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Input needed by some of the inhouse pro's.....

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  • Input needed by some of the inhouse pro's.....

    Hey guys, i'm trying to get some input as to a couple problems I have been having. I'm using the LCD method, a battery charger controlled by light dimmer switch, and all caswell products/kit. As far as I know, everything is set up as per LCD ano instructions.

    First off, my red dye is getting pink and no deeper. All other dyes seem to be fine, but red will not work. Is there a trick to red, or did I possibly get some weak dye, or did it possibly get contaminated(if so, how)?

    Next I was wondering some things. Will leaving the parts in the de-smut tank for longer periods of time have a negative effect on the whole operation? The desmut seems to remove some grime much better then the degreaser does, such as buffing compound, but I noticed that some parts that were in the desmut tank longer failed the water break test. Do you guys hand remove any buffing compound or let it for the chemicals? I know that the compound residue can be tiresome to remove and was simply looking for an easier method.

    I also had some weird issues with ending up with a chalky residue. Out of 5 parts in one batch, 2 parts came out like this but the others were fine. These 2 parts were the same type of part whereas the other 3 were different shapes and possibly a different series of alum. The finish on them was cloudy/chalky with a couple spots that looked ok. The chalky areas could be somewhat scratched/rubbed away leaving a powery residue on your fingers which was the same color as the dye in that area.

    I am wondering if it is ok to anodize different series of aluminum in the same batch. I would also like to know if when using the ano stripper, if there is suppose to be a black residue on the part afterwards, or if that means it was left in too long? I have had it go both ways with the stripper.

    I appreciate any input to my ramblings. I have been reading these forums for awhile now and after coming up with some random problems decided to see what advise the forum guys have to offer. Thanks in advance!

  • #2
    I can help with some, but not all of your questions.

    1. For the nice, deep reds that I achieve, I will dip my parts in the red dye for 3-5 minutes, then rinse in cold water. I've noticed that red alone is not deep enough for my tastes. I then dip the part in HBL black for a few seconds, usually 5-30, then rinse again. This will take the part to a much darker color, somewhat of a burgundy. I then dunk in the red dye for another 10-15 minutes to allow the part to soak up as much red as possible. What I end up with is a very nice red that suits my taste. There's some pics floating around in a thread somewhere if you'd like to see.

    Another option: mix some black dye in with the red. This might help you, but I would recommend doing this in small steps.

    2. I've never used Caswell's Desmut, but I believe it would be best to have the parts as clean as possible before desmutting. Possibly a good hot water/soap wash before desmutting would not be overkill.

    3. Different aluminum alloys may cause this. Also, you may just have some dye left on the surface after sealing. What was the surface finish on the chalky parts before anodizing? Gloss, satin, or matte?

    4. I've never tried anodizing different series of aluminum in the same batch, so I won't comment on this. It would only be a hunch.

    5. The black residue on the parts should easily clean off under running water with a cloth or toothbrush immediately after stripping. Less time in the stripper will help minimize this.


    • #3
      .....any other input?

      Also, any "bad" effects of using more dye then recommended? Im guessing it will just dye a deep color or dye faster....??


      • #4

        Thats funny that - I've recently been having a few problems with green - I'm getting good deep reds though. I know in my case that the green has probably been contaminated with tap water so I reckon this may be my problem. I'm going to mix up some more green and see how that goes.....

        The trouble I've found with removing polishing compound by wiping/brushing is the aluminium surface gets scratched by the very compound you're trying to remove. I would be really interested to know if anyone has a good way of handling and cleaning to preserve a nice polished finish. Do you anodise small parts ? - if so you can get a small ultrasonic cleaner quite cheap. I've just got one and the polishing compound comes off fantastically using one of caswells de-greasers as the solution. Unfortunately for me (and probably you also) it's not big enough so I am still regularly spoiling hundreds of pounds worth of goods. I'm just waiting for an affordable decent sized ultrasonic cleaner to turn up.


        • #5
          For some reason, im starting to wonder if it isnt more of an LCD issue for me. I had some parts laying around that I did with the old "normal" method and the blue looks alot deeper then it does now using the LCD method. I think that maybe I just notice how much lighter the red is now then I notice with the other colors. Anybody else notice this? Think I should try ano'in at a different current density?


          • #6

            What was your reason to change to the LCD method to start with??



            • #7
              caswell spoke so highly of it.......easier with better results they said


              • #8

                I say go back to the old method!!! This LCD just seems to complicated. I have had no problems with using a battery charger and let it rip. I know what my times should be and everything works great. It colors real well and has great hardness with my set-up. I know because I'm anodizing engine crankcases that have crankshafts turning 20,000rpm+ with no signs of anodizing breakdown. I will say that if you are using a new batch of acid with your LCD set-up that could be some of your problems. You need a certain amount of Al. in your mix. I don't know way it just works better after you have run some "junk" parts through it first. Also red is in fact the hardest for me too. I guess just the nature of the dye, takes a long time to get nice and dark. Same thing with the gold.


                • #9
                  I really dont want to change the ano bath mixture yet to go back to teh old method. One thing I hated with the old method is that I wasnt real sure how long to let the parts in. With the new method, it sounds like the connection to the part is a very large concern, which may run me into problems down the road. I just cant tap holes into alot of the parts that I will eventually be doing so that they have a super tight connection! Anyhow, anybody have advise as far as the LCD anodizing is concerned? Thanks!


                  • #10
                    Yes, you do need some aluminum dissolved in the electrolyte, about 2 grams per liter. That's because dissolved aluminum reduces the electrical conductivity of the electrolyte.

                    If you have effective current limiting, no aluminum content is necessary.

                    If you're hooking up a battery charger and "letting it rip", the only things providing any current limiting are: aluminum content, the instantly damaged electrical connections, and the battery charger being pulled down by the almost dead short.

                    You also can't possibly have any clue what the current density is you're anodizing at.

                    One day; either the diodes in the charger will blow, or the transformer will melt a winding and short out permanently.

                    Tim, I thought you knew better.


                    • #11
                      What effect will the dissolved aluminum content have in respect tot eh LCD ano method? I have anodized several times in this bath, so it isnt NEW. On the other hand, the very first time I anodized with the old method turned out fine, so thats why im wondering how much the aluminum content in the acid bath makes. Plus, I didnt see it mentioned anywhere before.


                      • #12
                        Like I said; if you have effective current limiting, you don't need any Al content. The lamp dimmer provides the current limiting if your using it as instructed.

                        The Al content doesn't hurt until it builds up to about 12 grams per liter, this applies to any anodizing method, not just LCD. The Al goes into solution at a rate of around 1 gram per sq.ft. anodized to 0.8 mils thickness. If you had 3 gallons of electrolyte, this translates to about 136 sq.ft. anodized. You'll toss the electrolyte long before you get that much because of dirt and crud that will find its way into your tank. That's why it wasn't mentioned. Anodizing with 12g/l Al content is reported to cause "mottling" problems in the anodized coating, but I have never experienced this.

                        The "let it rip" method is essentially a craps shoot; it depends on the electrical system degrading the same way and to the same degree every time (fat chance). There is no way to conclusively tell when you are finished. If the proponents of "let it rip" actually understood electricity, they would realize how unreliable it is.


                        • #13
                          well excuse me, but i belive most commercial electroplating shops use the higher current densities. if they are so unreliable, how do you account for the industry wide standard?

                          also, i have come to appreciate what ron newman was saying about detecting PAR. when the part is near PAR, the voltage is varying extremely slowly. So while you may say its only a matter of detecting when it stops increasing and starts to decrease, that change is extremely small and would be hard to detect on anything without a very good voltage detector.

                          While the LCD may help people deal with obtaining larger more expensive power supplies, ive yet to be won over on the quality aspect of it.


                          • #14
                            Yes, most commercial shops use 12 - 18 A/sqft current densities, but they don't use the ignorant "let it rip" method. They ramp up the voltage, which mimics a current source, the same thing the lamp dimmer does. I am against "let it rip" not high current density.

                            The slow peak in PAR only occurs at low current density; less than 6 A/sq,ft., it can be used at any current density. At 12 A/sq.ft. for example it is very apparent. I have a curve for 12 A/sq.ft. in my paper if you bothered to look. Don't feel bad, Ron missed that too.

                            As for as the "quality aspect" of LCD, you might try actually following the instructions, it does seem to help.

                            BTW, the dye manufacturer for Caswell does not recommend dyeing below 110 deg. F, 140 deg. F being recommended. They don't recommend room temp. dyeing at all. I wonder why that is?


                            • #15
                              Fibergeek- Please dont resign just yet....I know your the brawn behind the LCD anodizing and it's looking like I may need some advice from you!

                              Could somebody give me a decent outline on the best method of detecting PAR with the LCD method? Another thing I was wondering.....if anodizing several different sized parts at the same time, do they actually all reach PAR at the same time? Thanks guys!