Old tool Airfix B-25J

[Convair]

Hi, indeed, the model is already finished, these are just a few pictures of some parts of the kit during the build. This is the old Airfix 1/72 B-25J from 1964. Sorry for the very poor quality of the photos.

 

First, the entire surface of the kit was sanded to remove the oversized rivets. Then an ordinary scribing tool was used to scribe all panel lines. The original cockpit floor of the kit was discarded and a new floor was made, as well as the nose floor (including the "tunnel" that connects the nose with the cockpit). Some structural detail was added to the sidewalls, including several "black boxes" (bits of plastic, representing various equipment). Enough weight was added in several places of the nose and cockpit to balance the model. The seats were scratchbuilt, and ammunition boxes and more "black boxes" added to the nose.

 

I tried to improve the original top turret of the kit with several "plastic pieces", at least to get a "busy" look. I cut the "pedestal" at the bottom of the turret and installed a pin (a piece of copper wire) to serve as a fastening axle. The "pedestal" was movably installed on a lower floor attached to the cockpit floor (sorry, a computer virus destroyed several photos of this kit, including the images that showed the interior). A hole with the diameter of the pin was drilled on top of the "pedestal". So I could install the turret after assembling and painting the whole kit, and the turret would be rotatable.

 

  

 

  

 

The original carburetor air intakes of the kit are squared, OK for postwar B-25s, but I wanted a plane used during World War II with the oval-oblong intakes. Thus new intakes would have to be made. After some experiments, I decided to use a piece of metal tube to make the intakes.

 

 

 

 

 

A plastic insert was cut and sanded to have a width and thickness slightly smaller than the intake. The insert is necessary for not to "smash" too much the metal tube. The new intakes, having the correct WWII shape (oval-oblong) and the required length, were cut from the metal tube with a suitable saw.

 

 

I removed the squared intakes. Holes for the recognition lights were made on the tip of the right wing. In this case it is easier to drill through holes. Bits of coloured plastic (R, G, Y) were glued in the holes, and gap-filling superglue (cyanoacrylate) was applied and sanded. Later, the painting on top of the wing will hide these recognition lights, which shoould be visible only at the bottom of the wing.

 

 

A slot was filed in place of the old intakes. The top of the wheel bay was painted with interior colour (zinc chromate). A plastic plate was glued inside the rear of the metal intakes, to facilitate and strengthen the gluing of the intakes.

 

 

 

 

In the photo above, I had applied a layer of aluminum paint to highlight possible imperfections.

 

The engine cowling provided by Airfix has 13 exhaust stacks with a strange shape. There should be 14 exhaust stacks (one for each engine cylinder). I sanded-off all of them and made new ones from Evergreen "channel" (no. 261) with 0.06" (1,5 mm) wide. I cut and sanded each exhaust stack individually, to get the correct size and shape. Yes, the Evergreen "channel" have squared corners and the exhaust stacks should have a rounded outer surface. After gluing all the exhaust stacks in place (I used an Italeri B-25J engine cowling as a positional reference), I sanded the surface of the stacks slightly, to get the rounded appearance. 

 

 

Meanwhile I tried to improve the landing gear. I cut the "base" of the landind gear and glued it inside the nacelles as per indicated in the Airfix instructions sheet. The idea was to install the landing gear (by means of pins of fixation) after assembling and painting the entire kit. Brake lines and an extra arm were added to the landing gear. The doors of the nacelles (one of the worst parts of the kit) were glued together with internal reinforcing strips. After drying, they had their length shortened (cut and sanded). They were glued to the opening of the nacelles (the landed B-25 keeps the doors of the wheel bays closed). The fit is very lousy, and tons of gap-filling cyanoacrylate were applied and sanded. Later, the contours of the doors were engraved with the scriber tool (a flexible ruler was useful for doing this). The nose landing gear bay received a similar treatment. As the size of the nacelle doors was decreased, it was necessary to make a new, larger rectangular door from plastic sheet, that was later curved (simply by forcing it with the fingers) to follow the rounded shape of the nacelle. 

 

 

The original engine is less than passable but with a little work it can be improved. The original "reduction gear casing" is very bad, but a new rounded casing (or "front cover") can be made by push-forming a piece of heated plastic sheet over a rounded "mold" (like a rounded back of a pen or brushstick having a suitable size). After push-forming it I cut off the "front cover" from the remaining plastic sheet around, and I sanded it until the exact diameter of the front of the engine. Then I glued the new "front cover" in place; later I drilled a hole on the "front cover" to pass the propeller shaft. Bits of plastic were glued on the "front cover" to represent magnetos and other details. 

A copper wire ring was made with the diameter of the "front cover" of the engine. The ends of 14 thinner copper wires were carefully glued on the ring (avoiding bulky bonding points), corresponding to the positions of the engine cilinders. Thin holes (0.4 mm, 0.016") were made near the top of each cylinder to receive the other ends of the thin wires. The wire ring was placed over the "front cover", and the length of the thin wires ("cables") was adjusted (cut). After the engine and the wire ring with "cables" were painted, the wire ring was placed again over the "front cover", with no glue on the ring. The fastening of the set is done by gluing the ends of the "cables" in the thin holes of the cylinders. A tweezer helps to position the "cables" and the ring in the exact places. It can be said that the ring is "floating", abutted against the front cover of the engine, without going out of place.

 

Edited August 24, 2017 by Convair

[Convair]

Some more pictures. The engine finished and in place.

 

 

 

 

 

The Airfix main wheels are strange, so I preferred to make a silicone rubber mold of the wheels of the Italeri B-25. I used the same mold for an Airfix P-51 wheel (kit 02098), which is almost perfect for use as the B-25 nose wheel. New wheels were cast in resin.

 

 

I did not use the side machine guns in this B-25, so I filled its holes in the fuselage. The bomb-bay doors were glued shut, and a generous amount of gap-filling cyanoacrylate was applied and sanded around the contours of the doors. Later, the contours of the doors were engraved with a scriber tool. The other doors on the belly were also glued shut, received gap-filling cyano glue, etc.

 

 

 

 

The original vertical tails of the kit are "anemic". Its height is good, but not the width, so I used a piece of thick plastic sheet to increase the width. The rectangular protrusions that fit the rudder were glued later. They were made with slightly larger dimensions for a better fit in the rudder.

 

 

I did not want to keep any of the control surfaces movable, so I cut off all the original fastening pins intended for "motion". New pins of wire were installed, and respective holes for the pins were made on the tail and wings. The ailerons were short, then extensions were glued and sanded at their tips, to obtain the correct length.

 

 

The upper turret and nose transparencies were replaced by others, made by means of push-forming a piece of heated clear PVC sheet over "molds", which I have prepared using the Airfix original parts. I filled the original transparencies with epoxy putty, placing a nail to serve as a fixing rod (to be holded in a bench vise, for example). Pieces of plastic sheet were used where necessary. All the original "heavy" frames of the clear parts were removed by sanding. Thus, the surface of the pieces became completely smooth, without external frames. This has contributed to slightly decrease its size, which is positive for the push-forming process (otherwise, the new piece formed by push-forming would be larger than necessary).

 

 

I wanted to add ammunition belts to some of the machine guns (nose and tail). There are excellent photo-etched ammo belts in 1/72 scale, but I wanted something fast, simple and inexpensive. I tried to use embossed paper to simulate ammo belts; I used the embossed paper lining the inside of cigarette packs. The embossed paper is usually plated in silver colour, which is the color of the ammunition belt chutes. On the other hand, the capsules of .50 projectiles have a golden (or brass) colour. In this case, simply paint the embossed paper with a golden color (if you intend to simulate an ammo belt without the chute).

 

 

The back face of the embossed paper is smooth, and is not metallized. To form an ammo belt, fold the embossed paper over itself, gluing it with white glue. After drying, a strip having the width of the ammunition belt is cut. A wash with black paint (or even dry pastel chalk powder) highlights the recessed reliefs of the ammo belt. To hold (glue) the ends of the belt on the machine gun and ammunition box, a thin hole (0.4 to 0.6 mm, or 0.016" to 0.024") is made on the side of the body of the machine gun, in the position where the bullets are fed into the body. The same thin hole is made on the ammunition box.

 

Once the machine gun and the ammo box are installed in place, the belt is placed experimentally, with no glue, connecting the machine gun and the box. The paper ammo belt is reasonably flexible and can be well adjusted (lying on the floor, or passing on specific places) to determine its lenght. The belt is then cut to the required length. A very small square is cut off from the ends of the belt, leaving only a short "pin" or tab of paper at both ends. These "paper pins" or tabs should be soaked with glue (cyanoacrylate). In the absence of good photos, I drew a simple sketch to illustrate the procedure.

 

 

After the soaked glue on the "paper pins" is dry, just insert (glue) the pins into the holes made on the machine gun and on the ammunition box. It is necessary to soak the "pins" because the paper belt is flexible and they (if not soaked) can "bend" when you are trying to glue a "pin" into the hole. Installed:

 

 

Far from perfect, but under a plastic transparency the paper ammo belt appearance is not too bad. At least there is no "void" near the machine guns (and they do not stay without "food"). A photo of the almost finished aircraft (more on "Ready for Inspection" section):

 

 

Edited August 25, 2017 by Convair

[Mitch K]

Super! I really like your technique for ammunition belts.

[bbudde]

Good progress so far. The extra work seems to be worth at any point, I think.

Something nostalgic for this one:

[Ventora3300]

Wow, fantastic result. I didn't realise that this 'vintage' kit needed so much work - 13 cylinders indeed. I have got my eye on it as a possible nostalgia build due to it having retractable undercarriage (I think) and a mostly silver colour scheme.

Well done.

Mike

[TonyTiger66]

Thanks for posting this  

 

Very well explained tips to improve the kit. The intakes look great; I've seen a similar solution by a South African Britmodeller but can't find the thread. It's not as easy as you make it look.

 

I believe this model was the Mad Rivetters 'pièce du résistance'. A veritable cactus. Well done on the rescribe.

 

 

TonyT

[Convair]

Thank you very much guys! Just an addendum: all Russian insignia were painted with star masks and airbrush. I did not want to use decals because of the separation line between the rudder and the vertical tail (I've had previous experiences wherein the decal broke in strange places, off the separation line, and did not fit well). This was a rebuild of a second hand kit, the previous owner had opened the pilot window, and I opted to maintain this feature just by adding the window sliding panel on the inside of the rear frame of the pilots canopy.

 

 

Edited August 29, 2017 by Convair

[Nicolas]

Hi. If not too much trouble, any chance of sending me a photo of the instructions for the oldie B-25 J? I just found an old kit w/o plans.

 

Thank you

Nicolas

[Convair]

Hi Nicolas, the website https://www.vintage-airfix.com/instructions.php allows you to download several old Airfix instruction sheets in PDF format. The instructions for the B-25 are in the letter "B", just click on "B-25 Mitchell".