Thanks Tweaky, but that's only the first few coats. The black part of the burst will eventually take up a lot more of the surface before I'm finished. Have a look half way down page 3 of his thread to see what I'm hoping to emulate.
The black scares me, so I'm taking baby steps - each coat encroaching a little further until I get is something like I want.
Definitely airbrushing next time. I don't have the patience for all this waiting.