I’ve used Barkeepers friend on a ton of porcelain signs over the years. I’ve yet to see it take any gloss away. It’s always worked wonders for me and I’ve used it with some force along with a blue scotch brite pad.

I think the key is to keep it really wet and moving. I never let it sit for more than a couple minutes before totally rinsing.

Last edited by 57-Chevy; Wed May 20 2020 08:25 PM.
KJV Psalms 16:11

Thou wilt shew me the path of life:
in thy presence is fulness of joy;
at thy right hand there are pleasures for evermore.