The threshold is most often installed in front of the front door to prevent drafts, dust and noise from outside from entering the room. Small thresholds at the bottom of the interior doorway serve other purposes. They contribute to the neat design of transitions between different floor coverings. Thresholds can be made from different materials, but the most preferred today are wooden products. They harmonize as completely as possible with the door leaf and floor covering, are an environmentally friendly material and, among other things, are durable. However, even such thresholds sooner or later become unusable. They develop chips, cracks, and scratches. If these irregularities are minor, they can be filled with wood putty and then sanded with a sanding machine or manually using sanding paper. After painting or varnishing, such a threshold will look like new and will last for several more years. If the threshold cannot be restored, there is only one thing left to do: dismantle the old product and install a new one in its place.
The threshold prevents dust, sounds and drafts from entering the house
What are the thresholds for?
Thresholds in a car perform several functions:
- are part of tuning;
- protect the body from mechanical damage and the aggressive effects of salt reagents in winter;
- serve to strengthen the bottom;
- act as a supporting element for the central pillar;
- provide full body rigidity and increase the passive safety of the car.
Original linings – moldings, surface treatment with special anti-gravel films, and additional varnish painting – help improve the aesthetics of the vehicle.
During movement, the element, along with the bottom of the car and the lower trim of the front bumper, experiences constant mechanical impact from flying gravel. Unlike other parts, thresholds are the first to react to corrosion hazards. They get more water during rain, acids and salt reagents in winter.
Initial shots of E. Ryazanov’s “Irony of Fate” and phraseology
Everyone's favorite New Year's film is preceded by cartoon footage that explains how it happened that the hero got on a plane in Moscow and got off in St. Petersburg, gave the address and ended up “at home.” Let's summarize the essence very briefly. In the cartoon, an architect created a design for a typical house. The accommodation was very beautiful. There were other buildings surrounding the house, the entrance, of course, everything was extremely sketchy. The hour came when the author had to knock on the thresholds of officials' offices. And they, with a light stroke of the pen, freed the project from the “superfluous” until all that was left was a simple rectangle with many windows. The cartoon ends with footage of typical Soviet dwellings walking around the planet. Fortunately, the prophecy did not come true.
This story, unfortunately, is well known to all people in creative professions who cannot find a permanent place for themselves. Translators visit the doors of book publishing houses, writers and journalists visit newspapers and magazines, and any unemployed person visits the offices of their potential managers.
After the reader has learned what the expression “beating thresholds” is (we have revealed and explained its meaning), we can only wish him to go around and ask his superiors for as little as possible.
Design features
Structurally, a car threshold is a hollow block that has an external element and a reinforcement. The outer part performs decorative and protective functions. The amplifier is part of the body and provides the entire structure with the necessary rigidity.
During any repair, the condition of the amplifier must not be ignored. This is often millimeter-thick metal that corrodes after moisture penetrates through the outer lining.
According to the type of attachment to the body, there are thresholds:
- plug-in or integrated;
- fake;
- removable;
- non-removable.
Fixed ones are welded to the base of the body and form a single system with the bottom. The element bears a significant force load when the car is moving.
Removable thresholds provide only protection from gravel and reagents; the force load on the part is minimal. They are installed from the inside of the passenger compartment, secured to the body with screws.
Integrated thresholds are part of tuning; they are installed instead of the standard plug-in, removable, or, less often, non-removable ones. The elements do not reduce ground clearance and are made of aluminum and ABS plastic. Integrated sills can withstand loads of up to 120 kg and provide the body with additional rigidity, which increases the passive safety of the car.
False thresholds are considered a type of integrated ones. The elements are attached to standard places, reducing the ground clearance by at least 3 cm. The running boards are made of galvanized steel and can withstand a load of up to 200 kg.
Origin
Folk memory has not preserved a special history for this occasion. Apparently, the phraseological unit arose from direct experience.
In Russia, from time immemorial, there have been two realities that do not communicate with each other: physical and bureaucratic. The main problem is that the second dominated the first. In other words, in order for something to move in physical reality, you need to seek permission and receive written permission in bureaucratic reality. By the way, this is why “Dead Souls” by N.V. Gogol is an eternal work! However, let's not talk about sad things.
Methods of protection
There are several ways to protect the threshold on a car:
- aerosol anti-gravel;
- overlays, moldings;
- armor film;
- mastic.
Each method has advantages and disadvantages. The only specificity of protective equipment is to protect the metal from wear, rust, and dents.
Using aerosol anti-gravel is a reliable method of protection. The product is applied to the treated surface, forming a thin layer of elastic coating. It ensures reliable preservation of corrosion sites and prevents its spread. The price of a cylinder starts from 300 rubles.
Moldings are decorative and provide mechanical protection. To ensure a complete corrosion block, before installing the linings, the internal surface is treated with an anti-corrosive agent.
If the threshold is new, it is recommended to pour oil or paraffin anticorrosive into the inner part before installing the linings; for this, use the technical holes in the body.
Anti-gravel or armor film is applied not only to the lower part of the body, but to all paintwork, mirror housings, etc. Provides complete protection of the metal from rust and impacts from gravel. Disadvantages of the coating: rapid wear.
Treatment with mastic in 90% of cases is carried out independently. Thresholds must be carefully checked before application. Bitumen-based mastic is considered the best protection for wheel arches and underbody.
What to do if the door hits the threshold when opening
Doors are selected according to various characteristics - sometimes appearance is important, and sometimes you only want natural materials. Regardless of the material, any door after a short time of operation can demonstrate such an incident - when closing, the threshold begins to touch. This situation is dangerous for the product and for the floor, so a solution needs to be found.
Features of repair and replacement
There are different procedures for removable and non-removable thresholds. To repair and replace removable parts you need:
- Unscrew the bolts or screws with which the element is installed on the body.
- Check the condition of the seal. If the metal is rotten, then it is necessary to carry out a full cutting. When minimal traces of rust are observed, carry out treatment: sand, apply mastic or anti-corrosive agent.
- The removed threshold is checked for corrosive wear and straightened. If necessary, the part can be partially replaced: install metal patches on the element, treat it with a primer, etc.
It is impractical to repair plastic thresholds; it is cheaper to replace the part with a similar one.
Cars produced more than 10 years ago, VAZ, Moskvich and other models have permanent sills, the repair of which requires special tools and skills. Depending on the defect, the procedure for repair or replacement is selected. For all cases, the preparation remains the same:
- doors are removed;
- The seats and flooring are removed.
If the part has a lot of corrosive wear, then a piece of metal is cut out and the seal is checked. When it is necessary to level out a dent, metal extraction is used.
With minimal corrosive wear, repairs using a cold method without welding are allowed.
It is necessary to change removable elements if the part is worn by more than 60%. In this case, the use of anti-corrosion, linings and anti-gravel coatings will not prevent metal rotting. Replacement is carried out at a service station; for self-repair, the following is required:
- Determine cutting locations.
- Use a grinder to remove the old paint layer.
- Follow the instruction manual to determine what kind of protection is behind the front panel and where it is attached.
- Make initial cuts of the front part, drill out the points of the factory fastenings in the area of the racks.
- Pull out the damaged part.
- Treat the edges to remove burrs and sand the metal.
- If, after removing the outer part of the threshold, rust is found on the amplifier, then cut out the worn part of the metal. When it is possible to remove a corrosion plaque without cutting out the amplifier, remove the rust and treat it with an anticorrosive agent.
- Adjust the new part of the element, stretch it, bend it, and weld the metal using gas welding.
- Clean the welding areas, carry out anti-corrosion treatment with bitumen mastic on the internal part and anti-gravel treatment on the external part.
If the old threshold is completely replaced with a new one, not factory-made, then be sure to leave drainage holes in the threshold.
How to repair it yourself without painting
Among all types of repairs, pulling out the threshold without painting is possible only in the case of slight deformation, without a sharp edge, when the paintwork is not damaged. A smooth dent without folds can be pulled out on its own in only two ways:
- using a pulling tool and hot glue;
- vacuum suction cups.
At service stations, a type of paintless body service using PDR technology is common. In this way, small, shallow deformations are eliminated. Craftsmen use special tools: levers and hammers, squeezing out a dent always occurs from the inside. When repairing a non-removable body element, it is necessary to use external tools; vacuum suction cups remain the best option. Considering that most defects are associated with damage to paintwork and metal cracks, the paintless method is not used when:
- The deformation of the metal has a sharp angle, and there is a crack in the protective coating.
- The first signs of corrosion appeared.
In case of such damage, it is necessary to carry out full surface treatment before and after reducing the dent.
How to pull out a threshold with a reverse hammer
Pulling out a threshold with a reverse hammer is considered one of the most popular and easiest ways to remove significant dents from a non-removable element. For repair you will need:
- grinding machine (grinder);
- reverse hammer;
- putty, hardener;
- sandpaper R-120, R-80;
- welding machine;
- automotive primer, degreaser;
Before work, you must remove the negative terminal from the battery and hang the car on a jack. We will look at how to straighten the threshold on a car with our own hands step by step:
- Grind the damaged area with a grinder. It is recommended to protect your eyes with goggles. When working, large grains of old paint and primer fly off.
- Clean the area with sandpaper.
- Weld the end of the reverse hammer to the threshold and begin to pull out the metal with small taps. The extraction is carried out starting from the edge of the dent.
- Weld the hammer, maintaining a distance of at least 1-1.5 cm. Walk across the entire dent, gradually pulling the metal to its original state.
You cannot start drawing immediately after welding the hammer; you must wait until the part has cooled.
- Sand the weld seams with a grinder and sand them.
- If there are any unevenness on the surface, level it with a hammer and sand it.
- Degrease and apply automotive primer.
- Dilute the putty with the hardener, treat the surface, leveling the part.
- The putty is applied with smooth, quick horizontal movements, and the protruding material is cut off.
- After complete drying, the surface is sanded with R-80 sandpaper. A second layer of putty is applied and processed in the same way.
- Auto enamel or any other protective agent is used: anti-gravel, film, etc.
Using a reverse hammer remains the most reliable way to repair permanent thresholds when deformed. It is guaranteed to be free from internal welding corrosion and is available at home.
Suction cup pulling
The use of a suction cup or vacuum hammer is justified in cases where the dent is small and repairs can be limited to without painting. However, if there is old damage, a complete surface treatment is carried out after extraction.
Drivers turn to the service station with one question: what to do if the threshold on the car is bent? Without understanding the nuances of the damage, they, as a rule, pay 70% more for the work of a tinsmith. To prevent this from happening, you need to remember: if the dent is corrected with a suction cup without additional painting, the technician spends up to 15 minutes on maintenance, and the cost of the work is calculated from time to time.
Types of connection
When repairing parts related to cutting, three types of connection of automobile thresholds are used:
- Butt joint using an additional insert. An internal lining made of processed metal will strengthen the connection of the new part of the part with the base. Using an insert allows you to quickly level the surface, the danger of burning through the metal disappears, and thermal deformation of the bottom is minimized.
- Overlapping. The most common type of connection, used for minor repairs when welding metal patches. The advantages of the connection include the minimal risk of burning through the metal during welding. To get a smooth surface, it is necessary to apply a thick layer of primer and anti-gravel.
- Butt. The welding method is used by specialized specialists. New parts are welded to the base without gaps. The seam must be thoroughly sanded and primed.
Tool needed
To replace the threshold we will need a set of screwdrivers, a welding machine, an angle grinder, a pneumatic chisel, hammers, hooks, straighteners, and a workbench.
If you do not have the skills to work with such a tool, then you can turn to people who have already encountered this for help.
