Cool sign, cleaned up the rust stains well. I had used barkeepers on the Gulf sign above but didn't use the fine steel wool that Tankar mentioned. I may have been a little impatient and went to the muriatic acid too soon but it worked. I have had trouble in the past with an orange black and white united states tire porcelain sign using barkeepers. It degraded the finish and removed some of the black lettering. It seems like some porcelain signs can be more delicate than others. So going slow, a small area at a time and with the less aggressive product to start may be the right path on most things.
