Hello colleagues! Why colleagues, because the fact that all of as try to do something by own hands. Many things we try to do it yourself, for two reasons: it would save money, or as they say, "if you want something done well, do it yourself." Today we talk about self-painting a vehicle, and more specifically on the preparation for painting. Painting - a delicate matter, and only strict adherence to all technological requirements will give the desired result. One such requirement is the purity of the treated surface. Surface cleaning - is the foundation of repair.
When a car pulls into the repair, the first thing to do - is to thoroughly clean it from road dust, dirt and grease, and even in winter, and from the taint of salt and sand. To do this, a good car wash with warm water and car shampoo.
Ideally, the use of high pressure cleaning apparatus, such as "Karcher". This unit allows you to effectively deal with pollution due to strong water flow (low flow). It literally sweeps away the dirt. For cleaning hard to reach places different at all indispensable thing. For washing, we will not focus, with this procedure, I think everyone will cope, will announce only the main points:
- the water should be warm, and the head - strong;
- for more efficient removal of grease, use car shampoo;
- it is desirable not to use a cloth, better - a soft brush or a special sponge;
- Pay particular attention to the lower part of the car - there accumulates the most dirt;
- after washing carefully dry the surface.
Suppose that our surface is ready for the next step - removing the old paintwork, corrosion and other defects.
Today let's talk about:
- stripping of small scratches, chips;
- removing old putty masses of soil;
- removing rust;
- removing anti-gravity;
- cleaning welds;
- removal of adhesive tapes;
- selecting abrasive grain.
Tools for grinding
To remove small defects will suit eccentric rotary vibration machine with eccentric stroke of 5-8 mm, rigid plate 115 mm diameter wheels P80 and P150 graduation. Speed of work - up to 10 000 r / min..
As an example, two-handed pneumatic or electric typewriter Festool WTS 150/7, sanding plate with 7 holes and sanding paper in a 7-hole circles.
Professional eccentric sander Festool WTS 150/7 (turn eccentric 7 mm)
Removing thick layers of paint
Unchanged tool for grinding of large lesions and thick layers of paint materials is the angle grinder, hereinafter referred to as "Bulgarian" people.
Stripping machine Festool RAS 115.04 E
From the materials for this type of work most commonly used fiber loops: conventional and with fastening "Velcro." This is a very aggressive materials (gradations P036-P060), so that they can easily cope with the task. But it must be remembered that the risks are too deep should be reground a fine abrasive.
Stripping fibreboard circle
The stripping fiber wheels with Velcro
Recommended speed circles - 10,000 rev / min.. For circles Velcro speed must be limited to 8000 rev. / Min., Since at higher speeds "velcro" on the edges of the circles can burn.
Cleaning disc on the basis of synthetic fibers SCM
Also an excellent job of removing thick layers of paint stripping following special synthetic fibers SCM. Because of its unique structure, this material is hardly clogged with particles of paint and leaves virtually no traces on the metal, thus avoiding regrinding the surface finer abrasives. So the following are suitable for the removal of small defects.
The granularity of these materials already designated «K» the letter. They have three grades: K060 (rough), K100 (middle) and K150 (small). To mount these wheels fit the same dish, and that for the aforementioned fiber discs with Velcro. Speed - no more than 8500 rev / min..
Perfectly suited for the removal of the old paintwork and the Grinding flap discs. Due to the abrasive pitch placed fan-shaped manner, these discs wear evenly and does not get clogged. They serve to 6 or more times longer than conventional wheels. The speed of operation of 115-millimeter discs - up to 13,000 rev / min..
Stripping petal disc
Too, should use the "grinder" To combat corrosion centers.
From the materials best suited fiber and flap wheels as described above. If the work of these circles remain rust pores further use SCM discs. They easily remove rust from recesses and pores.
This is all well and good, but in most cases we have to deal with rust, which is located in different remote places (on the threshold edges, recessed). The most convenient in this case axial grinder. Where to place the Bulgarian too small for such a machine may be enough.
In tandem with these toy cars are special grinding rollers and small Sweep circles. The speed of the rollers - to 23,000 rev / min, siafix circles -.. 15000 to 30000 rev / min.. for the 50-millimeter drives and about 13000-27000. / min. discs with a diameter of 75 mm.
As a result, small size machines and grinding materials provide excellent access to repair sites, and high speed - fast and efficient removal of rust.
Removal of anti-gravity
Stone Chip cover - "headache" of many bodywork, as the majority of grinding materials quickly clogged by particles of the coating of synthetic rubber. However, the market still has materials to help cope with the anti-gravity - Special Grinding Discs based on bulk polymer fibers. The firm Sia they called siastrip and have a gradation of K040. The company 3M is the wheels Clean & Strip.
Rough structure of these discs ensures trouble-free removal of old coatings Stone Chip, and they almost did not get clogged and less heat. The effectiveness of such circles and iznosoytoykosti surpass even metal brushes, and their size, shape and flexibility allow you to work in the most uncomfortable and inaccessible places.
Cleaning disc on the basis of the bulk polymer fibers siastrip
The speed of the disks siastrip should not exceed 6000 rpm. / Min. Optimally - 3500. The work is part of the end of the circle.
Welded seams must be processed in order to:
- remove scale, since no paint material does not adhere to it;
- minimize further work based flooring.
For cleaning welds will suit many materials already described today: fiber wheels, rollers, flap discs.
In the treatment of welds, special attention should be given force applied to the "Bulgarian", because if you burn the metal, it is again covered with scale.
Removing the adhesive tapes
Another problem faced by the tinsmith - removal of adhesive tapes from the surface (those which are attached moldings and emblems).
Circle for removal of adhesive tapes
If before they were removed primarily by scraping hand, spending a lot of time, nerves, and not quite censorship expressions, but now they can be quickly and efficiently repaired with special rubber wheels in a matter of minutes. It is desirable to operate at speeds of 2000-4000. Too high speed and strong indentation polishers can lead to overheating of the LCP, so you need to be careful.
We now turn to the rules of grinding
Tipped defect under Shpatlevanie need to remember that in order to putty good "caught" on-site repair, we must now follow certain rules. This is, firstly, the selection of the optimum grit abrasive material to be processed, and secondly, the correct processing of old paintwork boundaries.
Optimum grit abrasive
It is no secret that is optimal for the subsequent application of a smoothing compound surface treatment abrasive P80 grades. Such grain provides good adhesion to the surface of fillers, excluding the probability of sanding scratches as a result of shrinkage fillings.
However, in reality this is not always the case, and blind adherence to these instructions in some cases may do a disservice.
These cases include the elimination of minor defects, such as small scratches. Obviously, in this case we have to use a finer sandpaper gradation, for example P150.
After all filler layer in this case is small, and thus the risk that the putty "fail" in the deep scratches, which then show up on the finished coated, increases. A small layer of putty is successfully maintained on the surface due to the risks created by the finer abrasive, so work coarse materials (such as P80) is not appropriate.
In other cases, the main thing to remember that the thickest layer of putty is applied only in the center of the defect, and the closer to the edges of the filled area, the filler layer becomes thinner. Therefore, the peripheral areas also should be treated with abrasive P150 graduation.
Selection of graduation of the grinding material in the preparation of a Shpatlevanie
Processing old paintwork borders
A method of processing the old paintwork borders can also have a very strong influence on the shrinkage and shatlevki manifestation Stopper space.
Let's see how to behave putty in two different cases: on a smooth slant of the old coating (a) and on a sharp cliff (b).
Processing old paintwork boundaries: a) the smooth chamfer: b) a sharp break
For high-quality polyester filler is characterized by shrinkage of about 2%. So in the first case fillings shrinkage bordering neshpatlevannym place will be only 2 microns (i.e., 2% of 100 microns), in the second - 20 microns have all (2% of 1 mm). Therefore, in the processing of aiming to make the boundaries of the old paintwork as smooth as possible.
In the grinding surfaces that have previously been subjected to repair and are currently in the thick layers of filler mass, the main challenge will be to get to a good coat. After all, as a result of damage and deformation of the element, the elastic metal could lose traction with non-elastic putty. Visible signs of the times can not be traced, but once you start to grind, the whole lowdown (cracks, peeling putty) is detected.
So, our surface is sanded, corrosion centers and unusable LPC removed. You can smoothly start puttying, what are going to do next time. And for today. See you!