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first timer needs advice

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  • first timer needs advice

    Hey I just ran my first anno batch today and had some questions about my results. I am running 4 scrap pieces of metal with a combined surface area of 45 sq inches. I put this into the 720 calculator and it told me to set the amps at 1.38 and run it for 20 minutes with its peak voltage being 11.25. Now my first question is because of my PS, I can set the voltage on it but not the amps, there is just a analog readout of them. So how should I approach powering the parts up? What I did was set the amps to about 1.5 with the voltage dial and let it go. The first thing i noticed was that there were almost no hydrogen bubbles forming, except for from a hole that I drilled in the part a few weeks ago. After about 25 minutes I pulled the parts out and measured their resistance with an ohmeter. They all were in the 30-40 ohm range which I thought ment that they had a good layer on them but i guess not. I took one of the parts out and put it in the dye tank and left the other in for another 25 minutes. The one in the dye didn't take any dye and when I took the 3 out of the acid tank that they had been in for 50 minutes now they still ahd the same 30-40 ohm resistance. I used a voltmeter to measure the voltages on all of the wires while it was going and they all had the same so they are getting power. Voltage was around 11 after i had turned it up to 3 amps. Prior to putting them in the tank I put them in the degreaser for 5 minutes after which they passed the water test and then in the deoxidizer for 3 minutes. To attach the parts I threaded the radio shack wire into them and also into the hanging rack.

    Thats all the info i can think of now, ask if there is anything missing. Where am I going wrong?

    Also can you leave dyed parts out without sealing them and still be able to seal them later? If yes then how long?

    Thanks a lot for the help

  • #2
    Re: first timer needs advice

    First, your off on using the 720 calculator, with 11.25 peak voltage means you have 4.5 CD which is ok. The amp setting of 1.38 for a 45" SA is ok. The 20 minute run time is way off. It means you are attempting a coating thickness of between .1 to .2 mil. That's not enough to dye. Try .5 to .7 mil for good dyeing qualities.

    The PS is your next problem. Since it it not CC capable, you can adjust your voltage to get your amperage and keep adjusting to maintain the amperage whichmay get old after a 80 minute run for a .5 mil coating or turn the voltage to 12V and use light bulbs to limit the current or find a PS that is CC capable. Whatever you want. The easiest in the long term will be a PS that is CC/CV capable.

    You have positive to the part? Negative to the cathode? What kind of cathode and how is it attached?

    After you dye the parts, they can be left out. They will start to seal on their own but it will not be as good a seal.

    Cipher through this and see if you have any more questions. It takes a little to get going but it'll be worth it. SS


    • #3
      Re: first timer needs advice

      Alright well good news, after leaving the parts in for about 50 minutes they apparently did get annoed, I tested for conductivity and there was none. Though my next problem is that I left them in red dye at about 130 degrees for almost an hour and they still came out a pinkish color. Also the parts have some white dots and streaking on them. I don't have any pH strips yet so I am not sure what the pH of the red is yet, could that be the problem? Or was my anno layer not thick enough to take a deep color?

      I was pretty excited that I actually acheived something on my first try, I can tell how some people can get really into this!

      Thanks for all the help


      • #4
        Re: first timer needs advice

        Sounds like the anodize was too thin. Are you rinsing well between steps with distilled water or RO water? The streaking could be acid drag in. You see how it feels with a pink part, it gets better.


        • #5
          Re: first timer needs advice

          I was using distilled water to spray off the part over the tanks and then I rinsed more with reguler tap water, could the tap water make that much difference? I have been trying to decide whether to buy a RO machine or not, do you have any suggestions of good cheap ones?


          Also, if the 720 calculator gives me the wrong amount of time to keep it in how do i tell how long to keep future parts in?


          • #6
            Re: first timer needs advice

            Depending on how hard the water is or how much chemicals they put in the water to treat it will cause a long list of problems.

            All the RO filter systems I looked at started out at the same price Caswell offers theirs for and then go up from there. I couldn't do without mine. Most in that price range only do ten gallons a day, so I have to stock up with clean 5 gal. buckets for a big run. There is quite a bit of evaporation in the heated tanks.

            Paraphrased - can't find the original.
            720 rule states you can grow 1 mil of coating with 720 amp minutes of current.
            720 amp minutes X .5 mil (or desired coating thickness) = 360 minutes
            360 minutes / 4.5 CD = 80 minutes run time

            Peak voltage is calculated by 4.5 CD X 2.5 ohms = 11.25V
            A resistance of 2.5 ohms was derived from many tests run by Fibergeek and found not to be exact but fairly consistant with good electrical connections.

            Desired ASF(amperage per square foot) or CD / 144 = amps per square inch
            A 4.5A CD / 144 = .03125 amps per square inch
            .03125 X part SA = PS amperage setting

            You probably are familiar with most of this but I stuck it in any way. How's it going with your PS?


            • #7
              Re: first timer needs advice

              Alright well I guess that I should look into buying the RO system and hope that that solves some of my problems. I understand the 720 rule better now, thanks. My PS might be a problem though, I am in no condition to spend hundreds of dollars on a new CC rectifier so I think I will just ahve to make due with what I have. You said that I can set up light bulbs like I was using a battery charger and then set the PS on 12v? I might have to do that and see what kind of results I get.

              Thanks a lot