Porcelain? It's called cobalt blue, and you'll have a HARD time finding paint to match and look right. The porcelain is nothing more than ground up colored glass powder(aka frit) that's melted at something like 1600 degrees(?). That particular color is almost like trying to touch up candy paint with a brush I did an early Chevy sign and a Piedmont tobacco sign years ago---took the better part of a day---and they still look "fixed" any closer than five feet away. Started with a grayish-white base, then mixed some transparent blues and some violet.. My .02....You'd be better off to just clean it real good and replace the neon(which is relatively cheap) and enjoy it as is
If you're just going to make that cool old sign look like a brand new reproduction, why not just make a brand new reproduction... and leave the cool old one alone. Just my 2¢.
Neon to replace one side should be less than $400 - I assume that is the 6' x 3' version. I just got a quote on a double sided one for $722. I do agree that I would just leave it alone and put the neon on it. What you have there may be worth more than you think. My double sided sign with only chips on the perimeter and no neon sold for $4500. Complete double sided signs are in the $7K range.
Agree with the advice to just add the neon, don't try to touch up the porcelain... polish with a product called "Nevr Dull Magic Wadding Polish"... comes in a blue tin, and is a cotton wadding impregnated with a oil based cleaner specicically designed for chrome brass and porcelin.. made by The George Basch Co., Freeport NY... removes the rust instantly...
I agree, I like the way it looks, but its not mine, a customer wants it fixed up. I've scanned the sign and looked through endless paint chips and found nothing close, figured I would give this a shot.
I totally agree with Earl Scheib. I tried to match the blue color when I restored my sign and the repairs are noticible when you look closely. I had the PPG retailer do a computer scan of the sign and mix the touch-up paint. The neon is what really makes these signs special, so find a good repairman to do that work! Here are a couple of pics of my Ford sign. Jim