Dura®, Durachrome®, are trade names of Plating Resources, Inc. Copyright and all other World Rights Reserved, 1990, 1995, 2014.





Cr-6 Additive is a powder blend that is used to increase Trivalent Chrome level in hex-chrome plating baths. Low levels of trivalent, below 0.65%, can cause deposit roughness, loss of brightness and a lowering of the bath efficiency.

The optimum level of trivalent chrome is 1 % of the hexavalent chrome content. This 1 % level is needed for optimum bath performance. During plating, trivalent is constantly formed at the cathode surface and then re-oxidized back to hexavalent chrome on an active anode surface. The optimum 1 % level will stay constant whenever the system is in balance. Under certain conditions, however, the level can constantly decrease. An addition of CR-6 Additive is then needed; always base any additions on a thorough bath analysis. CR-6 is also used for new bath make-up to obtain the initial desired 1 % level.

Bath Additions:
Use the CR-6 Additive as shown below. Make additions when the tank is empty and parts are not being plated. Evenly distribute the quantity needed over the bath surface and use air agitation to ensure that it is completely dissolved and uniform.

New Bath Make-Up: 10 pounds / 1,000 gallons of bath
Trivalent Adjustments: Pounds To Add = % increase x gallons x 0.01

Regulations & Fume Suppressants:
All chrome plating baths produce misting and this can be reduced if lower chrome levels are used. This mist contains Cr(VI) which is regulated by the EPA for environmental and OSHA for worker safety issues. Be sure to follow all federal, state and local regulations for safe operation and hazardous disposal. Fume Suppressants like FS-600, FS-750, FS-900 and Cancel ST-45 are very effective in controlling Cr(VI) misting. These low cost – permanent type fume suppressants are compatible with the Dura bath and do not break down to cause contamination or pitting.

The plating bath contains chromic acid, sulfuric acid and the Dura additive outlined above. These are all industrial chemicals and must be handled carefully and in accordance with the directives provided in the individual MSDS forms.

Read and understand the MSDS on all of these chemicals before handling or using. Ensure that all regulatory standards are followed and limit personal exposure as required for Cr(VI) by OSHA.

Avoid personal contact with these chemicals, avoid splashing and avoid breathing any fumes released during operation. Do not inhale any dust, mist or vapors from these chemicals. Do not allow these products to contact the skin or eyes. In case of contact, flush immediately with large amounts of fresh water and seek immediate medical attention.

Wear protective clothing such as aprons, gloves, face masks and respirators. Be sure that adequate eyewashes and emergency showers are available nearby before handling or using any of these chemicals.

Designated work clothing should be worn while using these chemicals and the worker(s) should thoroughly shower and change into fresh-clean street clothing before going home. Decontaminate all work clothing before reuse.

The user is responsible for providing adequate work clothing, personal protection, and limiting personal exposure and providing any required clean-up, decontamination as well as any needed medical attention.