PRE-SHADING WINGS

Wing pre-shading is done to simulate light passing through the wing and when viewed from the bottom shows the shadow or dark image of the ribs and spars. In this demonstration I am painting the underside of the wings with CDL (clear doped linen) using Humbrol No. 121.

I first paint the entire underside of the wings using Humbrol Dark Earth, leave until dry.

The next step is to mask the areas you wish to highlight. For the ribs I used 1mm tape, the spars 1.5mm and the centre spar 0.5mm tape. Make sure the tape is pressed down firmly. This tape is available from most good hobby shops, I get mine from

www.jammydog.com a company based in England, great service at a great price.

I then gave the wings a light spray using the CDL colour, don’t apply this first coat very heavily, just enough to cover the surface. Remove the masking tape as soon as you have sprayed the CDL, this will prevent the thinners in the paint affecting the glue and making it stick to the surface instead of pulling off with the tape.

With the CDL, start spraying over the surface making sure only light coats are applied, once you have gained the correct colour over the ribs and spars you are nearly done.

The tricky bit is to fill in between the ribs and spars with more CDL. Using a double action air brush allow only a small amount of paint to flow and fill in the spaces between the ribs and spars, be careful not to apply too much paint, a small amount at a time and keep going back over it until you are happy with the result. Allow the wing to dry thoroughly Once dry sand the surface with very fine (1500) wet and dry paper only between the ribs, the end result should be similar to the next photo.

The next step is to apply a coat of matt clear to seal it all, once that is dry a coat of gloss clear can be applied to where any decals are to be fixed. After decals, another coat of matt clear will finish the job.

PRE_SHADING THE EASY WAY

USING GRAPHITE DUST FOR COLOURING TYRES

I use propelling pencils which are available from any newsagency or art supply shop. You can buy separate refills with varying degrees of hardness and colour.

Cut a piece of fine wet and dry paper to your own size and shape requirements and place on a hard surface.

Using only light pressure gently rub the lead (graphite) over the paper until you have a collection of dust, you will have to continually click and expose more lead as it does wear down very quickly.

The brush I use is a small cut down stiff bristle brush, a soft brush will not achieve the same result.

Begin by inserting a toothpick into the axle hole so you have something to hold. Load the brush with graphite powder and start by rubbing the brush over the edge of the tyre using a side to side motion, keep doing this until the whole side is covered. You will need to re-load the brush regularly.

Load the brush again, this time I am doing the tyre down to the painted fabric wheel cover. Press the brush against the tyre so it flattens out then working slowly move side to side while also moving down towards the centre, be careful not to get any graphite on the painted surface.

Once you have completed the  edge of the tyre continue with the graphite but this time around the outer surface of the tyre again using a side to side motion, keep the brush fully loaded with graphite. After the outer surface has been coated continue by doing the other side of the tyre

This is the tyre with the graphite completed. You will notice it has a shine to it, this is normal for graphite. Do not handle the graphite as it will rub off so it is essential that the tyre is coated with a clear. This is a very quick and easy way to colour the tyres and by using different grade refill leads a variety of shades can be achieved.

Using graphite to colour small moulded bracing wire

Much easier than trying to paint them

Sharpen a propelling pencil to a nice point then use it to draw over the moulded bracing wires inside the fuselage. This is a very simple and quick way to highlight the wires without the trouble of trying to paint them. Keep sharpening the pencil after every couple of strokes to keep a sharp point. The end result is a neat and near correct colour but it does need to be sprayed with a clear coat.

I made an error, this particular aircraft (Sopwith Pup) had two spars, not three, so the above picture shows the corrected wing pre-shading now showing only two spars. A coat of clear will seal it all.

To make your wing look like light is passing through it when viewed from underneath, the ribs and spars must appear as a dark shadow or dark image, here is a very quick and simple way to achieve this.

The wing I am using here is from the WNW SE.5a, the ribs are overly emphasized but it won’t affect the outcome.

I first painted the wing using Humbrol No. 121 with 30% white added.

Using a straight edge, either a flexible ruler or a length of stiff card, draw lines either side of the ribs and spars using a propelling pencil. Shade the wing ribs and the spars between the lines you have just marked, try to keep the lines as straight as possible. Be careful not to smudge the lines with your hand.

Once all the areas have been highlighted, using a small stiff brush go over each of the lines blending the graphite to a uniform colour. You don’t have to be perfect here, remember that you are creating a shadow so it won’t matter if the edges are a little fuzzy.

Now that all the lines have been brushed and the colour is even, it is time to spray more CDL to give the shadow look. The amount of shadowing is entirely up to you and how you want your model to look.

This photo shows the pre-shading almost completed. I sprayed using 18psi and thinned the paint using 65% thinners, I applied very light coats and kept going over it until I reach the desired look. Once the paint has completely dried I will give the wing a light sanding with fine micro mesh, if it still looks alright it will be clear coated but if it requires more CDL to lighten the shadows that will be done next.

As you can see, this is a very easy and simple way to achieve a good result. No masking is required and only one paint colour is needed. The graphite I used can be substituted with coloured pencils or pastels, and the colour is optional, use what ever colour you think will look good under your top coat of paint.

Here is a classic example of light passing through the wings making the ribs and spars stand out, notice the same result with light passing through the tail. If this prototype DH.1 had roundels on the top wing you would also see them through the wing. This is what I am trying to replicate with my wing pre-shading.

Photo from: Rosebuds WW1 and early aviation archives at http://www.earlyaeroplanes.com  

Here is a beautiful example of light passing through the fabric and highlighting the spars, ribs and fuselage frames, also shows to good effect the roundel on the top wing appearing through the wing. This is a Radio Control model from a photo collection on Photobucket for the

Tingalpa Model Aero Club by Brequet.

This is a photo of a Taube taken in 1917 as the aircraft flew overhead, a remarkable piece of photography for its time. This to me is the most beautiful aeroplane built in the early days of aviation, it’s graceful bird like lines depict the designers concept in those days that a plane would have to be shaped like a bird to fly. Ironically, the Taube, which means Dove, the symbol of peace, was the first aircraft to drop a bomb.