What is a marine tie-coat and when should it be used?
A Marine Tie-Coat is a general purpose chlorinated rubber type product used on metal surfaces and as a tie coat between different types of coatings. This versatile product can be used successfully above and below the waterline and over a variety of coatings as a tie coat. It is generally compatible with anti-fouling bottom paints and various types of topside finishes.
As Rust Bullet contains aluminum, when it is applied to a hull, the hull must then be treated as an aluminum hull. As most anti-fouling paints contain copper, applying it directly onto a cured Rust Bullet coating would create an undesirable Dissimilar Metal (Galvanic) Corrosion. This galvanic corrosion occurs when two dissimilar metals (in this case aluminum and copper) are in contact with each other in an electrolyte (salt water). Due to the distance between aluminum and copper in the galvanic series, a non-conducting insulator (e.g. rubber) should be placed between them or they must be isolated from the electrolyte. On an ocean-going vessel the isolation is not an option and therefore the tie-coat must be applied.