Those who have not visited the furniture factory site may not think of how complicated it is to make a small bench.
Cutting the wood into the desired shape is the first step, planing the surface is the second step, and completing the assembly is the third step. At this time, the shape of a small bench came out, but it did not end. Next, in the fourth step, the surface treatment is the focus of the final effect.
One, surface pretreatment
1. Repeatedly sanding and polishing with sandpaper to remove burrs on the surface. In order to obtain a high-quality surface effect, this step cannot be saved.
2. Dispose of the glue remaining on the surface of the wood, otherwise the traces of glue residue will become more obvious after dyeing or painting.
3. Eliminate surface flaws, including indentations, knife marks, cracks, holes, and gaps left due to unsatisfactory bonding.
Two. Wood surface dyeing
dyeing mainly involves the selection of dyes, how to match colors, and the treatment of the base surface before dyeing. This step is the most difficult and most problematic. When carpenters choose wood, most of the time they don’t have so many choices. The wood surface will inevitably have stains, spots, streaks, color differences, etc., but it is difficult to coordinate dyeing and post-processing to just right . Therefore, many carpenters will give up dyeing, but in this way, the final rendering effect will be greatly reduced.
Three. Coating on the surface
The addition of surface coating is the key to the final effect. It has a lot to do with the processing products used.
1. Oils, the most heard of is linseed oil, which ancestors praised as the god oil, and the current tung oil, which is soft after curing and has a thin coating. However, the current oil market is relatively chaotic, and I often think that I am buying oil. In fact, it is a varnish product whose concentration is halved.
2. There are many types of ointment waxes, such as beeswax, paraffin wax, palm wax, etc., which are softer after curing and have a good polishing effect, but the protection performance is poor, not as good as linseed oil.
3. Shellac, compared to oil, wax and resin, has a better bonding effect with wood, but it has weak chemical resistance and a short shelf life. In the early 1920s, it was widely used in furniture and woodworking products in Europe and the United States, and was gradually replaced by synthetic paint. Although there are now, it has been reduced to a niche product.
4. Synthetic paint is considered the ultimate wood surface treatment product. Not only is it easier to waterproof and repair than shellac, it also has stronger waterproof and chemical resistance, but it is toxic and not very environmentally friendly. Today it is the most widely used furniture surface treatment product.
5. Varnish, it is the most protective and durable of the common wood surface treatment products. It has good waterproof and chemical resistance. It has almost all the advantages of the desired surface effect, but it is also the most difficult to use. Yes, and will turn yellow over time.
6. Two-component, water-based, two-component, as the name suggests, contains two components. Once the two are mixed, they can react to form an extremely hard and durable film coating. It is the same as water-based products that there are fewer organic solvents than other products, so it is relatively more environmentally friendly, but water-based products are expensive to produce and difficult to use, so the demand has always been small.
Different products require different tools. Two-component products need to be sprayed with a spray gun, while oil and varnish products are wiped or brushed with a brush or rag. Shellac, synthetic paint, and water-based products can be sprayed or brushed.
Four, surface post-treatment
After finishing the coating, the surface of the coating also needs to be treated. Generally, it is necessary to use abrasives such as sandpaper, steel wool or abrasive paste, or mix several products to wipe the coating surface. This process is the same as the process of sanding wood. It needs continuous sanding to smooth the surface of the coating until the appearance and feel of the paint layer are satisfied.
The reason why woodworking is difficult is not just the above steps. Different wood materials have different colors, densities and textures, and processing methods will also be different. More consideration needs to be given to the characteristics of wood materials.
For example, pine wood is often the first type of wood used by beginner woodworkers, but it is also the most difficult type of surface treatment. There are two types of early wood and late wood, one with soft texture and the other with hard texture. Both have different responses to sanding, dyeing and surface treatment, and uneven effects are prone to appear.
Another example is oak. Its surface treatment is as difficult as pine. It is also divided into early wood and late wood. The density of the two is also very different. The early wood has large pores and the late wood is denser. It is difficult to average during sanding, so that after treatment, there will always be obvious dents in the early wood area.
It can be seen that to complete a piece of wooden furniture, it is not only the pre-treatment of wood, but also the later surface treatment. That is the soul of a piece of furniture. Without texture, any appearance will not look good. Of course, except for the small bench made by grandpa, although the craftsmanship is not so detailed, the meaning of victory is extraordinary.
Maybe many people are like me. They have never thought that furniture surface treatment can be so story-telling. We can often feel the mellowness of a piece of furniture, but we don’t know why it is mellow.
This may be related to our senses. Surface treatment belongs to the category of chemistry. This process cannot be seen from a visual point of view. Just as we can't tell the composition of paint through our eyes, we can easily see the difference between a dovetail tenon and an ordinary tenon joint.