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Boric Acid Titration problems in nickel plating

I am a new QC chemist ( 4 months) having problems with a Nickel sulphate bath plating on Copper. I am getting roughness and trees on the middle of the plating and some pitting near the edges. When the pits are welded the boric catch fire, which will make the issue worse. The causing factor seems to be Boric acid. However my titrations show me that the boric is at 5.85 oz/gal and I was told my target range is 6 oz/gal. Oh the bath is being ran at 146 degrees. I right I am using a Mannitol titration method with a good endpoint by leaving out the DI water. I am not sure what is going wrong. I was wondering if so one could point me in the correct direction to figure this out.

David Morrison
QC chemist - Titusville, Pennsylvania, USA
2004

I think that you are having a shelf roughness problem. Try to increase your plating agitation and filtration rate. You might have to cock the rack at a slight angle. Also, 6 oz per gal is higher than necessary. 4 works just fine unless you have some unique need for nearly 6. I bet that you have a huge amount of boric on the bottom of your tank.

James Watts
- Navarre, Florida
2004

I was running the boric down at 5.5 and it ran better. However then I started we ran it above a 6.0 and all of my other tanks are high. I can't angle the parts. but I am going to add more agitation to my next run. I think there maybe something in my bath however. I ran what I call a beaker cell's it is a 1000 ml beaker [beakers on eBay or Amazon [affil links] on a hot plate. When this was ran for 3 hours at 1 amp a brown red precip formed. This was the first time this occurred however. My filters have been coming out brown on that tank. Not sure why. Right now I am in the middle of trying to find out what the precip is. My best guess right now is a iron oxide.

David Morrison
- Titusville, Pennsylvania, USA
2004

That sounds like one or more parts on the bottom of the tank.

James Watts
- Navarre, Florida
2004

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There a big problem with a "beaker" test. You don't have a range of current densities available (BTB, you might not have the proper temperature). Get management to invest in an agitated, heated Hull cell. Not only will it help with this problem, it will also help with bath maintenance and troubleshooting in the future.

James Totter, CEF
- Tallahassee, Florida
2004

My Hull Cell heater gave out on me a couple days ago; this is as close as I can come. The Beaker was held to temp. And the bath was the operating range at the end of the test. Also the plate was curved to create a high and low current density. I will repeat the results with the hull cell when I get a new heater. Also my filters come out brown to a bright yellow.

David Morrison
- Titusville, Pennsylvania, USA
2004

How do you add Boric acid, I always used anode bags and let it dissolve, If you use bags to add boric acid, Check for holes also check anode bags for holes, this can cause shelf roughness also. I would also check for material on bottom of tank you may be stirring it up.

Chris Snyder
plater - Charlotte, North Carolina
2004

I ran a spot test (below) on some solid on my side wall dissolve in nitric added ammonium hydroxide until precip formed. And I got a red-brown precip.; according to the test this is Iron. However I test the Iron for ppm and it was only at 1 ppm. Could this iron be causing my roughness and if so how to fix this. Also I add my Boric through an anode polypro bag.

David Morrison
- Titusville, Pennsylvania, USA
2004