Edwin Monk's Truant

[NwBtBldr]

I'm new to this Forum. I'm also new to boat building. I've been searching for information on Edwin Monk's designs. In particular, the small sailboat, Truant. I've found a lot of information in this Forum on small boat designs and even a posting on his Curlew design. However, I've not found much on Truant. I like both the looks of the boat plans, its dimensions, and the detail in the plans. I also understand that Monk's designs are based on older technology. Has anyone tried to update Monk's designs to a plywood construction? I found a posting from someone who built a plywood version of Curlew, substituting 3/8" marine ply for the planking in Curlew. The modern designs of small sailing skiffs that I've found so far use 1/4" ply, but I'm wondering whether the lighter construction would have a significant adverse effect on the handling of the boat.

Just looking for some thoughts and advice. I'd like to try to build Truant, but with more modern methods.

[Tar Devil]

Phillip Maynard, a forumite, built a Curlew with plywood (and a Merry Wherry... and a Melonseed... and a Whisp... and an airplane). He'd be your best source...

Phil Maynard's forum profile (http://www.woodenboatvb.com/vbulletin/upload/member.php?u=6551)

Phil Maynard's home page (http://pmaynard.lunarpages.com/)

[Philip Maynard]

With the cerlew I made many changes (that's my nature) but none to the hull shape.

If you simply substitute plywood without changing the hull shape, then the sailing characteristics will be the same, that's ignoring very subtle possible side affects such as arguably plywood will yield a stiffer boat and that may affect the way the boat reacts to waves and gusts but my guess is few people would ever notice this.

Basically unless you change the shape or weight it will sail the same.

Generally lighter is better, however as the boat gets lighter, your weight becomes relatively greater and so the boat is more "lively" to your movement within the boat and it may tip over just a little sooner (but will be faster in the meantime).

Monk details putting together CB trunks with paint and threads of cotton in the joints. I still used solid wood in my CB trunk but used epoxy instead of paint and thread. When I built cerlew I wanted to avoid epoxy when planking and so I applied 5200 to the frames and between the plank edges and brass screwed the planks to the oak frames and then added a single layer of fiberglass to the outside. It seems completly stable, I see no sign of movement on the inside but this boat only rarely would spend a week in the water at one time. I did not do any interior fillets or taped edges, just painted the inside. However my advice would be if building truant, epoxy and screw the plywood to the frames.

Often on the forum if anyone says "I like such and such design" then a whole chorus rises up and says "My god man, do not build THAT boat, here build this one instead".

In the end if you like the design of truant, substituting plywood for solid wood is not a big change. I chose cerlew because I really liked the town class sloop but wanted something just a little smaller and cerlew was perfect.

[Thorne]

My god man, do not build THAT boat, here build this one instead!

;0 )

Welcome to the Forum! The only suggestion I'd make for new builders is to consider building a modern popular design that offers support from other builders and the designer.

These include boats from Arch Davis, John Welsford, John Michalak, Iain Oughtred, etc. These guys often have Yahoo groups of builders, many offer support via email, some have videos and instructional books, etc.

Worth a thought. As Phillip says, you need to build the boat you want to build -- but do take your experience and the costs of learning things the hard way into account also.

Happy Building!

[NwBtBldr]

Thanks for the quick replies and advice. I have two or three more questions/thoughts that I'd like to check out before I start.

By the way, I can't argue with the advice to use a modern design for building with modern methods and I much appreciate it. However, Truant has just caught my eye - no better explanation. Somehow the others (and I've searched a few web sites, including most of those recommended by many in this Forum) just don't do it.

I'm not entirely new to the boat building process - I am building a double ended sharpie design from the Instant Boat book. Truant appears to be of a very similar construction, although not double ended.

I wasn't planning to change the hull shape, but was planning to use epoxy. I was hoping to add some foam bouyancy fore and aft, and have a little wider cockpit.

I'm getting the impression that I'd need to keep the same numbers of frames and locations, despite the stiffer plywood material, even if I chose to use 1/2" rather than 1/4" for the bottom. Correct?

One other question - Monk states that his design could be easily enlarged by 10%. This certainly won't be a car top boat anyway, even at the original length and lighter plywood construction. Any advice on lengthening the boat? It seems to me that the sail area would also have to be modified to maintain the center of sail area relative to the center of the lateral resistance. Not sure I want to do this, but I thought it was worth exploring a little.

[Philip Maynard]

I would keep the frames spacing as shown - it's the basis of the layout. 1/2" plywood bottom is really overkill. 3/8" would be plenty strong and a conservative choice with 18" frame spacing, I'm not sure about 1/4" - other builders may have an opinion on that? As far as lengthing the design, there is plenty of information about that on this forum and in some boat building books. Typically thats done simply by proportionally increasing the spacing between the frames without making any other changes. This would in theory make a faster (non-planing) max hull speed simply based on increased water line length, offset by an increase in hull drag from the increased area and the boat would now be realtivly narrower. To keep the original sail balance you would have to shift the mast location so as to keep the center of the sail area in the same position relative to the CLR (center of lateral resistance) - again there are many boat building books that cover this but in simple terms - measure the water line length and locate the center of the centerboard within that, using the center of the centerboard as 1/3 back from the leading edge of the centerboard along it's fore and aft length. You want to keep the proportions between the overall length, CB, sail area the same. If you want to increase the sail area you can do so and in that case depending on how much you increase it you may not have to move the mast. None of these calculations are difficult if you read up on it and understand what you are doing. Some people are afraid to make those kinds of changes, others love to tinker. But very rapidly if you start wanting to make real dimensional proportional changes, then I would always suggest looking if another design (in it's stock form) is closer to want you want to end up with.

As Thorne points out, the benefits of a modern design is possibly better support as well as presumably you are helping put food on the table of a living designer which will help the current boating community. It is also certainly possible to get better support of an old design through the advice of other builders, etc, than a contemporary design depending on the willingness of a contemporary designer to provide support. All else being equal I would always go with a living designer/contemporary design. That being said I myself could not find a contemporary design I liked more than the cerlew (and 8 years later I still do not see one) and did not see the change to plywood as being the slightest problem especially as I would prefer plywood and build with plywood regardless if it was old, new, etc. So if the truant is the "one you want" then that may be your answer.

[NwBtBldr]

Thanks again.

The smaller modern plywood designs, up to about 16 feet generally, seem to use 1/4" marine plywood.

The reason that I suggested a different frame spacing is that the modern plywood designs that I've seen have far fewer internal frames than the older planked boat designs, like Truant. I understand that certain frames would need to be kept in order to acheive and maintain the proper hull shape, as well as to provide proper support for the mast, foredeck, and dagger board. I think that Monk indicates which are the most important frames. Modern plywood designs appear to use chine logs and shear clamps to reinforce the plywood - sort of a plywood I-beam approach - and don't have nearly the number of internal frames.

[Philip Maynard]

What you are pointing out is directly a result of designing with plywood epoxy construction which requires much less internal framing compared to older designs. The 2 methods are very different. I built a plywood stitch and glue melonseed with minimal internal framing. This was a complete redesign of the structure/construction method while trying to keep the original idea/shape of the boat intact. It depends how much you want to get involved in the design and how much you just want to build a particular design. Simply substituting plywood for solid lumber is one thing. Redesign of the framing is a whole different proposition. I just did mine on instinct and in general I overbuilt most of it and in particular I really over-designed the mast step, I would build it much lighter if I were doing it again. The contemporary designers would probably advise you to start with a clean sheet of paper and this would in fact result in a better more efficient design than a rework. However if you are like me and do not have the marine design knowhow to do a proper new design, then rework can make sense, understanding from the outset that this is not the optimum way to approach things. It's more of a "get the job done" with what is available approach. I'm probably going into much to much detail here, the simple answer is "yes - you could eliminate a lot of framing" how much? I don't know.

[Tar Devil]

There really isn't much I can add to Phil's comments, except I'm working on Monk's 15' skiff, and the construction process is similar with both boats... instead of offsets and strongback, Truant's side panel dimensions are provided and those are cut first. The rest of the boat is built around those side panels instead of building around a frame.

In other words, you'll have to figure out how to enlarge the side panels first. Since the distance between layout stations vary from 15 3/4" to 21 1/2" on the Truant, just increasing frame spacing might compromise the boat's proportions as you attempt to enlarge it. I might think this would be further complicated by your desire to eliminate some frames.

Someone with a bigger lightbulb between the ears than me may not have any trouble with all this, but I personally wouldn't try it.

[RodB]

If you don't have it, get a copy of "How To Build Wooden Boats" by Edwin Monk. This book has the design you want in it with lots of details... maybe you already have it. I got mine for very cheap price online either Abe's books or just on Amazon.

RB

[NwBtBldr]

Let me take this email thread in a different direction. I like the shape and appearance of the Truant design, but also because it is first a sail boat and the simplicity of construction, as Monk describes in his book. As I understand things, the shallow V hull should help with tracking off the wind. I also like the sail plan, with main and jib.

Perhaps there is a modern plywood design with similar characteristics that I've just not found yet. What I've seen thus far in this length of boat are combination rowing-sailing designs or flat bottom boats with single sails of various types.

Most of the flat bottom boats have skegs, which would also help with tracking. But, I intend to beach the boat alot, so I'd rather not have a skeg to work with. Granted, Truant also has a small skeg; which for me is a downside of the design. (Truant also does not have a kick-up rudder, which is one of the changes I was intending to make.)

Hmmm. Seems like I may be talking myself out of the Truant design - may need to make too many changes. However, appearance-wise, I've not yet found anything similar.

Any thoughts or advice on more modern plywood designs with similar appearance and sailing characteristics?

[Tar Devil]

Any thoughts or advice on more modern plywood designs with similar appearance and sailing characteristics?

You'll get no shortage of suggestions, :) and I'll start with Chesapeake Marine Design's (http://www.cmdboats.com/smlboat.htm?cart_id=3b7f76995869e645d44f161386452c 5b) Bay Skff boats. Karl Stambaugh has a pretty good selection of simple flat bottom skiffs for row and sail.

[Philip Maynard]

On my last boat "Bluegill", I left off the skeg, and used a kickup rudder instead of the fixed rudder shown, these are easy changes to make. If you leave off the skeg, the rudder should be a little bigger to compensate for some of the lost area of the skeg. If I were building truant for myself either as shown or stretched, I would leave all the internal framing as drawn and use lighter, thiner plywood - letting the framing do it's job. It's a nice boat but there are many other nice boats out there as well.