#22 Checking in - 1/48 Sierra Consolidated PB-2 vac-form

[jimmaas]

Mostly finished the radiator housing, with some stretched plastic tube and a box shape to provide depth,

 

 

 

[jimmaas]

Staying with the front end, I discovered something not clear from the plans – the prop shaft does not simply stick out of the front, but rather comes through a larger opening, with the front of the Conqueror engine  visible.  (Think Hawker Hurricane)  So it was time for some prop work.  The first step was assembling a prop.  The kit provides an injected hub and separate blades but I wanted a little more definition.  The hub was taken from an aftermarket set intended for the Grumman F4F.  The blades were harder.  The PB-2 prop rotates in a clockwise direction (viewed from the front) and most similar US blades (like the P-40 or F2A) that have the correct shape rotate counterclockwise,  But buried in the stash was an old AZ MS-406 with blades that fir the bill, along with  a scrapped Hasegawa Hurricane which would provide the engine front.

 

The next step is to open the front, holding the (still unglued) fuselage halves tightly together and scribing using a circle cutter compass.

 

Then fashion a backing plate to give a platform for the engine front. 

[2996 Victor]

Lovely work, Jim, this is shaping up beautifully.

 

If you wanted a more detailed engine "front" without dressing up the Hasegawa part, Ultracast do a very nice resin Hurricane Mk.XII conversion.

 

Cheers,

Mark

[jimmaas]

Just a short update, but rather chuffed that pasts are fitting where they ought.  Installed some plastic channel on each side to provide a location for the flat-plate-with-a-hole-in-it (maybe it has a name, but I don't know it) to slide in.  This allows for a little wiggle room when later glueing in place.  The pilot's floorboard, with seat, fits into a similar channel on each side.  The channel pieces at the top of the fuselage will also serve to insure good fit of the canopy when we get there.  So far, each component slots correctly!  Next step is the bizarre rear gunner's position, where the gunner's seat is on curved rails to allow tracking up and down (port and starboard is left to the Scarff ring).

 

  

[jimmaas]

Finished the seat modules - the pilot's seat as seen above, but now painted and decaled, the rear gunner's seat on the curved rails which allowed him to ride the seat up or down while operating the machine gun (not saying this was a great idea, the same designer came up with the Bell XFM-1).  

 

 

 

 

 

 

[jimmaas]

After an endless period of dealing with tiny tiny parts, finally moved to completion of the interior.  Lots of re-purposed parts, mostly from Curtiss types but that rollover pylon comes straight from my fav, the Brewster Buffalo,  The decking between the pilot's position and the rear gunner's position slide into channel styrene and thankfully fit on both sides.

 

 

 

[2996 Victor]

Superb work, Jim, that cockpit is looking splendid!

 

Cheers,

Mark

[jimmaas]

Closing the fuselage means heading in a couple of different directions.  The canopy must be fitted, and the mainplane is now front and center.  I've been struck by the family resemblance of the PB-2 and the later P-39, different companies but same city (Buffalo N.Y.) and same designer.  The lower wing is cut out, wheel wells opened up, and trailing edge scrapped and sanded to a fare-thee-well. 

 

In test fitting, the tail of the wing piece seemed difficult to line up (probably operator error!) so to keep life simple, it was cut off to add seperately.

 

 

The tail piece can be added more easily, and faired into the rear fuselage.

 

 

 

 

[jimmaas]

The kit instructions suggest that the wheel well bays, once separated from the backing sheet, should have the respective landing gear leg affixed and then glued to the lower wing.  That meant a lot of tricky masking and I’ve never been a fan of leaving things sticking out during assembly – too easy to break!  So first, strip styrene was used to set locator boundaries for the wheel well pieces.

 

 

Then, the landing gear legs were reworked.  The blobby part at the top depicts a canvas boot covering the upper gear mechanism, but trial-and-error showed they needed to be reduced in height. 

 

Once that part was done, the landing gear legs were separated from the boot, locating holes were drilled and the boot portion was glued to the wheel well piece.  I made use of the hole in the boot to temporarily insert a long bit of plastic rod,  This was to ensure that the boot would yield correct and matching angles, for the landing gear legs.

 

 

After painting the gear wells aluminum, and painting the boot a canvass color, I removed a small section of the lower wing (along panel lines) before gluing the wheel well piece in.  This was to give some room to mask the wheel well.  Next will come  mating the fuselage to the lower wing (the upper wing pieces will came after that).

 

[Mjwomack]

17 hours ago, jimmaas said:

The blobby part at the top depicts a canvas boot

glad you told me, because that just look plain nasty to me, Excellent work and patience on this build

[AdrianMF]

Smashing work on this! The interior sidewall detail and the inset tailplane root fixings are something I've never seen on a vacform kit before.

 

Regards,

Adrian

[jimmaas]

Bob Norgren, the fellow behind Sierra, made some fine vacuform kits, and these had a good eye toward buildability.

[jimmaas]

Okay, still dealing with the shift from IMGUR (I can see my photos but I assume UK folks can not).  Progress on the PB-2 got a little derailed by Real Life interfering, but some progress.  Tabs were inserted into the wing roots to insure a solid connection when the wing pieces were added.

 

The wings were then added and sanding commenced.  The lower wingtips were sanded a lot, to suggest the typical 'washout' seen on outer wingtips of early late interwar/early WW II USAAF types.

 

The radiator box below the nose was re-attached, and much angst followed fairing in the area behind that box.  Essentially, you have to fabricate a connection beteen the radiator box and the leading edge of the lower wing surface.  It can be equated to the process of making sausage - the process isn't pretty buy enough plastic sheet, superglue and sandpaper and you'll get there.  The rectangular opening is for an exhaust vent, yet to be added.

 

[Mjwomack]

5 minutes ago, jimmaas said:

I can see my photos but I assume UK folks can not).

 

It's true! Thanks though for moving things around so we can continue to enjoy this lovely build👍

[AdrianMF]

We can see the pictures in the UK and it's looking terrific. The radiator work sounds like a right fiddle but the installation looks good.

 

Regards,

Adrian

[LorenSharp]

On 8/10/2025 at 2:56 PM, jimmaas said:

The past week has been a time of little fiddles - lightening hole structure, addition of retraction gear crank column, pilots map bin, etc.

 

But it's time for one of the riskier steps.  Under the engine is a housing for the radiator and oil cooler.  Unfortunately, the radiator opening crosses the centerline, which makes working on it difficult until the fuselage halves are joined, and once that happens accessing the interior becomes a problem. 

 

So the compromise solution is to join the parts of the fuselage halves for the housing only, and then cutting the housing away (Wilkinson razor blades work superbly with vacuform plastic!).   

 

 

 

Beautiful work so far. It's been many a year since I've seen a "Safety" razor blade. You're a better man than I, Gunga Din

[jimmaas]

Loren wrote : "It's been many a year since I've seen a "Safety" razor blade. You're a better man than I, Gunga Din"......

 

It's not been a scar-free experience, trust me.....

[jimmaas]

No, not dead yet, although life has been interfering with this model's progress.  Ailerons removed to match rudder and elevators....

 

Getting close to painting, so mixed up a batch of USAAC Blue #23, which uses MRP lacquers; in this case 25% MRP 203 (Su-34) Light Green-Blue, 25% MRP 204 Dark Green Blue, and 50% MRP 440 Philippines Green Blue.  The comparison chip is in the Monogram "US Army Air Service and Air Corps Aircraft Color Guide' by Robert Archer.

 

Canopies have been added and faired in (I'm glossing over the less than fun part of that)

 The canopy over the pilot has semi-circular segments to fair it into the windscreen.  I'm using silver decal (to address the interior color) with circles of the correct size cut, to be over-painted with the Blue #23.  We'll see how well that works in practice!