P-51C Mustang - Converting D to C Part 2

Well finding time to work on my model continues to be difficult. Now that I have my A&P license I have been spending a lot of time trying to find my first aviation job and pack for a potential move. So if you, or if you know anyone, are looking for an entry-level A&P mechanic, write me a line. It would be appreciated.

On to the model.

After making the commitment cut, I moved to the cockpit. The fun of converting a D-model to a C-model is trying to figure out how much of the D model kit can actually be used. Here's a hint: not much. The Mustang C cockpit structure was a little different than the D, which means the kit pieces that contain the structure are going to be scrapped and scavenged for the few components that can be used. Using several photographs, books, station diagrams, and the existing kit parts for reference, I marked what structure will be needed in the C model. I marked the lines extra long at the bottom because in the step my lines will be gone.

The cockpit structure needs to be completely replaced for two reasons. 1: It has to represent a C model and 2: I'm going to make the formers and bulkheads look more realistic than just the rectangular shape slabs stuck to the walls. So I pulled out the handy Dremel with a sanding drum and away it went. Now I wasn't only trying to remove the kit structure references, I was also trying to thin the cockpit wall itself to about half its original thickness. This way when I add the new structure it will look more like the actual aircraft.

Note why the long lines came in handy. I gradually used finer sandpapers to smooth out the side wall and redrew the lines.

Here's the part where I wish I had some magically easy way to explain to people who may not have access to the tools I do, but I don't. Luckily several years ago, I drew accurate fuselage formers for both the Mustang D and C in AutoCAD and had them ready to go after a little scaling. If you don't have this sort of tool, you may just have to take some measurements off the model and grab a couple of books and through some trial and error you can come up with the right shapes for the C-model turtledeck. But even I first printed them out, cut them out, and test fit them in place just in case I needed to tweak them.

After the necessary tweaks, I drafted out the actually parts and printed them out on contact paper. This way I could cut out the parts and stick them to .030" plastic sheet in order to cut them out of plastic. I designed the parts with 3 notches so I could add a few stringers to give a little more support for the skin when its added later.

Cutting these parts can be a major pain on the fingers but its part of the gig. The numbers marked on them are the actual station numbers from the real Mustang.

And now for a test fit of all the parts.

So far so good.

 You can tell in this picture the difference between the D and C structure thanks to the kit part next to the handmade Station 200. At this point, I'm not going to glue anything together, even though I probably could. There is a little more sanding and tweaking needed before I do that.

I'm not going to do anything else with these parts for the time being. Next up I'm going to concentrate on making the new cockpit formers with what will hopefully by the next trick in my box....the world's smallest vacuform machine. Making that will be an article unto itself.

P-51C Mustang: Converting D to C

At long last, work on the Mustang is finally back on. For the past few months I have been finishing up school and studying long hours to get my Airframe and Power Plant license which I am proud to say I have achieved. Now the job search begins so I can get out of my tiny apartment and the job that has a tiny paycheck so I can have more space to build models and enough money to buy all the kits on my wish list lol. Isn't that the purpose of having a house and money: more room for bigger models :)

I have reached the point in my project where I have to make some big decisions. The biggest feature of this project was the converting of the D-model kit into the C-model Mustang. There are several major structural differences between these two aircraft which will require major modification of the fuselage and the wing as well as many subtle differences in the cockpit, landing gear, and gun arrangement. The only way to accomplish this modification is the start with a ton of research. Sometimes I think I spend more money on books about the aircraft than on the model itself. But if detail and accuracy is the goal then you have to be willing to pay the price of spending hours poring over black and white photographs, technical drawings, and google scouring for pictures of aircraft under restoration hoping to find the one view that tells you the key piece of information that allows you to take the next step. Anyone who has built a detailed model will tell you this is how it is. So if you're not willing to put in the time with research, then just follow the paint guide in the instructions and build it straight out of the box. Thankfully I have acquired several books and drawings on C and D model Mustangs over the years and I have the former shapes already drawn in AutoCAD from an earlier project. After gathering my sources I was ready to take the next step. 

When making a major modification such as this it's always best to figure out exactly how you're going to do it before doing anything. I wrote out my procedure and worked it all out in my head before I made any cuts to the model. I also needed to work out how the new structure would be built, what it would look like and how the details would be added. Basically the top of the D fuselage would be cut off along the top longeron panel line. The inside of the model would be smoothed of any reference to D structure in the cockpit since there are several differences. New formers will be made of plastic to create the C-model turtle deck. Plastic strips will be laid over the formers to form the support skin to give the fuselage it's shape. And then, in order to prevent having to cut in panel lines, on top of the plastic skin I will glue soda can aluminum in pieces to create accurate skin panels giving me instant panel lines. Plus this will give me scale skin thickness around the canopy. All of this will make sense in the upcoming blogs. 

Once I had all this figured out, I had to decide if I was going to actually do it, which was actually pretty hard. I could have left it as a D-model and used  the kit pieces. Converting to a C-model is gonna require several scratchbuilt components which will involve several headaches. But of course, there is no backing down from a goal. So here it goes. 

I started by trying a jeweler's saw to cut the top off the fuselage, but found it rather difficult to keep the cut straight. Instead I ran my X-Acto knife slowly down the existing panel line several times until I worked my way through the plastic. This resulted in a much nicer cut. 

Now there really is no turning back. The C-model is coming....