International Interprime 160 is a phosphoric acid based mordant solution for treating galvanised steel. International Interprime 160 is for the chemical pretreatment of galvanised steel prior to the application of protective coating systems, in order to ensure good adhesion where blasting or abrasion is not possible.

International Interprime 160 is only recommended for etching galvanised surfaces. It is not suitable for the pretreatment of other non-ferrous metals such as aluminium.

This product contains phosphoric acid. Before commencing application reference should be made to the material safety data sheet (MSDS), and the appropriate personal protective equipment should be worn, e.g. gloves, goggles, face-mask etc.

Apply to a suitably prepared, clean galvanised surface and then allow to dry. The mordant solution will gradually react and the blue colour will change with the surface blackening. This should finally achieve a uniform dark grey colour. If this does not occur due to the presence of oils, grease, flux or passivation of the surface then this area will require abrasion and a second coat of Interprime 160.

Over-application will produce a dense black powdery layer which is not suitable for the application of subsequent topcoats. This will require either abrading or washing with fresh water to remove excess acid or powdery deposits, otherwise blistering and/or adhesion loss of topcoats can occur.

Thinning is not normally required. However, if application trials result in a dense black powdery surface, then Interprime 160 should be diluted with clean, potable water and further application trials undertaken.

It should be noted that in all circumstances galvanised steelwork is likely to require a similar coating thickness for adequate protection as might be needed on steel substrates. Application of thin films can result in penetration of this paint film by zinc salts in wet corrosive environments.

International Interprime 160 has the following specification approvals:

• Complies with UK Department of Transport Item No. 155

International Interprime 160 was originally formulated to meet the requirements of British Rail's "T-Wash" solution.

Please contact Rawlins Paints' Technical Support Team on 0113 2455450 for more information.