1/72 Conversion P-47B "Double Twister"

[TheRealMrEd]

Hello again.

 

For this build thread, I've chosen the short-lived Republic P-47B "Double Twister", which as far as we know, only flew in this configuration one time, and of which only one photo was supposedly ever taken.  In fact, most people at Republic didn't even remember the aircraft, but the pilot did, almost killing himself because he forgot to set the trim on the rudder, to allow for the offset of the vertical stabilizer.

 

For those newer to modeling out there, let me explain.  On single engine propeller-driven aircraft, the vertical stabilizer was usually offset, from 1 - 3 degrees, to counteract the torgue of the rotating propeller.  This is still done today, on R/C aircraft -- not sure about real life.

 

A few decades back, the super-detailing crowd was fussing with kit manufacturers about not having this feature built into the kits (seriously complicating the molding process, by the way), and made a big hullabaloo when some manufacturer actually did it, as a selling feature.  I guess the kit had other issues, or didn't sell that well, because the whole mess finally just went away.  I can't even remember what kit or kits this involved, but I guess most manufacturers said "if you want it, YOU make it"; and many of us did, as was the fashion in those days -- when somebody did something, everybody else was expected to follow suit, whether it was Rub-'N-Buff Paste wax or Floquil Old Silver for natural metal finishes, to later using heat-stretched Bic Ball Point pen filler tubes (emptied and cleaned out), and stretched into tiny gun tubes.  I don't think that any of those products exist today, but back IN THE DAY, you just had to do it!  Nowadays, it would be black-basing or hairspray technique or the like.  Time marches on...

 

But, I digress.  Here is the said only picture of the said aircraft:

 

 

Not shown well in the photo, are the twin contra-rotating props, and while they worked, the gearbox was fiddly, and the speed increase, I believe, was only 1 mph better than a regular P-47B, so it just wasn't worth the effort to alter P-47 production at the time.  Also, you will note the odd color of the aircraft.  The actual color is unknown, but many claim it is just plain old yellow zinc chromate primer, which sort of makes sense, in a certain way.  Why waste the paint job if the plane crashes?.  On the other hand, the obvious gloss on the paint is not what you would expect from the primer, and if you're going to the expense of clear-coating the primer, why not just paint the thing O.D. like all the rest?

 

Maybe it's just oil smeared here and there, but I think it only had one flight, so - go figure.  I have massaged the photo in Photoshop every which way I can think of, and still can't come to a conclusion.  Since all of the Republic records were destroyed when Republic sold out, we will probably never know.  However, I welcome any comments, informed or opinion on the matter, before I get to that stage.  Otherwise, I will probably paint it yellow zinc chromate, just because its different...

 

To do the dirty deed, I will fall back on my sawing and hacking favorite P-47 Razorback kit, the 1/72 Academy kit, mostly because it's cheaper than the Tamiya, which is considered a better kit.  I'll save that one to build a real "D" model some day -- I hope!:

 

 

On the bottom row, from the left, a resin copy of six propeller blades I got from some resin kit or the other, wherein I decided to build the 4-bladed version vs the contra-prop version, probably the Alliance XP-72 kit, but I'm not sure.  Anyway it would not be that hard to take a larger prop spinner, perhaps from a P-40 and fill and sand it to shape and scrounge prop blades from the spares box.  In the middle, somebody's P-47 cockpit set from the spares box, and a set of P-47 razorback masks, mostly because I happen to have them on hand.

I also have a Rob Taurus canopy, which I will probably not use, but we'll see.

 

As with my XP-47 Prototype build HERE

 

I will begin by marking off the scale 8 inches of length that have to be removed from the front of the fuselage, below, where "A" is the scale 8 inch wide strip of tape I used and "B" is simply one of the pencil lines drawn:

 

Above right, the tape-cutting device I used allowed me to cut a piece of tape 3 times the 0.8mm width, or a total of 2.4mm in real life.  This, taken along with the width of the saw kerf, will get us right at 8 scale inches.

 

 

 

Above left, the arrows point to the marked lines, which have also been scribed, to help align the saw when I make those cuts. However, I like to start by sawing through the wing root vertically, up through the marked lines, to leave as much of the wing root structure as possible, allowing for less work and filling later.  Above right, the other lines are sawn through, separating the fuselage into two parts, and showing the removed plastic.

 

I will continue with the butchery, when I return, anon...

 

Ed

 

 

[Thom216]

Nice to learn of a new variant of the 47! Cut on!

[TheRealMrEd]

Back again.

 

The right side join line between the front and rear sections, turned out pretty good:

 

 

The right side, not as well.  I had to add a plastic shim to align everything.  What I like to do is glue together the front and rear halves of one side, after comparing fit atop the drawings, and the when the first side fits, I temporarily (white glue or tape) the other side parts to the just-assembled half, and then shim or sand as necessary so that both sides align.

 

When the sawed up parts glue has dried, some tape is added to the model, to protect detail, and then filler is added to wing fillet areas on both sides.  I like to fill and then sand each segment as I go forward with the build.  While this take overall more time than just waiting until everything is assembled, I find that doing these tasks as I go makes sanding and re-scribing much easier, than waiting to do it all after the model is almost completely assembled.  I have even had "burn-out" occur by having so  much to do at the end, that I used to put the models aside.  Doing these tasks in smaller increments help the build move along, at least for me.

 

 

Above right, the "X" 's show where kit lines have been filled with thin CA glue and allowed to dry, to fill the lines where the P-47D kit two lower cowl flaps must be removed on both sides, to make it a P-47B variant.  I like to use CA when filling shallow panel lines and the like, as it sticks well and also allows re-scribing over it, if needed.  It also sands down nice and smooth.

 

Next, the aftermarket cockpit is assembled, less the control stick and seat, which will be added just before the canopy goes on.  I won't show pictures of the cockpit, as there are many builds, etc. on line that show these details, and mine will either turn out better or worse.  Any any case, this particular model will have it's canopy closed, so not very much will ever be seen.

 

Below, the cockpit tube installed, after suitable sanding, etc. to make it fit properly:

 

 

Above right, the two fuselage halves, encasing the cockpit tub, are now glued together.  I like to glue one section of the seam at a time, to assure the best alignment that I can get, using a very "hot" liquid cement --  in my case, Weld-On #3.

 

After this dries, I'll be back.

 

Ed

[AdrianMF]

Did not know there was a contra-prop version of the P-47. Following along with interest.

 

Regards,

Adrian

[Dave Slowbuild]

A new one for me too, and some interesting work going on!
Will follow along please!

[stevehnz]

Nice idea for a build Ed, I'm not sure if I've come upon this bird before so a refresher will be well welcome.

Steve.

[TheRealMrEd]

Hi Folks,

 

The fuselage seam has dried and some Mr Surfacer 500 thin primer has been added to check fit and finish here and there.  Below, two other things have been done, the first being the four tapered bits of stretched sprue stubs which have been used to fill the hole for the weapons pylons, as they are not on this aircraft, and second, a bit of plastic card scrap has been added to the tail wheel mount.  This is because on Academy P-47's (in this scale, at least!), the main landing gear are about 1/8 or 3mm too long.

Having now built three of these kit, the first, I left alone -- weird sit of the model.  The second one, I cut the landing gear down, pinning the parts together, but since I also had to shorten the upper gear doors, etc. it was a lot of work.  Also, the original fit of the door and gear legs was so precise, I hated messing it up!

 

Anyway, I will try something new on this build, sanding a bit off the bottom of the main gear tires, and shimming up the tail wheel gear and try to "fake" the sit of the aircraft.  The rear gear doors may help this effort, and I used a thickness of plastic that would fit, and still not protrude outside the tail wheel bay.  Even then, I had to taper the shim halfway back, to allow for the rear taper of the gear well at back.

 

 

Above right, the needed cockpit area has been painted flat black prior to installing the canopy.  There was a bit of doubt in my mind about whether the quarter panels behind the headrest area should be black or interior green.  I went with the black, as the color photo seems to show that area as being about the same color as the propeller hub.  That's my story, and I'm stickin' to it!

 

Next, the wing tip lights are added from sawn off pieces of red and blue Lite-Brite pegs, from years gone by.  I couldn't determine whether the "B" series had clear lenses with colored bulbs or colored lenses.  Once most, if not all aircraft,  had all colored bulbs with clear lenses, and then I seem to recall that the green tinted bulbs became harder to get, so they later decided to use yellow bulbs behind blue lenses which gives you a nice green when fired up.  This practice continued on some aircraft until the advent of LED lights, etc. in the modern era.  Anyway, that's my story...

 

 

Above right, the canopy has been glued into place with clear G-S Cement, which after drying, was smoothed with 91% alcohol to sort of fill in any gaps.  Later, the previously-used set of masks were added to the canopy.  Did I say that I was cheap?

 

After adding some Parafilm "M" masking to the now sanded and polished wingtip light lenses, she'll be ready for a coat of Alclad2 grey primer, and then the final yellow color.

 

Before getting ready for paint, I glued up the 6 blades of the contra-rotating prop:

 

 

The props and hub will get a nice coat of Alclad2 black primer, which will give this assembly a slight sheen.

 

Well, that t for this time.

 

Later,

 

Ed

[TheRealMrEd]

Back again, with more on the paint dilemma:

 

 

 

Top view is, of course our subject aircraft.  The bottom view (above) is a picture found on line that purports to be chrome yellow.  Neither of these picture look like what they claim to be, a function of the weird color photography film at the time.  At least, the two look somewhat similar.  Researching in  Dana Bell's masterwork Air Force Colors (Volumes 1-3), I decided that this color may have been Identification Yellow, which Dana states was like our modern Insignia Yellow (FS 33538), but a shade darker.

 

 

The way I went was to first give the entire model a base coat of Alclad II grey primer, followed by a coat of True North Paints, Zinc Yellow Chromate.  It just didn't look right, so I over-sprayed the entire model again, this time with a very thin coat of Model Master FS 33538 Insignia Yellow, and decided that this was about as close to the picture as more poor aged mind could manage.  I added some Vallejo Grey acrylic wash here and these, more to simulate possible engine oil blow back more so  than exhaust stains, and decided to quite while I wasn't too far behind.  Someone with better artistic talent than I could probably do something a lot more convincing, but there you go...

 

Below, a closer view of the Yellow Chromate wheel well vs the Insignia (or Identification) Yellow lower wing surface:

 

 

Above right, some decals have been added.  I do not believe that at least the left underside of the wing had a star, but I went ahead and added the common, for the time, stars above and below each wing, the time frame being late 1942.

 

Anyway, I unmasked everything, added the kit pitot tube and landing gear, grabbed a rear view mirror (atop the Canopy) from a Tamiya 1/72 P-47D razorback kit, and scratched up the characteristic P-47B forward swept antenna from scrap card, and that was that.  In the teaser picture below, I also painted the guns with steel color vs gunmetal, as in the photo, at least to me, they look took bright even for oiled gun metal.  Also, the spinning prop in the photo gave no clue as to whether yellow prop tips any sort of propeller decals were present, so I left them off for now.  In the very unlikely even that more data surfaces in the future, they could be added later.  Alas, as I discovered when researching for my YF-105A Prototype build, all the records of Republic Aircraft were burned when  Fairchild was bought out: sad story here.

 

I believe that my little ploy of sanding down the main gear tire, and jacking up the rear gear strut worked out pretty well, as she seems to have a fairly decent "set".  What do you think?

 

 

Again, please remember that I am a far better "mechanic" than "artist"!  I shall post up a few more pics over at RFI HERE

 

Thanks for looking in,

 

Ed

 

 

 

 

Edited January 28, 2023 by TheRealMrEd
added link