HELP!
I'm really scratching my head on this one...
OK, I made a run last night with a mix of alloys and colors. All but one of the parts is 6000 series, with the one oddball 7000 series part.
The parts were to go three different colors... lime green, bordeaux red, and black. The one oddball 7000 series part goes black.
So I make my run the same as I always do, and the green and red parts turn out great, but only the one 7000 series part took black dye. The rest of the black parts turned out blue gray. What the hell
!!!
At first I thought the black dye was giving me problems (it's quite old). I didn't notice that the one part turned out OK until today, and that's when I realized it was the one 7000 series part.
So here is my setup:
3:1 battery acid mix
69F acid temp
connections checked at beginning of the run & OK
10A CC PS
111.65 sq. in of parts run at 4.6 amps for 90min
voltage climbed quickly to 11.5v, and stayed there for the entire run
All of the parts were prepared the same, run at the same time, rinsed and dyed at 140F, yet only the 6000 series black parts wouldn't take dye.
I didn't seal the bad parts, and this morning thought that maybe it was an error in my calculations... usually in the last 15min of my run the voltage begins to drop by .1 or .2 volts, but this time it stayed steady. So as an experiment, I removed the dye with dilute bleach, rinsed well, then followed up with 3:1 acid. With all of the color removed, and the parts still attached to thier wires, I went another 30min at the same 6A CD, then rinsed and dyed at 140F. The results were exactly the same... blue-ish gray.
Does 7000 series alum. take dye better than 6000 series?
Is there a problem anodizing at 6A CD when dying black?
Anybody else experienced this? What was the solution?
I'm going to have to strip the parts and start over now, and I don't want to waste my time with bad dye, but why would the dye work on 7000 series if it was bad?
I'm really scratching my head on this one...
OK, I made a run last night with a mix of alloys and colors. All but one of the parts is 6000 series, with the one oddball 7000 series part.
The parts were to go three different colors... lime green, bordeaux red, and black. The one oddball 7000 series part goes black.
So I make my run the same as I always do, and the green and red parts turn out great, but only the one 7000 series part took black dye. The rest of the black parts turned out blue gray. What the hell

At first I thought the black dye was giving me problems (it's quite old). I didn't notice that the one part turned out OK until today, and that's when I realized it was the one 7000 series part.
So here is my setup:
3:1 battery acid mix
69F acid temp
connections checked at beginning of the run & OK
10A CC PS
111.65 sq. in of parts run at 4.6 amps for 90min
voltage climbed quickly to 11.5v, and stayed there for the entire run
All of the parts were prepared the same, run at the same time, rinsed and dyed at 140F, yet only the 6000 series black parts wouldn't take dye.
I didn't seal the bad parts, and this morning thought that maybe it was an error in my calculations... usually in the last 15min of my run the voltage begins to drop by .1 or .2 volts, but this time it stayed steady. So as an experiment, I removed the dye with dilute bleach, rinsed well, then followed up with 3:1 acid. With all of the color removed, and the parts still attached to thier wires, I went another 30min at the same 6A CD, then rinsed and dyed at 140F. The results were exactly the same... blue-ish gray.
Does 7000 series alum. take dye better than 6000 series?
Is there a problem anodizing at 6A CD when dying black?
Anybody else experienced this? What was the solution?
I'm going to have to strip the parts and start over now, and I don't want to waste my time with bad dye, but why would the dye work on 7000 series if it was bad?
Comment