Nickel-Free Seals are the Responsible Choice

According to the World Health Organization, nickel is an essential element for the normal growth of many species of microorganisms and plants as well as several vertebrates. In small quantities nickel is absolutely vital but, when the uptake is too high, it can be a danger to human health.

Fortunately for anodizers, non-nickel sealants have established themselves as a reliable alternative with over 20 years of proven production success.

Because nickel-free seals contain no regulated metal and are relatively pH neutral, waste treatment is simpler, easier and cheaper compared to using a nickel-based seal.

These products can be applied alone or as the final seal in a two-step sealing system. Architectural firms can use nickel-free seals for electrolytic and clear anodized finishes. Many job shops apply them for clear and color work.

For job shop applications, the concentration of the seal can be lowered to allow a more frequent, yet economic, tank replacement while providing a fresh seal solution. This is particularly helpful in bright dip shops where phosphate contamination is the usual reason for seal tank replacement.

Bath life can be extended further by using an organic additive which can also improve the rinsing action of sealed parts, reduce sealing smut and improve sealing efficiency.

Nickel-free concentrates can produce a quality seal under mid-temperature conditions which will provide substantial savings in equipment for heating, exhaust and waste treatment.

Using a non-nickel seal in accordance with recommended practices, coatings will meet or exceed specified requirements using ASTM test methods B136, B117 and B680.

Nickel-free products also:

• Provide excellent salt spray resistance
• Do not cause yellowing of the coating
• Produce a smut-free hydrophobic surface
• Are easy to filter, titrate and control
• Extend bath life

This post was submitted by Mark Jozefowicz, VP – Technical Services for Reliant Aluminum Products.