The common ratio for nitric acid lightening (ash removal) is a 10% to 25% solution of nitric acid, and this ratio can be a volume fraction.
Nitric Acid Light Out Ratio and Time of Use
Author: Robby
The common ratio for nitric acid lightening (ash removal) is a 10% to 25% solution of nitric acid, and this ratio can be a volume fraction.
The application time is 1 to 3 minutes. In some cases, such as after chemical polishing, a higher concentration of nitric acid solution, such as 25 to 50 percent, may be used to enhance ash removal. Nitric acid solutions at concentrations of about 30% have a greater rate of corrosion of aluminum, which may affect the safety of the material and therefore need to be handled with care during operation.