Sandpaper, also known as sandpaper, is the name for sandpaper, a carpentry abrasive that has no analogues today. The material is used in various sectors of industry and life, from a construction site to an art workshop. Emery cloth is intended for manual and machine processing of wooden, plastic, ceramic and metal surfaces in the production of various products to improve the adhesion of elements when gluing or to prepare the surface for painting.
How to sand oak correctly?
Grinding
We start with 80 grit. We work with it carefully, removing only large irregularities. Then we repeat the treatment with sandpaper at 120, then at 180 and 240. During the work, we must periodically remove dust and inspect the surface to identify unevenness and other defects.
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Characteristics and types of sandpaper
Sandpaper
The correct choice of sandpaper should take into account the optimal parameters for purpose, type of abrasive, application method, grain size and water resistance, marking. Previously, grinding sandpaper was made from organic components, and was a mixture of corundum and magnetite. Today, the manufacturing material is aluminum oxide, garnet, or synthetic diamond.
Sandpaper for wood has many varieties that are used in the finishing process. It is important to pay special attention to the choice of material parameters to achieve the desired sanding result. The product range is presented in the form of sheets, rolls, open, closed options, commercial or industrial use.
Types of abrasive
Sandpaper for wood differs in the abrasive components applied to the base:
- electrocorundum;
- silicon carbide;
- pomegranate;
- synthetic diamond.
Electrocorundum types of sandpaper are distinguished by a high degree of rigidity and are resistant to pressure due to the hardness of the crystals. The material has excellent cutting properties. They are used at the stage of rough finishing of wood.
It is advisable to use sandpapers based on silicon carbide when grinding glass, plastic, or finishing wood. Small abrasive particles are fragile and crumble under pressure. The alloy is made from silica and graphite.
A very brittle garnet abrasive will help to sand wooden surfaces to a smooth structure. Small particles allow you to achieve excellent results. Diamond-based abrasive has a high level of hardness and durability. Rarely used due to its high cost.
Application technology
Sandpaper for wood processing is selected taking into account the technology of applying abrasive material to the base:
- Mechanical view. The application of the force of gravity allows particles to be applied to the base in a chaotic manner. The result obtained is not aggressive.
- Electrostatic method. The sharpness of the layer is achieved by using an electrostatic field to direct negatively charged particles. The result is a very sharp layer.
- On adhesive bases and resins. The material has excellent characteristics that increase the performance of the sanding layer (antistatic additives, dirt-repellent substances).
- With the use of binding components. The technology involves the introduction of additional binding particles, which significantly increase the strength of the material.
Sanding the surface of the array with sandpaper to achieve a matte finish is done with a fibrous sandpaper based on a non-woven mesh material impregnated with resins and an abrasive composition.
Sandpaper grit for wood
Coarse sandpaper
The material is used based on the type of grit. The level of this indicator determines the type of surface treatment performed. Sandpaper grit:
- 40-60 (rough, rough work);
- 80-120 (eliminates unevenness);
- 150-180 (final stage of processing);
- 220-240 (grouting process);
- 280-320 (gets rid of stains before painting);
- 360-600 (sand the surface).
The choice of material depends on the type of processing required. Too fine a grain of sandpaper should not be used for wood processing.
Labeling Standards
Types of sandpaper for wood and their characteristics largely depend on the country of manufacture. The markings allow you to navigate which sandpaper is best to use. There are several main foreign groups: USA, Canada, Japan and China. The FEPA standard is generally accepted and corresponds to the Russian system.
The grit index indicates the ratio of the amount of abrasive on the blade. The larger the grains, the fewer there are on the canvas. The low grit version is intended for roughing. A high grain size indicates the fine nature of the particles, which makes it possible to perform the process of polishing, or sanding the wood with sandpaper.
Water resistance
The water resistance rating will help determine which sandpaper to use for wood. A material with a high level of resistance to moisture is used for industrial woodworking in the field of furniture production.
Additionally, before sanding the wood, the emery is soaked in water to achieve the necessary elasticity. Sandpaper of this type is made on the basis of special resins and fabric, with varying degrees of grain size. The waterproof material is presented in a wide range of types, which allows the skin to be used at any stage of wood processing.
Processing of control results
The percentage content of grinding powder residues for the manufacture of abrasive tools (except for tools on a flexible basis) on control sieves is determined by dividing the mass of the grinding powder residue on control sieves by the weight of the test sample of grinding powder.
A sample of grinding powder complies with this standard if the percentage of remaining grinding powder of controlled grain size on the control sieves is within the limits specified in Table 1.
If not, then re-check the grain composition of the grinding powder using twice the number of samples.
When monitoring grinding powders for the manufacture of tools on a flexible basis, taking into account the presence of deviations between control sieves of the same size, determine the difference in the residual values of the standard sample sample according to the document and on the set of sieves used Δq.
Determine the value of the residue of the tested grinding powder q.
The percentage content of grinding powder residues for the manufacture of abrasive tools on a flexible basis on control sieves is determined by dividing the adjusted mass of grinding powder residue on control sieves (the difference between q and Δq) by the weight of the test sample of grinding powder.
A sample of grinding powder for tools on a flexible basis complies with this standard if the adjusted mass of the remaining grinding powder of controlled grain size on the control sieves is within the limits specified in Table 3. If not, then re-check the grain composition of the grinding powder on a double number of samples.
An example of recording the results of monitoring the grain composition of grinding powder with a grain size of P80 is given in Appendix A.
The approximate correspondence of grain sizes according to this standard and according to GOST 3647 is given in Appendix B.
Grain composition
The grain composition of grinding powders with grain sizes from F4 to F220 must correspond to that indicated in Table 1.
1 – Grain composition of grinding powders with grain sizes from F4 to F220
| Test sieve cell size 1 W1,mm (µm) | Remaining grinding powder on control sieve 1 Q1, % | Test sieve cell size 2 W2, mm (µm) | Remaining grinding powder on control sieve 2 Q2, %, no more | Test sieve cell size 3 W3, mm (µm) | Remaining grinding powder on control sieve 3 Q3, %, not less | Test sieve cell size 4 W4, mm (µm) | Remaining grinding powder on control sieves 3 and 4 Q3Q4, %, not less | Test sieve cell size 5 W5, mm (µm) | Remaining grinding powder on control sieves 3 – 5 Q3Q4 Q5, %, not less | Remaining grinding powder on the pallet ΔQ, %, no more | |
| F4 | 8,00 | – | 5,60 | 20 | 4,75 | 40 | 4,00 | 70 | 3,35 | Not regulated | 3 |
| F5 | 6,70 | 4,75 | 4,00 | 3,35 | 2,80 | ||||||
| F6 | 5,60 | 4,00 | 3,35 | 2,80 | 2,36 | ||||||
| F7 | 4,75 | 3,35 | 2,80 | 2,36 | 2,00 | ||||||
| F8 | 4,00 | 2,80 | 2,36 | 45 | 2,00 | 1,70 | |||||
| F10 | 3,35 | 2,36 | 2,00 | 1,70 | 1,40 | ||||||
| F12 | 2,80 | 2,00 | 1,70 | 1,40 | 1,18 | ||||||
| F14 | 2,36 | 1,70 | 1,40 | 1,18 | 1,00 | ||||||
| F16 | 2,00 | 1,40 | 1,18 | 1,00 | (850) | ||||||
| F20 | 1,70 | 1,18 | 1,00 | (850) | (710) | ||||||
| F22 | 1,40 | 1,00 | (850) | (710) | (600) | ||||||
| F24 | 1,18 | (850) | 25 | (710) | (600) | 65 | (500) | ||||
| F30 | 1,00 | (710) | (600) | (500) | (425) | ||||||
| F36 | (850) | (600) | (500) | (425) | (355) | ||||||
| F40 | (710) | (500) | 30 | (425) | 40 | (355) | (300) | ||||
| F46 | (600) | (425) | (355) | (300) | (250) | ||||||
| F54 | (500) | (355) | (300) | (250) | (212) | ||||||
| F60 | (425) | (300) | (250) | (212) | (180) | ||||||
| F70 | (355) | (250) | 25 | (212) | (180) | (150) | |||||
| F80 | (300) | (212) | (180) | (150) | (125) | ||||||
| F90 | (250) | (180) | 20 | (150) | (125) | (106) | |||||
| F100 | (212) | (150) | (125) | (106) | (75) | ||||||
| F120 | (180) | (125) | (106) | (90) | (63) | ||||||
| F150 | (150) | (106) | 15 | (75) | (63) | (45) | |||||
| F180 | (125) | (90) | Not regulated | 40 | (53) | 65 | Not regulated | ||||
| F220 | (106) | (75) | (63) | (53) | (45) | 60 |
An example of a symbol for silicon carbide grinding powder with grain size F100:
Silicon carbide F100 GOST R 52381-2005
The maximum deviations of the grain composition of the grinding powder sample during interlaboratory determinations must correspond to those indicated in Table 2.
The grain composition of grinding powders with grain sizes from P12 to P220 must correspond to that indicated in Table 3.
3 – Grain composition of grinding powders with grain size from P12 to P220
| Test sieve cell size 1 W1,mm (µm) | Remaining grinding powder on control sieve 1 Q1, % | Test sieve cell size 2 W2, mm (µm) | Remaining grinding powder on control sieve 2 Q2, %, no more | Test sieve cell size W3, mm (µm) | Remaining grinding powder on control sieves 1 – 3 Q3, %, not less | Test sieve cell size 4 W4, mm (µm) | Remaining grinding powder on control sieves 1 – 4 Q4, % | Test sieve cell size 5 W5, mm (µm) | Remaining grinding powder on control sieves 1 – 5 Q3, %, not less | Remaining grinding powder on the pallet ΔQ, %, no more | |
| P12 | 3,35 | – | 2,36 | 1 | 2,00 | 14 ± 4 | 1,70 | 61 ± 9 | 1,4 | 92 | 8 |
| P16 | 2,36 | 1,70 | 3 | 1,40 | 26 ± 6 | 1,18 | 75 ± 9 | 1,0 | 96 | 4 | |
| P20 | 1,70 | 1,18 | 7 | 1,00 | 42 ± 8 | (850) | 86 ± 6 | (710) | |||
| P24 | 1,40 | 1,00 | 1 | (850) | 14 ± 4 | (710) | 61 ± 9 | (600) | 92 | 8 | |
| P30 | 1,18 | (850) | (710) | 14 ± 4 | (600) | (500) | |||||
| P36 | 1,00 | (710) | (600) | 14 ± 4 | (500) | (425) | |||||
| P40 | (710) | (500) | 7 | (425) | 42 ± 8 | (355) | 86 ± 6 | (300) | 96 | 4 | |
| P50 | (600) | (425) | 3 | (355) | 26 ± 6 | (300) | 75 ± 9 | (250) | |||
| P60 | (500) | (355) | 1 | (300) | 14 ± 4 | (250) | 61 ± 9 | (212) | 92 | 8 | |
| P80 | (355) | (250) | 3 | (212) | 26 ± 6 | (180) | 75 ± 9 | (150) | 96 | 4 | |
| P100 | (300) | (212) | 1 | (180) | 14 ± 4 | (150) | 61 ± 9 | (125) | 92 | 8 | |
| P120 | (212) | (150) | 7 | (125) | 42 ± 8 | (106) | 86 ± 6 | (90) | 96 | 4 | |
| P150 | (180) | (125) | 3 | (106) | 26 ± 6 | (90) | 75 ± 9 | (75) | |||
| P180 | (150) | (106) | 2 | (90) | 15 ± 5 | (75) | 62 ± 12 | (63) | 90 | 10 | |
| P220 | (125) | (90) | (75) | 15 ± 5 | (63) | (53) |
An example of a symbol for silicon carbide grinding powder with P80 grit:
Silicon carbide R80 GOST R 52381-2005
Sandpaper for grinding machines
Sandpaper for grinding machines Find out
There are different types of sanders; a power belt tool can be used to sand wooden surfaces.
Carrying out work using equipment requires the correct selection of skins. Sandpaper for grinding machines is presented in the form of triangles, tapes of various widths, round sandpaper with a Velcro surface, roll, or sheet for mechanisms.
The grain size is selected depending on the type of work performed. “Nulevka” sanding material is intended for final polishing of the surface. It is important to remember safety precautions, no matter what the grit size of the sandpaper. Always sand with safety glasses, a respirator and gloves.
GOST 3647
| GOST R 52381 | GOST 3647 |
| F4 | – |
| F5 | |
| F6 | |
| F7 | |
| F8 | |
| F10 | 200 |
| F12, P12 | 160 |
| F14 | – |
| F16, P16 | 125 |
| F20, P20 | 100 |
| F22 | – |
| F24, P24 | 80 |
| F30, P30 | 63 |
| F36, P36 | 50 |
| F40, P40 | – |
| F46 | 40 |
| F54, P50 | 32 |
| F60, P60 | 25 |
| F70 | 20 |
| F80, P80 | – |
| F90, P100 | 16 |
| F100, P120 | 12 |
| F120, P150 | 10 |
| F150, P180 | 8 |
| F180, P220 | 6 |
| F220 | 5 |
Key words: abrasive materials, grinding powders, grain size, grain composition, control of grain composition
Control of grain composition
The essence of control
The essence of the control is to determine the content of grinding powder residues as a percentage of the weight of the test sample, equal to 100 g, obtained by sieving on a set of control sieves.
Equipment
Machine for sieving samples of grinding powders type RO-TAP.
A machine for sieving samples of grinding powders is shown in Figure 1.
Type A Type B
– shaker; 2 – plug; 3 – test sieves; 4 – pallet; 5 – base plate; 6 – base
The machine must be equipped with a time switch.
A type A machine must be secured with three M10 bolts on a concrete base plate measuring 625 x 500 x 550 mm with a mass that prevents the transmission of vibration to it.
The concrete base slab should be installed on a vibration-absorbing pad made of hard felt to level out uneven ground conditions.
Machine Feature:
rotation speed – (285 ± 10) min-1;
the number of strikes of the striker in the center of the cover is (15 ± 10) per minute.
A set of test sieves according to GOST R 51568 with cell side dimensions:
(8.00 ± 0.25), (6.70 ± 0.21), (5.60 ± 0.18), (4.75 ± 0.15), (4.00 ± 0.13), (3.35 ± 0.11), (2.80 ± 0.09), (2.36 ± 0.08), (2.00 ± 0.07), (1.70 ± 0.06), (1.40 ± 0.05), (1.18 ± 0.04), (1.00 ± 0.033) mm;
(850 ± 29), (710 ± 25), (600 ± 21), (500 ± 18), (425 ± 16), (355 ± 13), (300 ± 12), (250 ± 9.9), (212 ± 8.7), (180 ± 7.6), (150 ± 6.6), (125 ± 5.8), (106 ± 5.2), (90 ± 4.6), (75 ±4.1), (63 ± 3.7), (53 ± 3.4), (45 ± 3.1) µm.
Test sieves should not have visible defects: ruptures, thickening, blockages of cells, mesh tension, as well as distortions of the frame (shell), soldering defects.
A set of test sieves should be used for the specific grit size of the abrasive powder sample.
The frame (shell) of the test sieve should have a diameter of 200 mm and a height of 50 mm.
Checking test sieves
Checking of control sieves, controlled grinding powders for the manufacture of abrasive tools, excluding tools on a flexible basis, is carried out according to GOST R 51568.
Verification of control sieves, controlled grinding powders for the manufacture of abrasive tools on a flexible basis is carried out using standard samples as follows:
The control sieve to be verified is installed third in the set of control sieves. The first and second sieves must be checked. The standard sample is sieved on a set of control sieves. If the sum of the percentage residues on control sieves 1, 2 and 3 differs from the tolerances specified in Table 3 by more than 1.5 times, then the control sieve subject to verification is considered unsuitable for use.
The control sieve subject to verification, which cannot be installed third in the set of control sieves, is installed fourth in the set of control sieves. The first, second and third sieves must be checked.
The standard sample is sieved on a set of control sieves. If the sum of the percentage residues on control sieves 1, 2, 3 and 4 differs from the tolerances specified in table 3 by more than 1.5 times, then the control sieve subject to verification is considered unsuitable for use.
Test sieves with cell side sizes of 3.35, 2.36 mm and 53 microns are verified according to GOST R 51568.
The frequency of checking control sieves is once every six months.
Scales with an accuracy of ±0.1 g.
Time relay with an error of ± 5 s.
Standard samples of grinding powders for tools on a flexible basis according to a document approved in the prescribed manner.
