With their outstanding mechanical and chemical properties, MAX phases are a family of very promising coatings for various applications. Among them, Ti₃SiC₂ thin coatings have been demonstrated by magnetron sputtering, reactive chemical vapor deposition or molten salt reactions. Yet, the obtaining of thick coatings, i.e. a few tens of micrometers still is an issue. We report on the synthesis of very thick Ti₃SiC₂ coatings, up to 200 µm thick, by high temperature reaction between graphite and TiSi alloys. Within a 5at% composition range, it is possible to vary the aspect ratio of the Ti₃SiC₂ grains. A higher Ti content favors the growth of long and thin columns. The deposit is perfectly conformal, making the process able to cover complex 3D shapes. The formation of this thick coating will be discussed from a mechanistic point of view. Finally, study of wet corrosion behavior of the coatings is presented, showing an excellent resistance in strong acids (HCl, H₂SO₄) and also in physiological liquid.