Newbie needs some help to fine tune the process.

[pa_viper]

Forgive the long post but I have searched in the forum and can not seem to find the answer that I need. I am trying to anodize some antique car parts and I do not know the alloy that they are made of so that is a bit of a hindrance. Please also realize that this was an experiment to see if it would work to some degree before I jumped in this full bore. It seems that I had some success so I think I just need to fine tune some things a bit to get the results that I need. The parts that I am anodizing need to have a high shine and so no dying is needed. I did not have access to any de-oxidizer/de-smut so that may be some of the problem too. The part was polished to a high shine which looked really nice before I anodized it, now it looks dull and flat almost like a gray primer paint with a little shine to it. I hope that there is a way to get some shine to these part and that there is something I did wrong. But this was my first try with what I had available, hope that there is some out there in this forum that can point me in the right direction. Below are the parameters of what I used and what was done.

Part was polished to a high shine with buffer and went down to the white compound from Caswell's

Part was washed/degreased in Castrol Super clean solution and did pass the water break test (I was also wearing nitrile gloves)

Did not have de-ox/de-smut so this was not done.

Bath temp was 63 def F

Part was placed in anno bath for 84 minutes as determined by the 720 calculator Part size 55.75 sqin .7 mil thickness Amperage was set to 5 on the rectifier. This may have been were I went wrong.

Pulled out the part and scratched my head cause it looks like ****.

The anno bath was 3 gallons distilled water and 1 gallon battery acid. There were bubbles coming off of the connection point on the part and on the GP plates in the bath, but none on the part itself that I could see. I did have to use a stainless steel screw and nut to secure the wire to the part. I know, not good, but that was the only way I was not able to find any aluminum connectors this weekend.

It did seem to anodize because there is no continuity on the part when checked with a multi-meter.

Thanks in advance for any help that anyone can she on what I need to fix.

All the pictures can be seen here a few are below. Anno Pictures

[sswee]

Your calculations are off a couple of places

Surface Area 55.75 In²
0.39 Ft²
Thickness 0.70 (0.1-1)
Current Density 12.00 Amp/Ft²
Set Current 4.65 Amp
Time 42.00 Minutes
Peak Voltage 30.00 VDC

A 84 min run time is for a 6 ASF CD with an amperage setting of 2.32A on the power supply. Basically you doubled the CD and ran it twice as long as needed.
SS

[sage]

You should remove the stainless from the bath. It could be messing it up.

Sage

[pa_viper]

Thanks sswee and sage,

I didn't think the stainless was helping things but I didn't really know what else to use. I am going to try to find some aluminum screws until I can get some titanium ones.

As far as the amperage settings go I'm a little confused there. On the 720 calculator there are boxes to input data sqin, mils, and current density. Since I am doing LCD shouldn't that be between 4.5 and 6 amps? If so, then I should have had the current set to 2.32 and done it for 84 minutes? I saw the 6 in the top box and had a brain fart and set my current to 5 not 2.32. I have the Caswell rectifier so fine tuning the current draw is a little tougher and the voltage is not adjustable. Maybe I'm really confused and need a lot more help than I think I do. I guess I am going to strip it and try again. Comparing it to what is on the car now it looks really bad.

Thanks for the input.

[acidrain]

Since you are going for clear, I suggest lower current densities... 4.5 - 6 amps per sq. ft. It will help keep the parts from turning yellow.
Some shine will be lost during ano. Try only .5mil thickness.
When you strip your parts, you will be able to tell what the alloy is. Heavy smut will be either 2xxx or 7xxx. Little or no smut will be 5xxx or 6xxx.
I have found that 2xxx and 7xxx alloys only need 3/4 of the run time. You can adjust your run times accordingly, and have good results.
Yeah, get that stainless out of there... it's really important. Home Depot sells aluminum screws.

[sswee]

From everything you've posted, you're not far off. You just showed how changing one number can effect everything else. All your numbers were right until you set the PS to 5A instead of 2.32A. It'll be better next run.
SS

[pa_viper]

I was able to find some aluminum screws this morning, they will do until I can get some Titanium ones. I really have no idea what Ford used when making these parts, but after polishing they do not turn black if left sitting. I also hope that they did not use Electopolishing or Bright-Dip when finishing them. That is going to create another host of issues if they did.

Do you think that the bath may be contaminated becuse of the stainless and should I switch it out? I have read other post where people had the same problem, and it seemed that after another run in the bath things were fine. Just wondering.....

[sswee]

The electrolyte bath should be ok.
SS

[pa_viper]

Going to try again this week and see how things go. Will post the results when done. Thanks for the help so far!

Paul