In this article you will find detailed information and step by step instructions with explanatory photographs on how to sharpen with sandpaper by hand on wood.

There are professional carpenters who quite seriously argue that the grinding of wood is a science. Most certainly perceive such a statement as a clear exaggeration and a manifestation of unbridled professional pride. That may be how any of that. The claim is in any case a hint that grinding is actually advanced vocational technology how simple tasks may seem.

Polishing the wood is wholly essential for all painting work and for practically all wallpapering. When all the fancy paint jobs, it is also a matter of sharpening by hand. If you look closely at the picture of the beautifully decorated painted coffin here next door, you can see the marks on the coffin lid.

Some are impact marks, but the streaking in the wood longitudinal direction at the right, transverse, black bracket are traces of the original coating. Such badges We accept, of course.
They may even have value, because they can tell you about the coffin age.

Probably these brands traces attempts to otherwise than with sandpaper to remove notches after a plane irons. The marks are so serious that they can hardly be sanding marks after sanding. And sandpaper did not come into common use until the early 1800s.

On new wooden surfaces, we accept no marks of this kind either on furnishings, door frames, window frames or the like. This is of course the fact that we now have the technology to obtain very smooth, smooth wood surfaces premise of a perfect painting.

Various grades

Ordinarily speaking, most of us still like sandpaper. Professional painters, by contrast, abandoned long term. The reason is obvious: the sand is now used infrequently as the abrasive, but has been replaced by the far more efficient materials.

Now called the sandpaper and the working material is abrasive. Furthermore it distinguishes between natural abrasives and synthetic abrasives. Natural Abrasives can be flint, garnet and glass, crushed to different grain sizes and glued on special paper.

Synthetic abrasives made of eg silicon carbide and corundum the latter a hard material of aluminum oxide. The difference between natural and synthetic medium is quite large. Natural abrasive grains often become quickly dull and cut as bad. The synthetic is harder and stay sharp better. Sandpaper with synthetic coating cuts not just better, they also hold much longer.

Different grain sizes
There are both Swedish and imported sandpaper. The papers are graded according slipkornens size.
The table is a European and an international scale. There you can also see which grit size suitable for different kinds of work. Since it is quite common to inherit or otherwise assumes tool kits happens that you meet on the older numbering. In the past, a distinction was made between sandpaper, sandpaper and waterproof sandpaper. Sandpaper numbered from 1200, which is the finest, the 10th

 

Warning

Do not use abrasive pads or oscillating abrasive additive in combination with a hobby machine on surfaces to be ironed with a clear coat. Lacquer surface acts as a “magnifying glass” and enables the circular grinding pattern emerges particularly clearly.

Tip

Feels a sandpaper very plain to the manufacturer to have put a thin glue layer of abrasive. It wears off when you start to grind. When renovating older furniture is the finest steel wool is a very good abrasive especially at the final sanding. Fine-meshed steel wool is also the most appropriate abrasive on surfaces to be polished.

Worth knowing about sandpaper

A slip of paper is either open or dense grit coating. Open coating is best suited for coarse grinding of porous surfaces, a dense hardwood. The International grit graduation is attributed to the term of stitches per inch. used during the sifting of abrasives. With your hand you can feel how effective a sandpaper. Is the paper very sharp, it may be that there is grit on top of the actual grains. Such paper may cause scratches. Abrasives which may also exist in rolls, graded from 500, which is the finest, to 40. Water-resistant sandpaper, finally, 50 numbered 600. It is used only for so-called wet grinding for example, water or diluents.

The groundwork

How extensive preparation required before you can grind a surface to be painted or papered, depends on the condition of the surface. Damage, cracks and other imperfections must be repaired or covered with strips and leveled with putty. Level out so carefully that you do not get streaks and other marks that may be difficult to grind away.

Grinding Technology

To a painted, varnished or stained surface to be perfect surface must be smooth and clean. The same requirement applies to wallpapering. The perfect wood surface, which should be both beautiful and give good adhesion to the paint, you can not obtain any other way than by grinding. When sanding wood surfaces always apply: Sand the wood in the longitudinal direction, ie with the grain!

Coarser unevenness, for example, filling, you can get away with a paint scraper. Scrapers of hardened and ground steel with convex edge gives vestiges. Abrasive papers and canvases are available in many types with different effects. To specify a particular grain size for a specific job is almost impossible. You get that professional painters, experimenting.

Some rules of thumb are abrasive paper:

• Soft wood, such as pine, should not be sanded with finer paper than P 120th

• Harder wood, such as mahogany, should not be ground finer than P 150th

• When wet grinding is used as fine paper P 220 400. Wet sanding is done only on already varnished or painted surfaces. The liquid may be, for example water or white spirit.

Steel wool or nylon cloth, other abrasive, but beware of cleaning pads, which are normally used in the household. The river too hard. Although steel wool have different sizes. The finest used for final grinding. When hand sanding, you need a block, around which the sanding paper or cloth is laid. Wooden blocks are too harsh to provide smooth grinding surface. Therefore, choose blocks of cork or felt.