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Chrome flaking off nickel

March 17, 2008

Dear sir,
I am an engineering student researcher and I have problems when chrome plating nickel the chrome seems to damage the nickel when I plate it and sometimes misplates, I usually start by grinding the material with 120 grit sandpaper then 600 sandpaper and finally polishing the steel with white rubbing compound. Then I wash the product with detergent and finally electroclean it in sodium hydroxide after that I dip it in 25% HCl sol'n for a few seconds and wash it off with deionized h2o, then I dip the part in a watts nickel bath for 45min. at a temperature of 45 to 55 °C, after polishing the nickel plated material to a shine I wash it with detergent again and I electroclean it finally I wash it deionized h2o. I don't dip it in chrome live since I have a hard time with racking. my anodes are 1 to 2 inches away from the part. chromic sol'n is 100:1. plating time is 2 min. at 1 to 2 amps per square inch. Thank you for your help.

Chris Sian, 3rd year usls student
engineering student, researcher - Bacolod City, Philippines

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Hi , if the nickel is passive , the chrome will not adhere .
sounds like you are making the plating process very difficult for yourself .

Make sure you re-activate the nickel before you chrome plate , - either by cold , cathodic cleaner , or even a few seconds in a sulfuric etch - this acts as an electro-polish , and will re-activate the nickel . rinse , and immerse in the chrome live as soon as possible .

Depending on the size and shape of the part you are plating , you may also need to strike the chrome first , then lower it to what is needed -this will help the chrome "throw" into corners , or any recesses the part may have. hope this helps .

Jay Smith
- Essex, UK
March 19, 2008

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Dear Mr. Smith,

thank you for your response, I tried striking the chrome for 5 seconds and I ended up with more blisters and now the nickel came off the substrate. please help. thanks.

Chris Sian
- Philippines
March 28, 2008