Do-it-yourself car sill painting

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Young people often buy used cars older than 10 years. Sometimes with body defects and rotten thresholds. Many of them, due to limited financial opportunities, have a question: how to paint the thresholds yourself? This article will help you find the answer.

What is important to know about painting metals

Sometimes in auto enamel stores, buyers ask to sell paint in cans for metal. But for the field of car body repair, such a request is incorrect. And that's why. In order to paint the metal reliably and for a long time, any paint must be applied only to the ground, otherwise it will soon begin to fall off the iron. In addition, metallic or mother-of-pearl paints are almost transparent. They are difficult to paint over white, black colors and bare steel. Therefore, in order to save money, it is better to use a neutral gray primer.

In advertisements, you can find the expression "paint in spray cans for metal." In such cases, we are talking about matte or semi-matte paints intended for touching up defects on metal tiles. Moreover, their colors do not match the car.

Three optionswork

Painting car sills is a fairly simple operation. It is quite easy to perform due to the narrow shape of the parts and their location at the bottom of the machine, where any repair flaws are not evident.

Usually coloring is done for three reasons:

• they had to be changed (digested) due to serious corrosion or after an accident;
• they have a slight through corrosion;
• a dent appeared on the threshold.

In all three cases, the technological process will be different, although in many respects similar. Let's consider each of them, but first, let's get acquainted with the order of work.

Painting thresholds

The basic order of work looks like this:

1. Cleaning the surface in the repair area.
2. Putting.
3. Masking up adjacent machine parts before priming.
4. Priming.
5. Soil grinding.
6. Masking adjacent parts of the car before painting and applying a protective anti-gravel layer.
7. Applying a protective anti-gravel layer.
8. Painting thresholds.
9. Polishing the joints of new and old paint.

Necessary paint supplies

To complete the work you will need:

• Degreaser.
• Polyester automotive putty.
• Sanding paper in sheets of gradations P 80, P 120, P 240, P 800.
• Paint tape.
• Grey acrylic primer in aerosol can.

• Spray paintballoon.
• Clear varnish in an aerosol can (if the car was painted in metallic or mother-of-pearl).
• Repair kit made of polyester resin, hardener and fiberglass to repair through corrosion.

Polish from the company "3 M" No. 09374 in the amount of 50 grams for polishing the joints of old and new paint

Scotch brite gray (abrasive sponge)

Painting thresholds after replacement

After replacing the thresholds, welding seams remain, which will have to be puttied with polyester putty. But first you need to remove any dirt from the repair area and, most importantly, all bitumen, oil, grease stains with a degreaser.

Remember the rule: before applying any materials, the degreaser must completely evaporate from the surface!

After degreasing, sand the paint and black primer on the new threshold in the area of the weld to a width of at least 5 centimeters in each direction. Putty holds well only on a surface sanded with an abrasive. Mix putty with hardener on a steel spatula. But it is more convenient to spread it on the welding joints with a rubber spatula. The intricacies of the process are shown in detail in this video.

While the putty dries at the joints, you need to use sanding paper with P 80 abrasive to remove the protective black paint from the new threshold. Sanding the threshold, you can find small dents, which should also be puttied. From original thresholdsfor foreign cars, including Taiwanese, the protective paint does not need to be removed.

After finishing work with putty, cover with masking tape, film or newspapers all places on the machine where the primer should not get, degrease the repair area and apply two full coats of primer to the puttied places and bare metal. Allow 15 minutes between coats. After 40-60 minutes, the primer can be sanded.

To do this, take the fourth part of the P 1000 gradation sheet and carefully remove all debris that has stuck to the ground. Also remove dry dust particles in places where the soil breaks. If this is not done, then after painting this “looseness” will appear and spoil the whole work.

The next step is to expand the haze zone on the A-pillars, B-pillars, and rear wheel arches. For this we use gray scotch-brite, because it is very flexible and perfectly mattifies the factory varnish of the machine. The fact is that it is impossible to apply paints and varnishes on the glossy surface of the factory varnish. Even thoroughly cleaned. It is necessary to make it matte with fine abrasives. Scotch brite works best with this.

So, increase the haze area to 30-40 centimeters from the welds. Next, step back another 10 centimeters higher up the racks. This is the border of masking non-paintable parts of the car. Take masking tape, newspapers and everything above the masking line, cover from paint and varnish.

Finally comes the stage of painting thresholds. Use a tissue and degreaser to clean the entire repair area and apply paint to the primerlayer by layer until it is painted over. Between layers, pause for 5 minutes. Then, after 15 minutes, apply 2 coats of lacquer to the matte and gloss lines so that the gloss of your lacquer combines with the gloss of the factory.

One day after painting, you can start polishing the varnish at the joints. There it will be necessary to cut off with an abrasive P 2000 particles of a new varnish that have fallen on the factory varnish. Then take a small piece of clean cotton cloth, about 10 x 10 centimeters, place a little 3 M polish on it (about a teaspoon) and manually polish the marks from the P 2000 abrasive.

Repair of rotten thresholds without welding

When buying a car with rust through, the new owner may have a question about how to paint the sills without using welding to patch holes. Fortunately, modern technology can solve this problem as well.

If the old car is not planned to be used for more than five years, then the thresholds can be repaired without welding, using fiberglass for patches. To do this, in a specialized store that sells materials for painting cars, you need to buy a kit consisting of polyester resin, hardener and fiberglass.

Before preparing the resin for work, it is necessary to clean the rust and paint around the rotten place with a coarse abrasive. Then, with a light hammer, slightly upset the cleaned place inward. This is done so that the glued fiberglass does not protrude beyond the threshold contour. After gluing two to three layers of fabric and impregnating it with polyester resin, allow one hour to dry andcut off everything superfluous with an abrasive P 80. Now you can start puttying.

All the details of the process are shown in the video. Good luck!