Brushes
The choice of brush depends, to a great extent, on the type of finish we wish to achieve – fine, coarse, etc., and the type of material to be brushed – steel, aluminium, wood, etc. Furthermore, in the case of machine operated brushes, the characteristics of the machine in which the brush is to be mounted must be known:
- Maximum permitted diameter.
- Rotational speed (RPM).
- Characteristics of the arbor (diameter or type of thread: M14, 5/8″).
| Machine (Normal speed) | Normal brushes | Model | Brush diameter |
|---|---|---|---|
| Fixed bench grinders | Crimped and knotted wheels |
F-15, F-23, F-18, F-16 & F-17 | Between 75 mm (3”) and 350 mm (14”) |
| Angle grinder (5.000-8.500 R.P.M.) |
Crimped and knotted wheels | F-15, F-18 & F-26 | Between 100 mm (4”) and 175 mm (7”) |
| Crimped cup, knotted cup nylon cup, able cup | F-24, F-25, F-17 & F-16 | Between 80 mm (3.1/4”) and 150 mm (6”) | |
| Mini angle grinder (10.000-12.500 R.P.M.) |
High speed cup, conical and flat model brushes | LAR24, LARCO, LARPO, LAR25, LARCR, LARPR | Between 65 mm (2.3/4”) and 115 mm (4.1/2”) |
| Pneumatic Grinder and portable drills (15.000-20.000 R.P.M.) | Wheels and industrials end brushes with shank | F-21, F-22, BT, BE, TA | Between 12 mm (1/2”) and 100 mm (4”) |
| DIY drill (4.500 R.P.M.) |
Wheels,cups and end brushes with shank | BR, BO, FBE, FTA, FBR | Entre 22 mm (1”) y 100 mm (4”) |
The diameter of the wire affects the type of finish that is achieved:
- The thicker the wire the coarser the brushing with faster cutting.
- A fine wire gives a smooth finish
A long trim length results in a flexible brush, which allows a uniform effect to be achieved, even on irregular surfaces.
A shorter trim length gives a greater removing capacity.
Crimped brushes, because of their better flexibility, are suitable for working on irregular surfaces and give a more regular and fine finish.
On the other hand, knotted or twisted wire give to the brush a longer lasting and has a high removing capacity, but gives a coarser finish.
The great flexibility of the filaments allows the brush to get into areas that are difficult to access and avoids distortion and breakage, which considerably prolongs its life.
Abrasive nylon brushes do not behave like wire brushes. They should not be pressed too firmly onto the surface, this is to avoid the overheating of the abrasive filaments, and to prolong the life of the brush.
Abrasive nylon is treated in order to give perfect performance both when wet and dry, therefore cooling liquids can be used without
losing any brushing capacity.
The usual applications are: wood and furniture, plastics, cars, aeronautics, metallurgy and electronics. In each case, the best working conditions will be obtained by varying the abrasive grade, the working pressure and speed, the diameter of the brush and the trim length.
In these brushes the single wires or mono filaments are replaced by crimped cables made of several wires each one. These cables are made up of a set of high strength steel wires of 0.22 mm diameter which form a flexible, compact and aggressive unit.
The type of finish and cutting capacity are medium, similar to those produced by monofilament steel wire brushes with a wire diameter of 0.30 mm.
Advantages:
- Performance: The cable crimped wire will provide 50% more useful life because of its greater resistance to fatigue due to bending.
- Flexibility: The cable crimped wire better adapts to irregularities in the surfaces that are to be brushed.
- Safety: The cable crimped wire eliminates the occurrence of breakages of large pieces of wire.
The operating speed of each machine is a variable that has a direct influence on the performance of the brush and the safety of the operator. Therefore, the maximum RPM should never be exceeded. These indicate the free rotational speed limit at which the safety of the operator, using the normal protection measures, is totally guaranteed.
For each model and diameter in the catalogue, the maximum safety speed and the recommended working speed in RPM are indicated. For the majority of brushing tasks the optimum results are obtained at the recommended velocity, without the need to reach the maximum speed.
Knowing the machine speed is essential for the correct choice of the most suitable brush.
Recommendations for use
- Check before use that the brush is not damaged.
- Take care when mounting. Follow the instructions for use very carefully.
- The brushing task must be done with the ends of the wires.
- In contrast to abrasive tools, metal brushes do not abrade; that is, they do not burn the surface being treated.
- The advantage of brushes, with respect to abrasives, is due to the flexibility of the wire, it better adapts to irregular surfaces.
- Excessive pressure on the brush can cause an over-curvature effect on the wires, increasing fatigue, leading to premature breakage, and, therefore, to a considerable reduction in their useful life.
- If greater cutting capacity is required, instead of exerting greater pressure on the brush, we suggest the following:
- Use a more aggressive brush: a brush with thicker wire, with shorter trim length or with twisted knot wire instead of crimped.
- Increase the speed of the brushing with a model that can rotate at greater speed, or one with a greater diameter in the case of wheel brushes.
Safety warnings
In accordance with the European Standard EN 1083.2 on safety requirements for the use of metal brushes as machine accessories; the following instructions for use must be complied with:
- Always use safety goggles, clothes and suitable equipment.
- Do not use brushes in machines whose speeds are greater than the maximum speed of the brush.
- Do not remove any protective equipment from the machine.
- Do not use brushes in poor condition.
- Rust or any other type of chemical alteration to the wire can affect the performance of the brush.
- Keep the brushes stored on shelves, containers or boxes so that they are protected from the effects of the environment (
damp, acids, gases, etc.).
