Sanger's 1/48 scale
Ki-67 Hiryu "Peggy"

by Stefan Giachino
 

  

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The Ki 67 Hiryu Type 4 heavy bomber, or Dragon Slayer, was the best Japanese bomber of the Second World War. However, like many of the late war axis aircraft, it was simply too little too late. The aircraft only served for nine months before the close of the Pacific War. Although referred to as a heavy bomber, the Hiryu, or codenamed “Peggy” by the Allies, was actually a medium bomber. Its dimensions were similar to that of the American B-26 Marauder.

The Hiryu was first used in strikes against the B-29 bases in Saipan, and were quite successful at disrupting the Americans pre-strike preparations. In fact, the US media reported little of these raids as they did not want the Japanese to know how successful they had been. The Hiryu was later used as a torpedo bomber in the battle of the Philippine Sea and the battle for Okinawa while operating from Formosa (Taiwan). Like many Japanese aircraft, the Hiryu was also modified as a special attack or Kamikaze suicide aircraft. Had the Japanese had more Hiryus and, most importantly, enough experienced crews to fly them, the aircraft could have made a larger impact on the war.

 

I have always had an interest in Japanese bombers, but very few are available in 1/48 which is the scale that I work in. Aside from Tamiya’s Betty, there is not much else available. Based on this information, I decided to try my first vac kit. Sanger offers a rather extensive number of Japanese aircraft in 1/48 vac kits.

For a great pre-build review of the Sanger Hiryu, see Matt Swan’s review at www.swannymodels.com . I will avoid covering his material, and get to the build.

From the onset I made some erroneous assumptions. I started the project with the same mindset that I start all kits with: I could cut the pieces out from their sheets, and then it would be a lot like a standard plastic model but with a lot less detail. That was my first mistake. After cutting everything out, I began to glue the wing, horizontal stab, and vertical stab halves together. After they were dry, I began to look at the drawings and photos, and realized that not only were the wings, tail, and other parts too thick, but the real aircraft did not have a fully symmetrical airfoil. That was when I realized that I was going to have to do a lot more research and not take a thing for granted from Sanger. Every inch of the aircraft would have to be verified against drawings and other reference material.

I took the diagrams (1/2 of the aircraft) that Sanger provided and duplicated the other side of the aircraft giving me a complete 1/48 drawing of the aircraft. I also purchased the Hasegawa 1/72 kit and enlarged the decal drawings to 1/48 so I would have another reference. Throughout the project, the Hasegawa 1/72 kit was a great reference.

As I began to check my 1/48 pieces against the Hasegawa offering and the drawings, several glaring inaccuracies came to my attention. The Sanger wing is missing an important curve or “gull” in the wing. The Hiryu wing (when viewed from the front) comes straight out then bends up, similar to the Ju 87.

Also, the engine pylons or nacelles on the Sanger kit are not separated from the flaps at the trailing edge. The real aircraft had a rather noticeable gap between the aft portion of the pylon and the wing flap, so the fowler-type flaps could extend and retract and clear the engine nacelle.

Had I not glued the wing and tail halves together, I probably could have salvaged everything by simply sanding the halves way down. As for the symmetrical wing, which the aircraft did not have, that would be a little tougher. Because my wings and tail were much too fat, I opted to cast them in resin then sand my little heart out.

By using resin, I could also sand off the bottom camber on the airfoil and correct the symmetrical issue. I took imprints of the wings (both sides) and cast them in resin, then glued them together. As for the “gull” portion of the wing, I simply cut off the inside portion, inserted plastic card until the correct angle was obtained, then glued it in place.

One of the trouble spots of building vac kits is the wing joint. How do you connect the wings to the fuselage and achieve the correct dihedral and angle of incidence while maintaining structural integrity? This would be very critical in my case because my wings were made of resin and very heavy. This was addressed by connecting both wings together as one unit then removing the bomb bay area and dropping the wing section onto the fuselage from the bottom. The Bomb bay area was later reattached.

Clear Parts

When looking at a Ki 67, one of the most noticeable features is the amount of transparencies. The entire nose and tail are greenhouses. The Sanger transparencies for both the nose and tail that are included in the kit are unusable because they were vac formed as two separate halves. When painted, the window frames would not cover the seams. Additionally, there should be no seams at the tip of the nose and tail cone. Also, Sanger makes no provision for the viewing windows on the bottom of the fuselage behind the nose section.

To solve this problem, I decided to vac form the entire nose and tail sections as one piece and bring the glass aft far enough to have an extra half inch to glue and sand smooth. In order to do this, I needed a mold. I glued the kit glass together and attached it to the fuselage. After sanding and shaping the nose and tail to the correct shape, I cut the nose and tail off with a hack saw. The nose and tail sections were then placed in containers and I poured blue molding silicone over them. Then I poured resin into the silicone molds and I had my patterns for vac forming. Using my larger vac former (my heat source is my gas BBQ) I vac formed the nose and tail sections. However, this process took days of trial and error. The top turret transparency was also redone because, for some unknown reason, the Sanger kit had a flat spot on the top turret which is not present on the actual aircraft.

Click the thumbnails below to view larger images:

Interior

Given the number of transparencies, it meant that the entire inside of the fuselage would have to be scratch built, and look authentic. I could not detail the inside until after the vac formed transparencies had been secured to the fuselage. Because the contact points between the transparencies and the fuselage were pretty rough, I did not have the luxury (like with an injected production kit) of detailing the inside and then attaching the clear parts. But I had to tackle the dilemma of detailing the inside if it were sealed closed. My solution to this problem was to open the two cockpit hatches and the lower nose hatch and build the interior through the open those hatches. I used a razor saw and cut the tip of the nose cone off, as well as the tip of the tail cone. I was careful to cut at the rotation points for the forward and rear guns (both the nose cone tip and tail cone tip swiveled to give the gunner a greater field of fire). A rotary tool was used to cut out the other windows. Assembling the interior was akin to building a ship in a bottle and required a lot of work with tweezers, and a great deal of patience.

Nowhere did I find any conclusive evidence of the interior color of the Hiryu. It may be argued that the nose framework should have been Mitsubishi interior green instead of the elusive aotake that I chose based on my own interpretation. However, I later found some documentation to support the Mitsubishi interior green theory, so in hindsight I would have used this color instead of aotake.

The detailed and accurate construction of the interior would have been impossible without the valuable information from Maru Mechanic # 15. This book was my veritable Bible from beginning to end. I highly recommend any book from the Maru Mechanic series. Even if you can’t read Japanese (I can’t), these books are worth every cent if you are modeling a Japanese subject.

Landing Gear

The Sanger landing gear is made of cast pot metal. They have some detail, but the cross members are not the correct shape. Additionally, the pot metal would not be strong enough to support my model, which consisted of a large amount of heavy resin. A replacement was needed. I decided to scratch build the landing gear with aluminum tubing from the hardware store and it worked very well, and was much stronger than the pot metal. Aluminum is ideal to work with as its relatively soft, looks authentic, and cynoacrylate glue bonds to it very well. Also, the Hiryu landing gear legs were a bare aluminum color, so no painting was required on the aluminum.

Luckily, I was able to use the True Details tires for the Mitsubishi G4M Betty. They are the correct size and shape, and it seems feasible that Mitsubishi would have used interchangeable wheels between the Ki 67 and G4M.

Click the thumbnails below to view larger images:

Propellers

he Sanger props and spinners are pot metal like the landing gear. The blades are not quite the correct shape, but with a little filing and sanding, a satisfactory result can be achieved. In many ways, the end result is better than what you would get with plastic. The blades can be filed very thin and look to scale.
After some study of the Sanger supplied spinner against the scale drawings, it became apparent that they were too short and stubby. New spinners would need to be made. I attached a ball of Miliput to the end of a nail, and set it aside to cure overnight. The nail was then inserted into an industrial drill that I use as a lathe. I sanded and filed the ball of Miliput to get the desired spinner shape. A silicone mold was poured over the completed spinner. After the mold was dry, two resin spinners were made. Holes were drilled, and the props were inserted.


The Sanger spinner is overlaid on scale plans. Note the incorrect shape. To the left are the two new resin spinners. Above is the original made from Miliput and its corresponding silicone mold.


 

There is some degree of confusion as to the correct color of the Hiryus. Aside from the Ki 109 (fighter version) the Ki 67 was painted one color on top and one on the underside. This seems straight forward, but you see many variations of the top color.

Thanks to Jim Lansdale and Nick Millman from www.j-aircraft.com (both of whom had done research on Ki 67 colors) I was able to get several paint chips. Using these paint chips, I mixed paint for the top and the underside of the aircraft. The original topside color was an olive drab with a slight hint of brown in it. It is a good bet, that over time, this color further browned. I mixed Gunze paint to match the topside color chip, and used Tamiya Navy grey for the underside. The Tamiya Japanese Imperial Navy grey seemed a pretty close match to the underside chip that I received.

Although you may see some complicated squadron markings on some depictions of Ki 67s, I have seen few photos that verify these markings. The aircraft that I chose to depict has rather simple markings. Aircraft 7-60 was from the 7th Air Regiment of the 3rd company or “T-Force” that fought in the Battle of the Philippine Sea. These aircraft carried torpedoes slung beneath the fuselage.

All of the markings on my aircraft were painted. Sanger provides some primitive decals, but I chose not to use them.

Armament:

The torpedo was taken from a 1/48 Hasegawa B5N2. The torpedo was modified with the often seen plywood fins. My understanding is that the fins helped with directional control while the weapon was falling through the air. Upon impact with the water, the wood fins were ejected from the torpedo.

Note the wood aerodynamic fins at the tail of the torpedo

As for the machine guns, the Sanger guns appear to be of the 12.7mm type. Although the stocks looked OK, the barrels lacked the cooling jackets, so I scratch built the rest. It appears to me from research, that the early aircraft had 7.92mm guns. The 7.92mm were later replaced with 12.7mm, while the turret was replaced with 12.7mm or a 20mm cannon. I went with the 12.7mm and 20mm cannon option.


 

In many ways this project was a near scratch build. However, had I done my research a little earlier, I think I could have avoided a lot of work. I should have studied the diagrams before starting any construction. You must not assume, at least with this particular kit, that Sanger produced any portion accurately. If you do your research, you can save yourself a great deal of frustration and hours of labor.

In spite of my many mistakes, I have never enjoyed a project as much as this one. As much as I love assembling a great Tamiya or Hasegawa kit, there is something special about making everything yourself. You learn a lot in completing a project like this, and you have a very unique aircraft to show for it.

I would strongly encourage anyone who really wants to improve their modeling skills to attempt a vac kit like this. I plan on building much of the Sanger 1/48 Japanese bomber line. I would like to complete their Ki 48, Ki 49, Ki 21, and P1Y1 Ginga. What a unique collection that would be! With what I learned from this project, I believe that I could expedite the building process.

If anyone has any questions or comments regarding this or a future project, I would be happy to provide any information. I received so much help from the modelers at hyperscale.com and j-aircraft.com that the least I could do is pay it forward. I can be reached at dornierdriver@hotmail.com

 

Click the thumbnails below to view larger images:

Model, Images and Text Copyright © 2007 by Stefan Giachino
Page Created 20 September, 2007
Last Updated 24 December, 2007

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