ok here i go with a brief tutorial on how to paint a helmet. now only about 15% of the time spent painting a helmet is going to be actually painting the helmet. the majority of the time is all about prepping the helmet for paint. with the rubies jango one piece, a few things to do before you get started. carefully pry off the right ear cap, it's glued on there pretty well so to keep it in one piece slowly work around it with a small screwdriver or probe, prying a little bit at a time. next find a metal or wooden craft ring to mount inside the helmet to help it hold it's shape and rigidity (you can find one at most craft stores, though i don't remember the size you're going to need). i used hotglue to hold the last one in place. once you're got that taken care of you can begin prepping the surface for paint. first strip the old paint off as best as you can, you can start with 120 grit and a mouse sander, then go to 220 grit again with the mouse. after that you're off to hand sanding. 400 grit and wet-sanding should be your next stop, and make sure you get as much of the toothmarks from the mouse sander as you can. then wet-sand it again with 800 grit.
now you're ready for primer (a good primer makes the world of difference between a good helmet and a great helmet), don't skimp on your primer, use the best spray primer you can get. 2-3 light coats the let it dry real good and wet-sand it with 800 grit. put another 2 coats of primer down and this time wet-sand lightly with 1000 grit. and if you're feeling particularly OCD, put another really light layer of primer on and wet-sand with 1200 or even 1500 grit.
from here you have a surface that is ready to paint. if you're painting it up like jango i don't suggest using spray paint. i would recommend rub'n'buff (
Rub-N-Buff Finish - MANY COLORS : craft paints : decorative painting : crafts : Shop | Joann.com the stuff called silver leaf). here's a good tutorial on how to rub'n'buff,
YouTube - How to make armor with Sintra, Rub & Buff, and weathering it's kinda long, but i think it was uploaded by another member here, seeker. you can skip towards the end to get to the part about r'n'b. after you get that taken care of, set the whole thing aside for a couple days to let the r'n'b really set up and harden. because after that it's time to...
start masking!!! use a low tack painters tape, the blue or purple stuff preferably. then to reduce the tackiness even more stick it to your pants leg a couple times. mask off all the sections that you want staying silver, i.e. the dome, the lower cheeks, and the back. prime the rest of the visible area again and sand with 1000 grit. now you are ready to finally put paint on.
i like to start with the lighter blue, even though it covers more area than the dark blue, it's not as tricky to tape off later. 2-4 light coats are all it should take depending on coverage. now set it aside for the night, and come back tomorrow to do more masking. mask off the visor, mandibles, the head band, and around the ears leaving only the upper cheeks and ears exposed. again, 2-4 light *light* coats with the darker blue until you're satisfied with the coverage. unmask the previous layer of blue and clear coat just that if you'd like. clear coating r'n'b is a disaster.
unmask the entire thing, give the silver another buff if it needs it, then feel free to weather. there are plenty of great weathering tutorials out there, much better than one i could give.
hope that helps.
Mike