Hard rubbers (ebonites) are widely used in the field of corrosion protection due to the outstanding chemical resistance. But the conventional application of rubber-sheets is time and cost consuming. So called "liquid ebonites" based on low molecular polybutadienes have the disadvantage, that only thin layers can be realized. It was the objective to develop a solvent-free hard-rubber coating, that can be applied in short time and preferably by spray application in a thickness of > 2 mm. That could be achieved by introducing a 2-step curing process, consisting of pre-crosslinking at ambient temperature and vulcanization at higher temperatures.