TWILIGHT 2007-2009 by MAGIC's Craig - Scale 1:16 - RADIO - Pacific Northwest cruising powerboat

[MAGIC's Craig]

This build will be a POF scale model of a planned sturdy powerboat for Vicky and I to "retire" to when we had to give up sailing our schooner, MAGIC.  This tale started in the early 1980's when we began exploring the channels and islands in the coastal archipelago stretching north from the state of Washington into British Columbia.  We were then sailing an engine-less gaff cutter and after a frustrating day of light winds and rude, large-wake-dragging Bayliners, we took the morning to hike ashore across to another cove.  An older converted troller was heading out and across the still waters of that cove , we could hear her slow-turning engine effortlessly (and quietly) pushing her along with little wake. It sounded like, "potato... potato... potato ..."  We decided there and then that if we had to give up sailing for a powerboat, it would need to be driven by something like that "easy-to-live-with" engine.

 

Many years passed by before it became obvious that we were aging off of our schooner, but we also had learned a bit about these heavy, old, slow turning engines.  A chance encounter connected us to a fellow who owned a "spare" rebuilt Gardner 6L3 diesel of 1956 vintage - which was not in a boat any more - and we struck a deal to purchase it.

 

These British diesels are large, measuring about 9-1/2 feet in length and weighing in around 7,000 pounds. They were designed to be reliable and idled at 200 rpms while putting out their maximum power at a maximum of 900 rpms. This one needed a boat to go back into, of course, so off to my drafting board I went to begin the process of designing such a craft.  Early on,  Vicky named the design, TWILIGHT and I carved a couple versions of half-hulls as explorations into a suitable hull shape. We had been befriended over the years by naval architect, William Garden, and after seeing my drawings and half-hulls, he offered suggestions on which hull and house shapes might work well in the often rainy, occasionally rough waters of the PNW. I drew up our interior preferences for a liveaboard boat and fitted them around the need for a suitable engine room.

And, as often happens, life made changes to our plans and the drawings were shelved. The Gardner Diesel was sold to a good home.

 

When the model of MAGIC was completed, I was often asked, "Well, what are you going to build next?"  Eventually last fall (and probably suggested by my better half), the idea of building a R/C POF model of TWILIGHT surfaced.  The drawings of the preliminary design were resurrected along with the suggestions and design revision ideas we had entertained before that project "sank".  A revised set of lines were drawn up to incorporate many of these thoughts. The wood racks were checked for suitable stock.  I started drawing construction sections in January, 2024 and I will pick up the build then to bring the log up to date (May, 2024).

 

 

I hope that you will enjoy the process.  I am inspired by the quality and work put into members' projects here and will strive to make TWILIGHT worthy.

 

[MAGIC's Craig]

Construction sections from the revised Lines drawings were drawn up to the planned build scale 3/4" = 1' (1:16).

A plank of Alaska Yellow cedar was used to mill the necessary futtock stock and double layers were glued up to make the sawn frames.

 

The frames were all marked with the location of the DWL and then suitable height cedar blocking pieces were made up for each station to position the DWL at a constant height.  After the frames had been erected and blocked in place on the building form, an inner stem profile was set up for laminating the scarfed-together Basswood inner stem to a laminated full length keelson. A "bread-and-butter" stack of basswood layers which would eventually be shaped to be the stern was mounted on supporting blocks aft.

 

 

[MAGIC's Craig]

The keelson tied the frames together along the centerline but additional stiffeners in the form of twin bilge stringers were glued inboard of the frames before fairing could begin. The stern "block" was rough shaped to the profile and checked with a cardboard template. Blocking was carved and fitted to the outboard locations of the forward continuation of the stern's "knuckle" on each side.

After a sternpost was glued in place, centerline wedges were added above and below the keelson to provide solid support for the shaft log.

 

As the fairing of the frames and keelson proceeded, I also realized that fitting in blocks to serve for the electric motor's mounting bed would be far easier to do before the garboards were fitted. 

 

To accurately locate these blocks in the vertical plane, we took the time to drill for the shaft.  From aft to forward, the propshaft rises at a shallow angle, so the model's building board was shimmed up at its forward end until a horizontal laser line defined the path for the drill.  Using a long drill, with Vicky calling out from amidships whether the laser stayed centered along the length of the drill, while I sited along the keelson's centerline to avoid wandering off to port or starboard, we managed to drill from aft to forward and were relieved when the bit emerged in the proper location.  (Unfortunately, we were too busy to capture an image of the drilling set-up.)

 

With the shaft temporarily in place, the motor could be attached and aligned, providing the necessary angles and heights for a pair on mounting blocks to be mounted to the keelson between stations 4, 5 and 6.

The shaft hole and motor mount blocking can be discerned in the above image taken while the initial frame and keelson fairing was proceeding. 

A batten was sprung along the deck sheer line to check the probable run of that plank edge.

 

The next post will take up lining out for the planking "belts". 

[MAGIC's Craig]

While I planned to sheath the hull with an epoxy/'glass layer for strength and watertightness, I wanted to try a proper planking technique as discussed on the "Modeling Techniques" portion of this site for practice.  My drafting board drawer still had some rolls of 1/8" wide drafting tapes, so I utilized them to help define the bands of planking which would be necessary.

The tapes certainly assisted eyeballing fair curves around this 3 dimensional curvilinear shape.  Once the locations seemed suitable, as recommended  I divided the space within the bands at each frame into equal widths and marked that frame.  To transfer the plank width markings to the other side of the hull. I overlayed a clear plastic strip on the marked frame, put dots on the plastic and then shifted the strip to the same frame on the other side. An awl was used to punch through the strip at the appropriate points. The divots were then highlighted with a pen.

The inboard edges of garboards would initially meet at the centerline "above" the keelson, so these planks were made about 2-1/2 times wider than the "standard" planks. The keel would sit on a flat formed by planing the garboards back from the centerline 1/2 the width of the keel, which would visually return the garboards to a more normal double width.  The two runs of broads would follow at a width of about 1-1/2 times standard plank widths before the rest of the planking was to follow.

The transition of the rabbet line aft was adjusted by gluing on thin, tapered pieces of basswood to each side of the projecting deadwood from about station 7 aft to the stern post.

By the end of March, planking began to progress (though there were the occasional mis-steps). 

Offering up a piece of planking stock for scribing in as a broad strake

 

Edited May 10 by MAGIC's Craig
missing caption & deleted comment

[MAGIC's Craig]

The broad strakes were fairly straightforward to cut and fit, though they were offered up multiple times each to permit making tight fits to the previous plank.

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Once the planking sequence had moved beyond the curve of the forefoot, the landing for the keel was planed flat athwartships and a suitable thickness of stock was offered up to be scribed to the needed shape.  Here it is clamped in place to lay out the location for a stepped scarf to be cut for connection to the stem.

The next photo is actually posted upside down but it permits viewing the structure in the aft end of the hull (as well as a lot of drip-and-squeeze-out to be cleaned up).  The small "box" under the deck aft holds the rudder servo. I had meant to simply build the box into the stern prior to fitting the final piece of blocking and then remove the servo to keep it out of harm's way. However, I made it too tight of a fit and the servo remains in place.

The planking continued to be fitted working toward the stern's "knuckle" and the keel was tapered and glued in place. The design of the hull incorporating the"knuckle" was a suggestion of Bill Garden's for allowing some width to the deck level aft while letting the run easily release the water's flow without dragging a transom.  The "knuckle" blends into the rounded bilge as it goes forward by about station #6.

And as the plank strakes "turned the corner", this became clearer after the first topside plank went into place.

By April 25th, the rest of the planks to the level of the deck edge were in place and the stem had been bonded in place. Final fairing of the upper edge of the stern "block" awaits the turn-over of the hull as will the bulwark planking.

 

[Jim Lad]

That looks a good, sturdy boat. It will be interesting to watch her grow.

 

John

[Ian_Grant]

Nice work! Always happy to see an RC build!

[MAGIC's Craig]

Thanks to you all for the support and appreciation.  I will post again tomorrow.

[MAGIC's Craig]

Before skinning the boat with a fine-weave fiberglass cloth set in epoxy, there were a few details to be completed.  The first was to drill the hole for the rudder post. This rudder post is perpendicular to the DWL and after some careful measurements and a check for prop clearance, I used an awl to dimple where the hole should emerge from the hull.  Once again, we leveled the building board and set up the laser level on a stepladder (and blocks) perpendicular to the boat's centerline with the projected horizontal line at the DWL and the light of the vertical line "emerging" from the hull on the centerline of the rudder post. Vicky called out whether I was plumb fore and aft while I sighted along the boats fore and aft centerline marked on the bottom of the keel.  The technique worked well.

Because the hull is rising toward the knuckle (when right side up), a wooden bung was cut out with a plug cutter and, before being removed from the stock, a centered hole was drilled in it to permit the rudder post's upper bearing to sit square with the rudder post.  The "holed" plug (or boss) was slid down the drill bit representing the rudder post until it contacted the hull and scribed to accommodate the angle of the hull at that location.

The boss was glued in place and the drill retracted. 

While we had the laser set up, I took the opportunity to put tick marks along the line of light representing the DWL.  While I know where it should be from the drawings, it is always a bit of a treat to see it in 3 dimensions.

The next phase is to seal the hull with the epoxy and fiberglass cloth sheathing. After doing this with MAGIC, I realized that this would be easier for me to do one side at a time. I attached some planks to the side of the building board to permit the whole structure to lay on its side.  Once clamped to the trestles, the cloth wa smoothed on dry and then wet down with the epoxy.

Once both sides were initially sheathed, the building board was returned to its usual position and additional smoothing coats of epoxy and sanding filler were applied, scraped down and sanded

I will pick up the rudder construction next.

 

[MAGIC's Craig]

For the rudder, I borrowed ideas/techniques from Ken Foran's excellent  Model building with Brass as well as Cangarda 1901 by KeithAug .  The rudder post is 1/4" dia. brass and the through-soldered fore-and-aft supports are 1/8" dia. brass.  The notched-out core portions of the rudder are Alaska Yellow Cedar and the cheeks, laminated to each side, are made from 3/32" baltic ply. A card template was used for reference.

The cheeks had recesses carved in them to accommodate part of the diameter of the rudder post to keep the rudder assembly from being too fat. The various layers were epoxied together.

 

The shaping of the rudders foil was a process of filing/sanding the cheeks and core , evenly exposing the parallel glue lines of the ply until a satisfactory shape was achieved. 

A removeable brass lower gudgeon was soldered up to accommodate the lower rudder bearing at the correct distance aft of the sternpost.

It was then epoxy-sealed and (temporarily) fastened in place.

And with that, we are current with the build (as of Mother's Day, 2024)