Anodizing calculations (720 Rule)

[bp]

When I first introduced to 720 Rule to this website in January 2004 it was a response to help in color consistancy. I am very impressed in how far the 720 Rule has progressed on this web site. I have not been able to visit or respond to forums on this website due to contract obligations with an employer, but that is now completed and I have been reading the forums again on Caswell and again I am impressed by the knowledge passed along. Please keep it going!
And just a side note on the firguring of rack size and the 720 Rule- Yes, you will need to figure in rack size only if you are doing eletrolytic color. Some of our rack designs have been over 1,000 ft2 alone per 30' load bar.

[manishnjain]

Hi,
I have put up with a new plant of hard anodizing.
Please can u guide me in how to get the best results for my anodizing.
I am anodizing utensils but i am getting gray color anodized. I need jet black.
please guide me on the bellow question: -

1. What temperature shoult i anodize.
2. What should be my acid mixture(and how pure should be my acid).
3. What volts and amps should i anodize .
4. What other chemicals can i us.
5. How should i do the sealing.

my tank size is:- length=13ft
Width= 3ft
Hight=3.5ft

please guide me.
thanking you
manish

[manishnjain]

Hi,
I have put up with a new plant of hard anodizing.
Please can u guide me in how to get the best results for my anodizing.
I am anodizing utensils but i am getting gray color anodized. I need jet black.
please guide me on the bellow question: -

1. What temperature shoult i anodize.
2. What should be my acid mixture(and how pure should be my acid).
3. What volts and amps should i anodize .
4. What other chemicals can i us.
5. How should i do the sealing.

my tank size is:- length=13ft
Width= 3ft
Hight=3.5ft

please guide me.
thanking you
manish n jain

[sswee]

Originally Posted by manishnjain

Hi,
I have put up with a new plant of hard anodizing.
Please can u guide me in how to get the best results for my anodizing.
I am anodizing utensils but i am getting gray color anodized. I need jet black.
please guide me on the bellow question: -

1. What temperature shoult i anodize. 32*F
2. What should be my acid mixture(and how pure should be my acid). 1:1 or 1:2 by volume
3. What volts and amps should i anodize . Depends on if using CC or CV
4. What other chemicals can i us.
5. How should i do the sealing. Distilled water boil if for eating utensils

my tank size is:- length=13ft
Width= 3ft
Hight=3.5ft

please guide me.
thanking you
manish n jain

Your questions are out of the scope of this forum. The answers I gave are from my study of the anodizing procedure and are not from this forum. What you are asking about is Type III Hard anodizing. It is not a DIY project.
SS

[manishnjain]

WHAT IS CC AND CV RIGHT NOW I AM ANODISING AT 90 VOLTS AND 500 AMPS.
What should be the level of sulphuric acid in my tank the capacity of my tank is 3000 lts.

[acidrain]

Originally Posted by manishnjain

WHAT IS CC AND CV RIGHT NOW I AM ANODISING AT 90 VOLTS AND 500 AMPS.
What should be the level of sulphuric acid in my tank the capacity of my tank is 3000 lts.

Wow, you own a large anodizing company and you don't know how to do it?
CC is controlled current, and CV is controlled voltage.
If you know the titration levels of your ano bath, you can calculate the volts for CV operation (most commercial set up use this method).
What you are asking for are closely guarded secrets. I'm sorry to say that commercial anodizers don't share secrets much.
You also need to realize that we are all (for the most part) home/hobby anodizers. We really don't know the answers to your questions.

[manishnjain]

Thanks for the imformation. and ya now i got what is cc and cv.

[Z]

Sulfuric concentration should be 15%/wt = 22.0 av oz/gal = 12 fluid ounces/gallon = 9.3%/volume = 165.3 grams/liter. Hardcoat or Softcoat both concentrations are the same.

If you are going for a jet black you gotta go with type II anodizing.

From my notes if you want black for 2024 or 6061 you need a thickness of over 3 mils. thats doing it type III hard coat at 32F. 24-36 amps per sq ft. I don't have any experience with Hardcoat just what I've read.

[manishnjain]

Thank you very much can you tell me where is Oxalic acid used.

[Z]

its used in the sulfuric acid anodize tank solution. its 14 to 20 gm/L