Color depth vs. anodizing time

[Sid03]

M_D- I'd like to see somebody mix up a new batch of red dye and measure the Ph to see what it is. Something tells me it will be higher then they recommend before you even use it.

Also, i'd be interested in seeing how all your reds turned out, esp. the ones you did previously before letting the part anodize longer.

[Fibergeek]

M_D,
One more comment about connections and then I'll shut up (I promise).

A peak of 13.8V @ 6A/sq.ft. is a PAR value of 2.3 Ohms/sq.ft. That's within 92% of 2.5A/sq.ft. No connection problems here. People having problems with connections have seen 3.5 Ohms/sq.ft. and up; and lousy results, probably regardless of anodization time.

Regarding pH of newly mixed dye:

I'm no dye expert but it seems clear that anodizing dyes are sensitive to pH. It also seems to me that if the dye manufacturer could have made the dye more tolerant of pH, he would have. It's to his business advantage to make his product as easy to use as possible. I've not seen any anodizing dyes available premixed; maybe because even if they were the pH would still be off after some time. The end result is higher costs due to the increased labor and the volume of liquid, and no improvement in pH stability. Pushing the premixing and pH adjustment tasks on anyone else doesn't solve the pH problem, it just raises the dye prices.

[Sid03]

Fibergeek- thats not really what I meant when talking about the dye. I simply have a feeling that even newly mixed red dye wouldnt fall into the range that the manufacturer recommends.

[Fibergeek]

That wouldn't suprise me either.

[M_D]

Fibergeek, one of the things I have learned is you are right and that the connection is important. I haven't got a lot of experience, but for the last 6 weeks have been anodizing parts every day almost. When I first got a "real" power supply, I was seeing peak voltages of 13-15 at 4.5 amps per square foot. The area calculations of individual parts are from a CAD program where the parts are modeled in 3D, so that part of the equation is likely pretty good. I thought the connections were good, and questioned your figures and power supply meter accuracy. I was using wires with aligator clips to make the connection to the hanging wire (away from the sollution). When I changed that, the voltage dropped. Then I realized the aligator clips were not making as good of a connection as I had believed.

Even though it is somewhat related to color depth, I'll start a new post about the dye, I believe I can share some expeience and insights I have learned that may help those having problems.

[Fibergeek]

I'll be looking forward to seeing your dyeing post.

I use alligator clips too, clear of the electrolyte of course. They work fine if they have teeth to bite into the wire, Wiggling them a little after clipping them on, so that the teeth dig into the wire is a good practice. Using clips with strong springs also helps.

[M_D]

My problem was small cheap aligator clips, apparently they lacked the required spring power. Even after working them on the wire, they didn't seem to work as well as possible.

[Fibergeek]

NeoMoses, I now have the eddy current thickness gauge back.