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POOR ADHESION OF ELECTROLESS NICKEL ON EDGES ON ALUM.

August 19, 2008

PLEASE I NEED YOUR HELP WE HAVE BEEN ENI PLATING FOR 16+ YEARS (THE SAME PLATER) AND WE HAVE A PROBLEM THAT WE HAVE NEVER SEEN BEFORE, US AND 2 DIFFERENT NICKEL SUPPLIERS
WHEN WE PLATE EVERYTHING LOOKS GOOD BUT WHEN WE DO THE BURNISHING TEST ON THE EDGES
AND TAPE TEST THE NICKEL PEELS OFF, NOT ON THE FLAT SURFACES ONLY THE EDGES, WE HAVE TRIED CHANGING OUR 50% NITRIC, ADDING AMMONIUM BIfluoridE, HYDROFLUORIC, MAKING A NEW ZINCATE
( 2 DIFFERENT BRANDS) USING IT AT DIFFERENT TEMPERATURES. MAKING A NEW ALUMINUM ETCH,
WE HAVE TRIED NO ETCH, LIGHT ETCH, HEAVY ETCH,A NEW DEOXIDIZER, AND NOTHING IS WORKING. IT IS ONLY WHEN WE GO STRAIGHT ON ALUMINUM WHEN WE COPPER FLASH IT, NO PROBLEM. WE HAD OUR NICKEL SUPPLIER AND THEIR PLATER HERE FOR 10 DAYS AND COULD NOT SOLVE THE PROBLEM. WE CHANGED SUPPLIERS GOOD FOR A COUPLE OF DAYS AND WE SEE THE PROBLEM AGAIN.

P L E A S E H E L P!

MARIA PEREZ
Q.C AT PLATING SHOP - CHATSWORTH, CA,

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I have been plating EN high phos on aluminum for 5 years and have not seen this problem. My usual issues have been blistering after the EN bath gets old or using a high concentration zincate that gives problems in the recess areas or radius areas on a part. My steps after alkaline cleaning are: short 1 min deox in 50% nitric, 2 min etch in sodium hydroxide at 1 lb/gal, 50% nitric,1 min, followed by 1 min in 50% nitric acid/ 25% sulfuric with ammonium bifluoride( for 6061 only), 1 min Zincate. Then I strip this off in both deox solutions and use a final 30 sec zincate. My products are from Sirius for the zincate and EN solution. I hope this info helps.

Mark Batich
- Roswell, Georgia
September 19, 2008

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September 22, 2008

1. Dilute zincate and rinse
2. 4 oz/gal sodium carbonate ⇦ this on eBay or Amazon] and rinse
3. ALKALINE electroless nickel strike 5 minutes and rinse
4. Regular acid EN.

Robert H Probert
Robert H Probert Technical Services

Garner, North Carolina

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September 29, 2008

IT SEEMS TO BE A STRESS PROBLEM
IF YOU CHANGE THE ENI BEFORE 2 TURN OVERS COULD BE OK
YOU CAN ALSO HEAT TREAT THE PARTS BEFORE PLATE TO STRESS RELIEVE AT 150 °C FOR ONE HOUR

Ricardo Burstein
Bnei Berak, Israel