Before applying the finish, the project should be sanded with sandpaper in grain 150 to 180 before finishing. Be careful when sanding with a force sander, as the surfaces on the plywood veneer layer are quite thin, so it is easy to sand the lower layers without realizing what is happening. Keep the direction in which you sand in line with the wood grain to avoid visible scars in the grain. When sanding, keep your sander in line with the wood grain for as long as possible.
After sanding the box with 120 grit sandpaper, it is recommended to sand it one last time with 180 grit sandpaper before staining. If you want to dye your box, you should touch something - up and primer the areas where the primer has been sanded away. Sand the primers dry and wet, then retouch and primer again with a dry sander, sand, and sand. When you are done, wipe the dust with damp cloths and let the workpiece dry.
Then apply the stain and leave to rest for the time indicated on the label. You can choose to apply a wood conditioning prior to staining, which helps it to accept the stains more evenly along its grain.
I improved from 180 - 220 to the last grinding grains with 180 / 220 and then to a final grain size of 220 / 200. It is a good policy to sand before applying the stain, but not before staining.
When sanding on a flat surface, use the flat block to secure the sandpaper and advance to the next finer sandpaper. I used the same sandpaper that I used for the last machine grinders, but if you sand a little longer, you can use a finer grain. The most efficient way to remove all three sanding processes is to remove all sanding dust with a sander with one or two grains of sand and then with two or three grit sand sanders.
Examine your workpiece and decide what you think is necessary and beat it again with what you can find within reach. Some areas may need a little color enhancement, especially if the color you use has a lot of shine.
Most plywood parts have a front frame that covers the edges, and guiding the board with a planer or a blunt knife requires, like veneer, coarse grit.
You do not want to start with grit that is too coarse, because otherwise you run the risk of scratching and it would be a total waste of time and energy. For example, you can finish the surface with 180 grit, but you can also start with a coarse grit of 100 or even 200 grit. If you start with a fine grain (100 - 150 grain), you cannot even start.
If you choose a powered orbital sander for light sanding, you should be careful not to sand the thin outer layer of plywood. Softwood layer is usually covered with several steps to the sand, which is used by many DIY enthusiasts, you should consider this when using it.
When sanding the sides of the plywood and the edges, you should use a pad that is 80% sanded. If you start with lower gravel, such as 150%, the sand on the side will color much more easily than if you start with higher gravel. In order to achieve the desired shine, a lot of sanding should be done in the first few hours.
I used sandpaper with 120 grits and a plywood cutting saw, and it was quite fast, so I wiped the wood clean with a cloth and then embedded the iron veneer I had tried back then.
Thorough sanding is super important at this point if you want to paint the box rather than paint it. If you do not completely sand off all the scratches on the 80 grit sandpaper you used in step three, you can highlight them by applying the stain.
If you just paint the box, a general smoothing of the surface is sufficient, but if you decide to paint it one last time, you can achieve an even smoother finish.
The sanding after the first coat of paint brings to light the unevenness and discrepancies that the roller brush brings with it. Use 220 grit sandpaper and attach the paper to the sander conveyor belt and let it run extremely easily over the surface. Don't put the sander under pressure, except for the weight of your Sanders himself.
In addition, you should consider using an orbital sander, as it does not alter the appearance of the natural wood and does not damage the wood.
If you are trying to get rid of the increased grain, the ultimate goal of sanding should be a smooth wood surface. This promotes adhesion, solves the problem of increasing grain and looks better for overall processing, but may take some time to sand the wood. If you have painted wood before, you can sand with a sander for a longer period of time, up to a few days.