25 ft Hooper Island Draketail construction, Part 2

[Draketail]

It's been a while. Pretty well got the prep work of lofting, mold construction, and head scratching finished in early March. The professional life took over and I spent the rest of March and all of April and May on various student projects. Two of which are shown below:



A 20' concrete canoe, and



A 22' x 28' timber framed pavilion at a local elementary school.

To pick up where I left off with the draketail construction in March, I have been working furiously since graduation on getting the keel and deadwood assembled and ready to set in the molds. Following are some pictures of the process.

Here's the keel blank with the pattern taken from the lofting



The first thing I did was drill the shaft hole as I could use the full width of the keel blank to better reference alignment of the bore. Starting from both ends, the operation was successful.



After drilling the shaft hole, I rough cut the rabbett to depth with a circular saw and finished up with a slick and hand plane. Pencil marks in the saw kerfs made it vewry easy to tell when I had planed to finished depth. The deadrise of the boat is fairly shallow, particularly at the stern. I'm leaving the final planing of the rabbet until I have the keel and chine logs both mounted in the molds. Than I'll finish the rolling bevels.

[Draketail]

As I mentioned in a previous thread, my son is a machinist. He has made up the keel bolts, bed bolts, and a bed bolt installation tool. The various silicon bronze pieces are being used to hold the backbone together.

Bed bolts:



Installation tool:




Complete bed bolt and alignment tool:



You can also see where I reinforced the through mortice for the stern post with 1" locust on either side.

[Draketail]

And finally, here are some shots of the various parts of the backbone assembly:

Fitting the deadwood to the sternpost. There is a small section of shaft log that is not included in this picture. The small area of white wood is a white pine peg repair of an old bolt hole in the recycled heart pine keel timber. The heart pine came from a fertilizer warehouse on Baltimore harbor. You can also see the bed bolt installed.



Fitting the stem:



The assembled stern post and deadwood:



The stem through and bed bolted together:



And finally, s shot of the backbone looking stem to stern. And, no, I haven't finished shaping the stem.



Tonight I finish shaping things, disassemble everything after marking through bolts for final trimming, prime at least the contact surfaces with red lead, and plan to have it all reassembled and set in the molds sometime Sunday. I'll keep you posted.

[Rick Starr]

This is great! The draketail is a beautiful boat from a magnificent part of the country. (bias: family from there).

Please do keep us posted!

[Draketail]

Here's a picture of the completed backbone assembly just before I disassembled it for final shaping of the stem and priming. With any luck I'll get a second coat of red lead on everything tomorrow (Saturday) with reassembly and setting in the molds to come on Sunday.

[Draketail]

As hoped, the keel assembly was finished and set in place on Sunday. I'm glad I had a few friends show up, as what I thought I could get done in about 4 hours took three of us 4 hours, what with red leading the keel bolt holes and spreading bedding compound. And then more friends showed up to lay the keel in place, followed by a delightful cookout. Seemed like a proper start to the formal construction of the boat.

So, some pictures:

All the keel pieces painted with two coats of red lead and ready to be assembled:



Spreading bedding compound (Dolfinite) prior to assembly. A broken off piece of hacksaw blade held in small vise-grips worked as a notched trowel to spread the Dolfinite.



Moving the assembled backbone from the shop to the strongback and molds in the shed. The two wheeled cart is a timber cart we often use to move timbers when timber framing. The backbone was well within its weight limit.



My son helping set the backbone in the molds. Using two come-a-longs, we were able to lower the stern first and "zip" the backbone into place. Builders shims in the mold notches were used to centralize the keel perfectly.




The keel in place. The stem was then screwed to the building frame on the centerline. The forefoot still looks chunky because I'm waiting until I start planking until I trim to final shpe. It's easier to take wood off than to put it back on...



And finally, a shot with the lower stern hoop set sorta in place. I just had to see what the general shape of the boat would be in true size. So far, so good!



The next step is to fully shape the stern hoops, align them to the keel and molds, set the shear strake and chine logs and start planking. Should keep me out of trouble for a day or two.

[crawdaddyjim50]

That is great! I see the cat was checking your angle of exit on the shaft boring job. He must be a stickler for accuracy.

It will be a stunner. Almost as pretty as your sealant technician.

Jim

[Captain Blight]

The stem knee is a beautiful chunk of wood! What kind of ring count does it have down by its point?

[Draketail]

The stem knee is made from an off cut of the piece used for the stem. The entire backbone (keel, stem, deadwood) is made from recycled heart pine with a ring count of about 30 rings/inch. Some areas of the wood have so much resin that its almost translucent and looks like plastic. I'm assuming that I won't have to worry too much about rot...

[Jim Ledger]

I'm watching with great interest. I like the bed-bolt idea, it has a lot of potential for certain backbone fastening problems where a through bolt isn't practical. What do you use, propeller shaft?

[Draketail]

Jim,

All of the keel and bed bolts are made from 655 silicon bronze ordered from McMaster-Carr. Regular UPS delivery routinely the next day (order by noon) is nice when you live 200 miles from the nearest real chandlery.

On either side of the shaft log I used 1/4" rod for the bolts. It was kinda tricky drilling 18" of hole without blowing out the side. The keel bolts on the centerline of the keel are made from 3/8" rod. The bed bolts themselves (nuts) are from 3/4" rod, with 3/8" bolts screwing into them. The installation tool worked well, but some judicious wiggling is required to make the threads.

I "stole" the bed bolt solution from some engineering I had done for timber frames where a through bolt wasn't possible or desirable. A 18 in long bed bolt was a lot easier to handle than a 20 ft through bolt. I couldn't think of a better way to attach the stern post to the keel and the deadwood to the stern post.

As an aside, there's a coil of cotton string in bedding compound under the washer of every bolt that ends up on top of the keel. I'm hope that the string will stop any leaks along the keel bolts. My machinist son also domed the ends of the bolts to make them easier to drive through the holes and provide a more finished look.

[Draketail]

I've managed to get some work in on the draketail over the last two weeks. The concentration has been to get the curved stern ready to join to the keel and molds so the shear strake and chine log can be installed and faired to the stern.

The draketail stern is planked like a barrell with vertical staving. There is then a butt block for the tranistion from the vertical staving to the horizontal planking. I had some 10 year air dried osage orange stock that I used for the butt block. To install the butt block, I clamped it to the laminated stern hoops, shimmed guide strips next to the osage and then used a top bearing router bit to cut the dado's for the block.

Here are pictures of the process:

The routing guides



and the block fitted in place.



I then screwed the blocks in place and then planed them fair with the hoops.

The next strp was to fit the skeleton of the stern to the keel and molds, inletting the chine hoop into the keel. With the fitting done at the skeleton stage, it will be much easier to finally set the fully planked stern assembly in place.

Here's a picture of the stern assembly fitted to the keel. The strips are just to hold the shape during the fitting.



Then the hoops went back on the stern form to begin the planking process. Which led to a rude surprise. If the curved stern were a conical section, the staving would all lie in a radial plane. Unfortunately I just realized that the stern is not conical. At the sections of sharpest curvature, the staves need to both taper and twist. That's what I get for following the general drawings from historical boats. I knew the stern shape look interesting as I was making the hoops, but the implications of the shape didn't really sink in until I laid the first planks in place. Much head scratching.

So, planking continues, but at a reduced rate. A number of the stern lanks can be cut as flat planks and drawn into place with clamps. So far, there has been a minimum of creaking and groaning from the "easy" planks.

Then we get to the really curved ones. I'm having to sculpt them from thicker stock, planing the curved shape into the plank before attaching it to the hoops. A scrub plane and a modified round bottom smoother have been very helpful. Some of the planks twist 15 or 20 degrees from top to bottom in a length of 24 inches. At least it's a joy planing the heart pine planking stock. It smells wonderful and works very well.

Anybody got suggestions? All help gladly accepted.

Stern planking in progress:




Once all the stern staves are cut and fit I'll disassemble the whole thing, prime with red lead and reassemble with bedding compound and the addition of a strand of cotton wicking along the chine hoop. After that, the assembly will get planed fair and be attched to the keel and molds.

[Draketail]

The Hooper Island Draketail is a traditional Chesapeake Bay work boat, built using traditional Bay methods. As such, there are no complete frames. The bottom is cross planked (or "file" planked) without frames. The short bottom planks are screwed to the keel and the chine log and lap over the bottom of the side strakes. The bottom planks are about 15 deg off of perpendicular to the keel. The longest one on this boat will be less than 24 in.

What frames there are connect the shear strake and the chine log and serve as a place to attach the side planks. Yesterday, we (my building buddy and I ) finally attached the side frames to the molds. The frames were cut form air dried white oak, shaped and painted with red lead.

The back cut for the 1 1/4" chine log was made with on the table saw before attaching the frames to the molds. The plan is to then make the bottom cut for the chine notches as we fair up the frames. The frames were also left long at the shear so the hull can be braced when it comes time to turn the boat.

Frames from the stern looking forward:



And frames from the bow looking aft:



Progress will slow for the next two weeks as I'm off to teaching a timber frame rigging and raising class.

Thanks for looking.

[Bill Perkins]

Draketail ; I would think that halving the width of your vertical stern staving would halve the work , the waste , and the changes in dimension at the finished seams between staves when going through wet/dry cycles . The ones already shaped could still be used , just ripped in half and reinstalled .

Here's a frame bottom detail used by Pete Culler . The radiused ends trap no dirt . If you butt the frame ends to the bottom they will . It'll be harder to shape these after the chine log is in place , if you like the idea . I used the detail on the Culler 24 footer I built (a file bottom but not a draketail ) and there was plenty of meat left for fastening to the chine log .

Later: Got a chance to look at the 25 footer in Sucher . The staves do look narrower than yours , and more tapered . Did they: 1. set a parallel sided stave vertical at the stern centerline. 2. Mark off even divisions on the wider lower hoop from the side of this stave to the plank transition point ( the rear stave being the width of one of these ). 3. lay off the same number of divisions on the smaller upper hoop and taper each plank to fit it's division. ?

[Draketail]

Bill,

Thank you for both ideas. I had earlioer drawn the frame ends as you have shown. Somebody else talked me out of it. But, your (Pete Culler's) method makes more sense to me. I believe I'll head that way.

I will halve (or less) the plank width on the more sharply curved parts of the stern.

The planks already installed are 5 3/4" wide and are 25 ring/inch old growth heart pine. They have been fairly easy to install. Do you still suggest halving them. I'm a bit concerned about the extra screw holes if I saw them in half.

Thank you for your help.

[Bill Perkins]

I assume you're building from a true scale print from Sucher's plate 76, is that right ? I'd get hold of the drawing from the Smithsonian if you haven't . I would just scale the size of the staves shown . The men who built that boat used prime old growth pine too no doubt .The beauty is this has all been throughly worked out for you .

The bottom planks lap over the bottom edge of the side strakes on most of the boat but not on about the forward third , where side and bottom meet in a miter joint . This is because the joint between the side and bottom is a caulked joint in traditional construction . As the angle of intersection between side and bottom gets greater than about 130 deg. going forward the bottom plank ends produced by a simple lap joint become too acute to have the strength and stability required to form a good caulking seam .

You can see if you look at the sections shown that at sta.#6 aft the bottom laps the side but forward at sta#3 the construction has changed to a miter joint , with the thicker bottom dressed off in the plane of the side plank . The switch happens at a single point ; it's not a gradual transition ; but a bit further aft than sta .#3 I think . Again: where the included angle is about 130 deg. or less . Check some built examples if you can .

[Draketail]

Bill,

Thank you for the rational explanation of change in the side to bottom plank joint. I knew the joint did change, but never knew exactly why or at what angle.

The boat is indeed from Sucher's plate 76, but widened by 10% and with some more volume added aft. The original lines want to float down at the stern. My assumption is that as the waterman filled the boat with catch in the forward area, the loaded boat would float level. I won't be using the boat quite so hard, so we modified it to float level at low load.

Thanks.

[Bill Perkins]

I dug out the Culler plans to check the point of transition from lap to miter joint spec'd for my boat's bottom . It's shown where the bottom and side meet at about 140 deg. It partly depends on the quality of your lumber, I believe , how far forward you can use the simpler lap joint , but why push it ?

I now remember that I made the transition from lap to miter where the bottom and side came together at 135 deg. This was simply because the plank ends produced there were cut at 45 deg. , the limit for the skill saw I was using to trim the installed plank flush . Using modern power tools , I don't think there's significant time saved by using the lap joint forward of this point .

I did some coarse grit power sanding on the edge of the bottom as I brought it down flush to the sides ,but it sands at a different rate than the side plank . Depending on your material ,a power plane may blow big chunks out of the end grain . So I finished off hand planeing and long boarding to get the bottom dead fair with the sides .

I could have used my old low angle block plane for everything , but I would have felt a bit over matched against the 1 1/4 in. slab of end grain bottom . I'm so glad I sprung for a Lie-Nielson Low Angle Smooth Plane . It's good for many other tasks too of course . I deal with all end grain planeing with new confidence . Also the planeing of thick plywood edges .

Someone makes ,I think , an extension handle for low angle block planes . I would at least look into one of those .

[Draketail]

Bill,

Thanks for the further information on fitting, finishing, and fairing the bottom planks. Mine will be only 7/8" thick, so I may have a slightly easier time of it. I too am partial to the Lie-Nielsen planes, and do have the low angle smoother. I look forward to putting it to further use.

Progress is a bit slow right now as I'm teaching a rigging class in Minnesota. It's only a 1,400 mile drive from home.....

You say you have built a bay style boat. What type? And is there a thread here showing the build?

Thanks

[Matt J.]

Thanks for the thread and the work to document in words and photos the building.

I imagine that, like me, those of us from the Mid-Atlantic and/or with any connection to the Chesapeake have a deep-seated fondness for these boats.


(BTW, your worked on VMI's Concrete Canoe? How'd they do? I helped the University of Maryland at College Park with their program as a student back (OMG) 12 years ago, now).

[Bill Perkins]

Draketail ; I planked from aft forward at about 20 deg. back rake with 1by 4 just as it came from the yard , twist had to be planed in just on the forward planks .

I made a simple tapering jig for the table saw that would cut a 2 deg . taper on one side of a cross plank . Measuring from the knuckle aft I figured out where I needed to switch to these fan staves in order to bring the planking perpendicular to the keel at the point of the knuckle . The plank was run at this angle out to the bow . Of course I had to plane a twist in the fan staves after tapering the thick blank .

I also adjusted the width of the fan staving slightly so that a joint between planks fell right at the knuckle . This was necessary because where the straight keel meet the curved stem the planking turns a corner .It's not a fair surface like up at the chine . The bottom is smoothed at the knucle by planeing down the installed planking.

You'll see that I elected to go with a glued double diagonal bottom . The first layer is fitted just as in traditional construction .

The short frames are 18 in oc . Every 6 ft. I have a structural bulkhead through bolted to keel and chines to hold the boat together . I knew she would take a pounding at times and be stored on a rack ( 2 parallel rails) ,which is tough for a wood boat . One reason I choose the file bottom .

http://flickr.com/photos/27992927@N0...57605863728007


http://flickr.com/photos/27992927@N0...57605817831936

http://flickr.com/photos/27992927@N0...57605839992833

Here's the bow shape produced . The spray rail is set at the juncture of bottom with topside planking .

http://farm4.static.flickr.com/3025/...023b99.jpg?v=0

The chine fades out at the bow on this high chine model . She's Pete Culler's 24 foot Fast Launch .

http://farm4.static.flickr.com/3253/...e942a2.jpg?v=0

[Draketail]

Bill and Matt J.

Please each check for a PM.

Thanks,

Draketail

[Draketail]

Well, if the last plank on a boat is the "whiskey plank", can I call the last plank in the draketail stern of my build the "beer plank"? I've finally gotten the stern planked, thanks to good advice from Bill Perkins.

The whole process got more complicated than I expected because the stern shape was not conical. So, instead of being able to use repetative tapered staves , I had to make a bunch of twisted staves, all of a different size and shape.

But, I did figure out a way to saw most of the twist into the stave blank. Starting with a blank thicker than needed, I marked the saw lines on opposite edges. Then I grooved the bottom line into the plank with a wood carvers veining tool. (This picture is actually of setting up to remove the waste on the outside of a fitted stave.)



I used a finishing nail in a plank just in front of the bandsaw blade to guide the groove in the bottom of the plank. The top pencil line was sawn freehand. The nail in the groove twisted the plank as needed. You can see the groove and the finishing nail in the following picture.



Here's a picture of a sawn twisted plank. The cuts got smoother as I got more experience with the process. After fitting, it was also possible to saw away most of the waste on the outside of the plank using the same process.



Here's the stern with everything planked but the "beer plank."



After fitting the final plank, I started fairing up the assembly with a 3" power plane, a scrub plane, and finally,a #4 smoothing plane. After getting close with the power plane, I found that I had much better feel for the developing shape with the scrub plane. I worked at all sorts of angles, feeling the surface by hand at intervals while planing. Once the shape seemed close, I started in with the smoothing plane. I'm sure I'll find more to fair when I start with he sandpaper and long board. But, so far, I've gotten half of the stern planed. In the following picture, you can see the left side of the stern before any planing and the right half with the scrub plane marks. Seems to be hot work.



And, finally, here's where I stopped for the night with the finishing plane.



Hope to finish fairing the stern this weekend.

All for now.

Draketail

[L.W. Baxter]

...Seems to be hot work...

Yep. But with very cool results.

[Draketail]

After several more sessions of planing and sanding, the stern was ready for initial fit up to the molds and frames for the boat.. So, we pulled the stern off its building jig and carried it over to the mold for the boat.



Here's a shot of the inside of the stern:



Then we lifted it up into place and fiddled around until the stern was on all the alignment marks, height, centerline, etc..



Finally, we clamped some test sections of shear strake and some battens in place to see how everything faired up. It was very satisfying to see the shear strake section on the molds fall on the pencil line for the shear drawn using the stern building jig. AutoCAD seems to work at least "OK" as a lofting tool.....



After confirming alignment, my next step is to completely disassemble the stern, prime with red lead, and reassemble using bedding compound between the staves and the hoops. I didn't want to do the painting during the initial stern fit up because I wasn't at all sure what I was doing and how many staves I would end up replacing. Now I wish I'd done the painting as I went....

The reassembly process leads me to a question. I can either traditionally caulk the stern staves with cotton and seam compound, or I can seal the seams with a product like Sikaflex 291, 3M 4200, or possible PL Premium construction adhesive. The staves are air dried, recycled heart pine. The boat will be trailer sailed, living most of the year in the dirt floored covered shed where you see the hull being constructed.

Your thoughts and advice on sealing the stern staves? Please.

Thank you,

Draketail

[Draketail]

Well, durn, it's been a year since I've been able to update this thread.... Seems like the last academic year pretty well ate my free time. However, in the last couple of weeks, I've been able to return to the draketail and make some useful progress.

First, here's a shot of the planking bench and the 1/4" spiling batten I scarfed together:



And here are the shear strakes being planed into a matching set.



More to come....

[Draketail]

Continuing:

After fiddling with alignment, disassembly, red lead, bedding compound, etc, here is the stern being screwed into premanent position. At this point we're into the process of fitting the physical parts of the boat together as opposed to doing much work from the lofting. It all has to mesh in reality.



And here is the shear strake fitted in place:



Details of the attachment at the stern:





And the first attempt at drawing the shear strakes together at the stem:



That didn't work so well, so sacrificial blocks were glued on to give purchase for a couple of clamps. Much more successful....

[Draketail]

And continuing on with the chine logs. I spent much of the last 9 months trying to work out a technical way to fit the chine logs to the stem. The engineer in me said there had to be some way to jig it all up and make it "perfect". Then a couple of boatbuilder/woodworker friends said "just start and whittle 'til it fits." Good advice. Once I could see the chine close to position, it became easier to "remove what didn't look like a fitting chine." Stop over thinking and cut.



Seems to have worked out OK.



And some details of the attachment of the chine to the stern (other side of the boat). The locust block on the inside help to further connect the chines to the stern assembly. The chines are flush with the outside of the vertical transition plank.

No need for a block with the shear strakes as they land on the outside of the transition plank. You can see three screws through the transition plank into the shear at the bottom of the lower photo. And both the chine and shear also get heavily screwed into the laminated oak stern hoops.








Time to finish drilling screw holes, remove and red lead the chines and shears and then do final installation. More pictures later.

[Bill Perkins]

Great to see you posting again and the project resumed . Months after your last post I finally understood your technique for bandsawing the twist in the stern staveing .Very slick .

[erster]

I was wondering where you were with the boat project. Thats some nice work and will be looking foward to your continued progress reports. Thanks

[Draketail]

First, Bill and Mike, thank you for your kind comments. It's been a pleasure to be able to spend a couple of weeks concentrating on the boat. Fall classes will start soon enough, but maybe I can get something accomplished before then.

Picking up where the previous pictures left off, here are details of the completed attachment of the stern assembly to the chine and shear. One of the weak points of the draketail boat is the transition from the horizontal forward planks to the vertical staving at the stern. I hope that between the osage orange transition planks, locust overlap blocks, and the extensions of the laminated white oak stern hoops forward along the chine, shear, and planking that I've got the problem solved.





And here's a shot of it all coming together at the bow.



Another view of the bow from a bit higher up. Starting to look "boaty". The poplar test plank rolled into position and clamped onto the frames with no trouble. I hope that the permanant fir planks settle in as easily.



Now that the shear and chine are fit, it's time to remove them, paint with red lead, and reinstall with bedding compound on the contact surfaces. By the end of the weekend there should be a complete boat frame ready for planking. It's only taken two years to get this far..... I'll keep you posted.

Thanks,

Grigg

[erster]

Picking up where the previous pictures left off, here are details of the completed attachment of the stern assembly to the chine and shear. One of the weak points of the draketail boat is the transition from the horizontal forward planks to the vertical staving at the stern. I hope that between the osage orange transition planks, locust overlap blocks, and the extensions of the laminated white oak stern hoops forward along the chine, shear, and planking that I've got the problem solved.

Actually I tell folks that the planking in a lot of ways is just to keep the water out of the inside, meaning that the framing does one bang up job minimizing some issues such as working of the planks, especially the vertical staves. The problem with the old traditional boats for the most part was that many were also built with green lumber creating issues of substantial movement over time combining this with fasteners that consisted of nails, some iron ones that deteriated over time.

Another problem was always at the chines in the build them fast and get them working, and sure nuff thats exactly what they did, work the planks as most went no matter what the weather was and worked them loose because the fasteners at the end grains of the planks and water also became trapped between the seams when the planks loosened up.

You are taking great pains in the construction, fits and coatings unlike the mentors of the past in the region. A different mindset existed, not that there was anything wrong with it. Your biggest issue will still be keeping the hull stable in regards to moisture, your biggest obstacle down the road that you will experience, IMO.