everything i have read about this has led us to leave our tub the way it is for now and save up for a new one at a later date.We had it professionally done on our cast iron tub. It was pink and we got it reglazed white.
It looked fantastic for a few months. Then one day I dropped a shampoo botle and the edge dinged the paint. Then a little while later it was all starting to chip near the drain.
My husband just demo'd the cast iron and the walls as we got all brand new everything in the tub area. A lot of work but well worth it to see a new white tub and beautiful new tile on the wall.