Evening When rubbing down plastics (fairing) to repaint, how far do you go? Just enough to give the paint something to grip too? Or does all the clear coat need to come off? Or rub the paint off too? Thx
You can do either, the minimum from my experience is to at least remove the lacquer (rub down) to give the paint a surface to key to. If you have the time and patience you can rub down carefully to the bare plastic and that is the best option as it eliminates any possibility of a reaction when you are repainting due to non compatible paint remaining that might ruin the finish or react adversely to the primer or top coat\s. When rubbing down plastic it's very easy to be left with tiny "whiskers" that will show through the layers of primer, especially initial coats. Priming is the most important job to get a decent finish. If you find tiny strands of plastic showing through any primed areas then rub down the finish and then guide coat the panel or piece and rub it down properly. Use the correct colour primer to finish the job, an example being beige is the best primer for painting a panel red although in a few cases I have seen Ducati actually used white primer on panels and of course others were not even primed at all. It depends on the age of the bike.
As above but true answer is - if you are younger then meticulously remove all traces of original paint without roughing up base plastic too much. When older and you have tennis elbows like Popeye then you take off as much as necessary to achieve a flat face and then with fingers crossed experiment with paint hoping that it wont react. Last two 748 panels I did I went straight to top coat after finding every (non-trade) primer I tried reacted. As an amateur painter I would always choose to paint in warmer climes as paint has a chance to set harder which is important if you need to apply a second coat. At least with the later Cagiva/Ducati panels the old paint adheres well so there's a good chance you don't have to remove it all. With the older nylon-like/flexible panels you had no option but to remove the lot.
