I've been playing with ceramic the last few days and decided to really push the boundries of masking with the material and see just what can be done. Negative masking with paint is a fairly straight forward endeavor that gives the painter the opportunity to create multi-color features on a frame with ease. Negative masking tends to be more time consuming, uses more material, and carries the risk of knife marks in the protected layers during removing the masks than the use of positive masking and an airbrush.
I wanted to create a camo effect in ceramic. Normally, I would use positive masks and three airbrushes already loaded with colors to quickly move around the frame and fill in my camo. However, the ceramic is too thick for use in an airbrush, negative masking it is.
The hurdle with negative masking with ceramic is that once it begins to cure, it's like concrete, making removing the mask material quite a chore, impossible if you are not tuned into your temperature and cure times for detail work. I had to cure the layers long enough that placing masks on them would not cause visual damage, but not so much that I could not get the masks back up later.
Additionally, each time I cure off a layer, the one underneath will harden even more with the additional time at cure temperature. I had to create a tiered cure time table for the number of layers I wished to use so that at the end of the process, the first layer would be just at the maximum time for cure that would still allow me to get the masks up but the final layer would be stiff enough not to smudge during the removal process. Let me tell you, I'll not be looking forward to this complex of a ceramic finish again any time soon :)
The most difficult piece of the puzzle was the delicate masking that makes up the lower portion of my graphic, the frame model, and the owers name. As the layers go on, the thin masking gets buried and with the stiffness of the ceramic, is VERY difficult to remove. Careful Xacto knife skills are maditory. I'm not completely satisfied with the result, I've identified a few tweaks to use next time. For a first go, however, it's not too bad.
The advantage of this coating is that even with the multiple coats, it still builds less than the same visual finish in wet paint and is more durable. We've got a ways to go before I reach the true limit of this material on bicycles...I'm excited to see where we end up.