Colouring twinwall - trial and error
Over the years of working with twinwall we've tried pretty much every form of colouring technique thinkable from paints, through varnish to marker pens.
Few paints want to stick to twinwall at all, and the ones that do have such low adhesion that they will flake or scrape off very easily.
The solution found through years of trial and error is coloured polypropylene tapes. These are essentially similar to common 'brown' packing tape but are of a much higher grade. They are sold in 60 metre reels some 55mm wide - i.e. a good lot of tape for the money.
Using tapes allows fast covering of large areas with minimal weight addition. We've found that on an 800mm Evo, covering the entire top surface, elevons and fins adds 17g to the overall flying weight. We recommend covering only the top surface to allow better orientation during flight.
Nothing is as durable as colouring tapes for colouring twinwall. The high gloss finish remains brilliant and colour fast long after the average airframe has been retired.
If you have some patience and a sharp knife there are really no limits to what you can achieve with colouring tapes. Some of our favourite Evo designs have involved a fair amount of work, but with a little creativity (and some help from our tutorials - more to come) you can achieve a finish that will shame ready covered models and foamies!