|Jet Black Anodizing|
Amps: Amps will self regulate. Amps must fall during the process. Amps will fall fastest at first then slow down. The final value to dissolution will be about 70 - 75% of the starting amps after 5 minutes). In other words if the starting amps after 5 minutes is 2.0 then will be anodized fully at 1.4 to 1.5 amps.
Time: I go 1 hour 10 minutes. I go less on silver. Going longer time will hit dissolution. Really it's only necessary to go as much time as needed to take full dye and no burning.
Agitation: I use a wave maker. I don't like the bubble method but some feel is ok.
Acid: Sulfuric acid at a 10-15% ratio. There is a 720 rule or formula but I don't use it. Really complicated and how to find the surface area of a bolt? Change the bolt and new formula...hmmm. Most rookies start with way too strong acid bath. I use a hydrometer value of 1.4 baume.
This step is the hardest to get. My advice is a 10% bath and follow the above values. If it's too weak add a bit of acid. Remember its much easier to add acid then the split the tank to reduce.
New acid tanks can burn parts easier. Adding some aluminum matures the tank and helps resist burn. I add phosphoric and oxalic acid in very small amounts but isn't needed. This can help burn and black tracks. Clean Tanks are very important...I will follow up on this later.
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