Calcium Modified Coating - Freiborne Industries, Inc Calcium Modified Coating - Freiborne Industries, Inc

Product Type: Freibond 6

This excellent product has a built-in phosphate crystal refining agent, more commonly referred to as calcium modified. It is of particularly importance that it significantly enhances the detergence resistance of the paint film and has found wide acceptance in the appliance industry. A drawback of this product is that produces a harder scale on heating coils, etc. than conventional zinc phosphates.


FREIBOND 6 chemicals are formulated to provide dense crystalline zinc phosphate coatings on steel surfaces prior to painting.

FREIBOND 6A Make-up Chemical
FREIBOND 6B Replenishing Chemical
FREICLEAN Alkaline Metal Cleaning Chmical
FREICON Non-chrome final seal rinse

Stainless steel, mild steel, and high temperature acid resistant plastics are suitable for processing equipment. Utilizing 300 series stainless steel equipment will significantly increase the service life of the equipment.

The typical process sequence for Freibond D37 application consists of the following steps:
1. FREICLEAN treatment
2. Hot water Rinse
4. Cold Water rinse
5. FREICON post treatment seal
6. Drying

To charge the FREIBOND 6 tank, fill to the three quarter level with water and add 500 lbs. (41 gallons) of FREIBOND 6A for each 1000 gallons of working solution. Top up with water to working level and bring solution to operating temperature range 160-180°CF.

All metal to be processed in the FREIBOND 6 solution should be free from grease, oil, scale, or other soils. Your FREIBORNE Representative will recommend the proper cleaner for your application.

After cleaning, the work should be thoroughly rinsed with hot water. The rinse should be overflowed at a rate which will keep it clean and free from scum and contamination.

Processing times usually range from 2-5 minutes.

The properly cleaned work is now placed in the FREIBOND 6 solution for coating to establish the proper immersion time and temperature for your application. Once these parameters are established the time should not vary more than 15 seconds and the temperature more than + 5°CF.

After phosphating in FREIBOND 6, the metal is rinsed in cold water for 20 – 45 seconds. The rinse should be overflowed at such a rate that the Total Acid of the rinse is less than 0.2 points.

The final stage is the FREICON solution. The work should be immersed in this rinse for 30 – 45 seconds. The FREICON solution provides a protective barrier prior to painting enhancing the corrosion protection. This rinse is prepared with deionized water.

The work is now dried. The FREICON solution may be heated to facilitate the drying stage.

To maintain the bath’s performance it should be regularly tested and adjusted to within operating parameters. Normal processing time with FREIBOND 6 is 2-5 minutes but processing times may vary depending on your specific needs. Processing parameters can vary widely based on individual processes and performance requirements. Typical operating parameters are listed below. Your Freiborne representative will help develop the proper operating parameters for your specific needs.

Pipet a 10 ml sample into a suitable beaker or Erlenmeyer flask and add 5-10 drops of Indicating Solution 3 (phenolphthalein). Titrate with Testing Solution 11 (0.1N NaOH) to a permanent pink endpoint. An addition of 1.5 gallons (18 lbs) of FREIBOND 6 per 1000 gallons will raise the Total Acid by 1 point.
FREIBOND 6A is used only for make-up or in replacing points lost due to mechanical loss, such as leaks, etc.

FREIBOND 6B is used for normal replenishing of the bath.

During the phosphating reaction, sludge is formed as a by product of the reaction. This residue collects at the bottom of the tank and should be removed regularly so that is does not deposit on the work. The sludge is generally removed by allowing the sludge to settle to the bottom of an auxilliary tank, then the clear solution is pumped back into the processing tank from the top of the auxilliary
tank. A cone shaped bottom with a bottom valve is convenient for discharging the sludge into drums for disposal. Filter pressing the sludge will recover most of the solution and lower disposal costs. FREIBOND 6A Make-Up Chemical should be used to replace any points lost during desludge.

When the FREIBOND 6 solution has been heated for some time, scale will build up on the heating coils. Periodically the coils must be removed from the tank and the scale removed by immersing in muriatic acid or by mechanical means.

Additional Information

Temp Range



Carbon Steel, Galvanized Steel


Paint Pretreatment, Rubber-Metal Bonding

Product Type

Conversion Coatings

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.