CHAPTER I - Engine's 1st stage blades & afterburner construction
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.































Düzenleyen Nick_Karatzides - 04/04/2010 Saat 13:40

CHAPTER II – Air intake tube construction
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.





Source: http://www.f-16.net
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.











Düzenleyen Nick_Karatzides - 04/04/2010 Saat 13:44

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.




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.





Düzenleyen Nick_Karatzides - 04/04/2010 Saat 13:47

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.










After proper sanding, the air intake tube looks OK









Düzenleyen Nick_Karatzides - 04/04/2010 Saat 13:49

First,wellcome.It's good to see a foreigner modeler posting to our boards.

The rebuilding of the tube is pretty pretty impressive,at least I've never seen a modeler using this technique before.Good job,very well done.

Thanks for sharing with us,more please.

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.















Düzenleyen Nick_Karatzides - 04/04/2010 Saat 13:50

Wooowww... Interesting. Wish to see more...

Tolga

Wellcome Nick..!

Interesting project, impressive work..!

Looking forward to see it finished...

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.















Düzenleyen Nick_Karatzides - 04/04/2010 Saat 13:37