Question on Ano Flaws

I know how to anodize, ive done it succesfully on scrap aluminum. I tried to anodize my Popstar as a test for yoyos but after being in the electro bath for 30 min in came out with tons of black pitting. The yoyo was polished with mothers mag multiple times. My question is what could have caused this? The polish? Aluminum grade? Or some other factor? Any help would be appreciated thanks

I’ve been doing some research on anodizing, at least enough to know I definitely DO NOT want to do this myself.

Are you thoroughly washing the yoyo to ensure it’s free from contaminants before putting it in the electro bath? If you’re polishing, you’ll want to make sure all that is off, and don’t assume your eye is going to catch it.

Another thing I’ve noticed is that in all the anodizing videos, there’s some sort of agitation going on, ranging from in-tank aquarium filters to bubblers and other solutions to keep the fluid moving around.

About the only difference I can see is that the Pop Star is pre-anodized, so you have to strip that, either chemically or via sanding off the anodized layer. Your scrap aluminum is probably already bare. Regardless, you’re removing the anodizing on the PopStar. Are you 100% sure you’ve gotten all of that off? Also, have you thoroughly cleaned off the metal of any contaminants?

I’m guessing.

The popstar is basically what i test all my mods on so yes it was 100% de-anod but then i i sanded it down and polished with mothers. This is the point where i wanted to anodize it. I scrubbed it with 0000 steel wool and then a scotch brite pad with dish detergent so it was “clean” im just wondering if the fact that it was polished messed up the process

Well, all I will say is I see the other processes using a “smut tank”, which I guess is some sort of chemical rinse to help ensure the surface is the proper kind of clean.

I personally don’t see why the polish was necessary in the first place.

If the pits are actual depressions in the piece I would check the AC content of the power supply when the yoyo is in the electro bath (ie under load). Just switch your multimeter over to AC voltage and measure the same way you would DC voltage. It should be near zero.

note - I have never anodized Al, only Ti, which is very different.

Might want to hit up jasonwongzero since he has experience with anodizing and can probly give you some insight

Like anything else when coating the piece needs to be as clean as possible. Sometimes just because you don’t see it doesn’t mean it isn’t there.

Just to clear things up i polished the yoyo to make it have a mirror finish after i stripped it down to raw Al, After all of that is when i tried anodizing, i did clean it before hand aswell, but ill try sanding it down again and then maybe try an etch before the Ano process

I think you need to detail out your process a bit better. I think a critical cleaning process is being skipped.

Ok steps: started with raw, polished, un-anodized yoyo. Scrubbed down with 0000 steel wool, then with a scotchbrite pad and dish detergent then rinsed off with distilled water. Straight to the ano bath from there.

There’s your problem right there.

After the distilled rinse, you need to go through a “smut tank” process to remove any other greases and other stuff. Again, just because you think you got it all off doesn’t mean you did.

You’re getting it “food safe” clean, but you’re not getting it “anodizing ready” clean.

Hit YouTube. They got plenty of videos on this topic.