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  • Albacore 569
    replied
    Merriman's D & E 1/96 scale Skipjack is a excellent model submarine. Still have mine! I did a basswood hull master for the model. I turned two. One for a 1/96 static model of USS Scamp for the Vallejo Naval and Historial Museum Still there proudly on display with USS Permit - & another sent to Dave to just in his tooling. My modest contribution got me a turn key boat as payment. Thanks again Dave.

    So many happy times running this model. It won first place at the San Francisco Model Yacht Club military regatta in....was it 1997? I did test in the pool having just received it in the mail. Trained 'the crew' familiarizing myself and the next day was at that Regatta and won first in the submarine course. Thats how well designed she is, a land lubber can get his Model Dolphins. Hell...not a 40 day wonder but a 40 minute wonder! lol. Merriman's work made me look good, probably more than I deserved. Operating in that murky pond. Merrimans designs build's confidence in the drivers too. Like a classic great fighter plane, it not only looks good, it flies right instilling confidence in the pilot.

    I first balked when Dave said over the phone 1/96 scale? But Dave, that's too small isnt it? Nope! The tear drop hull, was perfect for the wtc-3 (3 inch diameter).. Funn how big these models are in the shop, but get them in the water, 1/96 or 1/32 makes no difference. They all become tiny in the vast 'ocean'.

    The Woke culture everywhere, still have to .persuade parks and recreation no we are not disturbing the ducks. LOL... Experience and video's on you tube concistanly show the ducks are fasinated with those peric cope feathers a the humans are and follow them. Disturbing the ducks? More like entertaining them!...lol F**king woke heads. We all will lead then gently! LOL. Never mind...lol.

    Just saying education and demonstrating the hobby is as important now as it was 2 decades ago. Now if we can get more radios in the lower frequencies to deal with the water in this digitized age, Its great for aircraft and rabid kids with 4 by 4 s, but... However I think Bob Martin in his resourcefulness an innovation has the frequency issues licked. But same time we need to make pals withhtes rbid kids too because they are flying drones. Getting a few helicopter dolly shots of our models in close diving and surfacing / beautiful bridal shots of that new boat.

    Steve
    Last edited by Albacore 569; 07-17-2023, 11:48 AM.

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  • He Who Shall Not Be Named
    replied
    Originally posted by goshawk823
    Ageless model. Looks as good today as it did back in the 90s, when I saw and drove yours at Lake Trashmore. Fantastic finish on this one,David.
    That takes me back a bit. Trashmore was the perfect venue.

    David

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  • goshawk823
    replied
    Ageless model. Looks as good today as it did back in the 90s, when I saw and drove yours at Lake Trashmore. Fantastic finish on this one,David.

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  • Das Boot
    replied
    Masterpiece.

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  • He Who Shall Not Be Named
    replied
    Originally posted by redboat219
    Okey, Takumi or master artisan in Japanese would be a better term for you.
    If I have to be pigeonholed. Sure.

    David

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  • redboat219
    replied
    Okey, Takumi or master artisan in Japanese would be a better term for you.

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  • He Who Shall Not Be Named
    replied
    Jessie represents your typical art critique -- someone who has no idea what art is but espouses on the topic professionally. Give Jessie a haircut, dress him smartly, put a wine glass in his hand, and give him an Oxford accent and plunk him into a rich-man's cocktail party and you have today's art critique; a smooth talking, varnished, unaccomplished, grifter; an empty vessel; a con-man.

    Heisenberg, on the other hand, knows the difference between art and Craft. I know the difference between art and Craft!

    The word Art, in today's world, has been so mis-applied as to have been stripped of meaning -- in a world where **** smeared on a canvas; a jar full of **** and a Cross; and the universal acceptance of Expressionism is deemed as art by elitest art critiques -- a world I abhor and deny.

    David
    Craftsman

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  • redboat219
    replied

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  • He Who Shall Not Be Named
    replied
    Well, I finally completed my 1/96 SKIPJACK.

    Again!

    I've built so many of these things – for friends, customers, and a few institutions – I've lost track. Each time I build one of these beasts with the intent of making it my own eventually someone makes me an offer I can't refuse, and it's gone.

    This one stays with me, no matter what!



    Three were two final detailing tasks before I considered the model done. The first was to represent 'scuff marks' on the non-skid portions of deck and atop the two fairwater planes. The non-skid itself is represented by a slightly lighter shade of the dark, dark gray of the upper hull, fairwater planes, and sail. Scuffing would be represented by a slightly darker color of that gray applied with a small stiff brush employing a stippling action done with a very light touch.

    Here I'm working out the shad of gray and technique on the test article. The medium of choice here was the old reliable Walmart acrylic, water soluble paints, well thinned with water.



    Once happy with the results on the test article I moved on to the model itself.

    Most scuffing is owing to foot traffic, so most of the scuffing was done adjacent to the two escape trunk access hatches and retractable cleats.



    The hardest part of the scuffing job was finding just the right brush to do the job right. This illustrates the selection process – all worked out on the test article.



    The scuff marks on the 'international orange' marker buoys was the same gray but watered down even more so as to reduce the pigment content – I only wanted the suggestion of foot traffic over these bright and contrasting surfaces.



    An access door either side of the sail permitted people to stand atop the fairwater planes (watch-standers, shark-watch, semi-naked go-go dancers... that sort of thing). So, the non-skid portions atop those planes also got some scuffing.



    The second job was to give the deadlights (the four supposedly clear 'windows' at the leading edge of the sail); the wrap-around lens of the emergency stern light, at the trailing edge of the sail; and the lens over the stern light mounted atop the upper rudder a clear gloss finish.

    I engraved some deadlight outlines onto the test article and tried both epoxy adhesive and two-part polyurethane 'clear-coat'. The clear-coat won being easier to apply with a brush than the glue.





    Here I'm brushing on some of the glossy clear-coat to the sails emergency stern light lens.



    The hemispherical lens over the rudders stern light got the clear gloss treatment as well.







    You can just make out the non-skid from the rest of the hull and fairwater planes, there being a slight variance in shade between the two.

    Also note the simulation of 'oil-canning' to the sides of the sail. Represented only with slight variations in color density, the effect is to produce the suggestion of metal distortion between stringers and frames.

    It's easy to over-state such things. Always keep in mind with weathering and paint detailing: Less is More!

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  • He Who Shall Not Be Named
    replied
    In addition to eight Dremel moot-tools – which conveniently hang off hooks over the primary work-station – I also wrangle three big drill motors and heat-gun. Until recently those big, clunky hand-held machines were forever getting in the way when not in use because – until yesterday -- I had no assigned storage caddie for them. They just sat where-ever I tossed them after use.

    Time had come to organize where those big hand-tools would go, and do so in a manner that would take up the least amount of room, yet make them easily accessible.



    I elected to make a simple drill-motor and heat-gun caddie and mount it to my wheeled tool-chest/parts bin which is usually positioned to the right of the primary work-station.



    Even the mundane tasks, such as the fabrication of this drill-motor and heat-gun caddie, if the job is to be done right, demands forethought, gathering of materials, and at least a simple shop-sketch to get arrangement and dimensions worked out.

    As a long-dead Junior High School shop teacher kept reminding us: “measure twice, cut once... you idiot Troglodytes!” (teachers in the early 60's were a different breed than today's blue-haired, woke Karin's who infest government schools).

    You sketch out an idea; look around and find the materials and tools that will get the job done; work up a simply isometric drawing denoting key dimensions; and only then cut stuff up and start the assembly.

    Measure twice. Cut once!



    With the exception of the two heavy-duty mounting brackets, I had everything needed at home. A quick trip to the local Lowe's got me the brackets. To work!





    Now I have unhindered access to the drills and heat-gun.

    A half-century ago these words still ring in my head:

    “Return your tools to tool-issue and police your work stations! Merriman, Loman!... you two hoods tuck in your shirts... now! SHOP CLASS... DISMISSED”.



    At the SKIPJACK's stern were four equally spaced rows of sacrificial zinc anodes – there to protect the brass alloy propeller and iron bearing hull from electrolysis induced corrosion. The zincs were CA'ed to the SKIPJACK's stern. The problem was how to denote their proper location about the conical section of hull.



    I first wrapped a narrow strip of masking tape around the circumference of the hull, well forward of where the eventual zincs would sit. The horizontal stabilizers and holes for the upper and lower rudder operating shafts guided me as I marked the masking tape with those locations. It was then a simple matter to find the half-way point – dividers was the tool of choice for this task – along the tapes circumference between each quadrant point. I then stuck down narrow lengths of masking tape running aft from a point to the stern. These strips of tape denoting the proper radial distribution and arrangement of the zincs.



    Either side of a longitudinal running strip of tape I stuck down a slightly wider strip of tape. The wider strips would help me corral the eventual zinc piece in proper place as I glued the zincs to the hulls stern.



    A centrally running longitudinal piece of tape was pulled off the models stern and stuck to the top of a zinc piece. The bottom of the zinc piece received a small smear of CA adhesive and the topside masking tape used as a handle as the zinc piece was positioned and pressed into place at the SKIPJACK's stern.



    Once the CA had cured hard, all masking tape was removed and I proceeded to other tasks.





    Unfortunately, when I pulled away the radially running length of masking tape it pulled away about a quarter-inch square portion of the carefully applied weathering – what was left was a virgin anti-foul red undercoat which stood in very sharp contrast to the weathered finish.

    Here you see the ingredients for a quick, almost perfect touch-up repair of the damage area. Using the lid of the water container as a palette I kept mixing water soluble acrylic paint colors till I got the basic orange of the weathered surface, then stippled in slight variations of that color to replicate the mottled finish of the surrounding below-waterline portions of hull.



    As each pass of paint went down I quickly dried it with the heat-gun, then moved on to a slightly different shade – playing around till the repaired paint-work was almost indistinguishable from the surrounding undamaged finish.



    To highlight raised portions of the model I dry-brushed on a light shade of gray artist's oil. This medium takes days to dry and blends well, so is the paint of choice for this work. Typically, a very soft fan-brush is used. The trick is to lightly load the tip bristles of the brush with the paint and to then vigorously wipe all the paint you can from the brush. What little remains is transferred, every so lightly to only the raised portions of the model.

    The brush is quickly swept back-and-forth over the models surface, the bristles barely making contact with the models raised surfaces. Only the projecting, sharp edges of the model pick up the paint. The light colored paint that is transferred to the model gives the illusion of sunlight impinging on those surfaces.

    Here I'm practicing on the test-article before committing to the SKIPJACK model.













    Time to assemble everything into a good looking, workable r/c model submarine.

    Here, less the fairwater planes pushrod and SubDriver (SD), are the control surfaces and linkages; running gear; and SD ballast sub-system induction snorkel.




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  • He Who Shall Not Be Named
    replied
    When the mission and design specifications were issued for the eventual SKIPJACK class it's now obvious that these combatants would hunt and kill submerged and surfaced targets and also, through the use of an extensive array of retractable sensors, grasp a real-time awareness of the surroundings through radio and optical instruments tuned to intercept just about every frequency across the sensible electromagnet spectrum. Add to the mix of sensors a snorkel mast and you have the proverbial plumbers nightmare within and atop a SKIPJACK's sail.

    The six boats of the class would have a ****-load of retractable masts! And that requirement dictated a huge sail to house all those antennas, masts, mast fairings, scopes and snorkel. Not to mention the open bridge for surface navigation.

    That huge sail knocked a few knots off the potential speed of the class and also presented a ship control problem during submerged, high-speed, high rate turns.



    Detail idiot I am, I provided my little 1/96 SKIPJACK with all retractable masts, save the ECM. Even I have my limits as to how far afield I will go in pursuit of making the display look 'busy'.

    The model sail, at an early stage of mast-to-sail integration. Most of the scope heads and antennas were cast from white-metal. The attack and search periscope tubes were lengths of aluminum tube, The mast-fairings were cast from carbon strand filled polyester resin.

    Additional metal parts seen here include the rudder anchor-light, and stern zincs.



    All metal parts were pickled with Ferric chloride acid. Each metal item was scrubbed with a stiff brush soaked in acid to oxidize its surface. Once a part had assumed a dark gray finish, it was rinsed in fresh water and set aside to dry. The pickling makes the metals surface receptive for paint adhesion; without the pickling, dried paint would just shrug off the metals surface.



    Unlike the sail mounted items, the pickling of the zincs was done for a different reason – I wanted the space between each zinc brick to stand out, and the dark gray of oxidized white-metal worked to to do just that once I came back and abraded away the oxidized surface of each grouping of zinc bricks. A hunk of Scotch abrasive pad was the perfect tool for that job.



    With the exception of the attack periscope, all retractable masts were sheathed in a streamlined fairing. Often the fairings were colored a haze-gray and camouflaged with what what called a leopard-spot scheme – nothing more than random sized and arranged black smears painted onto the gray fairings. The attack and search periscope heads also got the gray and spot treatment.





    I'm pointing to the combined diesel intake-exhaust snorkel mast. It's unique in that I used a strip of self-adhesive aluminum foil to represent the bare stainless steel at the leading edge of this mast. That forward cylindrical tube was the induction side, the exhaust side is aft of it and tapers to the sharp trailing edge of the streamlined mast. The exhaust portion of the mast is painted the same gray with leopard-spots as the other masts and fairings.



    The Bare-Metal foil piece was cut out from the main sheet and centered onto the leading edge of the snorkel mast. Using a very stiff bristle brush I carefully burnished the foil onto the mast – working from center outwards both sides, and a bit up, then a bit down, pushing out any air-bubbles that would otherwise spoil the look of this metal wrap.



    I see missing leopard-spots at the base of the radar antenna mast fairing – I'll fix that.

    As this is an r/c model submarine, and I tend to drive like a maniac, I typically only operate the model with a single 'attack' scope in place – no sense sheering off the entire array under some targets keel. Hey!... I went to all the work of representing most of the SKIPJACK's retractable masts and I didn't do so just to cream them in some 'incident at sea'. The mast array is there to make the display more interesting while sitting on the boat-stand at any event I attend. So, before plunking the model in the water all masts, with the exception of what I regard as a 'sacrificial scope', are removed and tucked safely away into my field-box.

    All I need to track the model when patrolling the lake is a single mast penetrating the surface to give me my visual ques. If you can't see it, you can't drive it!



    Regarding the actual SKIPJACK boats: In the very unlikely event of a submarine being stuck on the bottom – in water shallower than the boats design-depth – provision was provided to release a messenger/marker buoy to the surface tethered to a stout down-haul cable. In practice a McCann rescue chamber would be spliced into the down-haul cable and the chamber would reel itself down that cable till its circular seating surface made contact with the sunken submarines escape trunk seating surface. Venting the lower skirt area of the chamber produced the differential pressure needed to hold the chamber securely in place as personnel were transferred off the disabled submarine. Use of turnbuckles between the chamber and submarines pad-eyes were redundant – a back-up to the pressure differential holding chamber and submarine together during the rescue process.

    The down-haul cable ran from a cable reel tucked away in the free-flooding space under the submarines hull, running a short distance atop the deck, passing through the fairlead 'bail' over the escape trunk access hatch, and ran on to the messenger/marker buoy.

    I represented the down-haul cable with .005” conductor wire.



    Little shards of wax-paper served as painting masks as I darkened the installed down-haul cable.



    Any boat that has been in the water long enough eventually evidences a narrow, very light gray scum line right at the waterline. Dead 'sea grass'.

    I represented this with a white 'Artist's' pencil whose point had been carved to a wedge shape. This marking was done free-hand only at the bow and stern oval transitions, the majority of the pencils work done with the aid of cardboard straight-edges.



    Note the use of double-sided scotch-tape on one side of a cardboard straight-edge – this kept it from sliding around on the hull or upper rudder as I pressed pencil tip home and dragged it along the work.






    Last edited by He Who Shall Not Be Named; 07-09-2023, 02:04 AM.

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  • He Who Shall Not Be Named
    replied
    Originally posted by Subculture
    Have you tried these guys for polyurethanes. Well regarded on your side of the puddle.

    https://www.southernpolyurethanes.com/
    ... and it took this guy from the frig'n UK to give me the best steer as to a supplier of clear-coat I so desperately need!!! I'll talk with the SPI guys next Monday. Thanks, Andy!

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  • Subculture
    replied
    Have you tried these guys for polyurethanes. Well regarded on your side of the puddle.

    Southern Polyurethanes is a manufacturer of automotive coatings for the restoration, repair and custom markets. Epoxy Primers, Clear coats, Primers, Basecoat, single stage and more.

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  • He Who Shall Not Be Named
    replied

    Each pad-eye was tweezered into place, running each down into the little holes previously drilled about the circular escape trunk McCann rescue chamber seating surface. To insure that all pad-eyes sat the same height I placed one leg of an unused pad-eye blank into the space between the two legs of an inserted pad-eye and pressed it down till it sat atop the temporary length of .013” wire.



    A dab of thick formula CA adhesive was applied within the hull to glue each pad-eye permanently in place. This 'L' bent length of wire served as the ideal application tool. Gluing the pad-eyes from within the upper hull negated any possibility of glue smears spoiling the finish atop the models surface.



    Once the glue had set hard I reaching into the upper hull and snipped off the excess lengths of pad-eye wire with wire-cutters.



    Now came time to install the two escape trunk deck hatches. As these sat a bit below deck level within wells under the hatch fairings, each hatch piece was glued to a cast resin foundations. The foundation itself would be glued within the upper hull at the forward and after raised flange portions of each foundation.

    To make these white-metal parts receptive to paint I pickled each with Ferric Chloride acid quickly followed by a fresh-water scrub and rinse.



    Though the pickling oxidized the surface of the metal to a very dark gray already I wanted both the metal hatch and resin foundation to be a total black. So, after pickling the two hatch assemblies were were spray painted black with water-soluble acrylic paint.



    To give some 'life' to each hatch I dry-brushed all raised portions with white oil-based 'artist' paint. This gunk takes ages to dry so is the perfect medium for dry-brushing, streaking, and blending tasks. A soft 'fan' brush is the best tool for dry-brushing. The trick is to wipe most of the paint from the brush after loading it and to make multiple passes over the subjects with quick, light passes till just a small amount of the paint sticks to only the raised portions of the subject. What was once a black-hole then becomes a complicated structure of sharp contrasts – pleasing to the eye.



    The eight hold-down pad-eyes needed to be painted. But, before that they had to be pickled like the hatch pieces. First task was to remove all contaminates from the little brass wire surfaces. This was done by scrubbing each projecting pad-eye with a fiberglass abrasive brush – this brought each to a state of shiny cleanliness. I took care to mask the surface of the hull as I did not want to damage the paint work under each pad-eye.

    Each hatch assembly received a big gob of CA at its raised flanges, then I carefully positioned each under an open hatch fairing opening and pressed the assembly onto the hulls inner surface till the glue took hold.



    Pickling the pad-eyes. Note how dark the upper pickled pad-eyes are to the lower ones which have yet to be scrubbed with acid.

    Here you can see how the white dry-brushing of the hatch brings out its details – details that would otherwise be lost within the dark confines of the hatch well.



    Time had come to weather the little 1/96 SKIPJACK hull. I had already represented the mung and other nasties that clink to the below-waterline portions of hull. Now was time to capture the real-world streaking and filth that collects on the deck and sides of the above waterline portions of hull.

    Over the decades I've gathered a substantial file of real-world examples of submarine 'weathering' effects. Here, pages from my binder relevant to the job have been pulled so they would be at hand as I got to work.

    Rule of thumb when weathering: Less is more.



    Before screwing up... er... applying the weathering on the SKIPJACK, I first practiced a bit on an old test-article. Practice makes perfect as they say. Practice is where you determine the best medium, technique and application tools that will achieve the effect desired.

    Screw up your test-article... not your precious model!

    For small models I favor slow drying artists' oil paints when representing hull streaking and that's the type paint you see smeared all over this white plastic palette. I transfer a small dab of color up high on the side of the hull, then use a wad of cotton or old T-shirt to streak the color downward.



    Once confidence had been regained on the test-article, I switched over to the SKIPJACK itself and commenced hostilities. Work was done in minutes. I also applied some very light streaking to the sides of the boats very tall sail.



    And what would be a modern submarines upper rudder without bird-**** running down from its top!?...

    (Guys who worked deck-department (TM's MT's, FT's and NQP's) would truly appreciate this little detail!).



    I had already rubbed on the Woodland Scenics dry-transfers for the '585' sail sides, draft-numbers on the hulls bow and upper rudder, and 'SKIPJACK' either side of the diesel exhaust line fairing. However, some of those unprotected markings did suffer some damage during the below waterline weathering and general handling.

    Here I'm replacing some of the '585' numbers. It takes only a piece of masking tape over the marking needing to be pulled, and it's outta there! I then rub down a new number.

    Not to worry, once everything gets a heavy clear-coat the markings will be effectively locked down and won't rub off unless subjected to very harsh abrasion action from collision or careless handling.



    Up to this point the primer has been an air-dry acrylic lacquer, followed by the very durable two-part (2K in today's parlance) polyurethane black and red base colors – DuPont's automotive ChromaColor, which are no longer available (thanks, California!).

    All of the below waterline weathering was done with water-soluble acrylic, air-dry paints – not terribly durable to abrasion or chemistry, but quick to mix, apply and clean.

    No matter what type coats applied, its the final, clear-coat that becomes the shield against UV, chemicals, and abrasion. DuPont's ChromaClear system is the best I've found – and when it's cut with a proper flattening agent, it can be mixed either as a gloss or the deepest flat anyone on this planet can imagine! It's a ***** to mix; will tear up your lungs if you don't use a proper fitting charcoal mask; and demands quick and thorough cleaning of gun, mixing containers, and hands arms and face once the job is done. But the results are well worth the expense and effort.



    One of my old, trusty Paasche H-Model nuclear powered laser-blasters, set to kill... er... I mean 45psi, and equipped with the big tip. I use this tool on relatively small model submarines. The trick to achieving a uniform sheen to a clear coat is to put it down very wet – almost piled on to the point of running... but not quite. An acquired skill.

    Before committing to the hull and appendages, I first blasted the test-article to get the pressure, stand-off distance, sweep-rate, and nozzle setting right before blasting the SKIPJACK model.



    Note the various means of holding the appendages as they are given the clear-coat.

    Damn!... time for a hair-cut.






    I operated this 1/35 Bronco Type-23 at last years SubFest. It served as a platform for a FPV camera system contained within the models rather large sale. The model, though structurally completed and given the appropriate paint scheme and markings, had yet to get a proper weathering job. Now's the time! SubFest is only two months away.



    The yellow markings on the sail denote this as a relatively new boat still being worked up by its crew prior to being deployed for actual coastal war patrols (which, for these little coastal submarines lasted days, not months).

    So, supposing this boat represents a unit with little in-water time under its belt, I resolved to go easy on the above and below waterline weathering.

    Here's some of the documentation I gathered to help guide me as I mung up this r/c model submarine representing a short-lived combatant.



    I'll start with the below waterline crud – that task an easy one on this model as the parting line between upper and lower hull falls across that plane – the only masking required is at the bow and stern, where upper and lower portions are permanently joined.


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  • He Who Shall Not Be Named
    replied


    Finally, Jake has completed assembly of the big Disney NAUTILUS model. Time to plunk this monster-of-the-deep into the test-tank. First, I added fixed ballast weight low in the hull to lower its center of mass; then placed buoyant foam up high in the hull to raise its center of buoyancy. The greater the vertical distance between these two points of force, i.e. the CG to the CB, the greater the boats static stability about the roll and pitch axis.

    Here I'm placing lead bars down low in the lower hull half. About three-pounds of fixed ballast weight. That was found to be enough (along with the eventual buoyant foam needed to offset all that weight) to stabilize the boat so it doesn't roll too much in a turn or as a consequence of propeller torque.



    Jake and I produced a single, large hunk of closed-cell polyurethane foam. The goal was to have this buoyant foam up as high in the upper hull as possible, and to conform as tightly as possible to the geometry of the hulls insides. Also, we wanted the ability to make this one big piece of foam removable to ease the task of trimming it down to size so that its upward buoyant force would counter the downward force of the fixed ballast.

    Before catalyzing and pouring in the expanding foam liquid, the upper surfaces within the upper hull were protected with aluminum foil to keep the eventual mass of expanded and hardened foam from sticking.

    This is what the foam looked like before trimming it to afford clearance between it and the top of the SubDriver (SD). Note the use of brass brackets to hold the foam in place.



    Ballast weights and foam in place, the SD was installed, switched on, and the NAUTILUS' hull buttoned up for the first trial in the test-tank to work out how much – and where – foam had to be cut away and re-positioned to achieve proper submerged and surfaced trim. After a few hours of fiddling with that the boat was pretty much trimmed out.



    Initially, commanding a flood of the SD's ballast tank resulted in the models upper surfaces projecting significantly above the waters surface. Too much foam! Repeated testing in the tank guided me as I cut away portions of the buoyant foam until, with a flooded ballast tank, only the tips of the 'alligator eyes' projected above the surface in submerged trim with the boats pitch-angle very close to zero. Perfect!



    Blowing the SD's ballast tank dry got the boats upper works this high out of the water. Pretty close, all that was needed at that point was to relocate some of the foam forward – raising the bow up a bit, and lowering the stern to the height of the housed skiffs waterline. That done, the NAUTILUS model was in proper trim for submerged and surfaced operation.

    Almost ready for sea-trials!



    Years ago I made a 1/96 SKIPJACK class model for my good buddy, Fred Freketic. This year Fred will accompany me to the big all r/c submarine regatta at the Red Clay Resort outdoor 'swimming hole'. In support of that venture I just finished getting his big 1/72 THRESHER model ready, and now it's his little SKIPJACK's turn in the barrel.

    Fred reported two problems with this model at the recent Groton SUBEX 23: It was way too bow heavy. As I learned seen enough, Fred had switched to a higher capacity (read: heavier) Lithium-polymer battery, which demanded a re-trimming of the model. The major hang-up was water leaking into the SD's after dry spaces – I found that cracks had formed in the SD's Lexan cylinder permitting the ingress of water from ballast tank to dry spaces. Ouch!

    First things first. Re-trimming the boat.

    Since the boats trim was thrown way off by the added weight forward, that meant additional buoyant foam had to be jammed into the tight confines of the free-flooding hulls bow. To get an idea of how to shape the eventual gum-drop shaped foam piece I scissored out this cardboard template, and kept chopping away at it until it fit within the bow with little wasted space.





    Additional foam was needed up high in the upper hull. To insure non-interference with this additional foam and the SD I made this 'clearance template' out of cardboard, using it as a go/no-go tool as to the thickness of foam I could add without it contacting the top of the SD once the two hull halves were joined.



    A basic sheet-metal workers cheat is the use of cardboard mock-ups to verify function and fit of the eventual metal (or other material) assembly. First, a plan is worked out on paper, then a cardboard shape is scissored into life and folded (if required) to shape. The resulting cardboard analog is then fit into place to verify fit. It's an easy matter to make a new cardboard mock-up or simply hack away with scissors on the original until it's right.





    With all the cardboard analogs in place things are checked for function and fit.



    Once happy with the arrangement the cardboard analogs are removed, unfolded, and used as templates to mark off the actual metal (or GRP, foam, wood, Renshape... whatever!) parts.

    The cardboard mock-up saves you wasting time and materials. Paper is cheap, quick, and easy to form. Metal ain't!



    The leaking SD was servicable enough for use as I re-trimmed Fred's little SKIPJACK model.

    Once I had the boat working properly in both submerged and surfaced trim, I began the process of tearing out all the gear from the original leaking Lexan cylinder and transferring it to a properly annealed Lexan cylinder.

    Here the new, annealed, cylinder has been marked off for machining before transferring the bulkheads and devices from old to new cylinder.



    It seems that some ten years ago some (if not all) of the manufacturers of extruded Lexan tube either abbreviated or stopped annealing the stressed tube as it squirted out of the die. Lexan cylinder cracking on 'new' Lexan cylinders points to tobservation of mine. I have since made it a practice to perform in-house annealing in the kitchen oven after cutting a Lexan cylinder to length. Fun times!

    I'm pointing to the old, cracked Lexan cylinder. I've already populated the new, annealed Lexan cylinder.



    Here's the major crack in the original cylinder – this was the worst of the several cracks found on this cylinder; that bad-boy ran right over the after dry space ballast bulkhead O-ring and became the major conduit of water from ballast tank to inside of the after dry space.

    Bad ju-ju!!



    Industry standard allows for a significant variance between stated and actual cylinder external and internal diameters (the polite term is, 'tolerance'). What that means in the real-world is that one lot of cylinders will differ in dimensions from others. And this situation bit me in the ass on this job, as some of the original bulkheads – sized to fit the old cylinder – were found to be too small in diameter to permit a proper seal of their O-rings within the new cylinder.

    ****!

    I had to cast up more bulkhead blanks and machine them to make ever-so-slight interference fits to the new cylinder, after which I cut in the O-rings grooves.

    (I can almost see Bob Martin's smile of recognition as he reads the above).



    With all the goodies transferred from bad to good Lexan cylinder, time had come to do a thorough leak test and function validation. Into the drive-way test-tank it went.

    Gee... worked first time! I must be getting good at this ****!



    OK. The boat trimmed for the new, heavy battery. Check!

    The cracked and leaking Lexan cylinder replaced with a tight, annealed one. Check!

    Time to box Fred's boats up and await September's SubFest event in far-off Georgia.

    Now. To address the boats I want to brings to the event.

    A few months back I had gotten my own, new 1/96 SKIPJACK, 1/72 THRESHER, and 1/96 STURGEON models all done with the exception of detailing, flat clear-coat, and final trim and system check-out. Time to re-join those battles. SubFest is just over the horizon.

    On deck, the 1/96 SKIPJACK. It and its sisters had been sitting on the wall supports for several months, collecting dust, oily mist, and who knows what other crap floats around in this God-awful chamber of horrors I call a shop. Before proceeding with further weathering and touch-up painting those models had to get a complete scrubbing with soap-and-water.



    Once scrubbed and rinsed, the SKIPJACK hull and appendages were toweled off and blow-dried with low-pressure air. I let it all sit overnight on a work-table to completely dry out. Time had come to address the two escape-trunk deck hatches, McCann rescue chamber hold-down pad-eyes, and prep those metal items for painting and installation.



    The four pad-eyes, each formed from a strand of .013” diameter copper conductor were bent to shape. .013” holes previously drilled about the circumference of an escape-trunk McCann rescue chamber seat.



    One set of pad-eyes forward of the sail, and the other way back aft over the engineering spaces. (That's eight pad-eyes for those of you keeping score at home).



    However, after all the priming, painting and protective clear-coating those little holes I initially drilled got fouled up, so I had to bore them out again, with a .013” bit.

    In addition to the eight pad-eye holes I also had to bore out the two holes in the deck that would pass a length of wire representing the McCann rescue chamber down-haul cable that ran from an on-board cable reel and escape marker buoy … more on that later.



    A common hand-drill is too slow and bulky (and its chuck likely too gross to hold and center a small bit); and the typical moto-tool is too massive and produces too much torque to give you a 'feel' for the job as you bore into the work.

    What is needed is a drill motor that is high-speed, low-torque, and so light in your hand that you can 'feel' the drilling as it progresses. So, in pursuit of such a tool, I converted these cheap-ass Harbor Freight 'Micro Engraver' tools to serve as small drill bit drivers.



    Fortunately the chuck of these little drills is just a collar with a .092” bore, that collar equipped with a set-screw to lock the bits shank in place. So, all I had to do was take a selection of small drill bits, ranging in sizes from .030” to .013” and secure each in a .092” shank (formed from some polyurethane discarded sprue stock) and Presto-Blamo... a mini-drill motor and a fair selection of small bits to fit it.



    The smaller the drill-bit the faster it has to be spun, but the feed pressure has to be minimized and the bit driven into the bore with quick, light jabs to clear the bits flutes of kerf. Otherwise the bit will overheat and... SNAP!... the bit is broken, its tip buried deep where you're likely never to extract it, ruining the work. Dumb Ass!

    Small bits demand high speed, very light feed pressure, and constant jabbing to keep the flutes unclogged.



    Increasing the utility of this little drill-motor I turned a brass extension collar that permits me to mount any of the many types of .125” diameter shanked rotary bits I have at hand. Here you see both the drill-motor and a selection of bits all efficiently packaged together on this handy caddie.


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