Conversion Coating for Sandblasted Steel
SB Phos is a cleaner and conversion coating product. It is used in high to medium pressure wand washers. It deposits good quality iron phosphate coatings on steel surfaces. The coating improves paint adhesion and corrosion protection. It cleans and coats at the same time. An additional cleaning stage is not needed. It will also clean very light oils from steel surfaces. It does not deposit coatings on aluminum.
It is good for sandblasted and media-blasted metal. Because the surface of sandblasted steel has already been cleaned of oils and rust, high levels of detergent are not required. The metal is highly active and takes phosphate coatings very easily. You don’t need an aggressive cleaner or high temperatures to clean and coat the metal. SD Phos has lower acidity than most products of this type. If a more aggressive product is needed a product such as HP Phosphate should be used.
Using SB Phos in a pressure washer allows you to prepare large items for painting. The coating will be brown or blue in color. The color will depend on the coating weight.
If any very light rust occurs after sandblasting, SD Phos can remove it from the surface.
The product has two accelerators. One works at room temperature and deposits light but high quality phosphate coatings. The other deposits a heavier iron phosphate coating at high temperature. Higher temperatures produce better paint adhesion and corrosion protection.
Use
SB Phos is best used between 1 and 2 percent by volume. Higher concentrations cause flash rusting problems.
A water rinse is not needed but a rinse will provide slightly better corrosion protection to painted parts.
Although it can be used at room temperature, more corrosion resistant coating is obtained at 160-180 degrees Fahrenheit. Very short contact times are needed at higher temperatures to deposit coatings. Only a single pass over is needed. Use at room temperature requires a longer contact time.
It can be used to clean aluminum. It will remove oils but will not deposit any coating. No color change will occur on aluminum surfaces. No color changing will occur on zinc alloys or galvanized steel.
The parts can be air-dried but drying can be accelerated by using an air blow-off or an oven. Parts should be dried in humid conditions to prevent rusting. Parts should be painted as soon after cleaning and coating as possible.
Advantages
SB Phos has better flash rust protection than many other products. It may be used at room temperature if needed. Just a single pass is usually needed.
This product contains both low acid and low detergent concentrations. Material discharged to a sewer will be both cleaner and less acidic. If neutralization is required prior to discharge very little neutralizer will be needed.
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. Spray wand operations do not recycle so heavy metal buildup is not generally a problem. SB Phos does not have a high acidity level so it will not etch off high amounts of heavy metal. Although the ingredients of SB Phos are biodegradable, any detergent or cleaning chemical may have problems depending on local codes. Neutralization may be required. This product contains phosphate. It is shipped as a DOT non-hazardous product.
