Or mechanical grinding, right choice abrasive - important factor determining the quality of processing wooden surface... This is a simple task at first glance, in fact, it raises many questions. What kind of sandpaper should you use at different stages of sanding? How to understand the markings when choosing the right abrasive? What properties do different types skins? We will answer all these and other equally important questions in the presented material.
Anatomy of an emery sheet
Sandpaper or grinding wheel for a sander is made up of three main components: abrasive material, backing material and binder.
Abrasive material - a substance crushed to the state of small grains. For the production of sandpaper, use different types abrasives: aluminum oxide (electrocorundum), silicon carbide, garnet, glass, elbor, etc. The size of abrasive particles determines the most important characteristic of the abrasive paper - its grain size, which we will talk about in more detail.
Substrate - paper or fabric backing on which the abrasive material is glued. The fabric is most often used for belts, rolls and some types of sanding discs. Paper is commonly used for sanding sheets and most types of discs. Along with paper and fabric substrates, you can find options from polyester materials.
Binder - a layer of adhesive that holds abrasive grains. As a binder, flesh glue, synthetic resin (a more durable version) or a combination of these two materials are used.
Understanding the types of coverage
For various works with wood: its rough processing, preparation for finishing, interlayer sanding of coatings, polishing, etc., the following types of abrasives are traditionally used.
Aluminum oxide (electrocorundum) ... Is different high density and resistance to crushing. The most common abrasive for grinding wood and metal. Recommended for sanding untreated wood.
Silicon carbide ... In the process, the crystals of this abrasive split, forming new cutting edges. This feature of the grains ensures self-sharpening of the skin and prevents its rapid clogging. Silicon carbide sandpaper is recommended for delicate sanding such as intercoat sanding of finishes.
Garnet ... Relatively soft mineral abrasive. Has the ability to self-sharpen, but wears out quickly. It is traditionally used for finishing sanding treated and untreated wood.
Aluminum ceramics ... This is an aluminum oxide that has undergone an additional high-temperature treatment. Its abrasive properties are higher than that of the unfired analogue. Differs in maximum wear resistance, optimal for wood processing at various stages.
How not to be mistaken with grain?
Granularity - essential characteristic sandpaper. When the hackneyed question sounds: what kind of sandpaper to grind a tree - usually they mean not so much the type of coating, the nature of the binder, etc., but the grain size indicator.
The suitability of sandpaper for a particular type of work depends on the gradation of grain. At first glance, everything seems simple, but in practice, the choice of the right skin is often complicated by confusion in marking by numbers.
It so happened that on modern market in active use there are several standards of sandpaper at once: international classification ISO 6344 (it is fully consistent with the new Russian GOST R 52381-2005), the old Soviet marking (GOST 3647-80) and the American standard (CAMI).
TABLE: TYPES OF GRAIN SIZE OF SINGLE PAPER, PURPOSE OF ABRASIVE, RATIO OF LABELS
| Abrasive purpose | ISO-6344 marking (GOST R 52381-2005) |
Marking according to GOST 3647-80 (Soviet standard) |
CAMI marking (American standard) |
Grain size, μm |
|---|---|---|---|---|
|
Coarse abrasives |
||||
| Rough wood processing | 40-N | 40 | ||
| 32-H | 50 | 315-400 | ||
| P60 | 25-N | 60 | ||
| Primary grinding
Leveling the wood surface |
20-N | 200-250 | ||
| 16-H | 80 | |||
| 12-H | 100 | |||
| P120 | 10-H | 120 | ||
| Preparing hardwoods for finishing
Finishing sanding of soft rocks Grinding old paint for painting |
8-H | 150 | ||
| 6-H | 220 | |||
|
Fine-grained abrasives |
||||
| Finishing sanding of hardwoods
Sanding between coats |
5-H, M63 | 240 | ||
| 4-H, M50 | ||||
| Final sanding of the finishing coat
Polishing |
M40 / H-3 | |||
| M28 / H-2 | 360 | |||
| Superfine grinding
Removing micro-scratches |
M20 / H-1 | 600 | ||
What are open and closed abrasive fill?
Based on the peculiarities of the application of the abrasive material, skins with open and closed filling are distinguished. This is another one important parameter, which is worth paying attention to when choosing sandpaper for working with wood.
In sandpaper with open and semi-open filling, abrasive grains cover from 40 to 60% of the working surface. The sparse grain filling prevents the rapid clogging of the abrasive with wood chips, resin, paint and other waste. This sandpaper is optimal for machine sanding, processing wood for painting, working with soft and resinous wood species.
In closed or solid sandpaper, the abrasive grains cover the entire work surface. Such a skin is more effective in hand grinding working with hard rocks wood, finish polishing.
How to extend the life of an abrasive?
As the chips and resin become clogged and the abrasive grains wear out, the sandpaper loses its working properties. Clogged abrasive, especially when machine sanding, leaves dark marks, compresses the fibers and polishes the surface, due to which the wood does not absorb the finishing compound well.
To keep the abrasives working longer, start with a coarser sandpaper, gradually moving to finer grit paper. For soft and resinous woods, use a thinned sandpaper with a special stearate coating (dry lubricant to prevent quick clogging of the abrasive).
When working with a sander - take your time. Overheating of the surface softens the binder and accelerates the wear of the abrasive grains. An important factor is the storage conditions of the grinding material. Cold and critical humidity can render it unusable. Optimum temperature storage 15-25 ° C at a relative humidity of 35-50%.
All of the above cleaning methods in to a greater extent relevant for grinding abrasives. For cleaning regular skin, you can use a brush with stiff plastic bristles.
And the advice, in my opinion, is just wonderful. This did not occur to me, although I also ran into this problem ...
So, we will talk about cleaning clogged abrasive wheels, belts, strips and others Supplies for grinding tools. When working on removing old paintwork or wood conifers even new belts and circles quickly become unusable due to the fact that the spaces between the abrasive particles are clogged with paint, resin and other nasty things, which, when heated, acquire great plasticity.
At the same time, the abrasive particles sit on the belt, their edges are sharp, and the grinding process is no longer going on ... What to do? Previously, I put the tape in a suitcase and took out a new one (the toad did not allow me to throw out material that was still suitable, in the future, - HOW SHE WAS RIGHT)))).
Sergey offers an easy way to clean up. First, it is necessary to heat the abrasive surface so that the clogging agent regains some fluidity. This can be done with a building hairdryer. 
Then we pick up metal brush and just clean out all the dirt. It is removed much easier than "cold". 
After that, we are glad that there is no need to spend money on consumables, we put the skin back on and get to work. 
Another modification of the method is processing clogged sandpaper with WD-40 deep-penetrating grease instead of heating it. They say that the brush cleans after the WD-shki in the same way as after heating ... I'll have to try.
The nature of the damage to the grinding wheel is determined by the material from which the part is made. In addition, the characteristics of the circle itself matter. There are products on the market that have the ability to self-sharpen. However, this is only relevant for those cases where wear is determined by simple mowing of the grains.
It is known that the granular surface of the grinding wheel is in the form of crystals. If during operation they lose their shape, smooth out or fall into the structure of the abrasive layer, then self-sharpening of the wheel takes place. This function is provided by the manufacturer; it brings a lot of convenience to the owners of such equipment.
But not every grinding equipment is capable of self-sharpening. As a rule, this is only true for soft circles. If the grinding equipment has a high hardness, then during prolonged or excessively intensive use, bluntness may occur. cutting edges crystals.
In practice, this is fraught with the fact that the discs can break out of the ligament. Indeed, as a result of clogging or salting of the upper layer, the surface of the circle is produced unevenly. As a result, the geometry of the product is violated.
This is fraught with not only poor-quality grinding, but also traumatic situations. Any grinding wheel is fraught with potential danger. This equipment can be safe only if its owner has kept the original performance characteristics... Therefore, the question of how to clean the grinding wheel becomes paramount.
What is Grinding Tool Grease?
Another side of the problems associated with heavy use of wheels is the clogging of the abrasive layer. This term in a professional environment refers to the process as a result of which the chips removed from the workpiece fall into the pores of the circle.
The cutting ability of the tool is reduced or completely reduced to zero. This is because the removed shavings clog the pores along with the abraded crystals. Filling with abrasive not only leads to a decrease in the quality of grinding, but can provoke a burn-through. Cleaning the grinding wheel can restore tool performance and its previous cutting properties.
Remember! After grinding, the abrasive wheel is usually clogged. This is especially true if there is a small grain on the circle. With this unpleasant phenomenon it is possible and necessary to fight: to clean the instrument. After all, the grinding wheel becomes literally smooth. The stones on it are smoothed out, and there can be no talk of any grinding.
If the emery wheel is dirty on the machine
To solve the same problem craftsmen adapted to use diamond cutting disc for cutting ceramic tiles... There are diamond inclusions in the face of the disc. Cleaning can be carried out from the end of the grinding wheel or from the sides.
The movements of the disc are carried out in the direction from the center to the edge of the circle very carefully, since there is a risk of leaving scratches on the instrument. The end part is also cleaned extremely carefully and within literally a few seconds. After such an operation, the circle becomes new, as if it had just been brought from the store.
Using a cleaning bar is safer and more gentle. Cleaning occurs as the disc rotates from center to edge. Just a few movements with the bar, and the circle becomes like new. The grain becomes visually noticeable, and the disc regains the same roughness to the touch. You can continue sanding.
How to remove resin from the flap disc?
The emery wheel is often used for grinding wooden parts... During processing, microscopic chips come off the top layer. Wood is a resinous material, so the microscopic dust that forms during the sanding process has a viscous structure. This is detrimental to the abrasive layer.
Pine is especially resinous. When working with pine lumber, the abrasive disc experiences tremendous frictional forces. This process involuntarily provokes high temperatures, which, in turn, soften the resin.
As a result, the abrasive is wasted, because its pores become greasy. The first sign that the abrasive is clogged is a dark coating on the disc itself and on the workpieces. Why is it important to know how to clean a flap disc? The fact is that an abrasive clogged with resin is completely unsuitable for work. It presses the wood fibers, which will subsequently make it difficult to absorb the finishes and antiseptics.
How to remove resin from the flap disc? This can be done easily with a diamond pencil. The emery wheel from wood is literally cleaned with one touch in working mode.
The cleaning bar also extends the life of the disc and cleans it almost instantly. Therefore, the bar in a professional environment immediately began to be called a cleaning eraser. To remove resin from the grinding wheel, attach the abrasive to the grinding head and bring it into working position. The bar should be drawn from the center to the edge of the disc and carefully along the end part.
When deciding how to clean the resin from the wheel, you can wipe the wheel surface with a brush or sponge and a mild abrasive. For heavy salting, a steel brush can be used, but again, this must be done very carefully.
Chronikulus 31-07-2007 23:55
I make myself a small knife to carry in my pocket. The handle is made according to the recipe from Rumoko from jeans and epoxy. Faced a problem - I grind the handle on a grinding wheel on a drill and the sandpaper becomes very quickly clogged with material and clean up its problem. Current with water, but the sandpaper itself is already creeping from the water, or it must be dried for a long time. Tell me how you can quickly clear it. I really don't want to buy grinding wheels in such huge numbers- the golden knife will turn out ...
Snowman696 01-08-2007 12:56
quote: Originally posted by Chronikulus:
a golden knife will turn out ...
It will be possible to show friends with the words "I made it myself, some consumables flew into the N-th ..."
bs4u32sr30 01-08-2007 01:24
if you rub it on the skin, everything is wonderfully cleansed.
SanDude 01-08-2007 01:55
Rubber or bronze (or something similar in appearance) brush.
But the most important thing is to buy a good waterproof sandpaper. As a result, it will be much cheaper.
chief 01-08-2007 09:01
Fine wire brush (I could only find a cup-shaped drill)
Chronikulus 01-08-2007 10:25
quote: Originally posted by chief:
Fine wire brush (I could only find a cup-shaped drill)
O! I have one! thanks, I'll try
Or maybe try a rasp or an ordinary file and then smooth the surface with sandpaper?
yes it turns out faster and more beautiful and the result is better visible - IMHO naturally
quote: Originally posted by Snowman696:
It will be possible to show friends with the words "I made it myself, some consumables flew into the N-th ..."
well, what a fuck my wife is already grumbling
quote: Originally posted by SanDude:
But the most important thing is to buy a good waterproof sandpaper. As a result, it will be much cheaper.
I understand that it’s cheaper but there’s no current nearby, and as a rule, there’s not enough time to go specially for it. I'll try to brush it
Chapaev 01-08-2007 10:39
Hand wire brush cleaning, works well. And I also agree with other comrades, high-quality sandpaper is a capital saving of funds, you spend it corny less, it lives many times longer.
OSG 01-08-2007 17:19
less speed - epoxy is melted, you can see ...
or abrasive cloth on a cloth basis and even sand in water.
Mutant 01-08-2007 20:19
Use an abrasive mesh instead of sandpaper - it almost does not clog. Only she's pretty rude.
Chronikulus 01-08-2007 22:17
I just need a grinding circle for a Velcro drill
and so the thought was ...
Chronikulus 02-08-2007 11:04
2 OSG
I have the opposite problem - epoxy leaves more or less easily, but the fabric, on the contrary, is bad. The villi remain - it does not turn out very nicely
OSG 02-08-2007 11:36
A! so this - how almost the finish (the current of the villi stick out) - either with cyanoacrylic, or (IMHO better) with diluted epoxy with acetone to cover thin layer, after drying, bring to the right kind... You may have to repeat it several times. Apparently the fabric is not soaked well.
Chronikulus 02-08-2007 12:23
I just squeezed it out well and it's easier to process it - you can even plan a little
besides, if you put it under the press anyway most of epoxy will still be squeezed out ... otherwise you don't need to pick out the squeezed out epoxy and think about how to remove it from the blade ... in general, it's more convenient, that's it.
When buying a grinding wheel, each of us knows that an abrasive tool will work for a long time therefore, information on how to clean abrasives is very important for those who use grinding discs to grind workpieces. Any grinding wheels or discs (even dense ones) will wear out when working on a surface or material. The more the tool works, the more it and its abrasive wear out.
Causes of wear and galling of abrasive wheels
Damage to the grinding wheel is determined by the material from which the workpiece is made. You can find discs that can self-sharpen. Such a grinding wheel will go to work where wear is determined by simple mowing of grains.
We all know that the grain, that is, the abrasive of the grinding wheel, is in the form of crystals. During the operation of such a disc, these abrasive particles lose their shape, over time the abrasive smoothes out, in this case, the self-sharpening of the grinding wheel is simple and effective option... This is very suitable for those who use a special grinding machine.
If another machine is used, such wheels or discs should not be used. If the grinding machine has a high hardness, the grinding wheel may become dull during grinding.
So, during grinding, the discs can break out of the bond. When clogged and dirty, the surface of the grinding wheel is unevenly developed. As a result of this grinding, the workpiece will deteriorate.
Any grinding wheel should be used according to the rules. Effective work machine and grinding wheels is possible if their performance characteristics are taken into account. The question is how to clean the grinding wheel?
Another problem with discs and grinding wheels is that they become dirty. abrasive wheel as a result of its use. Filling is called a process, as a result, chips get into the pores of the disc, which is removed from the workpiece.
In this case, the working capacity of the grinding wheel is greatly reduced. It turns out that such shavings clog the pores of the wheel together with the worn abrasive. Filling the abrasive of the grinding disc affects the quality of the grinding and also increases the burn-through rate. If you clean the grinding wheel, you can put it back into operation and use it like new.
Everyone should remember that after sanding, the abrasive wheel clogs up. This is especially true of those circles in which there is a small grain. Therefore, you should clean the discs. The grinding wheel will be smooth immediately after processing. When the abrasive wears out, grinding with such a disc is out of the question.
Some have found a diamond disc for themselves, with which they solve the problem of grinding wheel grease. There is an abrasive at the end of the disc. Cleaning can be done from the sides or from the end of the grinding wheel.
The cleaning bar is more effective method cleaning. A few strokes of the bar are enough - and the disc looks like a new one. After that, the grain will be visible.
How and with what to clean a flap disc?
Several processes affect the life of the grinding wheel:
- Filling is when the wheel is clogged by grinding the workpiece.
- Wear when grinding disc wears out during processing.
In such cases, the question follows how to clean the grinding wheel. Because cleaning will extend the lifespan this instrument, and it will be possible to work with it as with a new one.
The way to clean the flap wheel is to use a diamond-embedded disc. In order to restore the original appearance of the circle, it must be applied from the sides or from the end. This should be done with care as the surface of the grinding wheel is easily damaged.
A special flap wheel can be used to clean it. The disc will rotate, and the movements should be made to the edge from the center. In the same way, you can clean the edge of the sanding disc; in a few seconds, the block will bring it to work.
It is simple, but there are many ways and technologies for such a procedure. At home you can use more simple ways, which will help clear the grinding wheel from grease.
How do I clean the resin from my grinding wheel?
For grinding wooden blanks many people use an emery wheel. When processing is carried out, chips are removed from the top layer. Since wood is a resinous material, the chips that are generated during the grinding process are viscous. This is unacceptable for the abrasive layer of a grinding wheel.
The resin content of the pine is very high. In the process of working with such materials, the abrasive grinding disc is severely abraded. When sanding with a circle high temperatures the resin softens. Therefore, the abrasive quickly becomes unusable due to the pores of the circle being salted.
If the abrasive is clogged, there will be a dark coating on the sanding disc, and so on the workpieces. Abrasive clogged with resin clogs wood fibers.
The resin can be removed from the grinding wheel with a special pencil. The emery wheel is cleaned almost immediately. A cleaning block can be used, which also extends the life of the sanding disc and cleans it quickly. To remove resin from the flap wheel:
- attach the abrasive to the grinding head;
- carry a bar from the center to the edge along the end part.
The abrasive also removes resin from the grinding wheel. It is enough to wipe the surface with a brush or sponge. Special brushes can only be used if the grinding wheel is heavily soiled, but this should be done very carefully.
From the above, it is clear how to clean the flap disc from resin, grease and extend the life of the working tool. Applying these tips in the process, you can qualitatively grind the surface of the material or workpiece.