[Nick_Karatzides]

[center]

Hello my Romanian friends. I'd like to present my latest project to you
[/center]
1/18 scale Lockheed Martin F-16CJ Fighting Falcon Block 52 Hellenic Air Force
BBI - Elite Force conversion & scratchbuild

The following article is to describe step by step the 1/18 scale Lockheed Martin F-16CJ Fighting Falcon Block 52, currently flying with Hellenic Air Force, conversion using the BBI - Elite Force toy model kit, bought from the States a couple of years before for less than $60.

[center][/center]
Despite my enthusiasm when I finally got this 1/18 model in my hands, as soon as I opened the box which exceeds in length the 3 feet (!!!), I realized that I would face hard time and massive scratch building and I'd need to spend hundreds hours on my hobby bench to make it look descent. In the substance, it is not even a model to assembly but a game for children which could be ready in less than 2 minutes. The detail convinces only if you look the model from a distance while points such as landing gear system, engine nozzle, panel lines etc are real dramatic. Luckily, the model is accurate on dimensions and could possibly be used as a F-16 exhibit model that do not interest on conformity of colors, special details etc.

[center][/center]
So, I decide to begin the building from the zero and give life in this 82cm long monster with no detail (comparing to scale models by Hasegawa, Tamiya etc) but however this 1/18 F-16 toy has almost unlimited possibilities of becoming a high detailed scale model. It should be noticed that the model's airframe comes straight from the box already sealed and I had to open it and work it from inside. That's a hard work to do, because the fuselage remains stuck with internal reinforcing possessors and metal supports & screws that I should locate and carefully remove without causing any damage on plastic material.

[center]



82cm long beast, immediately after opening of packing box. I am already start thinking about finding the proper window to place this Falcon[/center]
By selecting heavy metal on my CD player (in order to I become aggressive and get the "Friday 13th" feeling) and using a saw and a Dremel tool, I opened the fuselage, the basic airframe pieces were cut and useless parts such as landing gear, engine nozzle, a part of the air intake etc were removed and led to the garbage.

[center]CHAPTER I - Engine's 1st stage blades & afterburner construction
[/center]
Beginning the construction from behind, I should first scratch build the Pratt & Whitney F100 turbofan engine (F-16CJ Block 52) nozzle, the afterburner compartment etc as detailed as a curious and indiscreet eye could see. Considering the huge dimensions of the model, I should theoretically scratch build almost everything! Using plastic cards, my new X-Acto blade, F-16 related bibliography, photographs and the T.O service manual used for the real F-16, I started.

[center]

[/center]

Building the engine's air intake & blade fans was quite easy. Using an old 1st aid kit tape cap which just fit on 1/18 diameter engine 1st stage blade fans, I placed carefully plastic blades as shown in the following pictures. Molding some epoxy putty, I build a basic item of a cone, then stuck some steel pins on it and removed them after 20 minutes, as soon as the epoxy putty was solid rock. Spinning the epoxy item with the Dremel tool and sanding as required, I formed in to a cone shape and finally I placed a pitot tube sensor on the top of the cone spinner as shown in the real Pratt & Whitney F100 turbofan engine pictures.

[center]













[/center]

Aceasta postare a fost editata de Nick_Karatzides: 16 September 2009 - 05:12 PM

[Nick_Karatzides]

[center]















[/center]

[center]CHAPTER II – Air intake tube construction
[/center]
Because the main BBI - Elite Force kit was very poor on detail and had the air intake tube sealed, I had to first open the air intake by cutting the plastic and then build from scratch the approximately 30cm long tube, leading to the engine's 1st stage blades described in detail into previous Chapter I. Just because the F-16's air intake tube is not just a straight line tube, the idea of scale building with plastic card was rejected from the first moment. If you notice, the F-16's air intake tube is curved in both X and Y axes while heading to the engine's 1st stage blades.

[center]

Source: http://www.f-16.net[/center]
For this reason, I decide that a "negative image" cast of the air intake tube should be made and build the tube model using this cast, with two available & different methods:

• The first method is based on a solid rock (made by balsa, epoxy filler, plastic etc) "negative image" cast of the air intake tube on which I would try to vacum form some air intake tube "half" parts (left-right or upper-lower). Some very thin (and fragile too) plastic parts could be produced, but with doubtful contact between the two "halfs". For sure, the tube "halfs" would leave visible contact line marks across the construction, that should be filled with putty and carefully sanded on a fragile and extra thin plastic material.
  
• The second method is based on a deliberately fragile and hollow "negative image" cast made by soft materials (such as plaster and cardboard), that could easily be decomposed and removed after sinking into water. I decide to follow the second method, knowing that I had only one shot to try, with no mistakes allowed, considering that the cast would be destroyed after use, but I could have one-piece tube as a result, without any marks or lines inside the tube and also avoid unneccessary sanding with doubtful results.

By selecting the second way, which was more desired and realistic for me, I finally produced one solid rock one-piece air intake tube, very accurate on scale, following exactly the real air intake tube curves and present to fellow modelers a mighty unconventional way of scale building to keep in their mind for any future projects of their own. That's why, I present the project with step-by-step pictures, to provide any possible help to understand how did it. After all, I believe that scale modeling is not just cutting plastic parts straight from the kit box or maybe use some resin accessories already checked to fit perfect into models, but combining arts, skills, techniques and finally use our brain to invent new methods in order to have a realistic result.

Having the official F-16 Block 52 blueprints copied from the T.O manual, I got the exact dimensions of the air intake tube, print them down on a cutaway image and using scissor and simple cardboard, I create a the "negative image" of the air intake tube, basic spine. As soon as the spine made by cardboard was set on a straight line, it was wrapped around with a cloth net found into the 1st aid kit. Small quantities of plaster, highly thinned with water, applied on the cloth net with a brush, to build the first layer of a hollow plaster cast, which would become the "negative image" of the air intake tube.

[center]







[/center]
Materials like plaster, start as a dry powder that is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after drying, and can be easily manipulated with metal tools or even sandpaper. These characteristics make plaster suitable for a finishing, rather than a load-bearing material and that exactly is what I'm looking for on this air intake tube construction. Keep in mind that adding salt into wet plaster mixture, reduce the plaster's hardening time and adding vinegar into wet plaster mixture, extend the plaster's hardening time. When the first layer of thinned plaster applied on the net was dry and hard enough to hold the basic spine made by cardboard, a second thin layer of plaster was applied to form the curves of the air intake tube, following the lines of the pre-cutting cardboard. The basic idea, is to keep this plaster cast hollow, accurate on scale and as thin as possible trying not to apply extra stuff where is no needed. When the plaster cast was dry and hardened, tiny quantities of modeling putty added to close minor scratches and pores on plaster cast surface, brushed with water based clue, painted in black color, dry sanded and finally sprayed overall with gloss shiny coat.

[center]







[/center]
Johnson's baby oil (thin layers of vaseline based mixtures can be used also) brushed as a segregative material for later purpose and generous quantities of polyester filler applied on the plaster cast. The specific polyester filler I used, is enriched with fiberglass grains to enforce the final construction. The filler should be always used with the proper catalyst which provides a solid rock build and approximately 5 to 10 minutes time window to form it into shape.

[center]

[/center]
When the plaster cast used as a "negative image" of the air intake tube, was fully covered with a 3-4 mm thick layer of polyester filler enriched with fiberglass grains and had enough time to polymerize and get solid rock, it was sunk into water and stayed wet overnight, in order to let the enclosed cast made by cardboard and plaster get moistened and decomposed.

[center]


[/center]

Aceasta postare a fost editata de Nick_Karatzides: 16 September 2009 - 05:54 PM

[Nick_Karatzides]

Staying underwater for few hours, waiting for the enclosed cast made by cardboard and plaster to get decomposed and become soft, mixed pieces of cloth net, thinned plaster and moistened cardboard were removed with caution.

[center]









[/center]
By the time all the thinned plaster, dissolved cardboard pieces and cloth net remains were removed, the tube was sanded properly, washed and attached by using cyanoacrylic glue on the F-16 lower fuselage "mouth" housing. Epoxy putty and polyester filler used to close the huge gaps.

[center]







[/center]
After proper sanding, the air intake tube looks OK

[center]





[/center]
Using plastic card, I formed a 1 inch wide ring and placed it to the air intake tube's end, in order to fit perfectly the Pratt & Whitney F100 turbofan engine's 1st stage blade fans structure, which displayed earlier. Epoxy putty filled the gaps and formed the tube's end diameter to a perfect circle.

[center]



[/center]
As it is well known, the Block 52 F-16s (using the Pratt & Whitney F100-PW 229 afterburning turbofan engine) air intake shapes are not the same with older "big mouth" F-16 versions such as Block 30 and Block 50 (using the General Electric F110-GE 100 afterburning turbofan engine) also used by the Hellenic Air Force Squadrons. The newest Block 52s have a larger nose tire which required the intake to be reshaped to accomodate the new tires size. For this reason, the Block 52 F-16's newer air intake have a noticeable bump about 4 feet in on the lower surface.

[center]











[/center]

[center]CHAPTER III - Engine's afterburner area construction
[/center]
Starting to work behind the engine's last stage blades and the afterburner's spoked frame, I had to simulate in scale the inner embossed detail on the afterburner's area. Following the exact blueprint plans of the T.O service manual used for the real F-16 and after converting numbers to 1/18 scale, I did calculate the AB area dimensions, cut a piece of plastic card, fold it to cylinder and reinforce it externally with plastic bands, to ensure that it'll keep in shape. This cylinder is the base to host the inner embossed detail on the afterburner's area. As soon as the base cylinder was ready, I opened randomly more than 30 holes, using a 2mm drill - the reason will be explained into following lines.

[center]



[/center]

Aceasta postare a fost editata de Nick_Karatzides: 16 September 2009 - 06:13 PM

[alaur]

Woooooowww !
Fulminant entrance.
Welcome to our asylum !

[Mr32]

Just,WOW!!!!!!Amazing!!!!!
I want to see more.

[Nick_Karatzides]

Having a couple of different methods in mind to simulate in scale the inner embossed detail on the afterburner's area, but knowing that the following method is much accurate to scale and easier to re-do if something goes wrong, I tried a visit into my local PC store and searched for a cable tape used into PCs to connect the motherboard with the HDs or CD/DVDs etc and transfer data between them. I found a plenty of PC cable tapes, but I finally got one with intense embossed detail between the cable lines. After calculating the base cylinder's inner circumference, I cut the brand new cable tape on exact length, sprayed it with light gray base coat and placed it carefully into the cylinder, trying to avoid folding marks on the cable tape surface.

[center]





[/center]
After placing the cable tape into the base cylinder without spreading clue, I pressed it against the plastic using my thumb, to eliminate any possible bumps or waves that may appeared. Thank to accurate calculations the cable tape ends, came exactly one against the other, almost in a perfect facing touch. To secure the cable tape in this place, I dropped cyanoacrylic clue through the opened holes on plastic.

[center]





[/center]
[center]










[/center]
[center]







[/center]
As I personally believe that following simple techniques and sometimes unconventional methods, result in superior effects, I usually do not use enamel or acrylic paint to wash, because I feel risky when applying the paint mixture and let it run. I prefer an easier technique that can be undone if the results are poor - that makes it the perfect technique. I use hard chalk pastels to wash (NOT oil pastels). The hard chalk pastels, look like a teacher would use on the blackboard in school. Do not use the soft oil pastels that artist use to draw on paper. The hard chalk pastels are easy to find in a variety of colors into your local art store or maybe Wal-Mart if in US or ASDA if in UK.

To do the wash, I use an X-acto knife, a small metal or plastic container, an old brush, dish washing soap and a bit of water. Begin by scraping some chalk powder from the side of the chalk pastel stick, carefully put this chalk powder into the small container and add a tiny amount of water and stir. It is important to add a tiny amount of water in order to make the mixture look like mud - not like soup! For this reason, I use a syringe to add just few drops on the hard chalk pastel powder and I stir using the old brush. Because the chalk powder doesn't mix well with the water, a drop of dish washing soap is needed to break the surface tension of the water and also acts as a "glue" to help the chalk powder stick to the model.

[center]











[/center]

Aceasta postare a fost editata de Nick_Karatzides: 16 September 2009 - 07:12 PM

[Nick_Karatzides]

Once the chalk is fully dissolved into the water/soap mixture it is time to "paint" this mixture on the inner embossed detail on the afterburner's area. "Painting" the mixture is simple - just apply it anywhere it is needed to darken recessed detail. The mixture can be applied carelessly, because any mistakes can be completely removed and redone.

[center]





[/center]
When the chalk wash dried, I rubbed off the high spots with a slightly damp dry (not wet) Q-Tip cotton swab (Kleenex papers can be also used) and I wiped the dark color from the areas should be light colored. The high spots were cleaned to the basic finish and the low spots were left black. I did the chalk wash on the inner embossed detail on the afterburner's area in about 15 minutes which makes it a very quick and effective technique. You can also read about this into Steve Bamford's article, by clicking HERE.

Some of the wash mixture is re-applied and the wash being wiped completely out of the narrow points. If you follow this method, it is adviced to not rinse out the wash container till you are finished this job. You will probably be touching up certain spots a few times, so it helps if you're not mixing up a new chalk mixture each time because you kept cleaning out your container of the chalk wash mixture. I repeated the the wash process with lighter colors where needed. Using micro cotton batons found into cosmetic shop for less than 1£, I applied some lighter colors such as yellow, white, sand, brown, burned iron etc & also black chalk pastel powder on the inner embossed detail on the afterburner's area, to make it look weathered and extensively used. I repeated the weathering process until it satisfied me and finally I sprayed a clear coat to seal the chalk powder in place.

[center]













[/center]
The F-16's hot air exhaust of the ECS (Environment Condition System) comes in two different shapes. The old A/B types come with small cover. Here is the way it is covered nowdays on newest Block 52s F-16C/D. The basic shape of the ECS cover made by plastic card and the air exhaust detail will be added later.

[center]



[/center]

Aceasta postare a fost editata de Nick_Karatzides: 16 September 2009 - 07:31 PM

[Nick_Karatzides]

[center]CHAPTER IV - Main landing gear bay construction
[/center]
The main landing gear bay is one of the most complex areas on this 1/18 scale model. I did the dimension calculations, sand the outer surface of the air intake tube carefully, cut pieces of plastic card as required and placed them to start building the bay.

[center]

[/center]
[left]Using 0.75mm drill, a single hole opened on the air intake tube, to later host a pitot sensor which is normally can be found just before the engine's intake fan. This drilling should be done now, before connecting the main landing gear bay construction with lower part of F-16's surface and the pitot sensor will be placed later.

[/left]
The air intake case, connected with the lower surface with ZAP cyanoacrylate super glue and the huge (approximately 2mm wide) gaps were filled with epoxy cream. I prefer to use epoxy putty (or polyester filler with fiberglass grains for special purposes) instead of normal scale modeling putty, to close gaps or build new items, because:

• It becomes solid rock within only few minutes or seconds,
  
• it does not shrink and does not crack after months or years,
  
• you can pour to any shape that you want but you need to work fast because as soon as you mix it with catalyst cream approx 5%, you have limited time before becoming solid rock,
  
• you can also put additional layers of epoxy or polyester filler to build up,
  
• you can sand it, you can drill it, you can use any type of scale modeling glue, any type of primer or enamel / acrylic paint on it with no problem,
  
• can be purchased at any good crafts store into 250ml, 500ml, 1lt (comes with a tube of catalyst hardener) or bigger canisters and if you can't find it, fear not and try your local decent hardware store and finally...
  
• it is cheaper than dirt - estimated prices are £3 to £10 depending the canister size, the quality, if contains fiberglass grains for maximum strenght etc.

Keep in mind that the chemical reaction after mixing the filler with the catalyst hardener, produces some heat that possibly effect on thin plastic parts, so test it first before try it on your scale model. I don't think that the produced heat is more than Fahrenheit 110, but better watchout.

Remember that epoxy materials are dangerous when breath or shallow and could result skin, eyes or lungs problems or even cancer when used for long period with no precaution measures. Always keep in mind, that a powerful vacuum system to suck away the epoxy dust should be used all time to keep the workbench area clean while sanding or milling epoxy or resin materials. Using an issued breathing mask and a pair of surgery latex gloves to prevent dust contact with lungs and fingers while sanding or milling epoxy, is also an important matter that you should seriously take care of! My recommendation is to also wear an overall working suit (as I do) to keep your clothes dust free while sanding epoxy. Some people might find it too much, but I wouldn't like to bring epoxy dust & grains from my work bench into living room and my beloved.

[center]



[/center]

[Mr32]

When it's done,you're flying with it??

[Nick_Karatzides]

The main landing gear possessors basic lines were copied from the T.O manual, lined out with green ink marker and later cut 'n' drilled from white plastic card. Blueprint copies enlarged to 1/18 scale, were used to cut the possessors on exact shape & size and later set into place.
[center]

Starting to place cables, actuators, fractional DC motors, hydraulic lines, securing hooks & stuff into the model's main landing gear bay. It may look quite empty now, but everything will be in place and look realistic as the project continues.

[/center]
I used hair thin copper wire cut off from a simple electric cable to bond plastic spue together, to simulate the cable braids found into an F-16's main landing gear bay. The cables and hydraulic lines are placed carefully according closeup pictures of the real gear bay.

[center]

Found into my old sparebox, a cracked & damaged 1/48 scale fire extinguisher could be also be upgraded to become the metal oval shaped tank found into the main landing gear bay, known as the Halon 1301 (also known as Bromotrifluoromethane CBrF3, which is a an organic halide to provide fuel cell inerting to protect the fuel system from explosions due to combat threats) reservoir. Filling the gap with epoxy cream, sticking it on a nail and spin it with the Dremel tool against different types of sandpapers was enough to make it look like the real one.

[/center]

[alaur]

Till now everything's clear.
What about fuel consumption and maximum load ?


Back to school. It's september.

Aceasta postare a fost editata de alaur: 16 September 2009 - 08:08 PM

[AcidCod3]

Uau... that is amazing.