Heavy Zinc Phosphate Conversion Coating
ZP Phos HV deposits very heavy zinc phosphate coatings on the surface of steel. The picture above is a one by one inch section of a coated panel. The crystal structure is composed of zinc and iron phosphates. There is no calcium or other metal in the coating. Coating weights of 1500-5000 milligrams per square foot can be achieved.
Can meet the requirements of MIL-DTL-16232 (DOD-P-16232).
Use
ZP Phos HV is used at 3% to 5% by volume. Higher coating weights are obtained with higher concentrations. An accelerator is normally not needed. Temperatures are 150 to 180 F. Processing times are 5-15 minutes. It is an immersion only product.
The metal must be free of oil prior to coating. It may be cleaned in acid or alkaline cleaners. The metal should be well rinsed with clean water prior to the processing tank.
The free and total acid of the product should be tested periodically to make sure that the concentration is being maintained. Normally the free acid needs to be adjusted when the bath is initially charged. Usually only additions of product are needed to maintain the bath.
Addition rust protection can be obtained by using an oil such as Solve 140SE Rust Preventative.
Advantages
Very heavy coating weights can be obtained. Typically 2000-5000 milligrams per square foot. This provides excellent corrosion protection especially when a rust protective oil is used on the surface. It also provides lubricity to the surface. When properly oiled it can exceed specifications from most manufacturers. It prevents galling on fasteners threads.
It is easier to use than many other heavy zinc products due to it wide operating range. Less sludge is produced than other zinc phosphate products.
Disposal
Follow all local discharge regulations before putting this product down a drain. ZP Phos HV contains zinc and a small amount of heavy metal accelerators. It is an acidic product and must be neutralized prior to disposal. A waste treatment system should be used to remove the metals prior to any discharge. There are no organic materials in the product.
