Kawasaki Ki-100 Ia and Ib "Goshikisen"

Kit #9138 and 9144                            Collector’s Market Value Approximately $26.00
Images and text Copyright © 2008 by Matt Swan

Developmental Background
        What was possibly the best Japanese fighter aircraft of the Second World War came about by a chance act of desperation. The Germans had provided the Japanese Empire with technical drawings for the Daimler-Benz Db-601-A inverted V engine that was so successful in the Bf-109 series of aircraft as well as many other Luftwaffe machines. Akashi began development of this engine as the Ha-40 and installed it in Kawasaki’s Ki-61 interceptor where it obtained a moderate degree of success. The biggest issue with the Ha-40 was reliability, not performance. As Akashi worked to correct these issues with the improved Ha-140 engine Allied bombers put a halt to things when the factory manufacturing these engines was bombed to debris.
        Now there were 275 Kawasaki Ki-61 airframes sitting in the Kagamigahara factory gathering dust while the Japanese scrambled to put anything in the air that had a chance of intercepting the high flying B-29 bombers that were systematically pounding the Empire into rubble. With no other inline engine available Kawasaki was instructed to figure out a method to install existing radial engines to the Ki-61 airframe. At first this seemed like an impossible task however the design team was able to install a Mitsubishi Ha-112-II engine to three airframes and test flew these in February 1945. It was at this point that they discovered they now had a first-class fighter in there hands.
        By the end of May 1945 the remaining airframes had all been converted to the Mitsubishi engine and had been redesignated as the Army Type 5 Fighter Model (Goshikisen). Kawasaki identified the aircraft as the Ki-100-Ia. With the Ki-100-Ia being such a success production of the basic airframe was resumed with some minor modification such as having the rear fuselage cut down to allow for a better visibility bubble canopy. This version was the Ki-100-Ib. A total of 99 of this type were built before growing Allied bombing stopped production. A third development of the type was on the drawing board at this time that included an improved Mitsubishi Ha-112-IIru engine which incorporated a turbocharger for improved high altitude performance. By the end of the war only three of these prototypes had been built and flown. The Ki-100-Ia and Ib retained the armament package found on the Ki-61 which consisted of two fuselage mounted 12.7mm machine-guns and two wing mounted Ho-5 20mm cannons. They also could carry two underwing drop tanks to extend range. The type had a maximum speed of 367 mph with a maximum service ceiling of 35,000 feet, more than enough to intercept a B-29.

The Kits
        I listed two kit numbers at the beginning of this article but there does exist a third Hasegawa kit release number 9765 which is a later release of the Ki-100-Ib bubble top aircraft but for the purposes of this review we’ll just talk about two kits. Currently all version of this kit are out of production. Both kits have 90% of all parts in common with a few minor additions like a replacement spinal support for the b version with base plate, different canopies (all in a closed position) and a cut-down fuselage for the b version. As with the actual aircraft the master sprues are converted from the Ki-61 kit and still retain a few parts that are unique to that kit.
        As with the Ki-61 kit these are both very nice kits with few accuracy issues. All parts display finely engraved panel lines, nice smooth exterior finish and fine sprue gates. None of the parts have heavy injector pin markings, sink holes or flash. General parts fit is excellent with very little putty needed to fill seams. The biggest drawback I’ve found with both kits is that the canopies are both offered only in the closed position. Should the modeler wish to display the cockpit open the choice is very limited with the razor back version in that he will have to saw it apart with a JLC saw. The bubble top version can be replaced with a Squadron vac canopy but this option does not exist with the first kit.
        Taking an inventory of parts we have seventy nine medium gray high pressure injection molded pieces, 4 poly caps and four clear parts associated with the Ia kit; seventy seven gray plastic parts, four poly caps and four clear parts associated with the Ib kit. Now keep in mind that there are several parts in both kits that are leftovers from the Ki-61 like engine exhaust shrouds, propeller pieces and canopy pieces.

You may click on these small images to view larger pictures

Decals and Instructions
        Kit instructions for both kits are virtually identical being of the standard four panel fold-out that is found on so many Hasegawa kits. It opens with a historic background of the aircraft in English and Japanese and includes a complete parts map with paint code chart. Three inside panels contain the assembly instructions and include adequate color call-outs. Two outside panels contain exterior painting and decal placement instructions for two aircraft. All paint schemes offered are in Japanese dark green.
        Decals for both kits are pretty nice with plenty of service and warning stencils. The image to the left is the Ia set and to the right is the Ib set. Both kits offer instrument panel decals should the modeler not want to paint the detail. One thing I don’t like about the Ib set is the large clear panels provided for the flap markings. I think the approach taken on the Ia set is much better with a series of smaller decals that need to be combined for the final effect. Yes, it does require a little more skill and patience from the modeler but will offer a better end result. Every time I have used one of the large clear panel decals from Hasegawa I have had trouble defeating silvering with them. This seems to show up with only the flap decals. The decals are nicely thin with excellent print registry, color density and nice, vibrant colors. The Ia kit offers markings for 2nd company and a 3rd company 59th Flight Regiment aircraft while the Ib kit offers markings for two 2nd Battalion aircraft one of which is a trainer with somewhat different markings.

        These are some very nice kits with excellent engineering and excellent fit. Decals are good and instructions are adequate. Should the modeler build either kit straight from the box they are sure to end up with a very nice model. I personally have a hard time building straight from the box however and must fulfill my AMS issues with aftermarket goodies. Eduard offers a couple of very nice detail sets for the Ki-100 series that are pretty much interchangeable. The interior sets include precolored instrument panels with seatbelts, various cockpit levers and many other goodies that will keep you hunched over a magnifying glass for hours. They also have an excellent flap set that drops right into the wing once the molded flaps are removed. Squadron offers replacement resin wheels and a vacuformed canopy for the bubbletop version but not for the fastback version. Aires offers a resin replacement cockpit for the Ia kit but one thing to remember should you care to explore aftermarket sets is that most interior and exterior sets for a Ki-61 will be usable with these kits as well. At the moment there are no aftermarket decal sets available for either kit but then again you could scavenge Ki-67 sets to recreate just about any Ki-100 aircraft you could document.
        My final word on the review of this kit is just plain great. If you like Japanese aircraft you really should consider having one or two of these. These kits are great for modelers of any experience level.

        I’m starting with the Ia kit and have acquired the Eduard color interior set, photoetched flaps and Squadron resin wheels. I began construction with the cockpit removing various panel details and installing the pieces that would be painted interior color. For interior color I used Model Master German Sand. Once the base color was applied the balance of the pe parts were installed. Eduard gives us a great looking hydraulic panel but sadly it is completely incorrect. First let’s take a look at the aftermarket goodies I’ll be using;

        Here we can see how the Eduard cockpit stacks up against reality. The small instrument panel above the hydraulic consol and the cover to the hydraulic consol are part of the pre-colored part of the Eduard set and I have no idea where they got the idea of ‘green’ from. I had already assembled the Eduard pieces before fellow modeler Chris C. provided me with this picture. On the next one I’ll worry about correcting the color and general shape of the panel. I doubt that anyone not completely conversant with the interior of the Ki-61 or Ki-100 would ever notice the discrepancy.

        Next we have a series of pictures showing the construction progression of the cockpit. Remember, you can click on any of the small images in this article to view larger pictures.

        Now it’s time to close things up. After the cockpit sidewalls were installed and the engine completed and installed to one side of the fuselage I glued the two halves together then inserted the cockpit floorpan through the wing opening. Everything went together without a hitch. I did use just a very small amount of Mr. Surfacer 500 forward of the cockpit to fill a seam. The gun cover and nose cowling went on next. The gun cover was a poor fit and did need a large seam filled at the front area. The kit clear gun-sight part was cut apart and reassembled with the Eduard pe parts and some acetate screens. The wing was modified before being installed and I’ll talk about that in a moment but first another set of progression pictures.

        Let’s talk about the Eduard flaps next. About a year ago I made my first attempt at using Eduard flaps on a Tamiya Wildcat kit and had some difficulties but I learned a lot, a lot that will come in very handy with this build. The first thing I learned was ‘follow the directions – carefully’. After some intense study of the Eduard directions I first cut out the existing plastic flap with a JLC razor saw then assembled the first upper flap box. I found that by using the tip of my Xacto knife to pick up small amounts of medium super glue and applying them to the connection points of each rib prior to folding it into place made things a lot easier and neater. I also found that by adding some accelerator to the main flap surface first helped a lot. Even when accelerator appears to have dried it will still have some effect on the glue for several minutes afterwards. Once the flap box was complete I used it to check my cut size in the wing then adjusted slightly with a diamond needle file. I did divert from the Eduard direction with the hinge rod. They suggest using a piece of plastic rod or stretched sprue but I went with a straightened piece of magnet wire – it worked out very well for me. Okay, time for more pictures.

        I will not be installing the flaps until after all other color painting is complete so they are placed in a nice safe little box until that time arrives. Moving right along all seams on the model are double checked then I move to the canopy. Using my JLC razor saw I carefully cut the canopy into three sections. It was really not difficult at all. Once the canopy was separated I cleaned up the cut edges just to be certain there was not loose plastic dust hanging on then dipped them in Future and covered them to cure. The next day these pieces were masked with strips of masking tape and the forward and aft sections were attached to the fuselage with clear parts cement. For masking I used a combination of tape and damp tissue in the cockpit, damp tissue in the landing gear bays, radiators and engine cowling then was ready to start painting.
        Since I wanted this particular model to have some serious weathering I first painted the whole thing with Alclad Duraluminum. Once this had about 15 or 20 minutes to dry I started applying spots of water and sprinkling table salt over it. Once everything was nice and salty I set the model aside to dry overnight. The next morning I started adding some color to the model. I’m not really happy about the yellow and will have to mix that to be a little more orange and reshoot those parts tomorrow.

        You may be trying to figure out at this point which aircraft from the kit I am doing since this red tail simply does not compute. Well, I'm going off in my own direction with a little documented and possibly controversial scheme but more on that later.

       I mixed a few drops of Orange with some Yellow and reshot the wing leading edges and the drop tanks then let everything set for a few days to allow the paint to harden up. When I came back to it I removed all the salt from the painted areas then applied masks. I tried to take note of where salt needed to overlap color demarcations so I could replace it before the next coat of color. Before putting slat back on the model I applied another light coat of Alclad to even out the finish then got busy with the salt. Once this was done and the salt had dried overnight I shot the bark blue bands and set the model aside for another day to dry. Just as before, the salt was removed from the blue areas, masking tape was measured, cut and laid down then some salt was reapplied at select points along the masked line.
       As a final top color I started with White Ensign Mitsubishi Navy green and applied an even coat to all the upper surfaces. Next, I took a small amount of the base paint and lightened it with a couple drops of white and dusted this mixture across the centers of all the panels to create fade. After a short period of dry time the masks and salt were removed. The color scheme is starting to come together now.

You may click on the small images above to view larger pictures

       Next the landing gear were assembled and installed then the photo etched flap boxes were installed with a thin coating of superglue. Previous test fitting made this a very easy step – everything dropped right into place. From here the next step was to seal the model with a blend of Future and Isopropyl alcohol and let cure overnight.
       I guess it’s time to start applying some decals. Since I am deviating from the kit markings and have no subject specific sheet to work off of I will combine markings from the kit sheet and from the Techmod sheet #48052 which is really for the Ki-61 Tony. From this sheet I am using the fin markings, the upper Hinomarus, the kill markings and the blue numbers on the landing gear covers. All other markings come from the Hasegawa sheet. The Techmod decals did not respond well to Micro-Sol and had a difficult time settling into the recessed panel lines while the Hasegawa decals behaved marvelously. Once all the decals were in place I mixed some RLM-66 black/gray about 50% with Windex and lightly airbrushed exhaust tracks on the fuselage sidewalls. I was not trying to create the entire exhaust mark at this point, just laying down a translucent base marking. Next the model was sealed with Future and a wash was applied. After the wash had dried down I attached the final flap pieces with medium superglue then mixed a solution of Micro-Flat/Polly Scale clear flat 50/50 then thinned it with Windex before coating the model.
       Finally the last of the masks can be removed. The exhaust staining was completed with ground pastel chalks applied with a solid formed cotton swab. With everything in place I then reached into the open flaps with some fine tweezers and made the final connections of the flap actuators. The drop tanks had been painted and weathered earlier and are now attached. The propeller was assembled and painted, sealed with Future and had the three small decals applied then was pressed into the poly cap inside the engine. The center section of the canopy was masked and painted then attached with clear parts cement. A vac canopy would have been better here as the fit was not that great. Squadron makes a vac canopy for the Ki-67 that could most likely be used here and will be for the next build of this kit which is already in progress. The final detail is the installation of the antenna and I think this one is done.

Remember, you can click on the small images above to view larger pictures

       I thought I was done but as I look back I realized I missed two minor details; the kill markings never got placed and the landing light lens is missing. I’ll fix that then move on to the second Ki-100 build.

Construction of Unit #2 11/23/08
        Actual physical construction of the second aircraft is identical to the first so lets just skip ahead to the painting aspect. Now with this aircraft I am not doing the salt chipping so will not use an Alclad base. Once the basic assembly was complete I used the kit canopy as a mask for the cockpit simply covering the entire thing with masking tape and tacking it in place with a few spots of clear parts cement. I will be using a Falcon vacuform canopy as the final detail on this build. Next the various identification colors are applied like the blue strips, red tail, yellow wing bands and black anti glare panel. Each of these is masked off and then the model is preshaded with flat black. The lower surfaces were done with light gray then the upper surfaces with done with Nakajima Army Green. Now things start to get a little different.
        The create my camouflage pattern I will be using a liquid masking agent called Incredible White Mask purchased from my local art supply store. This stuff is somewhat expensive but is safe with all acrylic and enamel paints. When I was at the store I noticed they had a nifty little tool for applying the material but it cost $8.00 and I figured ‘why spend eight bucks when I could use a paint brush?” So I did not buy that little gizmo and applied the material with a paint brush. When I was done putting the mask on my paint brush was done also. There was no way I could clean the gunk out of the bristles so my brush was now trash. Should have bought the gizmo, anyway, on with the build. I applied the masking agent is a random pattern then thinned out the same light gray I had used for the lower surfaces and coated the upper surfaces. Once the paint was dry I used a pair of fine electrical tweezers and simply pulled the masking agent off. I brushed the surface with an old toothbrush to remove stray flakes of paint and there is was – a nice camouflaged pattern. The rest of the masks were removed and it was ready for some Future and decals.

You may click on the small images above to view larger pictures

       Working with both the kit decal sheet and the TechMod decal sheet that provided marking for the first model the decals go in place on this one. I did have several issues with decals crumbling apart during placement and probably should have hit both sheets with a fixative before starting this. Due to the patterned camouflage I did have problems with the pattern showing through the Hinomarus however with now one complete and two partial decal sheets I had enough Hinomarus to double them up on the upper surfaces and fuselage to get a good enough color density to take care of the problem. I also started dipping my decals in Future once they were loose on the paper. I did this because on the first model I had several issues with silvering even though I had treated the model with Future first. Dipping the decals in Future before applying the wash.
       The wash was just a standard sludge wash, the exhaust staining after applying the Polly Scale clear flat is where things got a little different. I wanted a nice dark exhaust stain but had concerns about airbrushing the base layer like I did with the last build. This time I took a women’s hard cotton makeup swab, dampened the end in water then used that damp end to pick up some ground pastel chalk. This was rubbed across the exhaust area and resulted in a very dark stain. Next I took another dry swab and buffed the area a little which lightened it up somewhat. Now I came back with dry sponge swabs dipped in more ground pastel and finished the effect. The last items for this build were attaching the canopy, some secondary gear doors and the antenna. One note on the canopy – I used a Falcon vacuformed canopy from their Japanese set on this build. The canopy as a whole for the Ki-100 did not fit well and I ended up only using the center section of the vac piece and used the original fore and aft sections cut from the kit canopy.

You may click on these small images to view larger pictures.

       And now it’s time to move onto the third Ki-100, a bubble top Ki-100b but then you knew that already, didn’t you?

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