(Reproduced from Scale Models International Vol 26 Number 310 - August 1995 Author: Bryan Ribbans)
|As the successor to the famous Walrus, the
Supermarine Sea Otter was largely an 'unsung hero', daily
going about its business be it Air-Sea Rescue,
communications and general duties or just as the squadron
'hack', with no fuss.
Yet, it was an important aircraft. First designed and flown back in 1938, the Mark I did not enter production until 1943 with the Mark II entering squadron service in 1944. Built under contract by Saunders Roe it bore a strong resemblance to the Walrus but the most significant change was that the engine was facing forward (tractor). It was altogether cleaner and faster, had more range and the water handling characteristics were superior. Production ceased in 1946 with a total of 290 airframes built most of which served overseas flying from aircraft carriers or shore bases. The Sea Otter II was the last biplane design from Supermarines and became the last biplane to see service with the Fleet Air Arm finally retiring in the early 50s in favour of the helicopter in the same role. It had outlived its predecessor by five or six years. Apart from a forward hull section in Australia, none survive today.
Aeroclub's new Sea Otter II is described as a 'Multi-Media' kit. The parts come carefully packed in the familiar stout white box and consist of: two vacformed hull halves; a clear canopy; injection moulded upper and lower wings, tailplane, floats, internal bulkheads, cockpit sides, floor and instrument panel. The bag of white metal parts cover the engine cowling, Mercury engine, wheels and undercarriage, propeller, exhaust and wing mounting struts. A large instruction sheet with a 1:72 scale plan, together with a decal sheet for one aircraft complete the package. The hull halves exhibit very good engraved detail, are crisply moulded, and when cut out and sanded down, match each other well. Do not cut out the cockpit area without reference to the canopy moulding as there is an attachment 'ledge' on the hull which is easily removed by mistake by the eager builder. The marked locations for hull handrails were backed with pieces of scrap card to provide more support for the rails.
The canopy is a large, superb moulding with feint frame details. I would have preferred having a spare one to hand in case of any errors made in cutting out and feel that this should now become the norm in this type of kit. Test fit this frequently when sanding the hull. The injection moulded wings, supplied as port and starboard upper and lowers together with the upper centre section containing the engine nacelle split into two halves (upper and lower) are superb. The ribbing detail is subtle, in scale, and even show where the wing spars are located. The trailing edges are thin and the ailerons are engraved correctly.
Joining all the wings together is by the 'slot and tab' method. Also supplied as injected mouldings are the floats, rudder and tailplane. Jewel in the crown though, is the virtually complete cockpit assembly, again injection moulded. This consists of a highly detailed floor running the length of the rear radio compartment through the pilot compartment forward into the bow area. Onto this are mounted the cockpit side walls, rear , mid and forward bulkheads all carrying internal rib details, throttle controls, instrument panel and even the curtain beside the door! Absolutely superb and the fit is excellent both to each other and inside the hull. That is with the slight exception of the mid bulkhead which stops short of the roof of the canopy. I suggest either packing the gap with strips of card and repeated test fitting or scratchbuild a new one using the kit part as a pattern. It's difficult to see how Aeroclub could have overcome this, but again a second canopy would mean I could cut it into front and rear sections which may also help in solving this small problem. All that is required is painting and highlighting to really bring out all that detail. I did, however, run into problems with the kit supplied plan.
Albeit, very clearly drawn with 1:72 profile, top, bottom, front and plan views there is no 'exploded' parts drawing which meant I had to figure out a number of things myself. More to the point though, the plan clearly shows side by side seating in the cockpit which goes against the kit parts and published photographs. (See addendum below) The kit has the pilot seated on the port side of the mid bulkhead with the radio operator in a similar location in the compartment behind him and a gangway running along the starboard side. I believe this to be correct. The Aviation News plans (see References at end) also show side by side seating. However, I suspect Aeroclub used these to re-draw for their kit and carried an inaccuracy across.
The kit plans also carry a camouflage pattern but this gave me a problem - more anon. Construction notes are printed on the reverse which are adequate but I did not build in the sequence suggested. Having gathered as much reference material as I could find I began by listing the following items, either missing from the kit, or those I wanted to add to my model as extra detailing:
(1) Aerial on cockpit roof. (2) Whip aerial on rear of engine cowling. (3) Mushroom rope stays on top of bow. (4) Filter over engine air intake. (5) Rudder navigation lights. (6) Handrails on hull sides. (7) Yagi aerials on wing struts. (8) Cowling clips. (9) Port wing landing light. (10) Controls on side of engine nacelle. (11) Navigation lights on wings. (12)Pitot on port wing strut. (13) Pipe on upper engine nacelle. (14) Float and hull tie-down rings. (15) Mooring rope on hull nose. (16) Seat belts. (17) Radio set.
The cockpit area was built and detailed first. The white-metal seats were fitted with belts from wine bottle foil with buckles from the Reheat range. After painting, the cockpit was slipped into the previously joined hull halves. Precautions were taken before joining the hull halves to strengthen the lower wing joint with Milliput to provide extra interior gluing surfaces. I had placed some scrap card tabs along the inside of the hull joint and with it all held together with masking tape, liquid glue was run around the hull and then the whole lot set aside to thoroughly harden overnight. The upper wings were tackled next. The fit of the upper and lower nacelle centre section is good. The upper port and starboard outer wing sections are joined by a slot and tab. The fine Mercury engine is designed to fit against the white-metal front cowling ring, which it does: but I cut and fitted a back plate into the rear of this assembly from scrap card using an Olfa Compass Cutter to stop the 'see through' look.
The collector ring which fits on the front of the cowling could have done with being a bit larger as in profile it leaves a double curvature look which is not present on the real thing. However, after painting it does not notice that much. The wing tabs as moulded are too thick for their respective slots so were thinned down before being glued together. When dry, they formed a strong joint which only required a touch of filler. On the lower wings I considered that too much of the hull wing root area would have to be cut away for the thick tab to slot into, which would leave a weak joint. Each wing tab was cut back leaving just 3mm at each end which was thinned down. Corresponding slots were cut in the hull and the wings were virtually butt joined with liquid glue. When dry a small amount of filler was used to smooth things over.
The landing light location in the port wing was cut out, a piece of clear plastic drilled and painted to look like a bulb, and inserted into the wing - all to be sanded back and masked prior to painting. The tailplane is provided as a one piece unit to slip through a horizontal slot cut in the fin which is moulded as part of the hull. This is fine but in practice leaves a weak joint as the cut has to go virtually all the way along the fin. It's better to separate each tailplane and butt join or pin through the fin before adding the rudder. This looks a touch too narrow on chord and a touch too thick at its forward end but once on the airframe this isn't too noticeable. Care must be taken again to ensure the fin area is not over-sanded whilst working on the hull halves or an ugly step will result. The tailplane engraved detail was too fine for me so I ran an Olfa 'P' Cutter over it. Be careful when sanding the wing joints not to destroy the ribbing or flatten off the upper hull radius near the lower wings. Re-drill the strut attachment points nearby when done and also deepen the oleo attachment holes for a stronger joint. With all the final details placed into the cockpit area the canopy was attached using diluted Kristal Klear. When dry I applied Squadron's Green Stuff filler very sparingly, sanded back and replaced canopy latches and handles lost on the hull with Microstrip.
STRUTTING MY STUFF!
Metal struts are supplied for the main engine supports but I found these to be far too short in height when compared to the plans. This phase is absolutely critical to the overall look of the airframe. The instructions state to cut the rear set of struts from a piece of supplied material but I substituted Contrail stock. Cut to a length of 2Omm these were mounted on the upper hull and the wing offered up. The metal struts were 3mm too short causing the engine thrust-line to point down to the bow hatch!
The answer, after careful measuring and checking of photographs, was to make new front struts the same length as the rear. With the rear of the hull at the wing trailing edge being lower than the area behind the cockpit, struts of the same length kept the relative wing incidences parallel. Both sets of plans show small inner struts abutting from half way up the main engine strut down to the hull roof. I can find no photo or reference to support this. The metal strut carries a cuff both top and bottom which would prove difficult to reproduce but here I got lucky because I found photographs of various airframes where these were not fitted (or at least appear not to be fitted) and indeed it was about this time that I changed my mind about exactly which airframe I would build (more anon) and this one did not have them fitted. It is tricky to mount the wing because with a metal cowling AND engine it is HEAVY. Take it one step (strut) at a time and ensure they are fully dry before attempting to rest the upper wing on them. Then carefully apply super glue to each strut tip and slowly lower the wing down. Continue to hold on whilst the glue sets.
When done you will be surprised at just how heavy the whole model has become, it is heavier than expected. Don't drop it, you will dent the floor! I was pleased with the results when all was done but noticed that when I test fitted the propeller it appeared to be too far forward. Alter studying the plans and photographs, the strut locations are about right. The problem appears to be that the length of the cowling from the wing root to the engine cylinder 'bumps' is too long pushing the rest too far out. The rear of the nacelle is okay. As the offending part is white-metal it would be difficult to correct. Were I to construct another kit, I would probably substitute a cowling from the spares box. This would also take care of the collector ring problem from earlier.
THOSE FLOATS AND MY SANITY!
If this kit has an Achilles heel, then the floats are it. What probably sounded a good idea in the kit planning proved for me, in practice, a pain. All went well at first The float halves benefited from a rub down of the mating edges, vacform style, before gluing together. Each float has a lateral slot in the top where a pair of handed white-metal struts fit, front and rear. These struts are not airfoil shape in cross section so two evenings were spent in sanding them to shape, filing the metal and generally tidying up the joints. This is not easy due to the restricted access between the struts and the fact that they are mounted on a double curvature surface. I found a Flexi-File the best for this work, and thus I persevered. Two more evenings later I had each float finished and in undercoat. Following the moulded dimples on the underside of each wing I proceeded to glue them in place. A while later, after the glue had dried, and whilst generally checking out the plans I realised something was not quite right, the floats looked wrong.
Then it hit! The rear strut locating slot on the float is 3 to 4mm too far forward. When looking at the side view of the airframe the vertical wing struts line up with the float struts. On the kit these do not, nowhere near. (The front and rear views are fine). Also the struts are angled up to the wing at the wrong angle. So there was nothing for it but to take them off! I pulled the white-metal bits out of each float, binned them, filled the slots with thick card and Green Stuff, sanded down and regained the curves, carefully measured the plans and made a jig for the new locating points. Using Contrail strut stock, I made new ones and glued them to the floats, reversing the jig for the opposite hand. This was actually very easy and to think I had very nearly done this to start with!
The completed floats were once again attached to the wings with no further problems. The exhaust was fitted to the top of the cowling. I suggest you cut off the mounting lug and bend the front end to a sharper angle to more closely follow the cowling at this point. The 'Hedgehog' detail is very well defined, be careful not to get any glue on this part. Before undercoating I masked off the cockpit glazing. Here again both plans carry the same fault They show an extra row of upper glazing in the side views which is not present on the plan view. Check out the very clear photo on page 326 of reference No.2 which confirms that the plan view is correct ie; no extra upper row.
I masked the whole of the canopy area, preferring to use painted decal strips at a later stage. This gives me much sharper edges and saves time. Don't forget that if using clear decal, paint the interior colour first before the top coat. Add the white-metal catapult hook to the lower hull after first thinning it down. Fair it into the hull with a touch of Green Stuff. The delicate tail wheel was added next with just a smear of super glue. The damper strut is perfectly formed, although very dainty, so handle with care!
THOSE PESKY HANDRAILS!
With everything substantially together only one major exercise remained - the handrails. Up till now I had been wondering just how to best represent these. Photographs show that they are delicate in the extreme with plenty of cross members exiting the hull. Standard fit was a pair at the forward end and another pair just aft of the lower wing. In the end I decided to drill holes into the hull (previously backed with thicker card, as you will remember!) and inserted florists wire cut to length and then very gingerly super-glued a length along the outer tips to form the rail itself. To ensure that I trimmed the tips the same length on each side I cut a card template and this also helped to keep them all level when trying to run the actual rail along them. But there's no getting away from the fact that this is not at all easy.
RINGING THE CHANGES
At about this time I realised I had a painting conundrum. The kit plan shows the camouflage scheme and colour demarcations of an FAA aircraft, JN135 of 1702 Squadron, Malta, 1949. This aircraft was painted in the Temperate Sea Scheme of Dark Slate Grey, Extra Dark Sea Grey (shown erroneously as Dark Sea Grey on the plan) and Sky. As a drawing it looks fine except that the lower wing camouflage pattern is not shown. Further, I found a picture of JN135 and the forward hull demarcation lines were clearly very different to this plan. The picture also shows a fair degree of re-painting on the hull. Reading up, it would appear that the late, fully camouflaged, airframes did not carry the lighter 'shadow shading' on the lower wings. I could not find any reference that would confirm this pattern so I was left with using the pattern from the Walrus or just 'fudge' it and guess, but having come this far I could not bring myself to do this. The plan also shows the camouflage running over the engine collector ring which is wrong and the spinner finished the same which I feel should be semi-gloss black. There had to be something better.
Then I had some luck! JN185 was a Sea Otter II serving with 728 Sqn FAA, the Fleet Requirements Unit, flying from Hal Far, Malta, 1948 until December 1952 and a very large and clear photograph appears in Ref. No.6. This aircraft carried the post-war Extra Dark Sea Grey/Sky camouflage with simple demarcations and best news of all, when pictured did not have the rear sets of handrails fitted - hooray! A clear picture in another book showed a front view of the colour scheme, completing the coverage nicely. As JN185 had an arrestor hook fitted and the Aviation News plans showed this I immediately set to work and re-shaped the bottom of the rudder and made the hook attachments from small scraps of plastic card. The hook itself was donated by the spares box. This aircraft carried the Yagi aerials on each outer forward wing strut. For these I adapted the new etched brass set from Eduard, No.72-096, which fitted the bill well. (This set gives a complete fit for the Catalina and similar airframes). These aerials were mounted on florists wire and painted, but not fixed in place until the very end to avoid damage.
An undercoat of Humbrol 127 Grey was sprayed overall followed by checking and sorting any flaws before the colour coats were applied. I added a touch of gloss varnish to Humbrol Authentic Colour HB5 Sky Type S (now called 90 Matt Beige Green), to make it smoother and also darkened it down a shade with black to remove the harshness. When dry, it was masked and painted with Humbrol's Authentic Colour HB7 Extra Dark Sea Grey (now called Matt Sea Grey). I would normally have masked up and sprayed the upper colour but on this type of airframe this would have been quite a task. Suitably thinned, the paint flowed on fine with no brush marks.
I sprayed on Johnson's Klear to provide the gloss coat for the decals which I found from a number of different sheets in my decal 'bank'. Incidentally, when photographed my aircraft bore no fin flashes. If you are using the kit decals you will not be disappointed, they are well printed with good colour, very thin, and the register is spot on - all very commendable. After washing with warm water to remove setting fluid residues a further coat of Klear was sprayed. Slight weathering was applied with thinned Raw Umber oil paint along aileron hinge lines, panel lines and around the engine. When dry the rigging was taken care of by stretched clear sprue affixed with tiny drops of super glue into the pre-drilled holes. This was tautened by the application of heat from the tip of an incense stick. A final coat of matt varnish followed fitting the wheels, prop and twin Yagi's which completed this interesting project.
l am delighted with the finished results and Aeroclub are to be heartily congratulated for choosing this subject and producing such a superb set of mouldings. The problems with the floats can easily be overcome once you are aware of them. The engine struts , I guess, are just an error, but again easily sorted. After all, this type of kit is going to require more thought, planning and work on behalf of the builder.
Aviation News: Vol.16 No.2 - 1:72 plans.
British Naval Aircraft since 1912: Owen Thetford - Putnam.
Warplanes of the Second World War: Vol.5 Flying Boats - Wm. Green.
Airfix Magazine: December 1968 - p.181 - side pic of JN135.
Seaplanes - Felixstowe: G. Kinsey - Dalton Pub.
Illustrated History of Seaplanes and Flying Boats: Casey & J. Batchelor - Hamlyn Pub.
British Flying Boats: G.R. Duval - Bradford Barton Pub.