Bilt Hamber Hydrate-80 is a rust converter: it treats existing rust rather than bare metal. Bilt Hamber states that it converts the iron oxides into a protective metal complex and so deprives the corrosion of the moisture and oxygen it needs. The result is a stable, black base that you overcoat with a primer, coating or anti-corrosion wax. You will find the Bilt Hamber Hydrate-80 in the shop.
What Hydrate-80 does
Hydrate-80 works electrochemically: it stabilises existing corrosion and converts the iron oxides into a protective complex, while binding the moisture and oxygen that feed the rust. The product is waterborne and chlorine-free, so you avoid the blistering that cheaper, acidic converters can cause. As it reacts it changes from a grey-blue tint to black. It is emphatically a base layer, not a finish: you top it with a primer, coating or wax.
How to use it
Prepare. Remove loose, flaking rust with a brush, abrasive paper or power tools. Then degrease thoroughly and rinse with clean water; poor degreasing causes flaws.
Apply. Apply two thin coats with a brush, about 30 minutes apart; apply the second coat at 90 degrees to the first and work sparingly.
Let it react. Let each coat dry and react, around 30 minutes at 15 degrees; below 10 degrees it works more slowly.
Overcoat. Let it fully cure, then apply a primer, coating or anti-corrosion wax on top; test your paint systems on a small area first.
A base, not a finish
Hydrate-80 is meant for open, accessible spots where you have manually removed the loose rust; it converts the remaining corrosion and protects until you overcoat it. It is not meant for enclosed, rusted cavities where you cannot mechanically remove the rust and dirt; for those you choose the creeping Bilt Hamber Dynax-S50. The whole sequence from de-rusting to conserving is in the guide rust prevention and underbody protection. You will find more products in the rust prevention and conservation category.