When heat treating steel to harden it, use these compounds to protect the surfaces you don’t want to harden. Also known as stop-off paint, all are compatible with gas mixtures that are used in gas carburizing and carbonitriding processes. Brush or dip the compounds on your surfaces and then air dry before heat treating. After heating, any residue that’s left behind can be easily washed away with hot water.

Solvent-based compounds stand up to temperature and humidity better than water-based compounds, so they dry quicker. To maintain their original consistency, use the optional xylene to thin these compounds.

Water-based compounds emit less VOCs (volatile organic compounds) than solvent-based compounds for less impact on the environment. To maintain their original consistency, simply use water to thin these compounds.

Compounds cannot be sold to the listed areas due to VOC regulations.