Conversion Coating for Aluminum, Galvanized and Steel
AL Phos is a cleaner/conversion coating product used in a high-pressure wand spray washer. It deposits a conversion coating on the surface of aluminum, steel, and galvanized steel. This improves paint adhesion and corrosion protection. It cleans and conversion coats at the same time.
Using AL Phos in a pressure washer allows you to prepare large fabricated items for painting in one pass. No long dwell times or second passes are required.
It will also prepare zinc and aluminum castings for subsequent painting operations.
It removes light to medium rust and often eliminates the need for sand or media blasting.
The product may be used at room temperature. However this product is normally used at higher temperatures since it provides better cleaning and paint adhesion.
Use
AL Phos operates at a very low concentration. It should be used at 0.75 to 1.00% by volume. Typically, it is used at slightly less than 1%. Higher concentrations should be avoided if it is used on steel, because it can cause flash rusting problems. If just aluminum is being processed higher concentrations may be used to accelerate the coating deposition.
A rinse is not required, a rinse will usually provide better corrosion protection to painted parts.
Although it can be used at room temperature, better cleaning and a more corrosion resistant coating is obtained at 160-180 degrees Fahrenheit. Short contact times are needed at higher temperatures to deposit coatings, just a single pass over. At room temperature a longer contact time is required.
The parts can be air-dried but drying can be accelerated by using an air blow-off or an oven. Steel parts should be dried in humid conditions to prevent rusting. This product leaves a highly activated surface and steel should be dried if possible to prevent flash rusting. Parts should be painted as soon after cleaning and coating as possible.
Advantages
AL Phos may be used at room temperature if needed. It can be used on aluminum, galvanized and steel metal.
It is used at exceptionally low concentrations, therefore has lower chemical discharges and less cost.
Disposal
Follow all local discharge regulations before putting this product down a drain. Because of the short contact times and the one-pass nature of AL Phos, heavy metal buildup or buildup or grease or oils are not generally a problem when coating steel or aluminum. However coating galvanized metal may dissolve some zinc. This can put the user close to or over discharge limits. Although the ingredients of HP Phosphate are biodegradable, any detergent or cleaning chemical may have problems depending on local codes.
