Versión en Español

Based in an article appeared in Fine Scale Modeller, March 1996.

For many years existing a process to recover the chromium plating of the automobiles, and is possible to use the same technique in the airplane models. The main ingredient in this completion is the old synthetic varnish of slow drying. Any brand can be used, with super glossy finished, and is available in paint stores of all the country. It serves to cover many models and its cost is very cheap. The synthetic varnishes are less popular than the acrylics, most of modellers prefer a shorter drying time and the cleaning of the utensils with water. But we are going to need the long drying time that the synthetic varnish produce.

Principle

Sand off the raised panel lines, or fill and smooth the recessed lines. Be sure that has planes and exact views of the model or some reliable reference, to recover the panel lines later. Complete the model normally, and place and mask the caopy and other transparent parts. Is recommendable to airbrush the model with a coat of silver base color or primer to emphasize scratches, collapses and other errors. Correct the defects and smoothly sand the model with 600 wet sandpaper or finer grit. It is not needed to polish the plastic until a mirror finish. In fact, a slightly rough surface provides "tooth" for the subsequent coats. Find a sure support to maintain the model firmly during painting and drying.

The magic moment

Now comes the difficult part -we will have to airbrush the model in a clean and free of dust surroundings, because the shining metalized finish will show each small dust speck. Is recommendable to work in a place like a garage, where the floor can be wet to diminish the dust and particles in suspension in the air. Luster the model with a rag cloth and apply a varnish coat: three parts of varnish by two parts of thinner or mineral spirit. Experiment to find the best mixture for your airbrush. Let dry the model by 24 hours, and soon inspect it looking for imperfections. This coat must be smooth like a glass. If "orange skin" is observed (small holes) it indicates that the mixture of the varnish is incorrect. Correct the defects sanding it with 1500 wet sandpaper (the type that use the car painters). If sanding arrives until the plastic, paint again with varnish. Clean the model with a cloth, varnishes again, and let it to dry by two hours. We are waiting for the "magical moment", when the varnish is dry in the surface but not totally cured underneath. We will have to be able to pass a finger over the surface, but to feel one slight friction when we do it. A secret: airbrush a test piece exactly of the same form and proves the subsequent steps first in that piece. Coil a wool rag around the finger, dip it aluminum dust (it is obtained in artistic paint stores) and polish slightly (the wool works well because is slightly abrasive). With this action, the aluminum dust will become "absorbed" in the varnish, Figure 1.

Figure 1: Here we see the difference between the aluminum powder before and after the polish.

If we polish before time (when the surface is not still dry superficially) the completion will see opaque. Wait for 15 minutes more and prove in different part from the test piece to verify if the surface is ready. If we polished too late the finished will be extremely shine, but transparent. If we do it when the varnish is completely cured, will not see any difference and will be transparent. In anyone of the cases, varnishes again and makes all the process again. Leave the varnish dries by two days before polish it. The smaller imperfections will disappear then. Polish the model with a rag cloth and finally seal with another coat of varnish. This will opaque the finish slightly. Let dry this last coat at least by eight hours, and soon it applies a final coat to seal and protect the finish. Now it will be able to draw the panrl lines and to apply the decals and other final details, or you can make some steps more to obtain a super realism.

Panels for experts

Verify the photographic reference to select the panels who vary in texture or color. After the second coat of varnish has dried by eight hours -but not more than 14- smoothly mask around the chosen panel with Tamiya tape or similar, with low sticky power. The self-adhesive Post-It of 3M also serves. Polish the panel with the wool cloth with aluminum powder. While more the polish, greater will be the brightness. Prove polishing vigorously in a side, and with a light one polished in another one. Mix graphite or gold color powders with aluminum to obtain different tonalities, Figure 2.

Figure 2: Different shades of metalized colors in a F-100 Super Sabre tail.

Lift off the masking tape and go to the following panel. Note: Throw the masking tape smoothly and to a small angle to avoid the varnish raises, and if you see that the varnish rises, stops! Use a cotton swab to draw the soft edges lines, Figure 3.

Figure 3: An Hercules tail with soft edges lines marked imitating the rivets lines.

Take aluminum powder with the cotton swab and polish with downwards movements. For defined edges, prove with toothpicks or the "plaque remover" toothpicks of Johnson & Johnson. Apply the powder with various movements ahead and backwards, using the end of the small stick. Use some flexible material that does not leave marks on the surface as guide to make straight lines on curved surfaces. The errors are easy to repair -simply clear the aluminum powder with a cotton swab dipped in water and soap, clean with a humid sponge and prove again.

On clear decal film

Another way to mark individual panels is applying a light coat of this covering on clear decal film. Airbrush the decal paper with varnish, polish it with the aluminum powder like before, and seal it with a simple coat of varnish. Now the good thing begins. Polish to the limit of the drying time for a more brilliant finish, and soon seal it. Deal with other pieces of decal film with graphite powder. In other pieces, paint with metallic paint different tonalities (can be of the buffing type or not) and seal it with shining varnish. This offers a variety of different metalized colors, to apply to the model as decals. Figure 4 shows these and other effects.

Figure 4: Different shades of metalic finishes.

Also you can mark panels with a fine drawing pen (Rotring type, that can be obtained in technical drawing stores). Simply erases the errors with a cotton swab dipped in paint thinner. Also you can draw on the decals. In order to draw fine silver lines, load an old drawing pen (feather type) with some silver color paint that can be diluted the sufficient. After treats the panels to your satisfaction, airbrush a final varnish coat to seal the work. Remember that this will leave all glossy, will have to cover the antireflection panels, walk lines on the wings, and other areas that must be matt finish. If the final result is too shining, paint a light coat of satin or matt varnish.