Does anyone know of a way to get yellow burn marks off a bathroom sink left there from my curling irons?

Answer 1

not without replacing the sink

Answer 2

You might try white rubbing compound (which you can buy in an auto supply store like Advance....it's usually used on cars, but someone suggested it to me for getting scorch marks off a countertop, and it worked.) Double check the label before you buy/use it to make sure it can be used on porcelain but I can't imagine it would be a problem if people us it on the finish of their cars.