As you can see from the porcelain clockface from my Wayne Model 866 pump it was looking a bit worn out and tired when I acquired it.
However, with very little effort you can bring porcelain back to life.
Start by cleaning your sign with a mild detergent. Next clean the sign using Mineral Spirits which is effective at removing layers of oil, grease, etc.
Clamp down the sign on a workbench to keep it stationary so that is does not move while you are working on it.
Using a hand-held buffing wheel, dab a small amount of 3M Super Duty Rubbing Compound, or comparable product, onto the sign. Using the appropriate pad will be just as important as the "right" compound. Start with an aggressive pad, such as a 3M Superbuff III Buffing Pad, which is fairly abrasive.
This particular 3M product is an aggressive rubbing compound, so let the buffing wheel do the work for you. It will maintain a high rate of cut if you maintain constant pressure, so keep a close eye on the sign to make sure you will not remove too much of the porcelain. If you are too aggressive with this step you can damage the sign.
With the aggressive compound doing the trick you can hand buff or work your way toward softer materials to remove micro-fine scratches that remain.
The finished sign face is like new:
Thanks to Fred Hill for teaching me these steps.
