Description

These etching reagents Solution 1 – Fry’s reagent, Solution 2 – Nitric acid. 15 per cent, are commonly used for Steel surfaces (chassis and engine of cars, guns, gas cylinders etc.)
Preparation of surface
1. Clean the surface using preferably benzene or acetone to free it from grease or paint. Solvents such as gasoline, commercial paint remover or 50/50 mixture of acetone and chloroform may also be used.
2. Hand polish the area to a smooth, mirror like finish or a reasonably smooth surface with emery cloth, or other fine abrasive.
Procedure.
1. Apply the Solution 1 by swabbing the surface for approximately 2-3 minutes with cotton wool dipped in the reagent.
2. Look for any digits revealed and record these. Clean the surface with acetone (not water). Examine again.
3. Apply the Solution 2 by swabbing the surface for approximately 1 minute with cotton wool dipped in this solution.
4. Look for any digits revealed. As soon as number appears a photograph need to be taken because it may disappear after subsequent application of the reagent.
Prevention Before applying etching reagent…
1. The chemical etching method is the simplest and most effective method for restoring obliterated numbers.
2. The techniques involved require considerable skill and great patience.
3. The materials used are potentially dangerous and should be used with full awareness of health and safety requirements.
3. Rubber gloves will protect the hands from corrosive acid and when using volatile liquids work in the open air away from any seat of naked flame, if laboratory conditions are not available.