Yikes!!

[Ed Allen]

Hi everyone. I am very new to wooden boat building or any boat building for that matter. Until I started this project I didn't know a single boat building term but I have learned lots since. I am building a Brook's designed Ellen as a learner project and at this point the hull is off the molds and I am working on the interior. However, after reading the discussion on epoxy without fasteners on Oct.7 I am rethinking my decision to go glued lapstrake. I have visons of being out on the lake and the boat exploding in a tangle of planks. I epoxied the strakes no fasteners and buried many stainless steel screws. Having said this , would anyone have a picture or a sketch of how a dagger board trunk is constructed and fitted. Up to this point I have been able to figure my way through most of the building process but this part has me a bit confused. If I figure out how to send photos I will do so in the near future.

[Bruce Hooke]

Welcome to the forum! I wouldn't get too worried if the anti-epoxy crowd freaks out about the idea of trusting glue alone. The glued-lapstrake construction technique has been proved sound many times over. Your boat is not going to explode into a mass of planks.

On the daggerboard trunk, is there a particular section that the plans you are building to do not explain well?

[JimConlin]

Immediately order John Brooks's VERY GOOD BOOK on how to build that very boat (from our hosts) and sharpen tools and clean the shop 'til it arrives. Turn to page 173.

Seriously, How to Build Glued-Lapstrake Wooden Boats by John Brooks and Ruth Ann Hill is the best how-to-build-a-particular-boat book i've seen. It is an act of great generosity for a boatbuilder to reveal so many little how-to tips.

Nice boat. A good choice.

Jim

[ 11-08-2005, 12:31 AM: Message edited by: JimConlin ]

[Billy Bones]

Welcome.

If it is any consolation, my screwless pooduck skiff is now several years old, has been blown off the trailer and around the yard during a hurricane, has patiently put up with people, dogs, rocks, beaching on cobble, and some of the worst the caribbean can throw at it. It is showing several places where stress and abuse are taking their toll. In NOT ONE of those places is there a glue joint at issue.

When one reads these forums I have found it helpful to, well, frankly, to ignore all those who do not qualify their comments with some demonstration of their degree of experience.

To put it another way, nothing brings out the armchair "experts" like discussions of screws and plywood.

Trust the designer. The glued lap plywood technique is proven. In this technique screws are disposable clamps.

I am a professional woodworker who has built two boats. Here is more about my skiff...

My Pooduck Skiff Page (http://www.boats.rkstarr.com/skiff/pooduck.html)

Good luck.

PS: I keep calling my skiff the screwless skiff and that isn't entirely correct. There are a few screws, holding the thwarts down, for example, and the cap to the centerboard case. Hardware is screwed in place too, of course. The only place in the hull proper where I used any screws is between the hull planks and the centerboard bed logs.

[Ed Allen]

Thanks for the encouragement on the epoxy issue fellows, I am going to put that one to rest permenently. Jim I do have John Brooks book which my wife refers to as my bible and I think it is very well written indeed. As to the dagger board and trunk which until recently I didn't know their function, maybe I am looking for something more complicated then it is. How much stress would be exerted sideways? How much will the dagger board rub on the inside of the trunk? Should the trunk be finished inside with fiberglass? These are a few of my concerns in this area. Bill that was a neat way to refer to the screws as disposable clamps. By the way, great looking skiff and a beautiful setting.

[Steve Lansdowne]

Properly done epoxy joints are stronger than the wood they connect. Try a test piece and see where it breaks. If you mix the epoxy up right and put it on right, you'll have no problem keeping the boat from coming undone in the middle of the lake. Become a believer in epoxy and all your worries will vanish.

[David W Pratt]

Bow of my stitch and glue kayak came off roof rack at 45mph, it was repairable and could have been used.
Good luck.

[paladin]

my boat izz 44 feetz 9 inches on deck and there ain't no metal fasteners in the hull or deck, it's been around the world 1 1/2 times and it ain't broke yet......all 'poxy....and wood..

[Thorne]

Ed -

I'll attempt to give you a little info on the daggerboard case, but there are much more knowledgeable folks on this forum and great resources at your local nautical bookstore.

I'm building a centerboard case for my dory, and as far as I know daggerboard cases are very similar. Much seems to depend on the design of your keel and/or bottom planks.

Centerboard cases are shown in Gardner's Dory and Small Craft books as two posts with sideplanks. The oak posts go through the bottom planks (at the fore and aft ends of the slot cut through the bottom) while the sideplanks are are shorter and attached to the bottom planks from underneath.

CB cases are also often supported by thwarts/seats that run from side to side across the boat, usually onto the internal frames in some way. And they are sometimes supported fore and aft by being attached to two thwarts or one thwart and a frame.

Daggerboard cases are much shorter so the bracing may be different, but the same potential forces apply -- particularly if you run aground or hit underwater objects!

Try a search of this and other WB forums for daggerboard, centerboard and see what comes up.

Here's a pic of the CB case pattern for my dory from the Mystic Seaport Museum plans, showing my planned modification so that it fits under both thwarts:

http://www.luckhardt.com/cb-design1.jpg

[ 11-10-2005, 04:38 PM: Message edited by: Thorne ]

[marsbar]

Hello Ed....I built an "ELLEN" several years ago before John's book was available. I sure whish I had it at the time. Thought I would share some pics of my daggerboard trunk with you. Its really quite simple if you follow the plans carefully. Would be happy to share my building experiences with you if you like...its a GREAT dingy and I sail it often on Barnegat Bay, NJ.

Partially assembled trunk:
http://images.kodakgallery.com/photos1597/3/50/48/37/43/4/443374850303_0_ALB.jpg
Routing slot in the keelson:
http://images.kodakgallery.com/photos1597/3/50/48/8/16/5/516084850303_0_ALB.jpg
Assembled trunk:
http://images.kodakgallery.com/photos1597/3/50/48/86/98/6/698864850303_0_ALB.jpg
Installed:
http://images.kodakgallery.com/photos1597/3/50/48/8/28/2/228084850303_0_ALB.jpg
Finished:
http://images.kodakgallery.com/photos943/2/90/49/98/20/7/720984990203_0_ALB.jpg

[merlinron]

thorne, if you consider the effort needed to raise the board, i think you'll find that the hump where the painter is attatched yeilds some mechanical advantage in lifting it. without the hump, the line, in order to stay out of the water and cause drag, has to attatch much further up the board towards the pivot point. this greatly increases the effort needed to raise the board. staticly, with the boat upright,it might be ok to lift, but under sail and heeled, there are some side loads on the board against the case and you'll need more effort to raise it. the hump moves the attatchment further away from the pivot point to increase the leverage arm without moving the attachment point so far down the board that the line is in the water.
edit to add....
consider the painter's attatchment point as drawn and then extend the line of the bottom of the hull through the board and attatch the painter to the aft edge of the board, just inside the case, you're lifting arm is only avbout half as long, essentially making the board twice as heavy to lift. add to that, a little side load and the new geometry of the mechanism and you might be cussing yourself for changing it.

[ 11-11-2005, 08:49 AM: Message edited by: merlinron ]

[Thorne]

Marsbar -- there are a number of threads and FAQ's about how to post images, and yours would be VERY valuable in this discusion. The images must be posted on a website (try http://www.picturetrail.com/ ) and then the web address (URL) posted here.

(Being the guilty party, I'd like to suggest that rather than continue to hijack this daggerboard thread, we should move Centerboard discussions to my very own thread on CB design:
http://www.woodenboat-ubb.com/ubb/ultim atebb.php?ubb=get_topic;f=2;t=004539 (http://www.woodenboat-ubb.com/ubb/ultimatebb.php?ubb=get_topic;f=2;t=004539) )

Merlin -- I (more or less) understand the risks in messing with traditional designs, but don't want to lose the forward thwart to the hump-design centerboard case.

The board will only weigh 8 pounds or so, and I've rarely needed to pull one up when on a reach or heeled -- usually only when heading downwind or slowly approaching the shore to beach the boat.

But I'll certainly try to get the most mechanical advantage that my modified design will allow. I plan on putting the attachment point right at the waterline (as you point out), and have the pennon run straight up to a pulley embedded in the centerboard case top, then aft over the center thwart to a cleat on the aft post of the CB case (where I can reach it when singlehanding).

I'm apparently not the only one to go for the longer & narrower option to save that thwart. Mike Bailey of this forum kindly sent me the following:

I would like to draw your attention to two passages in John Gardener's book "Building Classic Small Craft".

On pages 244-245 he talks about his thoughts on designing a centerboard for Lizzie, a Sea Bright Skiff:

"None of the photos of Lizzie shows a centerboard...... consequently I had a free hand (in the design). In addition to centering it (the centerboard) approximately under the combined centers of effort of the two sails............... I have made the board quite long, yet narrow enough to fit under the rowing thwarts. The extra length makes up in area what the board lacks in width....... When a long board is raised and lowered, the center of lateral resistance shifts considerably in the fore-and-aft direction. This affords flexibility in achieving balance of the rig."

[ 11-11-2005, 10:57 AM: Message edited by: Thorne ]

[JimD]

The inside of my plywood CB trunk is glassed per designer's instructions (Glen-L)and since the glass's main contribution is abraison resistance the inside of the trunk seems like the place to use it even if you glass no other part of the boat. Also, it is fir plywood and I would not consider using fir plywood without sheathing for any part of a boat.

[ 11-11-2005, 11:08 AM: Message edited by: JimD ]

[Ed Allen]

Thorne:Thanks for the information and i am going to order Gardener's book today.
JimD:You answered my question about glassing the inside of dagger board trunk.
Marsbar:Your photos were exactly what I was looking for. You could have been sitting in my boat as it is at the same stage as is yours in the photo. I would appreciate any further information on the construction of your boat.

[Keith Wilson]

Oops - sorry, mistaken post.

[ 11-11-2005, 05:26 PM: Message edited by: Keith Wilson ]

[marsbar]

Thorne,

I don't understand your suggestion regarding my posting of pictures, can you please elaborate? I'm not new to this forum and have posted pics many times without feedback/issue. My pics are posted on OFOTO and I enter the URL after clicking on the "IMAGE" button. I appologize if I am totally misreading your remarks. Thanks for taking the time to keep us "honest" :)

Thanks for your advice.....Mark

[StevenBauer]

Mark, I can't see your pictures either. :( but not one to be denied pics of a nice boat like Ellen I went to the page source and cut and pasted your url to a new browser window and was able to see them. Then when I went back to the thread there they were! Still don't quite understand. Oh well. Nice job.

Steven