G.A.L. ST.12 Monospar - Aeroclub 1/72nd vacuformed + Arctic Decals

Photo from Geoff Goodall Australian aviation website* (a really extensive and well informed source for modelers) -from the Ben Dannecker collection:

http://www.goodall.com.au/australian-aviation/gal-monospar/galmonospar.html

*(I hope I am not stepping on anyone's toes by posting this photo, there is a credit and a link to point at the source)

Certain planes are so charming that I can’t resist building them more than once. I don’t do this often, as I like variety, but some aviation jewels exert on me such magical attraction that I have to. Examples in this blog are the several DH89 Dragon Rapide, Caudron Simoun, Beech Staggerwing, Hansa Brandenburg W.29, Bellanca Pacemaker, Fairchild 71, Clark GA-43, Vultee V-1, DH88 Comet, Lockheed Vega, Gwinn Aircar, Boeing 100, Boeing 247, Bel Airacobra and Kingcobra, Vought Corsair (civil), N.A. Mustang (civil), Hawker Hurricane (civil), Bristol Racer, Beech 18, Junkers 86, Northrop Gamma, DH60, Farman 231, Boeing Monomail, Comper Swift, and many more. All of which you will see built in different guises two or more times here in this blog among the 500 or so models posted.

Another aspect of the hobby that exerts an irresistible attraction on me is vacuformed kits.

So, with that in mind…how much did I enjoy the lines of the G.A.L. ST.25 Monospar!:

https://wingsofintent.blogspot.com/2021/09/gal-st-25-monospar-azur-172nd-injected.html

And I am building the Special Hobby kit of it too in parallel:

https://wingsofintent.blogspot.com/2024/08/gal-monospar-st25-dubbele-arend-of-van.html

AND… I am the lucky owner of a little treasure: an Aeroclub ST.12/25 Monospar vacuform. You see, the Special Hobby injected kit only caters for the Pobjoy version in its single or twin vertical tail, but the Aeroclub kit offers the ST.12 option with the inline engines! And guess what… Now you can buy from Dekno 3D-printed Pobjoys and DH Gipsy Majors!

The Aeroclub vac is of very high quality and comes with white metal accessories and a clear vacuformed canopy. I am already seeing those Gipsy Majors installed inside the vac engine gondolas!

Unlike the ST.25, The ST.12 is scarcer regarding peppy liveries, but I found three of them, VH-UTH/UTK/UTM that could be finished in a blue and red Airlines of Australia scheme (like their beautiful Stinson A), and another pleasant scheme -also worn by one of those three- as the recently restored and last surviving example VH-UTH which flew from Australia to England in blue and white with red regs with a little cute kangaroo on the tail. So it’s going to be one of those for the Aeroclub ST.12 kit.

 

Crisply molded, a good quality vac:

The white metal accessories covering both variants, interior and exterior detail:

Vac canopy:

Schematics and instructions:

You may have noticed that the flying surface parts are molded on an inclined plane, trailing edge up. This is a very clever idea, because the plastic stretches and thins as it's pulled up/sucked down during the molding process, thus resulting on thinner trailing edges, less sanding work:

And this clever idea may be... could it be.. is John Adams, the owner of Aeroclub, actually... a hiding Sherlock Holmes?:

Here are the cute 3D-printed Dekno engines, that can be used to dress up this and the Special Hobby injected kit:

Fortunately, the parts not used from the SH kit (if you are doing the double tail version) can be rescued and used here, saving a bit of time cutting and shaping and gluing the vac parts:

As per tradition, a sharpie is used to contour the parts to be cut, serving later as a sanding help:

Parts off:

Parts refined. Of course the white metal Pobjoy will not be used in this case:

An access panel removed and the Dekno Gipsy:

I think it will look good:

And the other side of the nacelle:

These curved bits will need to be removed and added to the nacelle sides, once they are in the wing for correct contouring matching the leading edge:

Firewall:

The air intake at the front of the nacelle is carved:

Note: if you feel tempted to build the Kings Cup winner, G-ACTS, remember it's an ST-10, and it had a different cowl with rectilinear/faceted "bumps", and not teardrop ones as both kits have, no aft windows, single vertical tail (not double), and the race number 15. It is seen in photos with two-blade and four-blade props. Photos corroborate this drawing:

 

Now, and just as a feasibility exercise for those wanting to build an accurate ST-10, if you modify the cowls, sand away the teardrop bumps, fabricate the angular helmets and add them...

You can do that with just one cowl and for the other nacelle just use the Dekno Pobjoy "in maintenance".

Important: if you are using the Dekno Pobjoy engine, bear in mind that at the moment of separating it from its 3D-printed cradle, you need to differentiate between exhausts and printing pillars, removing ONLY the later:

Watch out, and carefully remove the pillars one by one, leaving the exhaust connectors:

These exhausts connect the ring to the engine cylinders. Pay extra attention to the "flying" exhaust at the end of the ring, the one here at the bottom right:

If you brake one, no problem, you can use thin soldering wire to replace it.
 

Fuselage halves held in place:

Tabs to help alignment and increase gluing surface:

Wing halves glued:

Base colors for some of the parts for both builds:

This is a vac kit from the 90's, and pretty good considering it's about 40 years. The only thing I could say is that perhaps the engine fronts could have been rendered separately as Aeroclub also sold those engine fronts with a prop as aftermarket accessories, being apparently one of their first items (photo from the Net):

The white metal seats provided in the kit are being readied:

Painting parts for the two Monospars continues:

And who is here seating in the Monospar?

The VERY John Adams of Aeroclub fame!

Thanks John for the photo! I hope you don't mind! it's for your fan base!

A little work on the seams before attaching the vacuformed transparency:

Once the transparency is added, it will have to be blended too:

The transparency is carefully adjusted (you have one shot at this), removing very little material at the time ans testing the fit each time (dry run here):

Notice that the aft side windows molded on the fuselage have been puttied over, as they were not present in this particular plane.

Transparency bathed in clear acrylic after trimming:

Glued on. Now the work of masking the windows begins. Some panels are just easy straight rectangles, but others have curves that will require some trial and error:

The canopy windows are masked. The horizontal tail (from a left over Azur kit build) is glued:

Dekno's engine looks really nice inside the engine nacelle:

A metal spar is inserted. A mock cylinder for the other nacelle is fabricated:

Once the mock cylinder is glued inside the other nacelle, it is closed:

A rough approximation to the fit of the nacelles (still not tidied-up) on the wings:

The nacelles are glued taking care of their angles. Some filler will be needed to blend them in:

Oopsy! I dropped the model and the metal seats in the cockpit -which have more mass and inertia than the vac frame- insisted on remaining in  motion once the floor was hit and thus de-glued themselves  (ripping a layer of paint with them). This produced a beautiful, sonorous, modeling maraca for which I had no immediate use, so I had to remove the canopy that so painstakingly I blended with the rest of the fuselage:

Repairs underway. Seats glues back, canopy scrubbed with a bath in Simple Green and then floor polish:

Canopy re-glued:

Masking again:

And priming again:

Wings on. At this point control horns and aileron balances are also added:

A gloss white base is airbrushed as a background for the red and blue colors:

This plane (VH-UTM) wore two Airlines of Australia liveries at different times. One had the front of the engines, LG, and all control surfaces red, and the rest blue (with silver outlined red regs and cheatline). The other was overall blue with the same red regs and cheatline. Depending on how I feel, I will do one or the other. The company´s Stinson A had a similar livery.  

Red is airbrushed to the areas and ancillaries that will be that color:

 The rudder has a mass balance, and some of my other projects do too, so I am mass-producing them:

The light red is masked, blue is applied:

Masks off. A few touch ups, the addition of a few canopy frames (using strips from the painted decal to the left) and the assembly can continue:

Once the decals are on, the props will be added. Dekno's DH Gipsy engine can be now seen inside the nacelle:

To be continued...