Alodine Systems

Alodine, also referred to as iridite, is a chromate conversion coating that is applied only to the surface of aluminum. It gives good corrosion protection as well as providing an excellent base for painting. The process, developed for a major commercial aircraft overhaul facility, involves a cold alodine application followed by a cold water rinse and a final hot water rinse.

The alodine stage is improved using a turbulation system. The turbo is powered by a high volume all stainless steel pump. Closed looped manifolds with multiple injectors direct the coating solution to the working zone. The system provides an even flow of turbulent solution over, under, around and through components. The flow is adjustable. ACT turbo systems have been proven to accelerate processing time in most immersion applications. A filtration system is included with the turbo to remove fine particulate. It uses a stainless steel filter canister with a bag element and is equipped with a stainless steel oil filled pressure gauge.

Finally, MultiPort™ Oscillation, or 9-point Oscillation (see above and below) is added to the alodine stage to further enhance the coating process ensuring solution reaches all surfaces of complex components. MultiPort™ permits platform oscillation within different zones of the process chamber. With MultiPort™ seven strokes are available to choose from, each with a distinct altitude and zone of operation. As an example you can oscillate in and out of solution using a short stroke in just the upper half of the chamber, or switch to an extended long stroke in and out of solution through the entire chamber. This feature lets you fine tune applications for the optimum agitation stroke, turbo flow pattern and zoning for filling/draining of cavities without ever having to adjust solution levels.

The above system uses modular DFP immersion washers. The same alodine process line was also manufactured for another aircraft overhaul facility using the A2 Console Series (below). In this application the customer's parts were smaller and the compact and the A2PRR had the ideal size/weight ratio. Load and unload roller conveyor sections were added to facilitate staging through the system.