Process Stainless Steel Polishing 

Stainless Steel Polishing Solution EP 8511

Product Overview: Stainless Steel Polishing Solution EP 8511 enhances the smoothness, gloss, and sharpness removal of stainless steel surfaces. It achieves a true mirror-like finish, is non-toxic, non-flammable, and non-explosive. It is easy to operate and maintain, capable of etching up to 1 mm of stainless steel surface. It increases the durability of stainless steel and reduces surface stress. The solution works quickly, with a wide range of temperature and current settings that can be adjusted according to the job. It does not contain halogens or chromates and has a long service life.

Usage Instructions:

• Solution Composition:

  • Stainless Steel Polishing Solution EP 8511: 100%

• Electrical Current:

  • DC Voltage: 4 – 9 Volts

  • Current: 15 – 45 Amps/square decimeter

• Temperature:

  • 50 – 80°C

• Etching Time:

  • 3 – 10 minutes

• Cathode:

  • Lead plate

Solution Maintenance:

• Drag Out:

  • Since EP 8511 tends to drag out frequently, it's advisable to have a drag-out tank to recover and replenish the solution. Control the solution concentration by monitoring the drag-out amount and measuring the solution's density.

• Precipitation:

  • EP 8511 is prone to sedimentation (e.g., metal salts from the etching process will settle at the bottom of the tank), so periodic removal of sediment is necessary. This is crucial for extending the tank's lifespan.

• Balancing:

  • After extended use, the solution will need balancing (in addition to replenishing losses due to drag-out and sedimentation) through strip testing or chemical analysis.

Stainless Steel Polishing Process:

1. Cleaning:

   • Clean the stainless steel surface with Soak Clean B1 solution at 60 – 75 grams/liter.

   • Rinse with clean water (preferably running water).

2. Polishing:

   • Immerse in the EP 8511 polishing solution.

3. Rinsing:

   • Rinse with clean water.

   • Optionally, rinse with a 10 – 25% nitric acid solution to remove white stains or tarnish from the surface, which often results from the polishing process.

   • Rinse with hot, clean water to remove water spots and speed up drying.

Surface Condition and Finishing:

• Cleaning Before Polishing:

  • Ensure the parts are clean before electrical polishing. Methods such as solvent cleaning, steam cleaning, soaking, or electric cleaning are all effective.

  • Remove oil or dust to prevent film or residue formation.

• Polishing:

  • Adjust time and temperature for uniform results. Lower temperatures and shorter times give a satin finish, while higher temperatures and longer times increase gloss.

  • High temperature and current density can reduce etching time and improve edge removal and part size control.

Electrolytic Polishing Technique:

• Temperature Limits:

  • Solution temperature should be between 50 - 70°C, ideally between 60 - 70°C. Generally, 3 to 8 minutes provides good polishing and smoothing.

• Voltage:

  • Recommended voltage is between 4 to 9 volts. Lower voltages may be used but are not recommended as higher voltages can cause burning and surface blemishes.

• Current Density:

  • Amperage typically ranges from 0.4 to 1.5 amps per square inch.

• Workpiece Positioning:

  • Arrange or hang parts appropriately for efficient electrical flow. Polished parts should be positive, and lead plates should be negative.

Maintenance and Equipment:

• Hangers:

  • Use copper hangers for high electrical conductivity. Hooks can be made from copper, brass, or phosphorus bronze.

• Cathodes:

  • Typically made from lead, though stainless steel series 300 is also suitable.

• Heat Source:

  • Use titanium heaters.

• Polishing Tank:

  • Generally made from steel lined with PVC, or alternatives like Polyethylene, Polypropylene, fiberglass, or stainless steel 316. PVC should be checked for temperature resistance.

• First Water Rinse Tank:

  • Can be made from stainless steel series 300, rubber-lined steel, lead, ceramic-coated steel, fiberglass, PVC, Polyethylene, or Polypropylene.

• Acid and Water Rinse Tank:

  • Similar materials to the first water rinse tank.

• Final Rinse Tank:

  • Similar to the first water rinse tank, but if using hot water, stainless steel series 300, fiberglass, Polyethylene, or Polypropylene are preferred.

Note: For small laboratory setups, Pyrex glass is suitable for all parts, including the polishing tank.