Methods for material build-up on a tip of a blade of a gas turbine engine are provided. The method can include inserting a material supply and an inflatable bladder between the tip and a shroud such that the material supply is exposed to the tip and the inflatable bladder is positioned between the material supply and a shroud, inflating the inflatable bladder to force contact between the material supply and the tip, and causing relative movement between the material supply and the tip. The relative movement, in combination with the radial biased contact between the material supply and the tip, creates heat through friction. As such, the relative movement can frictionally weld new material from the material supply onto the tip of the blade. For example, the heat created can be sufficient to melt the surface of the material supply to transfer material from the material supply to the tip.