S-Model 1/72 Boulton Paul Defiant

S-MODEL 1:72 BOULTON PAUL DEFIANT

Reviewer: Phillip Weston (rec.models.scale)
Kit Review submitted: 13 January 2008

Kit Details:

1/72 Boulton Paul Defiant - S Model # 72004

Aircraft History:

Descended from the successful concept of the Bristol Fighter of World War One, the Defiant was designed to the Air Ministry specification F.9/35 and the prototype, K8310, first flew on 11 August 1937. This specification also resulted in the Hawker Hotspur turret fighter, which did not enter service even though many thought it a better aircraft. The Defiant was a beautiful example of 1930’s design, with a clean and attractive all-metal airframe powered by a closely cowled Merlin engine. As an aircraft it displayed excellent flying characteristics, but as a fighting machine it had two serious flaws. Firstly, the bulk of the four-gun Boulton Paul turret made the Defiant slower and less manoeuvrable than contemporary fighters using the Merlin engine (despite the inclusion of retractable fairings to cut down drag) and secondly there was no forward firing armament. Either flaw on its own would have been serious-enough, but the two together were to prove fatal in combat situations.

264 Squadron took delivery of the first Defiants on 3 December 1939 and used them in action for the first time on 12 May 1940. When the first engagements with enemy fighters had a number of successes, the turret fighter theorists claimed justification of the concept. 65 enemy aircraft were shot down, largely over Dunkirk, before opposing fighters overturned the element of surprise and losses began to mount alarmingly. In August 1940, despite the skill and valour of Defiant aircrews, the aircraft was entirely withdrawn from daylight operations.

Following its increasingly disastrous daytime operational career the Defiant was re-deployed in a night fighting role equipped with elementary airborne radar, and in the period following the Battle of Britain it had the highest number of enemy fighter kills of any other fighter type during the winter of 1940-41. Total production of all types was 1064 aircraft including many later variants with turrets removed and which were used as gunnery target tugs, training aircraft, air sea rescue aircraft and army co-operation aircraft. Production was completed in 1943.

Introduction:

I found the S Model website whilst looking for a 1/72 kit (any kit) of the Boulton Paul Defiant that was an improvement on the Airfix offering. You know this Airfix model. It’s been around since plastic-bag-with-paper-header days, and since it has decals for the night fighter version it’s moulded in black plastic. The first article in the book “Battle of Britain Aircraft” has detail and excellent drawings for correcting the manifold errors in the Airfix kit; and it’s not for the faint-hearted with (basically) a new nose, new fin and tailplanes, alteration of the fuselage and wings and an awful lot of cutting, filling and sanding on the way.

The S Model site (www.s-model.lap.pl) has a number of interesting models in both vac-form and resin and I ended-up getting a Defiant and a Blackburn Roc. The astute will notice these are both “turret fighters” and both vac-forms, for me an irresistible combination; and they were cheap even after the currency conversion into $US! The kits arrived promptly, and well-packaged so S Model get my recommendation for service and it’s a bit of thrill to think that they came all the way from Poland with just an internet order.

The Kit:

The model consists of a zip-lock poly bag containing one sheet of vac-form components, a smaller bag containing the transparencies, a double-sided A4 sheet of instructions and drawings, and a small coloured header. The main components are closely formed in a single sheet of white plastic with the reverse side in yellow. That’s a bit of a surprise, but no problem. All the main components are well formed, with finely recessed detail and panel lines. Only the prop spinner looks as if it could be a little thin at its extremity. As per standard vac-form practice there are some components (like undercarriage legs) that would be better if replaced from scratch-built items. I also planned to replace the prop, exhausts and guns with Aeroclub parts. I’m sure that the kit offerings, and plastic rod, would give good results, but I admit that I have a bit of a “thing” about Aeroclub accessories and always have a stock of them on hand.

The transparencies consist of the main and turret canopies and are duplicated for the benefit of those of us who make mistakes. They are well formed and have good, clear framing lines. On one side the instructions have an assembly schematic and parts layout, and a short history, but in Polish. How is it that S Model answered my (English) enquiries in excellent English yet I cannot understand a word of the Polish? I suppose that such is the isolation, and ignorance of a Southern Hemisphere dude!

On the reverse side of the instructions are the line drawings. The 4-views agree in dimension, form and detail with those in the “Battle of Britain Aircraft” article, but most importantly the outline of kit components agree with both. This is a far cry from the old Airfix kit.

Building the S-Model Defiant:

Construction of the model starts, as for all vac-forms, with the time honoured process of drawing around the components with a soft pencil, separating them from the backing sheet, and then sanding on a flat board to remove the fine edges and create a true joining surface. The careful layout of the components on the backing sheet means that there is little extra material to be discarded.

There is a rudimentary set of interior detail items including seat, floor and instrument panel. Yes, I know that this next statement will cause a deal of anguish to some but in 1/72 scale, with the canopy in the closed position there is very little to be seen inside a model so I used the kit components, added a control column from an Aeroclub pack, painted the interior and added some seat straps from tape; there were no internal structures, no pipe work and no individually painted instrument faces. That’s not to say that all manner of internal detail could be added if desired with one of the positive aspects of vac-forms being that areas like fuselage sides do not need extensive thinning-down as injection models do. The instrument panel needed careful trimming before its shape conformed to the interior. Using your available references make a careful check of the exact positions of these internal details as the instruction sheet only shows them in general layout.

Before gluing the fuselage up I decided to add a little strength to the structure by packing areas with epoxy; the rear fuselage, the “bumps” at the rear of the wing roots and the nose behind the prop were areas that received attention. Don’t get me wrong this epoxy-thing was not really necessary. It’s a legacy from the days when vac-forms always had a few really flimsy areas that supported nothing, and were easy to push-in during construction. The epoxy I used is called “Knead-it” in New Zealand, and consists of a stick of material that is cut to length and then worked in the hands to mix it into a firm white paste. It hardens in less than 30 minutes and is easy to sand and cut.

Before closing-up the fuselage I carefully cut out the exhaust stacks with a sharp knife and then filed the slots straight and square. Aeroclub stacks were inserted from the inside of the fuselage halves and the stacks and the slots covered with a layer of epoxy. This served the double purpose of not only holding the metal stacks in place, but also filling any slight gap between them and the slots. It goes almost without saying that you have to be careful with the amount of “protrusion” of the stack, and that they are both on equal levels. (The kit’s exhaust stacks, by the way, would be fine just left alone.)

There is enough width of material in the components, especially the fuselage sides, to cement them directly together without needing strips of reinforcing material on the inside. I was impressed with the general fit; the panel lines and control surfaces corresponding correctly, and most importantly the parts being of the same size at the joining surfaces. You will probably have your own method of constructing vac-forms, but mine is to tape the components together and then “wick-in” thin cement, leaving the tape in place over night before removing and cleaning-up.

The strength of the wing assembly is assured by its clever five-part construction that also acts as a check for dihedral. I found a small amount of filler was needed at the wing roots, and also the fuselage joint, to get a gap-free result. The tail planes are butt-joined to the fuselage and, if the joint is well prepared and some tube cement is used, it is strong and hassle-free. I cut out the undercarriage wells before assembling the wings but with the wings assembled I think that they are a little too shallow; no matter, it’s not a problem. I cemented a piece of 5mm card inside each well to act as an anchor point for the undercarriage legs. They were drilled to accept the ends of the oleo legs I was going to fabricate. The leading edge wing lights were filed out and the space filled with clear sprue that was later sanded to the form of the leading edge. 5 thou card was used to box-in the wheel well areas.

The Defiant’s undercarriage is, in reality, a little more complex than just two oleo legs, and is further complicated by incorporating a curved leg section above the wheels. The retraction mechanisms would be very fiddly to scratch build and are not a feature of the system, so I decided to concentrate on the oleo legs, wheels and doors. The legs were fabricated from lengths of Contrail round strut and tube, but could just as easily be made from stretched sprue of the correct diameter. (Once again it would be possible to use the items provided in the kit, by filling them with epoxy and sanding to shape - although I didn’t try this). Check your reference photos carefully to decide how much detail you are going to incorporate in this area. The IPMS Stockholm picture page is excellent.

You could find wheels in the spares box, or use Aeroclub items, but I sanded the insides of the kit wheel halves flat and stuck them together by filling them with epoxy. A quick sand of the tread area, and drilling out the mounting holes for the axles produced a most acceptable pair of wheels. The kit undercarriage doors are perfectly usable, but you may want to replace them with thin card items. Be aware that the relationship between the two main undercarriage doors changes according to whether the system is loaded (as on the ground) or unloaded (as in the air). Check the references to ensure your model has the correct set-up for the doors. I got the tail wheel from a Hasegawa Hurricane spare. It’s a small unit and it would be fiddly to try and use the kit item, or scratch build one.

Before a coat of light grey primer I wet sanded the entire structure with 1200 grit, re-scribed any panel lines that had got a bit shallow, and then masked the cockpit and gun turret areas. The undercoat displayed a detail I had missed in the preparation and one that is peculiar to vac-forms. Small holes used in the mould translate to “goose-bumps” on the surface of the model. It’s the vac-form equivalent of ejector pin marks on mainstream kits and, like ejector pin marks, they’re no problem provided that you know they are there. This kit doesn’t have many of the small bumps and a few minutes spent with a sharp blade will remove the offenders.

Meantime, I started work on the turret that consisted of a circular base, a transparency and some shapes that, combined with stretched sprue or rod, form the gun unit. The kit turret is designed as a static representation only and if you want rotation or elevation this is going to take much more time and considerable ingenuity. (I don’t think the Airfix turret would be of much help here either.). I used super glue to attach the two Aeroclub gun units to a length of Evergreen rod, setting the spacing by the slots on the turret transparency. It goes without saying that the gun barrels are small, thin and easy to bend out of shape. It would be okay to tweak them back, say, a couple of times but anything more and you’re asking for disaster of the “snap-off” kind. The completed gun assembly was mounted on a couple of card trunnions. You need to decide about the elevation in which you are going to display the guns, checking some photos to see what was done on the actual aircraft; I opted for the “not being used” flat position.

You have to be more-than-a-bit careful when it comes to removing the clear turret part from its backing; it’s thin and easy to deform. Use a new blade in your modelling knife with the minimum of pressure and just slowly work around the shape where it joins the sheet. Continue with minimum pressure and repeat the line until the shape comes away from its backing. If you press too hard, or try to speed up the process, you will likely make a mistake and then have to use the second, spare item. Then, using the same basic process and in good light, identify and cut out the two slots for the guns. You could just as easily use small sharp scissors to do this. Some trial fitting will be necessary to get the transparency sitting just right over the guns and the turret Paint the interior and guns to choice and then glue the transparency to the base. I used “Kristal Klear”, but PVA would do the same thing, and some prefer super glue… and yes, I’ll admit that I stuffed-up the first attempt and had to use the second transparency for my model!

Painting & Finishing:

You will have your own method of applying the chosen colour scheme to your model. I wanted the (camouflaged) day fighter version, but the all-black night fighter may appeal and there are some interesting air sea rescue variants in dark grey/ dark green schemes.. I used a combination of Gunze and Tamiya acrylics applied with an airbrush and also used the Johnson Klear (“Future”) sealing coat. I used painted clear decal film cut into narrow strips to represent the canopy framing, but the turret framing beat me with this technique and I masked one line at a time and brush painted them.

I get frustrated when I read articles (like this one) that assume you have access to, or ownership of, a huge selection of decals. You know what I mean; the author mentions casually that the roundels came from this sheet and the serials from that manufacturer, and that they hand-painted the squadron codes. I was wondering how I was going to cobble together the required roundels and serial codes for this model and then I saw an old sheet of ESCI decals (sheet number GB 37) for auction on eBay, and on an impulse, bought them. It serves me right for thinking I’d be smart; they were truly dreadful! The roundels were so far out of register that they were unusable. So I ended up using just the grey squadron codes and the serials and having to “cobble together”

a set of roundels that I think I got from a Hasegawa sheet and some old Frog sets. The moral is that if you are going to build vac-forms you need a stock of decals to finish them, or you need to select a model for which some good after-market decals are available as a sheet. Neither the ESCI decal sheet nor the plans offered any clue as to what stencils were applied to Defiants in service, and most of the period photos are taken at a distance from which none are visible, so my model has no stencilling applied. The final assembly involved fixing the pre-painted Aeroclub prop, making a small sprue pitot head and giving the model a sealing coat of Klear mixed with a dab of Gunze flatting agent. No attempt was made to “weather” the model because I quite like the new airframe look, and the cynical will point out that Defiant day fighters just didn’t last long-enough to get weathered (!)

Conclusions:

I think S-Model is to be congratulated on a very good vac-form. The Defiant model has components of a high standard, is accurate in outline, has no pitfalls during assembly, and I really enjoyed building it. Although I opted to use some Aeroclub items to replace the kit offerings I have no doubt that (apart from supplying decals) the model could be built entirely from the kit. A good measure of the completed model is that it looks “right”, and has captured the visual “essence” of this early Second War aircraft. An experienced vac-form modeller will find this kit no problem. An intermediate modeller will find it challenging, whilst a novice will probably need some supervision.

References:

http://ipmsstockholm.org/magazine/1997/08/stuff_eng_detail_defiant.htm
www.s-model.lap.pl
Battle of Britain Aircraft, Argus Books 1990
Hall, A. RAF Fighters of World War 2, Airfix Magazine Guide Number 6

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