TABLE OF CONTENTS The processes and solutions described in this section are intended to give a general guide to surface finishing procedures. To operate these systems on an industrial scale would normally require recourse to one of the Chemical Supply Houses which retail properietary solutions.
Used to remove excess oil and grease. Components are suspended in a solvent vapour, such as tri-or tetrachloroethylene.
Note: Both vapours are toxic and care should be taken to ensure efficient condensation or extraction of vapours.
An emulsion cleaner suitable for most metals can be prepared by diluting the mixture given below with a mixture of equal parts of white spirit and solvent naphtha.
| Pine oil | 62 g |
| Oleic acid | 10.8 g |
| Triethanolamine | 7.2 g |
| Ethylene glycol-monobutyl ether | 20 g |
This is used at room temperature and should be followed by thorough swilling.
| Metal to be cleaned | Composition of solution | Temperature | ||||
|---|---|---|---|---|---|---|
| oz gal -1 | gl -1 | F | C | Remarks | ||
| All common metals other than aluminium and zinc, but including magnesium | Sodium hydroxide (NaOH) | 6 | 37.5 | 180 200 | 80 90 | For heavy duty |
| Sodium carbonate (Na 2CO 3) | 4 | 25.0 | ||||
| Tribasic sodium phosphate (Na 3PO 4.12H 2O) | 1 | 6.2 | ||||
| Wetting agent |
 | 1.5 | ||||
| Sodium hydroxide | 2 | 12.5 | 180 200 | 80 90 | For medium duty | |
| Sodium carbonate | 4 | 25.0 | ||||
| Tribasic sodium phosphate | 2 | 12.5 | ||||
| Sodium metasilicate (Na 2SiO |
