tarbrush

Mahuna, holy smokes!  this is drop dead gorgeous!!!!

Mahuna, holy smokes!  this is drop dead gorgeous!!!!

The book Chesapeake Sailing Craft has some actual photos of the reconstruction, framing and others, pgs.  238 - 242 Also a great picture of the round chine.

Mahuna, holy smokes!  this is drop dead gorgeous!!!!

Mahuna, holy smokes!  this is drop dead gorgeous!!!!

Part 4 – The Keelson – cont’d


 
I should have mentioned wood selection in the prior post.  Kathryn has a mixture of oak and pine, with the oak being used primarily in structural components.  The HAER documentation does a good job of identifying the type of wood used for each component.  I’m using madrone (very similar to pear) for the components made of oak, and castello for the pine components.  Madrone normally is fairly pink, like pear, but my current stock of madrone is much paler than what I’ve used in the past.


 
The centerboard slot is cut through both the keelson and the keel, so the first task was to add the keel in the area of the centerboard slot.


 
The oak keel is very thin from the bow through the area of the centerboard slot – only 3” thick.  Since the thickness is consistent in this area a single piece could be milled.  The following photo shows this keel piece being glued in place.


 

 

The milling cutter would not mill the entire depth of the slot from the top of the keelson – the keelson would need to be flipped for completion of the slot.  Pilot holes were drilled through the keelson at each end of the slot location – this enabled proper location of the slot when the keelson was flipped.


 
The following photo shows the centerboard slot being milled.


 


The mast step in Kathryn is actually a longitudinal mortise, so this was also milled at this time.  The following photo of the completed keelson shows the centerboard slot and the mortise for the mast step.


 

 

In the interest of full disclosure, I need to admit that I cut the centerboard slot too far forward after misreading one of the various marks I had made on the keelson.  The end of the centerboard slot was in the proper place, so this was easily corrected by inserting a small plug in the forward end of the slot – as seen in the following photo.


 

 

Kathryn’s bow consists of an inner stem, and outer stem, and the cutwater.  All of these components will be made of oak.  The inner stem sits on the keelson, and is supported by a stem knee.


 
The inner stem needed to be shaped so that it inclines at the same angle as the forward edge of the keelson.  I was also concerned about the inner stem being sufficiently secure, so a tenon was formed on the stem and a corresponding mortise was cut in the keelson, as shown in the following photos.


 
 

 

I was also concerned about attaching the outer stem, which will lie against the inner stem, so 2 pilot holes were drilled in the inner stem for aligning the outer stem in a later step.  These holes needed to be fairly horizontal, so the inner stem was held in the milling vise at the approximate angle of installation.  A centering drill was used to assist in drilling at that angle.


 

 

Once the centering drill started the hole, a #60 drill was used to complete the drilling.


 
 

 

The setup for gluing the inner stem to the keelson was a little unusual, since it was necessary to ensure that the inner stem and the forward face of the keelson stayed in the proper alignment.  A parallel bar was set in a vice for this alignment, and the keelson/stem knee combination was aligned with the bar.  A square was also used to ensure that the stem knee stayed vertical on the keelson.  The clamping setup can be seen in the following photo.


 

 

The following photo shows the keelson with the inner stem knee installed.


 

 


 
The next work will include the installation of the stem knee and completion of the keel assembly.


 

Part 3 – The Keelson


 
After a lot of time spent researching Kathryn and drawing the plans needed to start the build – it’s finally time to make some wood dust!


 
Kathryn’s keelson is a massive timber, consisting of two parts secured by a scarf joint.  The individual frames are mortised into the keelson, and a slot for the centerboard runs down the middle of the keelson.  The keelson is 16” wide and the height varies, decreasing towards the aft of the boat.  The bottom of the keelson below the level of the bottom of the frames is only 8” wide.  Following are a few cross-sectional views from the HAER drawings to illustrate the keelson:


 



 
The first step was to make the two main parts of the keelson.  After gluing the drawings of the two parts to the appropriate stock, these parts were cut out and sanded to the lines using the disk sander and the elliptical sander (for any inside curves).


 

 

These pieces were joined at the scarf and glued, using the clamping arrangement shown.  A piece of plate glass was used to ensure that the keelson was straight.
 

 

The next step was to form the narrow bottom of the keelson.  This would be best done on the milling machine, but an approach for cutting along the curve of the keelson was needed.  I fabricated a ‘table’ for the milling machine with a peg located in the table.  (I saw this in use on another build log – a great idea)




 
By keeping the keelson stock pressed against the peg, it was possible to follow the curve of the keelson with the milling cutter.  Light cuts were progressively made on each side of the keelson until the proper depth was reached.



 

The following photo shows the milled bottom of the keelson.
 

 

The next task was to cut all of the mortises for the frames in the keelson.  Since the keelson sits on an angle, a jig was developed to ensure that the frame mortises were perpendicular from the waterline.  This jig simply consisted of a piece of wood with the top cut at the appropriate angle.
 



 

This jig was positioned against two machine screws in the tooling plate to ensure that it was horizontal, and the keelson was clamped against this jig.  A laser center-finder was used to check that the mortises would be vertical.
 



 

The mortises were then cut on both sides of the keelson (the drawing of the keelson was mirrored and pasted to the port side after initial shaping of the keelson).  All of the mortises are 2” deep.


 

The ends of the mortises were rounded because of the shape of the milling cutter.  These were then squared off using a knife and a small chisel.



 

When reviewing the photos from the recent rebuild, I was able to see that the forward end of the keelson was rounded to the depth of the narrow keelson bottom.


 

 

A rotary tool with a medium stump cutter was used to form this end of the keelson.

 

 

The bearding line is very pronounced at the front of the keelson (shown as the dark line bordering the mortises in the above photo).  The keelson was shaped to this line, again using the stump cutter.


 

 

Finally, the forward 12” of the keelson tapers from its 16” width down to 10” – this was done on the disk sander.


 

 
 

 

So the keelson is now fully formed.  Next up is to cut the centerboard slot, begin installation of the keel, inner stem, and stem knee.


 
Thanks everyone!

Skipjack Kathryn
 
 
 
Part 1 – Background
 
 
 
I’ve always liked the lines of the Skipjack oyster dredging craft from the Chesapeake Bay.  A couple of years ago I found drawings of the Skipjack Kathryn on the HAER website, and thought this would be an interesting build. 
 
 
Kathryn was built at Crisfield, Maryland in 1901.  Kathryn is fairly large for a Skipjack, measuring 50 feet long and 16 feet 8 inches wide.  The HAER documentation includes the information that was provided for the nomination of Kathryn as a National Historic Landmark, and indicates that Kathryn is the oldest of the true “skipjacks” - the two-sail bateau built expressly for the oyster trade.
 
 
Kathryn’s hull is a modification of the standard hard chine skipjack design.  The hull has the same general form as the standard skipjack with a sharp convex bow, beamy midsection, and counter stern.  The difference is that Kathryn is planked fore-and-aft with a rounded chine rather than having a hard chine and being planked athwartships in a herring-bone pattern.  Only a small number of skipjacks have been identified with the same construction – the Susan May (1901) and Maggie Lee (1903) among them.  Kathryn carries the traditional Chesapeake longhead or clipper bow with a straight raking stem.
 
 

 
Kathryn underwent a major rebuild in 1954, which included the deck and siding, but retained her original form and many of her original oak timbers.  The HAER documentation was recorded as Kathryn existed in 1995.  Some modifications had been made to Kathryn’s outward appearance, mainly the addition of a ‘doghouse’ or companionway above the main cabin, and the replacement of the forepeak hatch with one of a lower profile.
 
 
In 2011 Kathryn struck a buoy during the annual skipjack race off Deal Island, Maryland.  “Stoney” Whitelock, the current owner and captain, said “When I hit that buoy, that was no big deal, but I found out there was no nails holding the planks onto some of the frames, they were eaten away.  Almost all of the frames at some point were rotten.”
 
 
A major construction project was launched to rebuild Kathryn, starting in 2011 under the guidance of Mike Vlahovich – a master shipwright and founding director of the Coastal Heritage Alliance.  The project was funded through grants and private donations, and much of the reconstruction work was performed by volunteers.
 
 
Kathryn was relaunched during the end of September 2015, and worked the 2015 oyster season.  I was able to spend a short time on board Kathryn during October 2015 as she was docked at Deal Island before the oystering season.
 
 

Part 7 – Frames


 
 
The HAER documentation says that Kathryn’s frames are ‘highly irregular’, rather than giving dimensions.  After measuring the frames in several of the drawings I decided to use a sided dimension of 4” and a moulded dimension starting at 5” at the sheer and increasing to 8” for most frames.  This makes the frames of the model 1/8” thick, and varying from just over 1/8” to ¼” in the moulded dimension.  All frames are single frames, so on the model they will be quite fragile until supported by the interior and exterior planking and other components.
 
 
Since Kathryn’s sides and bottom are flat, there are no curves to contend with in the frames – other than the rounded chine.  The following is the drawing for frame 12 – the forward-most square frame:
 
 

 
Pin-indexing is used to ensure the pieces of the frame line up with the drawing.  EdT in his Young America build log gives a good description of pin-indexing, and I also included it in my Dunbrody build log, so I won’t go into a lot of detail here.
 
Individual frame pieces as well as the pinning template for the frame are marked using a prick punch
 
 

 
And are then drilled using the Sensitive Drilling Attachment on the milling machine.
 
 

 
The frame pieces are then trimmed to the printed lines using the disk sander.
 
 

 
The frames will be very delicate, and there won’t be much glue surface keeping the frame components together or keeping them attached to the keelson, so some additional reinforcing is required.  The frames will eventually be secured to the keelson with structural bolts, and the joint of the frame pieces will be reinforced by dowels, so pilot holes need to be drilled.  The holes for the structural bolts are at an approximate 45 degree angle, so these holes need to be started with a center drill as shown in the following photo.
 
 

 
The pilot holes are then drilled in the frame components.
 
 

 
The drill used for pin indexing is a #63 drill, and the best approach is to use the sensitive drilling attachment for this drilling.  However, the drill used for pilot holes for the reinforcing bolts and dowels is a #55, and the best approach for this drilling is to use the z-axis hand-wheel to get sufficient force in the drilling.  This would normally mean constant changing of drills and chucks, but I’m fortunate to have another solution in my shop.
 
 
I’ve tried miniature drill presses, but have not been happy with the ‘less expensive’ options (less expensive until an x-y table is added).  Recently, Sherline offered a discount on the milling column for the lathe.  This attachment serves very nicely as a second drilling station (or mill if necessary), so I now have the sensitive drilling attachment with the #63 drill in the milling machine, and a chuck with a #55 drill in the milling column on the lathe and have no need to change drills or chucks in the middle of the process.
 
 

 
Constructing the frame consists of aligning the pieces by laying the bottom piece on top of the side piece (using the pins for alignment)
 
 

 
Then using a hobby knife to mark the joint on the side piece of the frame.
 
 

 
After the side piece is trimmed to fit using the disk sander, the pieces are then glued in place and left to cure.
 
 

 
When the gluing is completed, the hole for the reinforcing dowel is drilled into the side piece of the frame.
 
 

 
The dowel is glued into the frame and clipped off.
 
 

 
Since the frames are mortised into the keelson on each side, aligning the frame on the keelson requires that each side is aligned separately to allow for possible mis-alignment of the mortises.  A jig is used for this purpose.  This is the same jig that was used to align the Dunbrody frames.
 
 

 
In addition to the jig, a template for the frame, consisting of the frame drawing cemented onto a flat piece of 1/16” thick basswood, is clamped to the framing jig and aligned with the centerline.
 
 

 

 
 
The frame piece is clamped to the framing template while the glue attaching the frame half to the keelson cures.
 
 

 
 
The same process is followed for the opposite side of the frame.  The following photo shows the first frame (#12) installed.  Only 25 frames to go.
 
 

 
One last item:  I wanted a modeling setup that would allow me to work on all sides of the build without turning the shipway.  It would also be ideal if I could raise or lower the model depending on what was being worked on at the time.  I was able to find an adjustable table in IKEA – known as a Skarsta sit/stand table.  Using a simple hand crank, the table extends from a minimum height of 27.5”
 
 

 
to a maximum height of 47.25”
 
 

 
 
My old back is very grateful for the working height!!
 
 

 
 
Thanks everyone (and thank you IKEA!)!

Part 6 – Shipway and Mounting


 
It’s been a little while since the last post – due to some challenges.


 
In the last couple of posts I’ve shown the model shipway for Kathryn in use, but haven’t described it in any detail.


 
The shipway is constructed using a 12” x 48” x ½” melamine shelf, routed to take the Veritas T-Slot Tracks from Lee valley.  These tracks allow the use of the ½ thick shelving – other tracks would require a thicker board.  This is the same arrangement as used on the Dunbrody build, but is based on a longer shelf since Kathryn will be longer than the Dunbrody sectional model.


 

 

The devices at each end of the shipway are the jigs used for holding the centerline, and are the same as used in the Dunbrody build.  The other fixture in the center of the shipway is a jig used for setting the frames – it’s the same jig as was used for Dunbrody, but will be used in a different manner.  Its use will be described in a future post when frame installation is covered.


 
Kathryn is mounted using bolts that run through two spacers that were cut to hold the model at the proper angle.  The initial intent was to thread the shoe/keel/keelson combination to hold the mounting bolts to the hull.  However, when I started mounting the frames it became apparent that the model would need to be frequently removed from the shipway during the framing process.  Obviously the threaded holes in the wood components would probably not stand up to frequent jostling, so a different approach was needed.


 
Since there was no longer any way to embed a nut in the keelson, as had been done on Dunbrody, I needed to find a way to embed a threaded sleeve through the very narrow keel (8”, or ¼” at scale).  I decided to use an 8-32 pronged t-nut as shown in the following photo.


 


 
 
The entire flange needed to be ground off, so a method of holding the nut during grinding was needed.  The nut was screwed onto 8-32 threaded rod, which was held in a large pin-vise.  Two hex nuts were used to keep the t-nut from turning during grinding.


 

 

The flange of the t-nut was then ground away using a bench grinder.


 

 

The following photos show a threaded sleeve after grinding was completed, and both sleeves screwed onto the mounting rods ready for installation.


 

 


 
A #7 drill was the largest drill that could be comfortably used to enlarge the holes in the keel, so the sleeve needed to be further ground to fit into the hole.  The sleeves were then epoxied into the keel.  The mounting bolts can now be removed without any risk to the screw thread within the keel/keelson.


 
With the mounting work now completed framing can begin and will be the subject of the next post.


 
Thanks everyone for following and for the continued encouragement.

Thanks!  You fit in very nicely with the skipjacks.  I envy you and would love to get to the skipjack races some day.  It's a great photo and shows how the boom sags - I'll have to remember that when I get to that point in the build.

Great project!
 
I've raced with the skipjacks at Deal Island.  I'm tied between two of them in the photo.  Fun times!

Part 5 – The Stem Knee, Keel, and Worm Shoe


 
The stem knee supports the inner stem, has a 5” square socket to support the Sampson Post, and has a mortise on each side for the foreward-most frame.  The following photo shows the stem knee drawing, which was mirrored for aligning the two sides of the knee.


 
                                  
 


A small chisel was used to cut the socket and the frame mortises into the stem knee.  Because the knee was fairly small, I used the work setup shown in the following photos.


 

 

A 5” x 5” strip was used to check the accuracy of the socket for the Sampson Post.


 

 

The stem knee was then glued in place.

 


 
The rest of the keel (aft of the centerboard slot) was installed as two pieces.  The first piece was installed at the beginning of the curve in the keelson.


 



 
The aft keel piece was formed from 3 separate timbers.


 


 
This aft piece was then glued in place.


 


 
This completed the Keelson/Keel assembly.


 


 
There is a ‘worm shoe’ installed under the keel, as a protection for the keel.  This is made from pine and is only 2 “ thick.  The following photo shows the worm shoe being installed.


 


 
The cutwater and outer stem were fabricated, but only temporarily installed at this point.  The outer stem will cover the plank ends, and will be tapered from the planks down to the width of the cutwater, so this work will be left until the planking is installed.  The profile of the outer stem has been cut, and holes have been drilled to allow the outer stem to be temporarily mounted to the inner stem.  In addition, a slot was milled in the forward face of the outer stem for installation of the cutwater.


 

 


 
The following photo shows the completed Keelson / Keel / Stem assembly, with the temporary installation of the cutwater.


 


 
And, finally, mounts were created to keep the keel assembly at the proper height from the shipway, and the assembly was mounted to the shipway.


 


 
With the assembly now mounted in place, it’s time to start making and installing the frames for Kathryn.


 
Thanks everyone for following along, and especially for the Likes and comments.

Part 8 – Frames, cont’d
 
Framing Kathryn has been continuing – albeit slowly.  There have been a lot of other activities interfering with the modeling work, so there hasn’t been as much progress as I would have liked.
 
It quickly became apparent that the model’s frames are very delicate, and some additional steps were needed to strengthen them.  This resulted in some additional structures that are not in the actual boat, but these structures will be hidden by planking and shouldn’t cause any issues.
 
The first such structure was the addition of a reinforcing plate at the joint between the frame floor and the frame side.  This plate was added after the chine had been shaped and the glued-on drawing removed.  After the glue attaching the plate to the frame had dried, the plate was then sanded to match the curve of the chine.  The following photo shows one of these plates in place.
 

 
The individual frames are only attached to the keelson with a minimal glue joint, so individually these frames are very easy to disturb.  By tying the frames together the frame assembly would be much stronger.  I decided to tie them together by using 1/8 x 1/8 stock, cut to match the distance between frames at the keelson.  Since this distance varies from frame to frame, the braces needed to be measure individually.  They are then installed at approximately the midpoint of the frame floor to join the frames together.
 
The first frame installed – frame 12 – was held perpendicular to the keelson by the c-clamps shown in the following photo, and then the subsequent frames were joined to that frame via the braces.  The c-clamps were left in place until the first 4 frames were joined and the glue set. 
 

 
The first 4 frames were very stable after the glue had cured, and didn’t need to be held in place for installation of bracing for subsequent frames.  It was easier to use the long-nosed spring clamps for this work, rather than the miniature machinist clamps used in the prior photo.
 

 
As described in the prior post, structural bolts would be used to fully secure the frames to the keelson, and pilot holes for these bolts were drilled as part of the construction of the frames.
 
After the installation of the first six square frames (12 through 17) was completed, it was time to insert the first set of structural bolts.  The model was removed from the shipway and placed in an adjustable keel clamp.  This clamp was positioned so that the pilot holes were visible. 
 

 
This allowed drilling through the pilot holes and into the keelson, as in the following photo.  Pieces of 3/64 brass rod were then epoxied into these holes to serve as structural bolts.
 

 
While the model was in the clamp, the forward edges of the mortises for the cant frames were angled to allow the cant frames to be properly positioned.  This work was performed with a diamond bit in a rotary tool.
 

 
The middle 8 square frames are now in place.  Since each half of a frame is a separate installation, this is the equivalent of 16 frames having been installed.
 

 
The frames installed so far have not needed any dubbing (shaping) to allow the planks to lay flat against them.  The remaining seven square frames in the rear of the model will need shaping.  In addition, the forward eleven frames are cant frames, which will require a modified installation procedure.  These topics will be covered in the next post.
 
Thanks everyone! 

Part 9 – Frames, cont’d
 
There is no mention of cant frames in the HAER documentation, but in the drawings the forward most 11 frames on Kathryn appear to be canted.  I’ve decided to construct those 11 frames as cant frames.
 
The framing jig for the cant frames is essentially the same as for square frames, except that only one side of the drawing is used at a time, due to the angle the jig must be held at, as in the following photos.
 
 


It is also necessary to angle the base of the frame floor timber so that it sits flush against the keelson.  Each of the eleven frames will sit against the keelson at a different angle, so these angles were measured from the half-breadth plan and recorded.  Templates were created so these angles could be accurately created on the frames, as shown in the following photo.
 


The following photo shows a template being checked against the drawing on the shipway.
 

 
The templates were printed on card stock and are used to adjust the miter gauge on the disk sander to the appropriate angle.
 


A temporary batten – held by clamps – is used to double-check the fairness of the frames.
 


The cant frames were installed in the same way as the square half-frames.  A stiffening brace was added between frames while the new cant frame was still in the installation jig.
 
 


The aftmost square frames – 22 through 26 – need to be faired to conform to the rising shape of the keelson in that area.  The drawings for these frames indicate the fairing needed.
 

In this drawing the color and configuration of the lines indicates the shaping required:
·      The red lines indicate the aftmost face of the frame, while the green lines indicate the forward face.
·      The frame is cut out along the solid lines, whether red or green, and then the dashed lines indicate the edge of the frame that that needs to be reduced (the cutting line).
 
Since the drawing is pasted to the front face of the frame, the first task is to draw a line corresponding to the red dashed line on the aft face of the frame.  A compass is used to measure the distance of the dashed line from the edge of the frame, and this compass setting is used to draw a corresponding line on the aft edge of the frame.
 

 
The frame is then shaped using a stump cutter in a rotary tool.  First, the cutter is used to cut the aft edge of the frame down to the drawn line.  It is then used to flatten the entire outer edge of the frame at the appropriate angle.
 

 
The forward face of the frame is shaped by cutting to the green dashed line. 

The braces used for the cant frames and for the aftmost square frames need to be angled to fit securely against the frames they support, as shown in the following photo.
 


Cant frames 7 through 11 have been installed at this point.
 



The square frames have been installed to frame 23.
 


So this leaves 6 cant frames and the aftmost 3 square frames to be installed.  I hope to have these frames completed sometime next week.
 
 

There are a couple of frames in the midship area that concern me, and I may need to remove and re-install them.  But I won’t think about that until all of the frames have been installed.
 
Thanks everyone for following, for the ‘LIKES’, and for the encouraging comments.

There is nothing as forlorn as an empty shipyard waiting for Fedex to deliver my next model.

Dave, Up next is the SS Mariefred a little passenger boat, possibly a ferry but nothing says so, that operated between Stockholm and Mariefred in Sweden.
 
Bob

I used silkspan cut into scale 3 ft widths glued down with Artist's Acrylic Matt Medium.  The Matt Medium was painted on with a brush and the silkspan was laid down and pressed into place.  The next length was overlapped a scale 4-6 inches and continued the length of the roof.  When the adjacent strip was started I overlapped the first strip by 4-6 scale inches for the entire length and at each continuing strip.  I brushed a bit of the Matt Medium on the back side of each strip where it was to overlap the previous strip - didn't worry too much about any squeeze out as it looks like the tar that held the roofing material down.
It was very easy to do and many have commented on the authentic appearance of the roofs.
Kurt

Haha, no it's not attached, I just put it up for a pic.......(or did I)?
 
Never the less thx for the heads up.
 
I have been checking out the various photos I have of the real Chaperon, it was configured quite differently over the years but one of the most interesting was the inclusion and omission of the Texas Deck. Does anyone know the reason for this?
 
Sorry wrong pic

A couple of pics of the wheel, still a bit of detailing to do but the washes are complete.
 
Now it's back to attaching battens. ZZZZzzzzzzz!
 
Len

A bit difficult to describe really. The paddles sit on the end of the spokes of the wheel as it were. I just put a piece on top of the paddle were the paddle sits on the wheel.
If I had been really keen I should have put fake bolts through them. Let's see if this picture will help.
 
 

A pic of the lights so far, still have the Texas deck and pilot house to light up. All this is temp as I am still painting and finishing up lower decks.

Hi I have some updates to show, although currently only roughed in I think they are significant changes
The LED lights arrived and Rossi46 and I wired up the lower decks. There is a slight change to the layout of the lights that I posted earlier in this log but the effect dictated that these minor changes were required.
I wanted a very restful, dim illumination and the yellow LEDs did just the job, I am very pleased. I'll post night pics later when it gets dark.
Yellow lights all round, between 1,8 and 3mm DIA. The pics below show more detail than I can describe, you know what they say, A picture paints a1000 words.
 
Messy work bench, it got ugly, nearly pulled the chainsaw out.

Those are the hold downs for the pilothouse.  Made from brass strip with a hole in each end, the end bent down at a 45 degree angle - rigging line was taken down to the deck.  The attached photos show how I did them.  The photo with the rigging line on my Chaperon shows the rigging before I went back and tightened it up.
Fig 9 - shows a different type of wind brace/tie down - this is from Alan Bates' Steamboat Cyclopedium
The other drawing is from the old Model Shipways plans (for the solid hull kt that was never produced)
Also detailed on Sheet 4 of the instructions for the current kit.
 
Kurt

I have some of the lights added to the main deck.

T0 hide the wires I grove the 1/8" sub deck.