Hasegawa 1/72 Nakajima G8N1 'Renzan'

The Nakajima G8N Renzan or "Mountain Range" was a heavy bomber design submitted in response to the Imperial Japanese Navy’s need for a long range, land-based four engine bomber. The prototype commenced trials late in October 1942 and the whole program was severely limited due to the shortage of available wartime materials, in particular aluminum. Total production including prototypes amounted to just seven aircraft of which only four were completed.

The G8N was powered by Nakajima NK9K-L 24 Homare 18-cylinder radial engines and could carry a maximum internal bombload of nearly 9,000 pounds. In addition to the internal offensive armament, the Nakajima G8N was armed with six 20mm Type 99 cannons mounted in two-gun turret assemblies and in a ventral turret position, with a twin Type 2 13mm machine guns also fitted in the nose along with an additional machine gun in each waist gunner position.

The sole surviving aircraft, probably the fourth prototype, was shipped to the United States for evaluation, and thankfully this aircraft was photographed, even in color. This aircraft is the subject of this review.

My model of the Renzan was a present some 25 years ago but somehow it never got around to my workshop until the big box started bothering me in the Japanese kits’ wall unit earlier this year and almost simultaneously, I obtained a couple of books with excellent references. 

The model comes in the standard hard dark green plastic and true to 60’s and 70’s tradition with millions of rivets.  The overall shape and dimensions are quite accurate and the fit is good. My observations during the dry-fitting stage indicated that filler will be required in the wings to fuselage joint and in the engine cowl areas. There are other minor mould defects that require filler but nothing serious.

The small bits are a little unrefined but can be upgraded with a little work.

The first thing I did was to remove all rivets with wet and dry sandpaper applied very wet. I then proceeded to scribe a few panel lines in select areas.  When this is done, attention is focused on the vacant cockpit which is detailed with plastic card items from Evergreen plastic profiles. A couple of control columns and an instrument panel are added, even though once the canopy is fitted and painted, very little can be seen. The interior is painted in green FS34258 (I used Compucolor CAC27). I opened the nose area and detailed this with the canon support structure.  I added some more detail internally and eliminated the horrible bomb bay making room for the multiple lead weights which are necessary to get a good sit of the tricycle landing gear. I reinforced the fuselage sides and closed the bomb bay doors.  Two small side windows are opened at the front.  The small fuselage transparencies were very thick so I made my own by heating thermoforming clear acetate against appropriately sized pvc blocks. The fuselage halves were closed after filling all possible front areas with lead weight and making sure I had enough to get a proper front sit.

The turret bases were reworked and detailed to give a see through effect.  Masking the turret transparencies was completed by first applying a frame using a coloured vinyl tape and then masking with Tamiya tape.  When this is complete, the vinyl is removed to expose the frame which is later sprayed first in interior green and then in orange.  These will be fitted on last so a balsa plug in the turret hole served as a mask.

With the fuselage now done, I turned my attention to the wings.  These were constructed, sanded down, re-scribed and fitted to the fuselage. The rear cowls were attached and this was the worst fitting part of the model.  I included plastic card spacers in certain areas to get a reasonably good and straight fit. The top cowl detail was added using very thin card.  The tailplanes were subjected to the same treatment and also attached.

The front cowls as represented are very plain and benefit from scribing.  I manage to scribe the gills and the 3 latches sets on each side.  I tried to scribe the leading section of the cowl but found this to be too hazardous to achieve on the hard plastic so I left it at that.  There are no engines inside the cowls but you would not be able to make out any even if there were. The exhaust parts were drilled out, detailed with an intake, and generally cleaned up. Care must be taken if making another of the three aircraft as the exhausts differ on each individual aircraft.

The transparencies were polished using one of my little secrets – Whiteboard cleaner.  I didn’t like the look of the front nose transparency as it has an overscale canon shelf which bothered me, so I made an acetate alternative and opened up the cannon ports.

When everything was fitted in place and the model masked, I primed it with auto primer, rubbed it down and applied the first orange coat in medium tone.  In this case I used auto paint matched to a colour photo of the prototype in U.S. captivity matched to FS32246.  Next I applied the darker shade (orange mixed with dark brown) along the panel lines and when this had cured, I filled in with light tone colour (orange and white) to get the weathered panelling effect.  The engines are sprayed in auto colour silver, the gills are sprayed a shade darker metallic shade (Model Master Magnesium) and the engine cowl leading edge is sprayed black – slightly toned down - as per references.  Please note that every engine had a varying degree of black perimeter painted on each respective leading edge.

The propellers are coloured rust (I used Compucolor CSF7) and the spinners are painted black as per photos. All undercarriage legs are natural metal with suitable black acrylic wash to highlight the indents.  Tyres are dark grey with interior green hubs.

When the paint was done, I applied the gloss lacquer (definitely not a floor polish!) which is an auto adaptation.  The decals from the kit turned out to be out of register so I resorted to Aeromaster alternatives as they have a better shade of red than the kit decals.  I built the fourth machine and this did not have any numerals on the tail, just the six roundels and nothing else.

Next, I weathered the model using mostly brown acrylic for the panel lines and black in the engine areas.  Finally, a few streaks of pastels and the model was ready for a second coat of gloss.  After this had cured and the gloss rubbed down with 1000 grade wet and dry, the matt varnish is applied, the masking comes off the transparencies and undercarriage, aerials and turrets are attached. Each propeller blade is detailed with a small white marking at the base and a yellow flash across the tip. 

The resulting model is quite a satisfactory representation of this sleek bomber and makes a colourful splash in the showcase. It is pleasant to build and in spite of its age, it can easily be brought up to modern day standards with a few elementary additions.  I would recommend this model to anyone with even the most basic knowledge of model making.

1. Famous Airplanes of the World No.90 (Burin-Do / October 1977) – G5N & G8N
2. Japanese Aircraft Interiors 1940-1945 (Chapter 5, Pages 5055-5058)
3. Modeler’s Journal Vol.2 No. 3 – Review by Tom Knott

Aldo Chetcuti

 December 2008

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