Zinc Rich Primer
Zinc Rich Primers are widely used for the purpose of corrosion protection on iron and steel. Their performance characteristics are well known and their use has become ubiquitous in the coatings industry. A variety of products are offered, using either organic or inorganic binders.
But there are issues. Those based on inorganic technology are not user-friendly. They require meticulous surface preparation, will mud crack if applied at more than 4 mils (100 microns) and will not cure properly in wet conditions. They are extremely brittle, so resistance is poor to impact, flexing and thermal shock. Abrasion resistance ranges from good to poor. Some formulations cannot be topcoated for 18 to 24 hours, resulting in production delays.
These problems gave rise to the advent of zinc rich primers using organic resins as the carrier rather than inorganic. While these are slightly more surface tolerant and significantly more flexible, they will not cure properly at cold temperatures and have poor impact resistance.
Madison Chemical developed AlumiZinc® ‘S’ in order to take the state of the art to a new level. By incorporating both zinc and aluminum and by adding a variety of other anti-corrosive ingredients, AlumiZinc ‘S’ offers superior protection in a user-friendly and forgiving format.
AlumiZinc ‘S’ is surface tolerant. Not only will it work superbly under extreme conditions on a grit blasted surface, but it is also able to provide surprisingly good results in everyday industrial/commercial environments without blasting. For such situations, simply use Madison’s FerroGrip® Surface Conditioner, an easy to use soap-like non-hazardous compound. When sprayed on, FerroGrip will dissolve mill scale, remove rust and degrease the surface within about 45 minutes. Then, rinse off and blow dry the surface. FerroGrip contains Madison’s proprietary AP-50 Adhesion Promoter and, when topcoated with AlumiZinc ‘S’, which also contains AP-50, a tenacious bond is formed between AlumiZinc ‘S’ and the substrate, thereby providing adhesion comparable to abrasive blasting.
AlumiZinc ‘S’ handles like paint, cures at sub-freezing temperatures, won’t mud crack and has a pleasing silver metallic colour. The combination of abrasion and impact resistance exceed all other technologies. Corrosion resistance is on a par with the best of the traditional inorganic and organic formats.
A note regarding galvanized and weathering steel: If you are coating over galvanizing or weathering steel, technology now exists that will eliminate the need for blasting, even for heavy duty and severe service applications. Click here to switch to the GalvaClad overview page.