Clean off all old sealant. Fill the bath with water. Apply new silicon sealant (use best quality). Let it set. When set empty the bath. The bath edge will rise when relieved of the weight of the water and improve the seal.
Alternatively use a semi-rigid moulding which goes under the tiles when you retile. Still fill the bath before fitting the moulding and tiling.
Chicks Fan, December 2008
