Rust-Anode is a cold galvanising compound (paint or spray application) and it self sacrifices - which means if you scratch the metal - the Rust-Anode will self sacrifice and protect even the scratched part of the metal. The problem is that there are many companies out there selling Primers etc with Zinc but none have the amount of zinc or the highest spec of zinc to really protect for 20odd years. You need to carefully read the spec sheets. Also, these companies sell to third parties distributors who also want to make their cut so it can end up being quite a costly experience. We at C&P have been making Rust-Anode cold galvanising in the UK since 1952 and decided to sell the end user instead of distributors. Although this means we do not make as much profit - we are only a small family run business and are just happy to provide a good old fashioned service with a reasonable price for our products. You can have a look at our website for further reading, buy direct from us (24 hour delivery) and we are happy to answer all your questions - in fact we can answer your questions as we make the stuff and you wont be put on hold to some telephone place in another country - we are in Seaford. www.candpdevelopment.com