Neutral De-Ruster for Ferrous Metal Surfaces - Freiborne Industries, Inc Neutral De-Ruster for Ferrous Metal Surfaces - Freiborne Industries, Inc

Product Type: Freiclean NDR

Freiclean NDR is a pH neutral liquid cleaner designed to safely remove rust from corroded steel substrates.


Freiclean NDR is a pH neutral liquid cleaner designed to safely remove rust from corroded steel substrates. It may be used in a recirculating spray, immersion, and spray wand applications. After rinsing, the de-rusted parts may be immediately treated in a coating process or dried and protected with a corrosion control product.

• pH 6.2 – 7
• Specific Gravity 1.12
• Solvent System Water
• Color Colorless
• Storage considerations Protect From Freezing
• Method of use Spray or immersion
• Concentration 5 – 20 % by volume
• Process Temperature Ambient – 130°F
• Process Time 10 – 20 minutes minimum

Fill the process tank half full with water and add desired volume of FREICLEAN NDR. Fill to final working volume and mix. Heat the solution to operating temperature as desired. It is recommended to initially use Freiclean NDR at 200 gallons per 1000 gallons of process bath.


As corrosion product is removed and builds up in the bath, the pH will increase. As the pH increases cleanability will gradually degrade. Generally, the pH should be maintained between 6.5 and 7.0 for best results. Use Additive NDR FA to reduce and maintain a pH suitable for your particular process.

• To decrease the pH by 0.1 add 9 gallons of Additive NDR-FA per 1000 gallons of a 20% v/v Freiclean NDR


Concentration may be monitored using Refractive Index readings or by Total Alkalinity titration. Obtain a bath sample and filter the sample with filter paper.

Refractometer: Apply 2-3 drops of bath solution onto the main prism, read the result after temperature equilibration and consult the concentration table below.

Total Alkalinity: Measure exactly 25ml of FCLNDR bath into a 125ml beaker and add 5 drops of IS #2 (Bromocresol green). Titrate the solution from a blue color to a yellow end point using TS #20 (0.1N H2SO4). Consult concentration table below.

Concentration of Freiclean NDR by Refractometer or Total Alkalinity


The concentration of ferrous iron in a FCLNDR cleaning solution can be used to estimate when to dump the bath. Each application will have a ferrous iron level at which the FCLNDR bath will
become ineffective. This level can be identified through experience on the particular line.

Procedure: Measure a 10ml sample into a beaker and add about 15 drops of Testing Solution #44, then titrate with Testing Solution #18 to a pink color that last 20 seconds. Each point (1.0ml) of testing Solution #18 is equivalent to 0.1% iron in Solution.

Processing parameters can vary from application to application. Your Freiborne Sales and Service
Representative will assist you in determining the best processing criteria for your application.

pH meter Test Soln TS20, TS18, TS44 small burette funnels
Pipettes: 10 & 25ml Indicating Soln IS2
Pipette bulb Beaker 125ml
Burettes: (two) 25ml Disposable transfer pipettes “Dropettes”
Burette Stand Refractometer (optional)

FCLNDR is not safe on mild steel equipment. Equipment should be stainless steel or polypropylene. FCLNDR is safe on PE, PP, PVC, CPVC, Kynar, Viton, EPDM and silicone.

Additional Information

Temp Range

Ambient – 120


Carbon Steel, Galvanized Steel, Stainless Steel, Aluminum, Copper/Brass



Product Type


Product Line



Spray or Immersion

Ordering Information

To place an order, please contact our knowledgeable and professional customer service team:

If you are unable to find what you need or require a custom formula, please call and speak with one of our knowledgeable Formula Engineers. They can walk you through the ordering process quickly and professionally.