Czechmaster Resin 1/72 Short S-23
By Russell Bucy
Czechmaster Resin (CMR) released a superb kit of the S-23 in late 2008. For a complete description of the kit, see Jim Schubert's review in the September 2008 issue of Internet Modeler. I was commissioned to build this model for an airline Pilot friend, Derek Hughey, to add to his collection of Imperial Airways memorabilia.
Imperial Airways Short S-23 Empire Flying Boats provided luxury service to the Middle East, Africa, Australia, New Zealand and North America. The entire class of S-23, S-30 and S-33 flying boats numbered 44 aircraft with the S-23s being the largest group in the class. Mediterranean and Indian Ocean versions had smaller outrigger floats, different fuel tank arrangements and different engines than Atlantic versions since they could travel shorter distances between service stops. From 1937-1947, Imperial Airways, BOAC, Tazman Airways and Qantas flew the S-23.
When war broke out in September 1939, Imperial Airways continued to fly over neutral Italy and Spain to points in the Mediterranean and Middle East. With the entry of Italy into WWII in 1940, Imperial Airways was forced to fly it's S-23s around the Bay of Biscay, down Africa's west coast to Cape Town, then up the length of Africa to Cairo. This became famous as the “Horseshoe Route”. With the war taking a toll on passenger revenues and resources, British Overseas Airways Corporation (BOAC) took over Imperial Airways service. A detailed history the S-23 Flying Boats can be found in Brian Cassidy's comprehensive book “Flying Empires”. A free downloadable copy can be found at https://www.users.waitrose.com/~mbcass/I'd like to thank Mr. Cassidy for information he provided me for this model. Another excellent site is Bryan Ribbans “Seawings” Flying Boat web page, https://www.seawings.co.uk/which has hundreds of Flying boat photos and information.
Like the Handley Page 42 (see August 2008's Internet Modeler), the S-23 in Imperial Airways service were named for mythological characters from Greek or Roman history. S-23 serial number S.814 “Castor” was the seventh S-23 built and named for one of the twin sons of Zeus. “Castor” was employed extensively on the Mediterranean and African legs of the “Horseshoe route”. In May 1941, Castor was flown by Captain H. O. “Arch” Woodhouse on rescue missions to evacuate military personnel and civilians from Crete during the German airborne invasion. My airline pilot friend has some of Capt. Woodhouse's memorabilia in his collection. Therefore “Castor” became the subject of this model.
CMR's S-23 comes in a sturdy flat cardboard box. Inside are 9 pages of excellent instructions, line drawings and several bags of resin parts. The main components are the fuselage halves, top and bottom wing halves, and solid vertical and horizontal stabilizer parts. Ailerons and flaps are molded with the wings and stabilizers. Also in the box are several bags of nicely molded cockpit parts, engines, props and cowlings. There is a pre-colored etched fret from Eduard for the cockpit.
The resin in the kit is large and stunning. My experience with short run resin kits is with older models which have lots of “surface texture” and tons of air bubbles. Not so with this kit. I found one small air bubble on a wing leading edge, and that was all for the entire kit! There were no flaws, sink marks or protrusions common in other kits. The single piece engine cowlings are flawless, and included the exhaust collector rings and exhausts in two styles for S-23 variants. It's not a “shake the box” kit, but it is superbly designed for model builders with a little experience.
The cockpit sidewalls are accurately reproduced in photo-etch, as are the instrument and radio operator's panel faces. The control columns, seats, floor and radio blocks are finely cast in resin and fit together well. After assembling the cockpit parts, I painted the cockpit floor, sidewalls, seats and radio operator's position Alclad Aluminum, as on the real aircraft. I used small rectangles of black decal sheet cut to size to represent the anti-skid flooring.
The radio operator's table was painted Testor's Model Master Wood Brown, and the pilot's and radio operator's seat cushions and arm rests were painted Model Master Leather. I added lap belts from a spare Eduard RAF belt set. The pre-painted photo-etched radio and instrument panel were attached to the appropriate bulkheads and instrument blocks. Care in painting the cockpit details is essential, as the entire forward part can easily be seen through the large cockpit glazing.
The assembled cockpit was glued to the fuselage with cyanoacrylate; this is where I ran into a problem. The Eduard pre-colored photo-etch pieces are superb; however, the instrument panel has sharp, triangular-shaped ends. Photos of the cockpit show the instrument panel has more rounded-off ends. When I dry-fitted the assembled cockpit, I found the triangular shape of the Eduard photo etched part interfered with seating the cockpit in the fuselage. I carefully ground the triangular corners off the panel with a cut-off wheel in a Dremel tool and the cockpit fit snuggly into the fuselage.
The fuselage halves are the best fitting of any resin kit I've ever built (and better than many plastic kits too!). There is no interior provided other than the cockpit, but there is a wing spar and rear fuselage former to keep the rear fuselage aligned. The emptiness of the fuselage is not an issue, as not much can be seen through the windows of the model with the exception of the cockpit. Since the interior of the S23 was a medium forest green color, I airbrushed the interior Model Master Medium Green.
Normally, I replace resin clear parts with sheet acetate custom cut for the model. Not so in this case. The fuselage windows are crystal clear, and after a soak in Future, I carefully used a gluing needle to cyanoacrylate each window in the fuselage. Future prevents cyanoacrylate from “fogging” the windows.
In photos, the S-23's passenger windows all appear to be of the same rectangular shape with rounded corners. However, some of the kit's windows appear slightly oval, while others appear rectangular. I debated whether to replace the slightly oval windows, but decided not to bother. In the final result, it's hard to tell the difference after the kit is painted up anyway. There was a minor fit problem in some of the fuselage window ports, but I think this was because I “carved” the edges of the windows with my X-acto blade a little too much when cleaning out the flashed-over window openings. This was corrected with a combination of cyanoacrylate and repeated applications of Future to fill gaps.
I used scrap resin (from the mold blocks) and styrene strip super-glued along the edges of mating surfaces for seam reinforcement when joining the fuselage halves. The fuselage halves were joined and the fit was flawless. The kit's solid resin wing spar was passed through the fuselage and fit perfectly.
Wings and Stabilizers
The port wing in my kit went together perfectly. The starboard wing went together well, but I noticed there was a slight overhang on the trailing edge of the ailerons on the bottom wing. This should have been a give-away of a fit problem but it appeared minor—at first. I dry-fitted the engine cowlings to the wings and noticed there was a gap between the inboard engine nacelles and the circular exhaust openings in the wing (the S-23's exhaust came straight back from the cowling and entered the wing at the base of the nacelles, then exited through the top surface of the wing behind the engine mounts, this provided hot water and interior heating through a boiler fitted to the inboard exhaust).
When I dry fitted the wing to the fuselage, I found the starboard wing had a very sloppy fit over the wing spar caused by a considerable warp in the top half of the wing. I rubber-banded the top of the wing to a flat strip of metal that I use for correcting warps. I then carefully dipped the upper wing several times into water heated just shy of boiling for a few seconds. I found this didn't quite do the job, so I sanded the mating surface of the leading edge of the upper wing about 2mm, at the wing root, tapering to about .5 mm at the wing tip.
After assembling the wing, I found this corrected the problem but distorted the shape of the leading-edge air intake and searchlight opening (the S-23 had an “aim-able” searchlight in the starboard wing leading edge). I corrected these distortions by fitting different diameters of K&S Engineering brass tubing in the wing openings. I then attached both wings to the fuselage. The fit was exceptional, and required very little filler. I use “Porc-a-Filler”-- porcelain putty made by Kit Industries to fill any gaps. This is very fine-grained, acetone based putty so it dries in about 30 minutes and sands beautifully without lumps or air pockets. In 24 hours it's rock-hard—perfect for resin kits.
I attached the horizontal and vertical stabilizers to the tail. CMR thoughtfully molded two large retaining pins into each stabilizer for attachment. Upon dry-fitting the parts, I found the port horizontal stabilizer sat about 2mm lower than the starboard stabilizer on the model. There was a slight warp on the port fuselage half at the tail I missed in earlier dry fitting. The lesson learned is to dry-fit and measure all mating surfaces before gluing. In my kit I had to raise the stabilizer root on the model by 2mm. I accomplished this by sanding the bottom of the stabilizer root away and raising the top of the root with thin strips of Evergreen styrene and “Porc-a-Filler” reinforced with gap-filling cyanoacrylate. I then re-scribed the affected panel lines.
Beaching Gear, Engines and Props
The beaching gear is beautifully molded with just a trace of a mold line which is easily removed with a sanding stick. CMR molded the gear with small pins which mate to corresponding circular marks in the fuselage (the holes must be drilled out by the modeler). The first time I dry-mounted the gear to the fuselage, I snapped off one of the resin pins on the beaching gear. I replace fragile mounting pins on models with brass rod anyway. I drilled out the mounting points in the wings and fuselage to accept lengths of K & S brass tubing running through the fuselage from one side to the other (this came in handy to run wires through to support the model). I then replaced the six resin pins on the beaching gear with brass pins. “Rotating” the gear legs into place gives a tight fit without glue, making the beaching gear removable. The aft beaching gear simply “clips” onto the sides of the model, so I drilled out and added a fuselage retaining tube and gear pin to strengthen the join.
Engines, Canopy and Wing Floats
The engines are nicely detailed models in themselves. I drilled out the gearboxes for adding K & S brass tubes which would hold scratch built propeller shafts. The props were the only parts on the model where I found any serious flash, and the mold lines needed a bit of cleanup. Once this was done, I added the brass propeller shafts to the props.
CMR provides a single resin and two vacuformed canopies, along with a canopy masking set. On the real aircraft, the cockpit was constructed separate from the fuselage and attached in modular style. This section was called the “coupe”. I wanted to use the resin canopy for strength, so I polished it with successively finer grits of “Micro-Mesh” sandpaper. I finished by polishing with Dremel polishing compound on a felt pad in my Moto-tool, then I dipped the resin canopy in future. Clarity was fabulous, but it still wasn't quite as thin as the vacuformed canopy, so I went with the vacuform part. There really is not much difference in strength anyway, and the cockpit details are clearly visible.
I found I needed to fill and sand around the edges of the canopy to blend it into the fuselage, but not any more than most styrene kits. CMR's canopy and window masks fit the fuselage windows and canopy precisely. I installed the wing floats which were reinforced at the attachment points with brass pins and .005 stainless steel wires for rigging. I added the double radio antenna masts with brass pins for strength, and pre-drilled and mounted a triangular wire antenna “trapeze” insulator on the vertical stabilizer.
Everything received a coat of Alclad gloss black primer (this is really great stuff, but needs to be thoroughly mixed). My rules for Alclad are to apply it only over totally smooth, gloss black finishes. The engine cowlings were painted Alclad Aluminum while the props received a coat of Polished Aluminum. The cowling exhaust collectors received a mix of 50% Alclad Pale Gold and 50% Alclad Jet Exhaust, producing a nice “burnt copper” appearance. The engine gearboxes were painted Model Master Chrysler Engine Grey gloss, while the cylinders were painted gunmetal with dry-brushed aluminum highlights. I gave the rest of the aircraft a coat of Alclad Aluminum. By running wire through the fuselage beaching-gear attachment points, the handling of this large model was greatly simplified for painting.
After drying (less than 30 minutes for Alclad), wing leading edge panels were masked off and painted with Alclad Polished Aluminum and selected panels were masked and highlighted with Alclad Duralumin and Dark Aluminum. Aircraft in Profile # 84 shows a cream-colored planing hull surface and this is given as a painting option in CMR's instructions. However, most sources and every photograph of S-23s out of the water don't show any paint on the hull at all. Photos do show slight to moderate staining of the hull planing surface. I replicated this by masking a line from the rear of the planing surfaces to the front of the aircraft. I lightly sprayed Alclad Duralumin, Aluminum, and Dark Aluminum in streaks along this line to represent areas of the hull affected by salt water. Imperial Airways kept these aircraft spotless while they were in service, so with the exception of grayish-brown exhaust stains on the wings, there wasn't much additional weathering applied.
Decals and Special Markings
The CMR decals are exceptional in color and registration and they go on beautifully. I did use a little Solvaset setting solution in difficult areas such as compound curves and bracing wire locations. Registration codes for “Castor” are A-GDUW but the kit's marking options don't include a “W”. There are several “V”s and “L”s which I “spliced” into the required “W”s for the registration call-outs.
The red, white & blue wartime recognition marks and fin flashes for 1939-1941 are not included for this model either. I had some red and white decal stock which I measured into scale 2ft wide stripes applied under the registration codes. The blue stripes needed to match the CMR supplied registration code colors so I mixed Model Master Cobalt Blue, Flat White and Flat Black until I had the right shade of blue, and sprayed it on clear decal stock. When dry, I cut 2ft scale stripes and applied them to the model. For the name “Castor” I simply cut the appropriate letters from the kit supplied decal sheet.
A word should be mentioned about the colors of Imperial Airways registration codes and markings. Many Imperial Airways model kits (the Contrail 1/72 and Airfix 1/144 HP 42 kits for instance), and many paintings & profiles of Imperial Airways aircraft depict registration codes in black. I understand the test shot kits from CMR had these codes depicted in black as well. Subsequent research and correspondence with Brian Cassidy of “Flying Empires” reveals the codes are actually blue.
I added the engine cowlings and props, attached the unique double antenna (one side was for reception, the other for transmission) made from spandex threads (see my HP 42 article in the August 2008 Internet modeler) and gave the entire model a thin coat of Future to bring out the shine. I also built a boarding stairway as seen in various photos.
CMR has created an exceptional model of an important Golden Age aircraft. There were a few warp related fit issues with my particular kit, for which CMR likely would have sent replacement parts had I asked. I've had an opportunity to examine at least two other kits and found them to be warp free. For any modeler with experience in resin, this kit can easily be completed without much fuss in about 40 hours. The instructions are excellent and easy to follow. It would be a great “starter” resin kit for experienced styrene modelers wanting to get into resin kits. I highly recommend it if you're a fan of seaplanes and flying boats. My only recommendation for improvement would be to include more decal options in the kit for other aircraft in the class.
1. The Aviation Factfile, Biplanes, Triplanes & Seaplanes; Winchester, Jim Ed.; Grange Books, 2004, ISBN 1-84013-641-3, pg 220-221.
2. Aircraft in Profile Vol. 4, #84, The Short Empire Boats, by Geoffrey Norris; Martin C. Windrow Ed.; Doubleday & Co, 1968.
4. “Flying Empires, Short ‘C' class Empire Flying Boats”; Brian Cassidy; Copyright © Brian Cassidy 2008; ISBN 0 9529298 2 1;
5. “Seawings” Internet site; Bryan Ribbans, webmaster;