At high speed the air drag makes up for 70 percent of the total resistance, that is why a good coating is so important. The layers must be applied thinly in order to save weight and to keep the aerodynamic shape intact. An as smooth as possible LAK is used to minimise resistance.
We look at the requirements of the coating, for example regarding the ambient temperature in the Nevada desert. Then, the coating is applied at the Cromax training center. The preparations and appliance of the coating take up to a week, where different layers are applied, each with its own function and drying time.
First the carbon sealer (U190 Carbon Fiber Sealer) is applied on the shell, which will fill the small, porous holes in the carbon fiber. When this first layer has dried, the puttying can commence. By applying the putty imperfections in the shell are removed, resulting in neat lines in the design and a smooth surface. The putty is placed by hand with great precision onto the carbon fiber, where the years of experience of the Cromax technicians lead to the accurate result. They have to examine with feeling where to apply the putty and by which amount. For example by looking at the shape and curves of the shell and watch how water droplets travel across the surface, and subsequently light sanding leading to a smooth result.
After this, the 2k primer is applied to the shell. We have selected the LE2001 LE Primer Plus as the suitable primer. The primer covers the putty and fills small superficial scratches. After a night of drying in the Cromax training center, the surface is sanded again. It is almost time to apply the coating! But first, the shell is finished with a thin layer NS2602 Non Sanding Primer Surface: this layer makes sure that the coating will get an consistent coverage and that heavy sanded surfaces (where the putty could possibly be exposed) is again covered.
The primer only needs half an hour of drying, so the coating can commence after a short time. First, the white coating (Imron Fleet Line Elite 3.5 VOC 2K PU Topcoat, Ral 9016 Verkehrsweiss), giving the VeloX its characteristic white color. Our race takes place in the desert, so heat is an important factor to take into account. A white shell will reflect most of the heat, which is very convenient for Rosa and Jennifer inside the VeloX.
After this the shell can be wrapped, showing our design and partners. This wrap is like a thin sticker taped around the shell. Finally, the final layer is applied: the CC6500 High Performance VOC Clear is the clear (transparent) coating which gives a fantastic result with a high-gloss finish. This is the layer in contact with the air: the smoother this coating, the lower the air resistance working on the VeloX, and the closer Rosa and Jennifer can get to the world record!