DEOXIDIZER LNC / GARDACID P 4299

Chemical Characterstics

Chemical Composition ………………………………..Blend of iron salts, nitric acid and fluoride
Appearance……………………………………………….Dark reddish-brown liquid
Specific Gravity ………………………………………….1.48 at 20 °C (68 °F)
Normal Working Concentrations…………………..10 – 20% by volume
Normal Working Temperatures…………………….Ambient: 50° – 100 °F (10° – 38 °C)
pH…………………………………………………………….Less than 1.0 at 10% by volume
APPLICATION PROCEDURE
Surfaces should be clean and free of organic contaminants. Immerse in a 10 – 20% by volume solution of
Deoxidizer LNC at ambient temperature. Immersion time is normally 1 – 5 min. Process parameters will
vary depending on the age of the bath and the degree of smut, oxidation or other contaminant on the
surface. The solution should be air agitated. Rinse thoroughly in clean ambient temperature water.
A bath of Deoxidizer LNC has an etch rate on alloy 2024-T3 aluminum that ranges between 0.03 and 0.10
mils/surface/hour, depending upon the age and concentration of the bath.
SOLUTIONS CONTROL
Deoxidizer LNC should be monitored and replenished on a regular basis, for example daily, by the ferric iron
titration, Gardotest Procedure 25. On a less frequent basis, for example weekly or monthly, Deoxidizer LNC
should be monitored and replenished by the total acid titration, Gardotest Procedure 150.

Ferric Iron (Gardotest Procedure 25):
1. Place a 5 mL sample of the bath into an Erlenmeyer flask.
2. Add about 50 mL of deionized water.
3. Add 30 – 40 drops of Gardotest Indicator 195 (Sulfosalicylic Acid). The color will turn dark red.
4. Titrate with Gardotest Solution 90 (0.1M Disodium EDTA) until the color turns yellow.
5. Percent by volume Deoxidizer LNC may be calculated by multiplying the milliliters used by 1.1.
Total Acid Gardotest Procedure 150:
1. Place a 10 mL sample of the bath into an Erlenmeyer flask.
2. Add about 100 mL of deionized water.
3. Add about 10 mL of Gardotest Solution 10 (Potassium Fluoride).
4. Add 5 – 10 drops of Gardotest Indicator 2 (Phenolphthalein).
5. Titrate with Gardotest Solution 37 (1 N Alkali) until the solution turns from colorless to pink.
6. Percent by volume Deoxidizer LNC may be calculated by multiplying the milliliters used by 2.4.
Replenishment: Normal replenishment, based on the ferric iron titration is with additions of Deoxidizer LNC.
As the bath is used, the total acid of the Deoxidizer LNC solution tends to decrease. For each percent by
volume based on total acid, below the percent by volume based on ferric iron, add 9.5 gal of Gardobond
Additive H 7140/1 per 1000 gallons of bath.