After digging through the internet and FSM forums looking for tips, and after a day and a half of struggling, I sort of figured out my own method for painting the yellow stripes (or any color, really) on aircraft ordnance.
This method works for single stripe Air Force ordnance. Two stripe Navy ordnance might be a bit trickier since you have more lines to mask.
Anyway, I used a section of copper tube from a bag of various sized metal tubing you can get at Hobby Lobby. I think the package runs around ten bucks and for me, in scratchbuilding, it’s been a lifesaver.
First, I primed the missiles in white. Then I sprayed the front end yellow.
As in the pic, I used my assistant “hands” to hold the missile, with the tubing section pressed firmly against the nose of the missile. You really need three hands to do this anyway, since holding the tubing perfectly perpendicular to the horizontal line of the missile is very important.
After assuring correct placement of the metal tube, I sprayed with rattle can white primer. You could airbrush white paint but it’s going to take forever to cover the yellow.
Leave the missile in place for a couple hours so the white can dry. Then remove tube. You should have a nicely masked yellow section.
I haven’t gotten this far yet, but my next step is to dip the very tip of the missile in white to complete the stripe painting. I’ll update this post in a day or so with my results. Here’s a pic.
DSCF1358 by theirishavenger, on Flickr
Anyway, as much as I struggled with this, I thought I’d share what I came up with. Hope this helps someone else out there.