Hi this is Peggy. Here are some instructions for painting a porcelain sink. This Old House recommends using a rag to wipe the bonding agent on the sink's surface so acrylic urethane paint will adhere properly to the porcelain. One coat of bonding agent is sufficient to prepare the porcelain sink for painting.
How to Paint a Porcelain Sink | Home Guides | SF Gate
https://homeguides.sfgate.com › paint-porcelain-sink-20898
Hi Sherry. You should use acrylic urethane enamel paint on your porcelain sink. Proper ventilation is very important with it. Wear a mask with air filter. For best coverage, use a spray gun.
Epoxy paint is made for sinks like Homex or Rustoleum Tub n Tile..... or you can go for a pro product like KlassKoat.... its all about prepping the surface before painting. Excellent ventilation is needed. https://www.youtube.com/watch?v=m9m1kBzOjhI