Boiler Rust Inhibitor - Wood Boiler Chemical - Boiler Chemical - 1 Gallon - Treats 250 to 500 gallons of fresh water Boiler Rust Inhibitor - Treats 500 to 720 fresh water. Use in most outdoor wood boilers. Compatible with propylene and ethyelen glycol. Stops boiler corrosion. Compatible with Iron, SSTL, Copper, Bronze, and PEX. Turns the water pink for product residual and leak detection.