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  • Copy cad hazing issue

    Hello,
    I have the 1.5 gallon copy cad kit. I keep getting a hazing issue on the zinc layer when the part is removed and allowed to dry. It’s a thin chalky white appearance and will polish off fine. When i try to yellow chromate the part right out of the zinc bath, the yellow obviously shows the haze.

    I have added the recommended amount of brightener and I have the agitation pump submerged and pumping against the wall of the bucket. My zinc solution is about 1.25 gallons.
    My cleaning is perfect, all prior zincs removed, polished and then placed into the degreaser. Water test passes and into the acid etch it goes. Plating takes hold very well.

    I can plate smaller items like washers and they come out perfect. This is a barrel of a wiper motor and it’s 2.5 inch by 4 inch. I am standing it up to plate the outside only with 3 anodes at 5.3amps.

    The first time I plated this part, I had the amperage up too high and got a tiny bit of blistering. Not noticeable but if you looked hard you could find it. That was at 11 amps.

    I am starting to question if the PH is off due to the high amperage for 10 minutes or if enough of the brightener was burned off to make plating a larger part hard but enough that washers plate fine. Or could my amperage be too low.


    please help

    thanks

    Terry
    Last edited by TerryG; 06-10-2020, 08:40 AM.

  • #2
    What temp is your De greaser running at ? I have seen this happen quite a bit when the De greaser is to hot. When the parts are pulled from the hot De greaser they dry before they can be rinsed, causing a film on the part that can be seen once plating is finished.
    --
    Jason Vanderbroek
    315 946 1213 x116
    www.caswellplating.com

    Comment


    • #3
      Jason, That is a good thought....i didn't think of that.

      The barrel is very hot coming out of the degreaser. The last time around I didn't pay close attention to the temp but pulling the barrel out of the tank it was drying as it came out. I will correct that error and give it another try. Do you think it would be worth a final wipe down with isopropyl alcohol would be good for added measure?

      Terry

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      • #4
        No, just keep the De greaser around 140, no hotter than 160 and it should solve the problem.
        --
        Jason Vanderbroek
        315 946 1213 x116
        www.caswellplating.com

        Comment


        • #5
          OK, I was targeting 190 degrees anyway. I got that off the package of the degreaser.

          Comment


          • #6
            Just curious, have you made any positive progress ?
            --
            Jason Vanderbroek
            315 946 1213 x116
            www.caswellplating.com

            Comment


            • #7
              Good Morning Jason,

              As a follow up for anyone searching.... Lowering the degreaser temp only helped a tiny amount. I did add a teaspoon on brightener to rule that out.....again, helped a tiny bit. The hazing got progressively worse. I plated the barrel twice. I could polish the haze off and it was gorgeous, but that left the difficulty of yellow chromating after the zinc was hardened. That created its own challenges with some of the yellow being soft and easily wiped off 24 hours later. I got frustrated and changed out 1/2 the zinc solution with freshly mixed solution. Problem solved.

              I appreciate the help and hope this helps anyone reading.

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