The files which are widely applied in metalwork are rebated over time, losing former working qualities. Processing of parts such "greased" tool becomes inconvenient and unproductive. Especially strongly the quality of notch when processing soft metals, such as copper and aluminum decreases. Particles of material hammer space between file teeths therefore it is necessary to restore its working capacity.
It is required to you
- - metal brush;
- - acetone;
- - laundry detergent;
- - flowing water;
- - the concentrated sulphuric acid;
- - the concentrated nitric acid;
- - lubricating oil;
- - capacity for chemical treatment.
Instruction
1. Examine working part of file and in case of need clean surface from mechanical pollution and small particles of the processed material. After rough cleaning degrease the tool in solution of normal laundry detergent or means for washing of ware.
2. Before carrying out chemical treatment dismantle the tool handle. Then wash file with water and submerge in acetone. Similar processing will remove fat deposits from working surface. Boiling in soda solution within 10-15 minutes will also help to degrease the tool.
3. If on the tool rust traces are visible, submerge degreased file in capacity, filled with reducer. As it it is possible to use twenty-percentage solution of sulphuric acid.
4. Now prepare mix for chemical etching. It has to include 8 parts of the concentrated nitric acid, 6 parts of the concentrated sulphuric acid and 86 parts of water. Place in solution the file which is subject to recovery approximately for 10 minutes. At such processing, metal will be well pickled in deepenings of notch, and teeths will remain almost untouched. It leads to recovery of working properties of the tool.
5. Take out file from solution, wash out in flowing water and check its working qualities. If etching was insufficiently effective, carry out such chemical "sharpening" once again. After the full end of etching once again wash the tool with water and solution of soda to remove residues of acid.
6. Preserve the restored file as pure metal can become covered with rust very quickly. Lower product in the lubricating oil heated to temperature of 100 degrees, and sustain 20 minutes there. Take out file from oil, carefully wipe rags, dry and get on the handle.