To obtain a surface specular gloss on a part or any object, a different tool is used. Depending on the number of blanks, the volume and cost of work, this can be: a hand polisher, an electric drill or a sharpener with an established felt circle, specialized equipment.
For paintwork and car headlights, Venetian plaster, stone, furniture facades, stainless products, angle polishers and grinders are used.
Having fixed natural fur or synthetic foam accessories and reducing the diameter of the abrasive grain in the paste, scratches and microroughnesses are removed from the surface layer, bringing it to a mirror state.
speed-controlled angle grinder or polisher?
When choosing a manual power tool of this type, it does not matter for domestic use in the garage or professional for service stations, the requirements are set for it:
– Possibility of quick change of nozzles on a support platform with Velcro.
– The optimal weight. A heavy model, when working on a vertical surface, heavily loads the hands, and a light model, when working horizontally, will have to press and spend effort to keep it in a given position.
– The presence of a soft start so that the polish does not fly off the equipment at the time of switching on.
– Convenient controls.
– Adjustment of revolutions of rotation and a system of counteracting changes in revolutions when pressed or power surges.
However, all these possibilities are available on angle grinders and polishing grinders? Then what is better to choose?
Features of the tools when polishing the car.
The speed range on most polishes is from 600 to 3000 rpm, as on the Proton PEM-1300 or from 800 to 4200 as on the popular Sturm AG919CP.
In small angle grinders, it is from 4000-6000 to 10000-11000 rpm and the master has to adapt to these features.
As the angle grinder begins to work.
The speed controller is set to the minimum position.
Press the start button and press the foam or sheepskin disc to the car body.
As soon as, due to lack of power, the nozzle begins to stop, revs are added.
Maintaining a certain pressure, the master polishes until the tool comes off the surface.
After that, it spins up to such speeds that when you touch the car, the risk of quickly heating up the surface and burning off the varnish increases.
You have to slow down and start the cycle anew.
The low speed of the polishing machines allows you to avoid damage to the coating even in such problematic places as sections of the plane along the bend, and the polish does not fly apart under the action of centrifugal forces, being held in the foam pores.
The inconvenience for a specialist to use an angle grinder is caused by its main purpose: cutting and grinding.
During these processes, the line of contact between the abrasive wheel and the surface is very small. It rotates at high speed, abrasive grains in contact with metal and burnout ligaments fall out and are replaced by new ones.
The woolen or foam equipment of the polishing machines works with the entire end area (for a 180 mm circle it is 254 cm²), which causes much greater resistance to rotation and requires a different gear unit.
There are two types of polishing machines: with an electric motor vertically located above the nozzle and angular reminders that look like an angle grinder.
Models focused on working with cars have a rubber coating on the end and parts of the gear case, as on the DeWalt DWP849X.
At Vega Professional VK1600 along the axis of the case, in front, there is a rubberized additional handle, and on the rear main handle there is also a rubber platform. When, turning the tool over, put it on the car, then scratching is excluded
Video: Speed Grinder
The main different nodes.
Cover, protecting the user from rigging, as if on an angle grinder is absent as unnecessary: soft foam, felt, sheepskin circles at low speeds can not be harmful.
Handles on vertical models, symmetrical, allowing you to evenly control the force of pressure.
On angle polishers, they are closed, D-shaped, smoothly transitioning from a horizontal plane to a vertical one. This allows you to change the grip or position of the hands depending on the spatial position of the body part.
The comfort of use depends on the design of the handles, the tool has to be maneuvered a lot and moved smoothly, without delay.
For additional, as well as on angular grinders, there are two or three fixing points.
Gearbox. Unlike a conical pair of angle grinders, where the angle, shape, and ratio of the teeth of the primary and secondary gears are selected to create high speeds, it should create high torque on planetary polishing gears. This is necessary so as not to strangle the engine at a constant pressure of the entire equipment plane to the surface.
Sheepskin and foam polishers and their fastening.
The right choice of consumables and accessories plays no less role than the parameters of the power tool and the experience of the master.
How to set circles on a polishing machine.
One-piece non-separable nozzles, with a nut installed inside, are immediately screwed onto the spindle.
There are two ways to fix removable polishers to the support platform:
– By lacing. Usually this is a fur top stitched to a cloth base.
– Thanks to the velcro textile fastener. Most types are mounted in this way, which allows you to change the felt to microfiber or sandpaper for grinding in a second.
The support plate of the polishing machines.
It can be solid rubber or consist of three parts: a support flange in the center of which a steel nut is embedded, an intermediate layer of finely porous material and Velcro (contact with the circles occurs when two surfaces of microhooks and micro-loops adhere).
On one-piece rubber fasten polishers on the laces.
Three-component plates have different properties and vary in thickness, softness, porosity and base material, the shape of the edges.
Rigid is used for polishing smooth planes of wood; they do not adjust well to the surface topography.
Some soft models have thick rounded edges and their diameter is larger than the snap-in installed on it, that is, if the end surface accidentally touches the surface of the car, scratching is excluded.
Allows for fewer passes to remove deep scratches.
They are made from natural, artificial and a mixture of these two wools.
The effect on the surface is more aggressive than that of foam rubber and depends on: the diameter of the villi, their length and density (can reach 9500 per 1 cm2).
For the most delicate processing, sheepskin circles made of soft wool with a maximum amount of down are used.
Since air is contained between the fibers, polishing machines with installed woolen discs heat the treated area weakly.
The polishing process of any material consists of several stages; the use of synthetic consumables allows you to create nozzles with clearly defined properties.
With the same thickness, the models are distinguished by compressive stress, pore sizes, elasticity, and the shape of the end part (flat or embossed).
For visual identification, manufacturers designate them in different colors.
In contrast to the pile of wool circles, which cuts off the surface if it is short or scratches it, if it is long, the foam disks have a rubbing effect, causing more heat due to tight contact.
The application features include their ability to absorb polish into the pores and gradually give away, however, due to this, the consumption of polish also increases.
Maintaining set speed at a given level.
Choosing the best polishing machine and comparing models to this function most often pay attention.
The pressure on the surface, in each case, is individually controlled by a specialist. On vertical planes, this is only the force of the hands, and on horizontal planes, the weight of the tool itself is added.
The required result is achieved when choosing: a certain brand of polish, appropriate equipment and a given speed of its rotation, which changes, in machines without the function of stabilizing revolutions with jumps in the input voltage and amplification of its clamp by the master. With it, the electronics give the command to the electric motor to slow down or accelerate.
Infinitely variable speed.
It is set by the adjusting wheel, usually installed on the main handle in the area of the thumb, and, on some models, it can be adjusted by the power key.
On vertical devices, such as Einhell CC-PO 90 or Energomash PShM-8160R, as a rule, it is absent (from the controls only the start button).
Polishing machines for a car have an indicator of up to 3000 rpm, just no longer need. If the tool is chosen for universal work: furniture facades, stainless steel, finishing materials, including for grinding work, then it is better to focus on models with an upper limit of 4000 revolutions, like the Makita SA7000C.
Additional selection criteria.
Start-up smooth speed system with high-speed grinders it allows to exclude tearing out of the hands; polishing is used to prevent spray polishes.
Weight. The indicator is important for those who often have to process vertical surfaces.
Diameter of polishers. The standard for processing cars is 180 mm the size of the support platform. 125 mm diameters of the plates are on specialized machines with water cooling for polishing stones.