Method of electroplating an aluminum containing coating

Claim 1

IN A METHOD OF ELECTROPLATING AN ALUMINUM-CONTAINING COATING ON A METAL SHEET WHEREIN THE METAL SHEET IS ELECTROPLATED WITH THE ALUMINUM-CONTAINING COATING WHILE BEING PASSED THROUGH A BODY FUSED ELECTROLYTE FOR ELECTROPLATING AN ALUMINUM-CONTAINING COATING COMPRISING ALUMINUM HALIDE AND AT LEAST ONE ALKALI METAL HALIDE SELECTED FROM THE GROUP CONSISTING O SODIUM HALIDE AND POTASSIUMHALIDE IN A PROPORTION CONTAINING FREE ALUMINUM HALIDE, THE IMPROVEMENT WHICH COMRPISES MAINTAINING THE TEMPERATURE OF THE FUSED ELECTROLYTE AT ABOUT 250400*F., IMPORVING THE ADHERENCE OF THE ALUMINUM-CONTAINING COATING BY PREHATING THE METAL SHEET AND THEN ELECTROPLATING THE ALUMINUM-CONTAINING COATING ON THE HEATED METAL SHEET WHILE IMMERSED IN THE ELECTROLYTE THE SHEET BEING PREHEATED TO A TEMPERATURE SUBSTANTIALLY HIGER THAN THE MINIMUM TEMPERATURE NECESSARY TO PREVENT DEPOSITION OF FROZEN ELECTROLYTE THEREON AND TO A TEMPERATURE WHICH WILL SUBSTANTIALLY IMPROVE ADHERENCE OF THE ALUMINUM-CONTAINING COATING, THE HEATED METAL SHEET BEING AT A TEMPERATURE OF ABOUT 300-400*F. AT THE TIME OF COMMENCING TO ELECTROPALTE THE ALUMINUM-CONTAINING COATING.