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1/72 YF-105A Thunderchief Conversion

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Hi folks,


Not one to rest on past laurels  -- or pratfalls -- as I was nearing the end of my 1/72 Hasegawa F-110A Spectre model just finished, and, as is my custom, when nearing then end of such builds,  I immediately began work on another model, a 1/72 Revell F-101B, to add to my collection of U.S. "Voodoo" named aircraft.  But, after some major painting, and while removing the masks, I found a major problem!  I had been having problems with an airbrush, and having shot Alclad II grey primer all over, I discovered that I had not gotten the primer over all areas of the model.  The primer and model's plastic are nearly the same color, and my aging eyes failed to detect the missing spots. Then of course, I sprayed the model overall grey, masked it, then began painting the bare metal rear end parts and the darker areas on the nose.


Anyway, the paint started lifting here and there with removal of the masks and, long story short -- I decided to strip all the paint from the whole model and start over.  For what it's worth, Testor's ELO stripper ALSO removes Perfect Plastic Putty!!  Anyway, that project has been moved to the back shelf for now.  Maybe one day, I'll mention it again.


So, that left me with a conundrum on what to do next. I've had several ideas in mind, but with troubles on my last two modeling attempts -- both of which were more or less OOB.  I decided to fight back!  If I was going to have major aggravation with more or less easy builds, this time, I decided  to do a real barn burner, and REALLY challenge the modeling gods by building a YF-105A prototype, from before the time when the F-105 became "wasp-waisted"...


Now many of us builders of U.S. aircraft, or builders of prototypes have long wanted a model to play with. No such luck.  Even our friends at Anigrand or the many great vacuform makers of yesteryear ever saw fit to grace us with this beauty -- or at least none of which I'M aware!  As with my P2V-3 Neptune of a couple of years ago, I waited and waited, and then finally had to do it myself.;  In this case however, the driving force was a great Japanese modeler over on a site called "X-Plane Model Museum" out of Japan, I found where a Japanese modeler had done a YF-105A, in 1/48" scale -- which of course is an abomination to all that's Holy and Right....


Anyway, for those interested, here's a picture of his final result (grabbed from the website):




and here's a link to his building thread, which of course is all in Japanese:  Corrected 1/48 YF-105A Link


Now if you go there, you will find that the build consists of 29 articles, each with 4 - 12 pictures, and each with it's own Japanese language commentary.  Over 100 pictures in all, and most are very informative.  I used Google Translate to translate each one of those articles to English, which as is prone to happen, was in some cases, not very meaningful. Sometimes, things really are lost in the translation!  One of those thing that I could never figure out was the modeler's name. I think he just used a 'nym of just letters and numbers. I tried to contact him to say great job, but I found out you had to join the blog to get even close to a member's list or e-mail, and I did not relish the idea of translating everything I might encounter there.  Anyway for the purposes of my build, I shall refer to the original modeler as TGO  (the Great One) from now on.  If anyone reading this knows him (or her) please pass along my appreciation for his efforts.


After poring over what I found in his build thread, I began to examine ways that I could repeat his success, albeit with perhaps just a hair less work --  as I am actually quite lazy.  He did a lot of stuff that I won't do, such as dropping the flaps and the slats.  Since many 'Thud drivers state that they never left the flaps and slats open on the ground, and this will not be a "maintenance scene" type build, I won't be going there.  Feel free to look and see how TGO did it, however.


For my efforts, I'll use the old standard Revell F-105D, as well as the nose from a Hasegawa F-105B, taken from a Thunderbirds set I bought decades ago:




It was a bagged kit, so no box art there...


Having failed to find any usable 3-views, I will use TGO's pictures and a side view from the book "Famous Aircraft of the World #4":




This is as close to a flat view as I could get. Please note the 3 inch and 10 centimeter markings atop the page.  If you copy this photo and size it where either of those lines are exactly as stated, you'll have a 1/72 scale side view without having to spend a fortune, as there is really nothing much else in the book that is helpful to this effort.


Having armed myself with this wealth of material, I'll now press forward.  While TGO started off with the fuselage, I will not. I will start instead,  by answering a question that comes up on-line from time to time: Will the Hasegawa F-105B nose fit on the Revell -  Monogram F-105D?  Please understand we are not talking about the really ancient old "box scale" Monogram B model, but the newer, I guess 80's version.


I began by taping the Hasegawa "B" fuselage halves together, and laying a strip of tape around the nose just behind the kit's front gear well edge:




After making certain the tape was straight all around the curve of the nose, I used the X-Acto knife to scribe a line alongside the front edge of the tape. I then used that line to guide a Trumpeter panel line scriber for around three passes, to define a clear line for the razor saw to follow.


Below, you'll see one side cut and one side left to do:




Above right, you'll see the same procedure done to the Revell F-105D.  The tape has been pushed back a little on the right side to indicate the three verticle vents, the rearward side of which I used to help line up the tape vertically for the marking, scribing and sawing procedure.  I also fudges this cut a little in front of the landing gear well, to have some sanding room, if needed, As you can see below, after a little sanding the fit was pretty good:




This procedure was so precise, I probably could have cut both noses exactly on the front end of the gear well and saved some sanding. This however calls attention to the fact that if I had cut the B nose further back, the fit would have been about perfect. However, previous measurement had shown that then the nose would have been too long to be as accurate, because the difference  between the B and D models' length was about the same as the different nose lengths, plus removing the overly-long part of the Hasegawa front gear bay.  For what it's worth, both the Hasegawa and the Revell kit were dead on for the correct lengths for their particular versions.


Well, at least it's a start.  Hang around if you dare for some old-school, kit-bashing conversion action...







Edited by TheRealMrEd
corrected link
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Good start Ed.  I suggest TGO’s name may well be Ichiro Mitsui as per the side view drawing.  That would look like numbers and letters in Japanese as Ichi is one, and Mitsu is three.  I can see how this could confuse translate.



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Thanks hsr, I really messed that one up.  my mistake!  I've now corrected the link.


Could be Andwil, I just figured that the drawings, according to other pictures in the thread, belonged in a book or some such.  With the corrected link above, maybe one of us can figure out what book -- or, where to get the drawings!



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Yep Tommy, as said above that's where I got My side view. What I want to know is where TGO go HIS drawings - probably in 1/48 scale!


Anyway, moving along, for those of you that have not followed any of my builds before, be forewarned -- they will be long on photos and probably long on wind!  My philosophy (while we all like a pat on the back now and then) is to try and show the next modeler how I did something. Not try to say that this is the ONLY way, but to say "If  you do what I did, you'll be able to build the same thing yourself".  I got tired of seeing all these great models online, but always asked myself "How did they do that?".  I like to try to provide photos, drawings or even full-size templates, so that the next modeler can just move along.  The average model I build has about 30 hours of research. Some, like the P2V-3 Neptune, had hundreds of hours of research  --  and lots of help and suggestions from fellow modelers (and writers) alike.


A prime example -- and I don't mean to bad-mouth anyone -- the modeler did a heck of a job -- is the 1/72 scale XF-89 Scorpion done here a few years back. A great model!  I wanted to build one.  And if the name of the sub that he used to fashion the intakes, or the diameter of the plastic knitting needles used, or a full-size pattern of the keel he created had been given  --- why,  I would have had one myself!   AGAIN, HE BUILT AN OUTSTANDING MODEL -- but why not offer a little more information.  probably, he just didn't think of it.  A loss for everyone else.


But enough whining, let's move along on this build.


Next up is where TGO started off on his model --- the fuselage.  Of course the great bugaboo among us modelers is that the YF-105A had a straight-line fuselage, all the models produced have the "wasp-waist", or Coke bottle look.  I will do mine much the same way as TGO did his, albeit with a slightly different method requiring just a tad less sanding and filler.  Did I mention I HATE SANDING -- a tough attitude for a conversion fanatic to have, I'll admit!


The first thing is to draw a pencil line, with the front vertical part following the existing panel line in front of the intake, and two longer lines running down the fuselage.  How far apart they are is not critical, as long as they clear all the intake stuff molded on the fuselage sides.   Mine happened to be about 95mm or 9.5 cm long, each:




The exact length also doesn't matter, as long as they cover most of the depressed area in the fuselage.  Actually, the vertical line in front should properly be at the NEXT forward existing fuselage panel line, but I was afraid that going that far forward would necessitate widening the cockpit area, so out of an abundance of caution --- I chickened out!  Never fear, at the end of the trail I'll let you know whether that would have mattered or not.


EDIT:  It DID matter, as I later decided to measure from fattest part to fattest part on either end, and had to add another whole layer to build out the sides. If you try this, just shim the flap out further to line up, and same some work!


The way I did my scribing of lines was to tape a metal ruler to the fuselage, and then use the Trumpeter scribing tool to make about three clean passes in each line, to make a clean groove to guide the razor or micro saw or whatever you call it:




I did the front vertical line first, using a narrow piece of brass sheeting as a guide.  When actually sawing the lines for the cut-out, I found it was better to start in the middle of the line, then saw each way, to allow for a cleaner cut line where the corners met at the front:




The goal is to end up with a "flap" on either fuselage half, still connected (not sawn) at the rear end:




The next two photos show the piece of thin plastic sheet ( I started with 1mm thick, and later had to add an addition .25mm or so) spacer, glued to the inside of the flap, shown here cut overlong:




This strip is then trimmed to the exact width of the flap:




As stated above, I added another piece, around 1/4 mm thick, to further shim out the flap.  Then a longer, wider than the flap piece of scrap was glued over the shim on the flap and glued in the inner fuselage halves:




The net effect and the desired goal of this procedure is to force the flap away from the fuselage on the OUTSIDE to where the straight sides of the fuselage would end up. TGO said he derived the distance of the shims from the drawings. Lacking the top view drawings, I just eyeballed it with a metal ruler and an educated guess:




In the picture above, the clamp on the left side is holding the corner down. Both corners of the flap end should be standing more or less 1.25mm proud of the fuselage side.  This process was done to both fuselage halves.


While the glue is drying here, I'll move on to the next step, the vertical stabilizer.  Using the tail pattern from the drawing I supplied above, I cut out the pattern and fastened it to the  model:




In the photo (above left) the red arrows show the areas to be removed. I marked these with a pencil on the model. Photo above right shows the tail after nipping off the excess with sprue snippers, and then a little sanding. I left it a hair oversize, to allow for final sanding after the fuselage halves are assembled. These will also have to the sanded to a more scale-like thickness on the inside, as one would do when building a vacuform kit.  And later on, the tiny little open part at the rear of the vertical stabilizer, just ahead of the tailpipe will be filled after assembly, as this was a smooth, unbroken swerve on the prototype.  Also, darned near everything on the aircraft will need to be re-scribed!


Well, time for me to call it a day.  Hope to see you next time 'round.







Edited by TheRealMrEd
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I have wondered about whether or not this was possible, given my interest in prototypes. I shall be watching this with interest. Good luck.

I wonder if the chap who produced the 1/48th version is the same as the one who produced an XF-104.  That was gorgeous.


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2 hours ago, John R said:

I have wondered about whether or not this was possible, given my interest in prototypes. I shall be watching this with interest. Good luck.


Well, I'm watching :)




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19 hours ago, TheRealMrEd said:

Yep Tommy, as said above that's where I got My side view. What I want to know is where TGO go HIS drawings - probably in 1/48 scale!

Duh!  :oops:


Sorry about that Eddy.  Completely missed what you were saying earlier.  I find that as I'm aging, my mental acuity has decreased at roughly the square of my age such that now, I'm about one Taco short of a combination plate.  🌮

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Thanks guys,


Actually that's also MY question -- can I build this?   Guess we're all gonna find out together.... Damn the torpedoes!


Sorry Tommy  -- as you know, we're not here to discuss your personal shortcomings  -- or ear hair!



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Okay, back to work.


Next I'll repeat the sandwich/shim procedure on both fuselage halves, just behind the opening where the wing spar will eventually protrude:




The idea is to even up the cutout part and bring that surface into a flat plane with the front and rear of the fuselage:




Sighting down the side with a ruler shows we're coming along:




At this point TGO glued plastic strips all over the place, to help fill the other surfaces, and then after sanding, slathered the filler atop everything for final sanding.  I shall use a slightly more targeted approach, trying to reduce the amount of filler that will ultimately be needed, as everything will need to be re-scribed, and as any of us who've tried that over filler know, it's not a happy event!


Instead, I added a few strips of plastic cut from around 30 thou leftovers from cut away parts from an old vacuform kit.  These were not brought all the way out to cover all of the indentation on the fuselage sides:




Then some thinner scrap (about 20 thou) plastic card was used on the outside of that to sort of fill the rest of the indent. I used the thinner plastic to reduce the amount of needed ( and hated) sanding required:




Before sanding the plastic scrap, the existing spine of the aircraft is removed,  for more ease of sanding.  Also the tail hook is cut away, as the YF did not have one. TGO just used filler over the hook, but I removed it , and will add plastic card and sand to shape after the fuselage halves are assembled:




Now, everything has to dry several hours before further sanding.


Next time,





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Ed, Am I missing something? I thought that besides the waisting, bulges were added to the rear fuselage. When I first wondered if one could make an F-105A this was the thing that I thought would be the most trouble.

Maybe you haven't got around to telling us about this yet. I have not yet looked at the Japanese guy's website.


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Hello again.


I decided it was better to remove the spine from the "D" model, to make sanding a little easier.  These were, as before, scribed along the appropriate line several times, then snapped off:




Next,  everything was sanded again:




Another coat of primer and still a little filling needed:




This time, I decided to fill with stretched sprue from the kit and a few small pieces of plastic card here and there:




Forgive the terrible photo. What it fails to show clearly is that both the sprue and the bits of card were glued into place with liquid glue (Weldon #3) and then immediately smeared and pressed flat with a #11 X-Acto blade, held at about a 10-degree angle.  This does two things, it "smooshes" down the filler pieces into their cavities, and also flattens the filling pieces, requiring less sanding later.


After the glue dries and everything is sanded again, it looks a little better:




After another coat of primer, and the judicious use of some Bondo Glazing and Spot Putty, and another round of sanding, it looks like this:




The red spots are all the filler putty used to this point, in keeping with my desire to have a plastic surface to re-scribe.  I should also point out that while all the previous sanding had been done with an 80/100 nail sanding stick, for this last round I dropped back to a 220/320 stick.


I have now put on yet another coat of primer, and when that has dried, I'll be down to the tricky part: checking contours and smooth flow of all the body lines under a very strong light, to handle as many small imperfections as I can find at this stage. The Lord knows that there will be plenty more opportunities for correction after the first coat of bare metal paint goes on later!


Well, as you can imagine, more rounds of filling sanding priming probably lie ahead, so take a nap if you wish.  However, anyone else who later ventures down this path will probably undergo the same trial by fire, so pay attention...



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No John, you are entirely correct. I also think that bulges WERE added at the front and the back end.  I will eventually attempt to sand the rear end thinner, to help things a little, but as I mentioned earlier, the front end in an area that I don't want to get involved with, because of the cockpit and canopy.  I do not know if the sides were dead flat front to rear, or just a straight taper.


The major problem with this whole area of concern is that I have not been able to find ANY dependable top views of the aircraft, to exactly define what might need to be done.  TGO had access to far better drawings than I, and he did not worry about it, whatever the reason.  Therefore, as I am getting on in years, I'll simply do the best I can with what I've got, and leave a little trail for the next generation of modelers to figure out.


If mine can turn out anywhere as well as TGO's, I'll be a happy camper...




PS.  If anyone has any hard data about these bulges, ie. how much and where, I'd sure like to hear about it!

Edited by TheRealMrEd
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Ed, If you google 'Richard Ferriere' you will find a site full of 3-views and under Republic there is one of the F105D which shows the shape of the rear end.

In the book "Republic F-105 Thunderchief" by David Anderton published by Osprey there is a great underside plan view of the B and a plan view of the wind tunnel model.

Unfortunately they are copyrighted so I can't publish them without permission.


PS. I can't get your link to work. Same problem as the other guy

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Hi John,


The corrected link above just worked for me, but here it is also in plaint text:  http://fg786.blog87.fc2.com/blog-entry-1679.html?sp


I checked the Richard Ferriere stuff earlier and he offered no YF-105A drawing.  I already have F-105B, D, F and G 3-views, but nothing on the "A" model to compare to.  I can't even find a photo of the A that sights down along the fuselage side,  much less a good top view!



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Hi Ed, 


MMP Book's Yellow series edition on the Thud has drawings of the YF-105A. I'm having trouble with my scanner but will get you a copy if I can kick this thing in to action! ;)




Edited by RidgeRunner
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Apologies for my comment about the link, I clicked on the one in the quote - not your corrected one.

Looking at the Japanese guy's work it makes it look as if the rear fuselage was, in his opinion, not 'bulged' but the fuselage was waisted.

Now we wait for Martin's scanner to work...

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Hello, back again ---


this time with some very bad news!  I just found a link showing that virtually ALL the Republic papers, photos, drawings, etc. have been destroyed!!!    Link HERE


This saddens me no end.  So, probably, unless someone can find out what and where the drawings that TGO used are available and somehow accurate, looks like no magical detail 3-view drawings are likely to show up anytime soon.

But hope springs eternal --- be vigilant! --- perhaps someone will find some one day...


Anyway, soldiering on,  I decided to take the old pieces of fuselage spine I removed earlier, and re-use them as a filler on this model.  They were each glued back into place, but rotated inward from their original orientation, to present a flatter surface on the spine, and then when dried, they were sanded fairly flat on top:




Then after a couple of days mulling it over, I decided to reconfigure the fuselage bulge area. You'll recall that earlier, I had decided to fill the fuse sides only to the area on fuselage panel line ahead of the intakes.  Since I decided that this would now probably be the only one of these I'd ever build, to err on the side of making the "A" model as different from the "B" or "D" models as I can.  This means I decided to flatted the fuse sides from the biggest bulge at the front to the biggest bulge at the rear, whatever that meant for the cockpit area.


So taking my trusty steel ruler from high spot to high spot, I glued on short lengths of various thickness plastic card over the top of the already-smoothed surface, to avoid as much sanding as possible, while still given a pretty much solid plastic surface to re-scribe.  It looks now like this:




Which will entail another series of sand, fill, prime, etc.!


Meanwhile, to keep everyone (including me) from being bored to tears waiting for glue and paint to dry, I'll proceed with some more elements of the build, the wing intakes.


Taking one of the four wing halves, I marked the outer side of the intake 15mm back from the front end, and then marked the inside 16mm from the front end, then scribed a line to cut:




The ends were then removed:




Next, the removed ends were chopped up to fill the needed areas on the wing intakes, both top and bottom:







They both end up like this, before filling and final sanding:





  When all is said and done, I'm trying to end up with about 1 degree of taper, from inside edge to outer edge, as shown in what is so far the best image I could find of the area on the real thing:




Well -- it's drying time again, I'm gonna leave you....   (Apologies to Ray Charles).









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Yes Cookie,


Info on the YF-105A  seems pretty scarce, unfortunately.


Hi Stuart , or to paraphrase  "It's REALLY darkest right before they kick your .... behind parts"!




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