I had an old can of Evercoat putty that the hardening cream had long since dissapeared. Bought three of these to supplement and used with the putty to fill automotive surfaces. The cream worked great. Almost too good. particularly carely with mixing in percentage as recommended because this stuff catalyzes fast and the working time I found (even at less than 70 degrees) was less than 15 minutes. So, overall the cream worked great as a replacement to the original hardener that came with the putty. The name of the putty I had was the Evercoat Rage. Make sure that the recommended hardener for yours (if it is not Evercoat Rage) is compatible with the 361.