Chromates / Passivating

CHROMATES / PASSIVATING

Chromates are used in order to coat metal parts that have been Zinc electroplated to provide a longer life for the part. A procedure referred to as Passivating is commonly performed on zinc-plated parts using chromates to make them more durable. The chromate coating acts like paint, protecting the zinc from corrosion, this can make the part several times more durable depending on chromate type and layer thickness.

Jane Kits offers four chromates in blue, yellow and olive green and black variations. They are referred to as Gold Bright, Blue Dip, Olive Drab and Black Zinc. These chromates are trivalent chromium chromates and therefore have extremely lower toxicity to the traditional hexavalent chromium that was traditionally used.

Gold Bright is a traditional yellow chromate that is commonly found in many automotive and construction industries. The freshly zinc plated articles are immersed in the Gold Bright working solution for 5 to 30 seconds.

Blue Dip is a trivalent chromate conversion coating for zinc. The freshly zinc plated articles are immersed in the Blue Dip working solution for 20 to 50 seconds. It imparts a clear blue coating with no evidence of yellowing.

Both Gold Bright and Blue Dip chromates are included in our Zinc Plating Kits or can be purchased individually in various sizes via our website. Both of these chromates are very concentrated and will need to be mixed at a ratio of 1.5 % with water to form the working solution. (i.e. 15ml of Gold Bright or Blue Dip chromate to 985 ml water, to make a 1 litre working solution). Therefore, a 60ml bottle of chromate will make 4 litres of treatment chemical. Gold Bright or Blue Dip treatment baths should be run at a temperature between 21 to 30 degrees Celsius.

The Olive Drab chromate can be purchased separately on our website and is an extremely economical single dip chromate conversion coating, which produces a protective olive-green coating on zinc electrodeposits. Olive Drab produces a heavy chromate film, thereby providing maximum corrosion protection and a better base for paint. It can be used as an economical substitute for an organic primer under paint, saving both materials and labour, or as a final finish, providing both protection and colour. It is commonly referred to as a military colour.

Olive Drab is supplied as a liquid concentrate, which is mixed at a ratio of 7.5 % with water to form the working solution. (i.e. 75 ml Olive Drab to 925 ml water, to make a 1 litre working solution) The freshly zinc plated articles are immersed in the working solution for 30 to 90 seconds to produce a tough, olive green conversion coating. Olive Drab treatment bath should be run at a temperature between 24 to 32 degrees Celsius.

Black Zinc chromate can also be purchased separately on our website and is an extremely popular chromate option given the desirable black finish it produces. It is used to produce a black chromate conversion coating on either zinc or cadmium electrodeposit by simple immersion. This process gives a final attractive glossy black finish with very good corrosion protection. Unlike the other three Jane Kits chromate options, the Black Zinc chromate is not a concentrate that requires mixing with water, it is in fact sold as a ready mixed working solution. The freshly zinc plated articles are immersed in the Black Zinc working solution for 30 to 90 seconds to produce a tough and very desirable attractive gloss black finish. Black Zinc treatment bath should be run at a temperature between 22 to 31 degrees Celsius. The Black Zinc chromate is somewhat problematic to maintain, as a result, once the solution is not producing the desired result it is time to replace.

For Black Zinc passivation, an additional final water dip is required. The makeup of the final water dip should include 30% JPK Aqualac. This process will eliminate iridescence and can be introduced across other chromates if desired.

JPK Aqualac is a clear copolymerized acrylic, water-based lacquer used over metal parts to yield a corrosion and scuff resistant finish. It is predominantly used in the final water dip following the application of Jane Kits Black Zinc chromate. This process will eliminate iridescence and can also be introduced across other chromates if desired. It can also be used as a final clear finish over bright nickel, chromium, brass, zinc plate and zinc diecast. The film is very tenacious and will withstand swaging and cold forming. However, for a more advanced clear protective metal coating Jane Kits - Clear Shield is a more suitable option. See our website for more details regarding Clear Shield. The mixing ratio is between 10% - 30% with water. (i.e. 100ml to 300ml JPK Aqualac per 1 ltr water). The process is applied by simply dipping the part into the mixed working solution.

All of Jane Kits chromates are applied by a simple dip process, done in a separate bath than the Zinc electroplating bath and do not require any electrical current or complicated bath set up. The procedure is straight forward and is best done immediately after parts have been zinc plated. Following the zinc plating procedure, the parts continue through a cleansing and activation process.

The activation chemicals required for this procedure is called Metex IT. This is essential for good adhesion of the chromate. The parts are immersed in the chromate solution and left for the correct time.

The passivating procedure can be carried out in Ceramic crock, Type 316 Stainless Steel, Koroseal, PVC, polyethylene or polypropylene containers. Store the chromates in an airtight PVC, polyethylene or polypropylene container. Any internal heaters should be constructed from Quartz or 316 Stainless.

The mixed chromate can be used more than once. Store it in an airtight container for future use. Replace the mix when the results appear to be lighter.

NOTE only use deionised, demineralised, distilled or rainwater to create your plating bath. Do not use tap water. It may have too many additives that will contaminate your bath.

 

METEX IT ACTIVATOR

METEX IT is a dry acid material that is mixed with water. This is used as a pre-dip activator before passivating. It will improve the appearance of the passivating, enhance the adhesion and lengthen the life of the passivating solution. The Metex IT is mixed at a ratio of approx 20 grams per Litre and dip for 30 seconds.

 

JPK AQUALAC

JPK Aqualac is a clear copolymerized acrylic, water-based lacquer used over metal parts to yield a corrosion and scuff resistant finish. It is predominantly used in the final water dip following the application of Jane Kits Black Zinc chromate. This process will eliminate iridescence and can also be introduced across other chromates if desired.

It can also be used as a final clear finish over bright nickel, chromium, brass, zinc plate and zinc diecast. The film is very tenacious and will withstand swaging and cold forming. However, for a more advanced clear protective metal coating Jane Kits Clear Shield is a more suitable option. See our website for more details regarding Clear Shield.

JPK Aqualac is water-based and contains no solvents, it is non-flammable and produces no polluting fumes and fire hazards are eliminated. The final finish is stable to light and heat. The finish will also resist corrosive and weathering atmospheres.

The mixing ratio is between 10% - 30% with water. (i.e. 100ml to 300ml Aqualac per 1 ltr water). The JPK Aqualac rinse bath should be run at a temperature between 21 to 49 degrees Celsius. The process is applied by simply dipping the part into the mixed working solution. The part is introduced into the working solution wet, straight after the previous water rinse bath. Move the part around for 10 seconds, remove and shake excess from the part but do not touch it, simply hang to completely dry. Ensure there are no excessive gathering of the coating during drying. A periodic shake may be required during this drying process.

 

METEX IT Activator 100 grams – (you receive a 100gm bag of Metex IT)

METEX IT Activator 500 grams – (you receive a 500gm bag of Metex IT)

Jane Kits have four types of Chromates available. Gold Bright, Blue Dip, Olive Drab and Black.

Gold Bright and Blue Dip are available in various sizes and are both mixed at a ratio of 15 ml chromate per 985 ml water.

60 ml Gold Bright Chromate solution – (you receive 60 ml of chemical)

60 ml Blue Dip Chromate solution – (you receive 60 ml of chemical)

60 ml Combo Blue Dip/ Gold Bright Chromate solutions – (you receive 60 ml of blue Dip and 60 ml of Gold Bright chemical)

150 ml Gold Bright Chromate solution – (you receive 150 ml of chemical)

150 ml Blue Dip Chromate solution – (you receive 150 ml of chemical)

150 ml Combo Blue Dip/ Gold Bright Chromate solutions – (you receive 150 ml of blue Dip and 150 ml of Gold Bright chemical)

250 ml Gold Bright Chromate solution – (you receive 250 ml of chemical)

250 ml Blue Dip Chromate solution – (you receive 250 ml of chemical)

250 ml Combo Blue Dip/ Gold Bright Chromate solutions – (you receive 250 ml of blue Dip and 250 ml of Gold Bright chemical)

250 ml Olive Drab Chromate solution – (you receive 250 ml of chemical)

500 ml Olive Drab Chromate solution – (you receive 500 ml of chemical)

1 Litre Black Zinc Chromate solution – (you receive 1 litre Black Zinc Working Solution)

2 litres Black Zinc Chromate solution – (you receive 2 litres Black Zinc Working Solution)

5 litres Black Zinc Chromate solution – (you receive 5 litres Black Zinc Working Solution)

150 ml JPK Aqualac lacquer – (you receive 150 ml bottle of lacquer)

250 ml JPK Aqualac lacquer – (you receive 250 ml bottle of lacquer)

1 litre JPK Aqualac lacquer – (you receive 1 litre bottle of lacquer)

Although these are stock sizes, we will be happy to provide larger sizes if required. If you wish to purchase a larger size than the stock sizes listed, please email your request to sales@janekits.com.au

 

CLEANING & PREPARATION

With all Jane Kits products, the key to successful plating is in the preparation of the items to be plated. Parts must be chemically clean. In order to ensure that you get pleasing and consistent results, Jane Kits sell very efficient Cleaner Kits (see cleaners). Thorough cleaning is essential in the preparation of parts prior to electroplating.

NOTE only use deionised, demineralised, distilled or rainwater to create your plating bath. Do not use tap water. It may have too many additives that will contaminate your bath.

 

DISCLAIMER

JANE KITS do not accept any responsibility for any injuries or for any ill effects resulting from the careless or improper use of any of our products. No responsibility will be accepted for any injuries or for any ill effects or accidents resulting from the improper storage or lack of your safety markings on our products.

All products should be used with care and as per the instructions in this Plating Manual. All MSDS are available on request.

NOTE: Care should be taken by the bath operator no matter what type of bath is being used. Avoid allowing chemicals to remain on your skin for long periods. Safety glasses and clothing that covers arms and legs should also be worn. A well-ventilated room is necessary and avoid inhaling fumes that are present during the plating or mixing processes. A suitable respirator is recommended.