Automotive sheet metal putty-free painting repair technology

As I have worked as a sheet metal worker for three years, this "sheet metal data recovery" is easy to understand! The traditional sheet metal repair process is nothing more than pulling out the sunken sheet metal, leveling, reinforcing, polishing and "scraping putty" painting almost at the same time.

The so-called data recovery is actually the finishing of sheet metal, which requires a lot of work. First of all, we all know that there can be no automatic maintenance equipment for sheet metal maintenance. In fact, this high-end sheet metal repair technology is often done by the most primitive hands. In the past, when repairing sheet metal, it was usually enough to repair it, and the whole shape was filled with putty.

How to fix it without putty?

Only the sunken metal sheet can be pulled out slowly bit by bit, but many tools are used, and the whole repair process is extremely complicated and requires a lot of man-hours.

All sheet metal experts know that drawing is inseparable from meson machine. Let's take a look at the traditional meson repair process of metal plate:

After the concave metal sheet is polished and exposed, you can go to the meson machine, which is the principle of spot welding machine. When electrified, it is welded with the metal sheet. At this time, the depressed sheet metal can be pulled out by pulling back the inertia hammer block, and the strength and times of pulling the hammer can be determined according to the depth of the depression. However, this meson stretching sheet metal machine is powerful and fast, which is suitable for rapid plastic repair. You can almost polish it into putty!

If we want to treat local stretching accurately, it is difficult to control the strength. If you switch to a smaller meson machine, the strength will be better controlled. Therefore, data recovery machines are all special mesons, which not only have small solder joints, but also have higher control accuracy. Let's look at the stretching process of a special meson machine:

The spear head is not only several times smaller, but also has a bracket. Local depressions can be slowly pulled out with brackets. Even if there are dead folds and creases on the metal sheet, you can slowly pull it out with special puller with different maintenance brackets:

Not only can the concave part be pulled out, but also the convex part can be replaced by a special slider to flatten the part, which is impossible for ordinary mesons.

The whole process is like making handicrafts, which requires not only skilled technology, but also patience and patience. Without patience, it is impossible. Because the depression was flattened, wrinkles and creases were pulled out. If you want to repair without putty, you need to further refine it. Mesons will leave solder joints, and the metal sheet is not smooth after stretching, so it must be further polished with a metal sheet file. After grinding, in order to check whether the sheet metal is qualified, it is usually necessary to spray a layer of repairing agent similar to paint. After curing, use sandpaper to polish the repairing agent. After polishing, defects after sheet metal repair can be found, such as the part with excessive brightness and the part with residual repairing agent, and then targeted repair can be continued. Repeat the above steps, and slowly process until smooth with special puller and bracket.

For the parts of the metal plate that cannot be stretched due to local damage, such as pits and cracks, repair them with solder.

This principle is the same as the welding basin of foreign blacksmiths in the past. Solder has low melting point, easy molding and strong adhesion to base metal, which is very suitable for local repair of sheet metal.

These are relatively simple to say, but in fact they are quite complicated to do.

Many people learn about data recovery and repair through small videos. Photographers never photograph the restoration process, but directly photograph the comparison before and after the restoration. The whole process only emphasizes "data restoration" or gestures to sheet metal parts with instruments. Give a person a kind of inscrutable hurry, one of the most striking is Fang Gezi on the sheet metal:

These squares on the sheet metal painting look mysterious, and some people wonder if this is a mystery. In fact, it is drawn to restore sheet metal data and improve repair accuracy.

So how to get the data of sheet metal modeling?

Actually, this is very simple. This is done by the data recovery ruler:

This ruler, also called shaper, has scales on it. When in use, just press it on the measured metal plate, and when the ruler is removed, a metal plate shape will appear. Modeling ruler can be used as a reference standard for sheet metal maintenance. The whole process of perfect fitting with the modeling ruler after repair is data recovery. In fact, the data source of sheet metal maintenance is just a modeling ruler.

Automotive sheet metal is symmetrical, so it is convenient to take the original. Trim the metal sheet on the left, and then directly remove the symmetrical metal sheet on the right to get the shape. Even if you can't get the data of this car, please ask for a car of the same type! With a ruler, it is much easier to repair, at least the shape is more accurate than polishing putty.

This is the so-called data recovery principle. For the electric sheet metal spraying method, there is no putty on the sheet metal after data recovery and repair, and the paint has strong adhesion and is not easy to fall off. The paint film instrument cannot find out whether the sheet metal has been repaired. But the maintenance time is too long and the man-hour cost is too high.

In the past, the data recovery price of 200 sheets of sheet metal and painting will be multiplied several times. Therefore, most of these data repairs are aimed at luxury cars, and civil cars rarely do data recovery and repair.