailer than strip glass. The cheapness of strip/glass is one reason for a number of methods disapearing, in my view. And there are tons of trailer boats that specify strip, though my experience is mostly with multis.

One other option in the size mentioned is the Chebecco, there is a strip, lap, and ply version. There is a web site, and article in WB.

[Tomcat]

By the way, there are several good books for CM:

Gougeon Brothers on BB

Ruel Parkers book, though that is larger boats, his smaller boats tend towrads ply, and he has a new book coming out.

The Laminated Wood Boatbuilder: A Step-by-Step Guide for the Backyard Builder. By Hub Miller. This last book is ficused on the one subject, and one of the best organized I have seen.

And for scantling rules you could apply to most designs:

http://www.macnaughtongroup.com/scantlingscm.htm

[Mark Van]

Jay Benford has some nice designs for cold molded sail boats in that size range, the 20 foot keel catboat in the book "Pocket Cruisers and Tabloid Yachts" is really nice, and complete building plans are in the book.
Mark

[Zane Lewis]

Here's a southern option for you.
http://noelex22.orcon.net.nz/

The Noelex 22 has a great reputation in New Zealand and Australia as a tough little trailer yacht that will cope better than most boats when things cut up rough. Will go to windward happily in 30+ knots. (The cover Picture shows a boat with a poorly done deck/cabin line.)
These boats are 3x 1/8"& glass over CM'ed or Glass production hulls. Displacement light of approx 750kg and 200kg of lead in the Centreboard. an 8hp OB in a well.

I have been racing on one in a our Under 26 ft division. Only the sports boats will touch us in less than 5 knots or more than 15 knots. They are a great little sailing boat. If the cabin line is well done they are a nice looking little boat. Sleep up to 4???. Ment for a family of 4 realy.

Not the most tradisional looking boat but a very compentant one that looks good. and has a nice shear.

Zane

[bainbridgeisland]

As pointed out by others, cold molding produces fine boats. Most designers working in wood will provide plans for cold molding on request. But as stated before, expect to pay a bit more for the extra work. Before you talk to the designer though, get a clear picture in your mind of the particular cold molded method you want to use.

There is more than one way to build a cold molded boat. Each way has tricks that will speed up construction. Thus cold molding can be as fast as strip planking.

Here is an example in the size range you are interested in: 22'-4"' sailboat, 8'-4" wide, 1700 lbs displacement, 800 lbs ballast. 2 layers of 1/8" western red cedar over closely spaced spruce longitudinals, sided 5/8" molded 3/4".

The jigs needed to construct this hull are station molds on 24" centers plus extra molds at each end of the boat to make 12" centers. The molds are to the inside of the stringers.

Here is the construction process including some of the time saving tricks mentioned above:

Pre-finishing most components really speeds up the closely spaced, permanent stringer, construction method. Pre-finish consists of 3 coats of epoxy, sanded ready for final coat.

Get out the keelson, stem, shear clamp and transom frame, pre-finish and install on jig. Pre-finish all the stringers on 3 sides. Prefinish the first layer of cedar on one side.

Temporarily screw the stringers to the molds. Install blocking between the stringers for floor timber webs, mast step and so forth. Spile the first layer of cedar, pre-finish facing inside. Glue the planks as you go, the edges too. Don't get more than a few planks ahead and clean up the glue as you go. Remove the screws holding the stringers to the molds as you go.

Spile the second and last layer and glue it in place. Fair the outside (very little should be needed). Glass with one layer of style 7781 glass fabric. Paint. Turn boat. Install the inside flanges, for the frames and mast step, to the floors (3 layers 1/8" spruce). Varnish or paint the inside of the hull. Hull complete.

Each method of cold molding requires a different dodge to be efficient. In the example given, extensive pre-finish turned a one hundred hour finish job into 3 days work.

I plank this sort of boat at about 8 square feet per hour per layer. This is about 4 square feet per hour for the two layers, 55 hours planking time for this boat. For this hull, finish painted and varnished, I would estimate 145 hours labor. This is about 0.7 hours per square foot for a finished hull. Keep in mind an inexperienced builder would take longer.

[ 08-24-2002, 09:04 PM: Message edited by: bainbridgeisland ]

[Jim Budde]

I looked at the Eel and lots of other plans before I decided on another direction. She can be build carvel planked or cold-molded. I cannot find his e-maill address, but a builder in Australia build her CM. He sent me a lengthly review of both the experience and sailing her. A very attractice craft. You can find him in MY BOAT section of this magazize. The boat appeared to have everything you have been asking for.

And of, course, if you do not find what you are looking for, having someone design your dream boat is the next logical step ... I like that idea.

[Leon Steyns]

Wayne,

Check out the Atalanta design at uffafox.com, designed by Alan Vines and Uffa Fox. The production boats were hot molded ones @ 26', but you could also use the plans to build her cold molded. If that's too big, there are also plans available for the 24' prototype. The 26' plans include a purpose designed trailer (needs a heavy towing vehicle, though).

Greets, Leon Steyns.

[garland reese]

Hey Jim,

Below is a picture of "Glory", a William Garden Eel, cold molded construction, by Robert Albers, a North Texas boatbuilder. I've had the priveledge to be aboard this little boat. I already had somewhat of a love affair goin' on with the Eel design (I'm a sucker for a canoe yawl). Seeing Glory up-clos-and-personal-like did not help much in getting over my infatuation with her. She has a nice, comfortable cockpit and a minimal type cabin interior. I wish I could comment on the sitting headroom, but I was too busy ogling all the other aspects of her, I did not retain too many mental notes. As I remember, the cabin was very spartan, more-so perhaps than you'd like Wayne. But the interior area is one place where changes can be made relatively easily. I think I have a picture of the Australian Eel that you mentioned, Jim. Is it the one from the launchings section of WB a few issues back? I had some correspondence with the builder. I cannot remember his name, but he was very kind and helpful. And he is very happy with his Eel. He's had some nice adventures on her.
Anyway, here is "Glory" .... BTW...this boat may well be hanging in some office in CO by now. Mr. Albers told me he had an "offer he just couldn't refuse", from some fellow who wanted to taker her down the Mississippi, then put her on static display. Poor girl. I sensed that Mr. Albers was going to miss her badly...

I think this picture may be very early in her life. It looks like the designed rig here. Mr. Albers shortened the main's yard so it would clear the mizzen mast when it is down (I hope I'm getting my story straight here). He said he liked this arrangement much better. Also, since she is cold molded, he put another couple-hundred pound of ballast on her keel so he could maintain her designed weight. She is surely a bit stiffer than some other Eels. Unfortunately, we did not get to go sailing that day (blustery weather), just sat in her cockpit and had a very nice visit.
http://cyclops.flash.net/~ralbers/photos/glory.jpg

Garland

[ 08-25-2002, 08:53 PM: Message edited by: garland reese ]

[Wayne Jeffers]

Garland -- Eel is a handsome boat, no argument from me. But her accommodations are somewhat less than I would want. I wish I could find one just like her, but about 4' longer, with less Spartan accommodations. I wonder if she really draws only 5 inches with the board up!

This thread has been useful because it has caused me to re-read some books or chapters of books on cold molding. I've also ordered the MacNaughton book on scantling rules and we'll read it, too, when it arrives. Maybe converting a hull designed for carvel is a possibility.

I had forgotten how many kinds of cold molding techniques there are and that each has its advantages and disadvantages.

Aside from making shapely curved hulls which are light, strong, and trailerable, another thing that appeals to me about cold molding is that I can more easily work solo most of the time. Sheet ply or larger longer strakes are more difficult to handle with only one person. I can occasionally enlist help for turning the hull, etc., but for the most part I expect to be working alone.

This has also given me a few more leads to follow in finding a design which pleases me most. I may still have that boat designed for me, but I'll feel better about having looked around pretty well first.

Thanks all!

Wayne

[Tomcat]

I was just looking at the WB article on Roxane, by Irens. That boat hull was made of 1/2" WRC, and three layers of 9 oz cloth on the outside, apparently no glass on the inside, though you could if you could get at it.

When I think of cold molding, I tend to think of strip with some double diagonal (DD) veneers on the outside. I don't like the approach that uses just DD and a lot of permanent stringers. The approach that uses only DD and creates a thick hull is fine by me, but heavier.

At the end of the day nobody will know whether you DD the outside, or used two extra layers of glass. I know which is cheaper, and which is more likely to keep details like the centerboard trunk all nicely tabbed together. What do you all think?

What about a half female mold, and glass both sides?

[Kermit]

I've been aboard two Eels--one a stripper and the other coldmolded. As I recall, the CM boat was built by Schooner Boatworks of Portland, Orygun.The feller who owned it had the poor taste to sell it without informing me, or I'd be the present owner. It's one fine little boat.

[Pelican]

Dang, I always thought cold mounding was akin to ice sculpture. :D

[PeterSibley]

Hello .......what is the effective maximum thickness of a veneer in coldmoulded construction assuming 3 layers ?Most manuals seem to talk about 1/8" which is probably fine for very lightly built boats,but what about heavier vessels,hulls or decks?It seems to be limited but the ability of the adhesive to both encapsulate the wood and to overcome the expansion contraction of the individual veneers.If so, what do you feel is the practical maximum thickness?

[On Vacation]

This depends on the drastic shape of the hull. You may have to do 1/8" and four layers or on. It is very critical for the first layer to be fair and correct. The first layer can be thinner than the next layers for this very reason. 1/4" is not that bad in larger hulls and in many cases we use 3/8" ply. This type of construction will be more stable than a plank on frame for movement.

[PeterSibley]

Oyster, so a deck for a 32' heavy displacement yacht could reasonably be 3 x 1/4'layers?

[On Vacation]

If it is flat, you can laminate any thickness or scarf one layer and it will be fine. You also can do a ship lap which is mortise and lip equivalant to 8 to 1.

[Redshark]

I'm planning to built a small boat with the CM method, but I can´t find epoxie were i´m living now, but i can find poliester. Can poliester be suitable for CM?

[frameshop]

wayne; I built my Haven 12 1/2 using my own cold moulded tecnique starting in 1992. I haven't had a problem with it since. I have towed it from New Jersey to Cape Cod and back several times and it has survived many rough launchings up there. The boat with some photos can be seen at;

http://www.havenbuilders.com/netscape4.html

click on builders, and click on Roger Mullette.

If you would like to know more send me at email and I will be happy to go over the process I used with you. I retained all the ribs so from the inside you can't tell it is not made as suggested in Joel White plans. Roger :)

[ 09-17-2002, 02:16 PM: Message edited by: frameshop ]

[Meerkat]

FWIW, the first Oughtred "Eun Mara" (a lovely canoe yawl of a dreamboat) was cold molded in the UK and Water Craft had a serial on the construction. Mr. Oughtred sends a copy of the articles out along with his Eun Mara plans, but I would imagine he would part with a copy of the articles alone for a reasonbble fee.

It might be worth mentioning that CM has a bad rep in the UK. Don't really know all the details though. Perhaps the cousins will tell us.

Personally, I've lately come to favor glued lapstrake/clinker ply construction. Come to think of it Wayne, have you checked out Oughtred's "Grey Seal"? The c/b version might suit you, and I've seen (and have pics) of a the slightly smaller "Wee Seal" with a Welsford Penguin-like layout except without the double berth forward, which you _might_ swing (the double berth) in a Grey Seal or an Eun Mara (btw, Eun Mara has no compression post and instead relies on a pair of ring frames for mast carrying loads). There was a Grey Seal construction serial article in WB a few years back. Eun Mara also has bilge boards so the cabin sole is unencumbered by a 'great wall of china'.

[Keith Wilson]

In response to Redshark's question about polyester: In a word, no.

Cold-molded construction absolutely depends on good glue. Polyester isn't good glue. System Three (among others) will ship anywhere in the world. See this site: System Three Home Page (http://www.systemthree.com) You can also download their epoxy manual, which is the best short introduction to the technology I've seen.

[Redshark]

Thanks a lot for your advise

[Wayne Jeffers]

meerkat,

Eun Na Mara caught my eye early on, but I finally dropped it from consideration because of 1) difficulty obtaining information about the design and 2) apparent lack of sitting headroom (appears to be only about 24" of headroom above the seat.)

Grey Seal is a nice looking boat, and scaling the tiny drawings in WB #128, she seems to have sitting headroom. But the 2' 3" draft with the board up is too much for the ramps from which I must launch and 3800 pounds is more than I would prefer to deal with in trailering, given other lighter-weight choices. Welsford's Penguin is about the maximum size and weight I'm disposed to consider.

Wee Seal is attractive, except for unavailability of information, and the fact that it appears to be micro-miniature for a cruiser. I note the Duck Flat site says Wee Seal is 18' LOA, and 14' 6" LWL. It also shows this drawing: http://www.duckflatwoodenboats.com/dfwbphp/pictureDISPLAY.php?ID=136 If this is a Wee Seal (it looks different), and if the LWL is 14' 6", then the LOD can't be more than 15', with 18' being to the end of the bowsprit. But then, no study plans are available. So little information is available on the design that I can't see the point of trying to pose questions to fill in the gaps in information. The interior appears to include nothing more than a V-berth and a porta-potti. I'm not favorably disposed to spending a couple of hundred dollars for plans solely to see if I might truly be interested in building, when those marketing the plans are unwilling or unable to make sufficient general information available. How about posting your Wee Seal photos?

Given the minimal results of my search for suitable stock plans to date (I'm still awaiting some additional information that sounds promising), having custom plans drawn is still a very attractive option.

Wayne

[ 09-18-2002, 02:18 PM: Message edited by: Wayne Jeffers ]

[Meerkat]

Wayne, per your request, I have finally posted pics of the Wee Seal "Opus" here in Designs/Plans under that title.

I too thought that Wee Seal was too small and the accomodations where too spartan, but after seeing "Opus" I have an entirely different opinion! It reminds me that boats look smaller and different on paper then they do in real life and "small" boats get a whole lot bigger when you walk up to them - or when you think about building them smile.gif

Eun Mara is bigger then Wee Seal, and I think with a bit of creativity, you could build something similar to what's shown in the "Opus" pics and possibly even squeeze a double berth up forward.

Not shown in the pics is that "Opus" has cozy quarter berths extending under the cockpit seats and room under the bridgedeck for a potti that can be pulled out into the main cabin to do your business.