Quote:
Originally Posted by xgenmods
Yes this is a new tank. I did try the red dye and it came out a bit dull but otherwise ok. Should the aluminum be changing color at all during the process? I have done a form of anodizing a long time back on personal items with a battery charger. I just started doing anodizing again on a larger scale due to the problems and cost of the local anodizer. I figured cut the middle man and do it in house. I went all out this time and bought a tank and cc 50 amp power supply. Anyways my tank is 20 gallon with a mixture of 1 gallon to 3 gallons of distilled water bought from the store. Everything else is mixed with RO water. The tank uses aluminum for the cathode and has a surface area of around 12 feet. Its a u shaped loop. The tank is agitated with a pvc manifold and a 1100 gph little giant pump.
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Sounds a good setup
In the early days, after finding that we couldn't do black from a virginal acid/water mix in the tank, we used to run some test plates (just large coupons of 1.5mm sheet) to settle things in and 'seed' the tank. After doing test dye runs, we found that the less demanding lighter colours we do (red, green) will come out OK with virgin mix, whereas getting sufficient ano matrix to hold deep rich black requires a 'run-in' tank, and better temperature control.
With the LCD process type II anodising, we don't really see any noticeable colour change or tinting here during the actual anodising process.
You mentioned that you can get an OK but dull Red. Some of the dullness might be etching due to over-long immersion in the de-ox/de-smut - 6061 shouldn't need anything like 10 minutes in there.
Also, your initial process list went as far as the dye tank, have you been stopping there? - the best of the surface isn't really shown until after the boiling Nickel Acetate seal and then we air-line-dry and dip in / wipe with WD40.
You also asked about accuracy of surface area measurement. Opinions will probably vary on what you can get away with. Gross errors (e.g. only counting one side of a sheet plate) will certainly betray you. Overall, the better you can do, the better the result. Its also a question of whether you're doing one-offs or a longer / colour-matched run. If all your process tank temperatures, chemistry etc. are OK, then maybe you can get away with 10% errors in area for a one-off, but you should strive for perhaps 1% or better as that's one of the easiest variables to control or factor in. Because the lighter colours can work with a thinner ano layer, provided you err on the side of building a slightly-too-thick layer, there is more lattitude that there is for black etc.
Dave