Preliminary Requirements

Safety Requirements

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURERS MATERIAL SAFETY DATA SHEETS FOR CONSUMABLE MATERIALS INFORMATION SUCH AS, HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE, EXPLOSION, REACTIVITY, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

WARNING

STRONG ACID PRECAUTIONS

EVERY POSSIBLE CARE MUST BE TAKEN TO AVOID THE SOLUTION COMING INTO CONTACT WITH THE EYES OR BARE SKIN. PROTECTIVE CLOTHING INCLUDING RUBBER GLOVES AND GOGGLES MUST BE PROVIDED FOR THE OPERATORS WHEN PREPARING AND USING THE SULFURIC, NITRIC AND HYDROFLUORIC ACID SOLUTION. RUBBER GLOVES SHOULD BE CHECKED REGULARLY FOR PIN HOLES AND REPLACED IF NECESSARY.

SAFETY NOTICES MUST BE PLACED IN A CONSPICUOUS PLACE.

EYE-WASH BOTTLES AND HF BURN JELLY MUST BE PROVIDED AS CLOSE AS POSSIBLE TO THE PLACE OF WORK.

IF SKIN BECOMES CONTAMINATED WITH THE SOLUTION IT MUST BE RINSED WITH COPIOUS AMOUNTS OF CLEAN RUNNING WATER.

ALL BURNS, HOWEVER SLIGHT, SHOULD BE TREATED AT THE NEAREST SURGERY OR FIRST AID POST.

THE SURGERY MUST BE TOLD WHICH SOLUTION (THE ACIDS INVOLVED) HAS CAUSED THE BURN PARTICULARLY IF HYDROFLUORIC ACID IS A CONSTITUENT.

Procedure

1. SUBTASK 70-33-87-100-001 Make-up of the Etching Solution

   1. Composition.

      1. NOTE

         The solution can be made up by adding 1 volume of sulfuric acid (SG 1.84) to 1 volume of water. But, because this method generates sufficient heat to boil the solution, it is recommended that solution of the correct strength be purchased; together with a supply of sulfuric acid (SG 1.84), for making the additions. Tap water can be used when the chloride content is not more than 0.001 g/l.

         The etching solution is aqueous and contains 7.3 to 7.5 lb/gal (880 to 900 g/l) of CoMat 01-050 SULFURIC ACID H2SO4.

   2. Analysis.

      1. The etching solution must be analysed, as specified in SUBTASK 70-33-87-200-001.

2. SUBTASK 70-33-87-100-002 Make-up of the Neutralizing Solution

   1. Composition.

      1. NOTE

         To make sure that the residual acid on the parts is effectively neutralized, the solution must be discarded and renewed frequently.

         The neutralizing solution is aqueous and contains 9.3 oz/gal (70 g/l) of CoMat 01-030 SODIUM CARBONATE Na2CO3 or 4.6 oz/gal (35 g/l) of CoMat 01-086 AMMONIUM HYDROXIDE SOLN NH4OH or CoMat 01-361 AMMONIUM CARBONATE (NH4)2CO3 or 18.6 oz/gal (140 g/l) of CoMat 01-044 SODIUM METASILICATE Na2SiO3.5H2O.

3. SUBTASK 70-33-87-100-003 Dewatering Oil

   1. Control.

      1. Refer to the SPM TASK 70-38-05-380-501 for the details and method of control.

4. SUBTASK 70-33-87-100-004 Make-up of the De-smutting Solution

   1. Composition.

      1. The de-smutting solution, for nickel-base materials is aqueous and contains 6.7 oz/gal (50 g/l) of CoMat 01-027 HYDROFLUORIC ACID and 27 oz/gal (200 g/l) of CoMat 01-025 NITRIC ACID HNO3, TECHNICAL GRADE.

      2. To make up 1.3 gal (5 l) of the de-smutting solution, carefully add 35.5 fl oz (1010 ml) of nitric acid (SG 1.42) to approximately 0.65 gal (2.5 l) of water; then add 26.2 fl oz (745 ml) of hydrofluoric acid (30 percent HF w/w). Gently stir the solution, whilst making the additions, then add water to make up the solution to the specified volume.

      3. The solution must be contained in a plastic tank where it is maintained at room temperature.

   2. Analysis.

      1. No analysis is necessary, because the solution is discarded and renewed; when it ceases to be effective.