TECHNICAL DATA SHEET
GINTHOX Q 750
CHROMATE CONVERSION TYPE BRIGHT DIP FOR ZINC
Ginthox Q 750 is a zinc bright dip of the chromate conversion type that produces a clear, bluish finish without
leaching. The single dip solution produces a conversion coating which brightens, passivates and protects zinc
deposit from finger staining. discoloration and corrosion.
For optimum corrosion protection with Ginthox Q-750 a minimum deposit of 0.0002 to 0.0003 inch of zinc plate is
recommended. The lustre of the final finish is related to the brightness of the zinc deposit.
Operating Conditions :
Concentration
3 - 4 gm/l Ginthox Q 750 and 20 cc/l Nitric acid (400 Be)
Temperature
Room
Immersion Time
5-20 seconds
pH
1.0 - 1.5
To obtain maximum life of the bright dip, it is important that the parts be thoroughly rinsed after chromating, the
work should be rinsed in cold water then in hot water not exceeding 450C to dry.
EQUIPMENT :
Ginthox Q-750 solution can be contained in rigid PVC, PVC lined steel or polyethylene containers.
ANALYSIS FOR GINTHOX Q-750
Apparatus :
50 ml Graduated cylinder
50 ml Pipette
50 ml Burette
250 ml Erlenmeyer flask
Spatula
Reagents :
0.1N Sodium Thiosulphate (Na2S2O3 5H2O).
Dissolve 24.8 gm of AR grade Na2S2O3 5H2O in distilled water and ldilute to 1 litre in a volumetric flask.
Standardize as required.
25% by volume Hydrochloric acid (HCl).
Cautiously add 250 ml of AR grade HCl to 750 ml of water and mix.
0.2% Starch Indicator Solution - Purchase as a stable indicator.
Potassium Iodide (KI) - Crystals, AR grade.
Procedure :
1. Pipette 50 ml of Ginthox Q-750 solution into a 250 ml Erlenmeyer flask.
2. Add 50 ml of water and 10 ml of 25% HCl.
3. Add 2 gm. of KI crystals, mix to dissolve and allow solution to stand for about 2 minutes.
4. Titrate with 0.1N Na2S2O3 to a straw colour; add about 2 ml of starch solution and continue titration to a
blue-green end point.
GINTHOX Q 750
also available online at www.growel.com
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Calculation :
3.0 (ml Na2S2O3 x Normality Na2S2O3 ) = g/l Ginthox Q - 750.
ANALYSIS FOR NITRIC ACID :
Apparatus :
50 ml Pipette
50 ml Graduated cylinder
50 ml Burette
250 ml Erlenmeyer flask
Reagents :
1.0 N Sodium Hydroxide (NaOH) - Dissolve 40 gm of AR grade NaOH in water and dilute to 1 litre in a volumetric
flask. Standardize as required.
0.1% methyl orange Indicator - Dissolve 1 gm. of the indicator in 1 litre of water.
Procedure:
1. Pipette 50 ml of the Ginthox Q-750 solution into a 250 ml Erlenmeyer flask.
2. Add 100 ml of water and about 5 drops of methyl orange indicator.
3. Titrate to yellow end point with 1.0N NaOH.
Calculation:
1.4 x (ml NaOH x Normality NaOH) = cc/l nitric acid (400 Be).
CAUTION
Ginthox Q-750 salts and solutions contain chromates and are oxidizing in nature. Avoid contact with organic
materials and other reducing agents. Do not allow the salts or solutions to come in contact with the skin or eyes.
In case of contact, flush skin or eyes with plenty of cold water for at least 15 minutes. For eyes obtain medical
attention. Ginthox Q-750 salts tend to absorb moisture from the air. Keep the container tightly sealed and store
in a dry place.
Issued on 09.06.2009
Supersedes all earlier
GINTHOX Q 750
also available online at www.growel.com
2