CorrosionX Heavy Duty is for super long-term protection against serious rust and corrosion assault. For those really tough jobs where you need the ultimate protection against moisture, the answer is new CorrosionX Heavy Duty. There is no other product like it on the market today. It is a high performance, thick-film version of CorrosionX. It was developed specifically to provide maximum protection against moisture intrusion and resulting rust and corrosion.