Electroless kroming-did something Wrong

[benherr]

Finally got around to getting all the tanks and heaters for electroless Kroming. did my first piece today and it didn't come out very good, it fact it was pretty bad.

Polished T-6061 aluminum to high shine.
placed in SP Degrease bath at for about 60 seconds at 125 degrees
let drip dry
placed in Zincate bath at 75 degrees for about 20 seconds and let drip dry.
placed in nickel/cobalt bath for 1 hour at 175 degrees, but I think I had the mixture wrong as I had to add additional distilled water and chemicals as the level dropped from evaporation.

Piece came out very dark gray. Tried buffing but the coating(gray) was pretty bad and it didn't come out shinning.

Will need to dump the mixture and start out again from scratch.
Any suggestions from someone that's done the electroless Krome would be greatly appreciated.

ben

[KCV6]

Ben, did you thouroghly rinse off the sp degreaser prior to zincating? Did the zincate fizz violently? What did the zincated finish look like? Too much zincate can cause problems.

Mark

[benherr]

Originally Posted by KCV6

Ben, did you thouroghly rinse off the sp degreaser prior to zincating? Did the zincate fizz violently? What did the zincated finish look like? Too much zincate can cause problems.

Mark

Didn't rinse the SP, didn't see that in the instructions. The Zincate did fizz for about 10 seconds and then I removed it. Color was a medium gray looking. I didn't rinse that either, just let drip dry.

Ben

[CarWiz]

I can see how you missed the rinse. It's NUMBER 1 following the degreasing step. If you missed that, you probably missed the water break test too. What's the volume of your solution and the size of the item?

Try it again and follow the direction precisely. Including you solution volume and maximum load. It's a proven process. Even a caveman can do it.

Added: Checking the book I have, your plating solution wasn't hot enough. What does your book say?

[benherr]

Originally Posted by CarWiz

I can see how you missed the rinse. It's NUMBER 1 following the degreasing step. If you missed that, you probably missed the water break test too. What's the volume of your solution and the size of the item?

Try it again and follow the direction precisely. Including you solution volume and maximum load. It's a proven process. Even a caveman can do it.

Added: Checking the book I have, your plating solution wasn't hot enough. What does your book say?

CarWiz,
I stand corrected! that's always been one, well I'm sure I have more, problems. I don't read all the directions. In my haste to try something new I always rush it. Oh well, I always try and assemble something and only read the directions when I can't figure it out. Thanks CarWiz for reminding me to follow the directions, LOL.

ben