I am decorating my bathroom. I have a friend who said he knew what he was doing and decided to help me. I had to sand down the walls as there was quite a sheen on them, before I could apply the Dulux+ Soft Sheen Bathroom emulsion. He decided to use 40 grade sandpaper and ended up taking graunches out of my walls in places. He then said he needed to use pollyfilla to fill them and decided to use ready made pollyfilla in a tube. He said it had to be left 24 hours before it could be sanded down but it set like concrete. He was using the 40 grade sand paper again but still the walls are full of uneven bumpy places which looks horrible. He told me that he could not use an electric sander on the walls as it would take off the original paint and said that I was to go ahead and emulsion over the bumpy uneven messes and that it would even itself out. I didn't think it would work but did as he told me. Today I did my walls and just as I thought, they look like bumpy uneven messes.
Has anyone got any clue as to what I can do?