I have a glass numberboard from an EL SD45, and the paint is starting to completely chip off. I was wondering if anyone has any tips on repairing/repainting this.

The way I see it, I have three options - I can repaint over the areas that are chipping off, in hope of sealing the paint there and trying to blend it in to the original paint... I can repaint the entire numberboard over the existing paint... or I can mark where the numbers are, strip the entire board, and repaint the entire thing over clean glass.

Any suggestions?

Thanks!

Well I guess it depends on what you are trying to do with it. If your goal is to preserve it as a surviving artifact from an E-L locomotive I would suggest leaving it just the way it is. The paint that has flaked off is just a fact of life. If you repaint even part of it the item is no long what you originally obtained it as. If it is a perfect looking numberboard you are looking for might I suggest replicating it and placing the original into safe storage. The number board is just like any other artifact in that it needs proper care and storage including climate control and protection from unnecessary handling.

Here is one option to conserve paint that is flaking off. However I'm not sure how it would work on glass.
http://www.draytonhall.org/preservation/main_house/paint_conserve.html

Kevin O