How to repair through holes in a car body without welding. Using fiberglass in body work How to repair a hole in the bottom of a car

When getting your car in order, sometimes you have to find an unpleasant problem - a through hole in the bottom of the body. Some car owners immediately turn to a car service center for help, while others try to repair the hole on their own. In the second case, you have the opportunity to save time and money, and will also be able to master new car repair techniques, which is always useful and relevant.

Holes in the bottom

Many people do not have a large number of repair and construction tools and equipment, so not every car owner has a welding machine in their garage or workshop. In fact, if the hole in the body is no larger than a matchbox, it is quite possible to repair it yourself without welding. There are several ways to do this:

cover the hole with putty;
solder a metal patch;
seal with epoxy resin;
apply fiberglass and glue;
install rivet connections;
use galvanized metal sheet.

Galvanized sheet

Method for filling holes using putty

In the area of the hole in the bottom, the damaged coating, that is, the old layer of paint, should be removed, and the metal should be cleaned and treated. with a special drug– rust converter. Then the working surface is degreased and primed. Next, prepare a putty solution of uniform consistency. For greater efficiency Fiberglass is added to it (most often with large elements). Then the composition is carefully applied to the damaged area. This is perhaps the most important part of the job. It is necessary to seal all the holes, cracks and microcracks that may arise around it. Application of the solution should occur in several stages, allowing each new layer to dry.

Sealing with putty

To achieve maximum fixation of the putty on damaged area, a lining is applied to the reverse side. It does not allow the solution to spread, but acts in the area that needs to be repaired. If the hole in the bottom of the car is large enough, this method repair can also be used with auxiliary elements. Instead of a lining, a metal mesh is installed in the damaged area. Therefore, the putty is evenly distributed over it, filling the entire space. After the solution has completely dried, this area is treated with automotive paint putty. Then the damaged area is painted and a protective film is applied.

Putty for cars

This method of filling holes in a car is the simplest. But experts do not recommend using it, since the putty allows moisture to pass through and can deteriorate over time. Holes are also treated with a solution when repairs need to be done urgently and there are no other alternatives.

Soldering a metal patch

Soldering metal element into the damaged area - this is a method of sealing holes in the bottom or any other part of the car, when you can close a small hole. To repair a machine using this technology, you must have the following tools:

a piece of metal sheet;
powerful soldering iron;
flux or rust converter;
putty;
primer.

Materials in the car

So, first, the area that needs to be repaired is cleaned, paint, rust, and dirt are removed. Next, it is treated with flux and degreased. Then measurements are taken and a metal piece of the desired shape is cut out. Such an element will completely seal the hole, and the edges will overlap. When the part for the patch is ready, it is attached with a soldering iron. Then the edges of the patch are treated with flux. Finally, it is worth treating the area with putty and priming it. When the surface is dry, paint and a protective layer are applied.

This method of filling holes in the bottom of a car is the most popular. Experts note the durability of the soldered patches, since the connection is quite reliable. In addition, this method can be used to seal a hole of any size. In general, soldering a patch is quite simple, and even a beginner who does not have much experience in car repairs can handle it.

Sequence of actions when sealing holes in the bottom

Application of fiberglass and glue

For moderate damage, the method of sealing holes with fiberglass is often used. When this area has been processed and cleared of layers of paint and rust, it is necessary to cut several overlays from fiberglass, the size of the hole plus 2 centimeters. This area should be pre-primed and allowed to harden.

Repair kit for cars

An overlay is applied to the dry surface and secured with a mixture (polyester or epoxy resin + glue). The next “part” is applied and also fixed. Thus, all the fiberglass parts are glued, placing them one on top of the other. To prevent them from sagging or deforming, you should put a lining. When the resin and glue have dried, you need to treat the work area and paint it.

Fiberglass

Installation of galvanizing and riveted connections

Processing holes in the bottom of a car with galvanized metal is quite common. The main material required for this is iron sheet. Before installation, it should be secured with self-tapping screws and lubricated with mastic. It is best to use an anti-noise bitumen mixture. Then the galvanized sheeting is laid and bolted using a drill. Then you need to treat the area by special means, level the entire surface. When everything dries and the structure is fixed, it should be coated with paint.

One of the most problematic and expensive options for making a car look marketable is repairing holes in its body. This damage can be repaired at a service station or you can try to get rid of it yourself. The first method will require significant costs, but the second will be cheaper, but will take quite a lot of time. In addition, not everyone can properly repair holes.

Stages of repairing body holes

Work to eliminate holes in the body requires careful preparation of the area being treated. The area around the hole is carefully cleaned with coarse sandpaper, and its radius should be at least 3 cm greater than the size of the hole itself. They remove not only the top layer of paint and varnish, but also the primer. As a result, metal should be visible in the cleaned area, which is treated with an anti-corrosion compound.

Next you should solder the patch. Any piece of metal can be used for it suitable size. It is important to consider that similar repairs carried out from the rear side of the body so that the violation of its integrity is least noticeable. Before soldering, the patch, as well as the damage site itself, is tinned using flux phosphoric acid

Soldering of the patch is carried out continuously, leaving no loose gaps. After the treated area has cooled, you should check whether our patch is protruding as a bubble on the surface of the car. If, however, it turns out to be uneven, straightening is carried out with a small hammer, avoiding damage to the paint.

Next, the repair involves puttingtying the area with a patch in order to hide it as much as possible. First you need to sand the area to be repaired, then degrease it and dry it. Important: the putty should be applied in a fairly thin layer, because if its thickness is more than 3mm, the material will not adhere well to the metal. The priming itself is carried out in two stages: applying acid and acrylic primer. In order not to bother with preparing a two-component composition for the first stage, you can use a phosphate primer packaged in cans. Acrylic primer is also sold in aerosol form, which will be very convenient if you do not have a compressor and there is minor damage.

Alternative options for repairing holes in the body

To repair a small hole, you can seal the hole with putty mixed with fiberglass. This method is much faster and simpler than the previous one, but it will not last long - under the influence of precipitation, the hole will begin to swell and become too noticeable. However, this option may come in handy if you are preparing a car for sale.

If you don’t have the desire or ability to repair a hole, and you don’t want to drive with it, use car stickers. This is often done with corporate or work machines. This type of repair is conditional, but appearance stays on top.

If your car has serious damage, larger than a matchbox, it is best to eliminate them by welding. A professional at a good service station can skillfully perform them. Alternatively, you can do the welding yourself if you have the necessary experience and the necessary equipment.

It happens that before painting a car you have to pick off a small “bug”, and underneath it a through hole is discovered.

A quick way to disguise a hole in a car body without major repairs

What should you do: rush to the auto repairman with the money you have saved for gasoline or be patient and do this work yourself? Surely most drivers will choose the second option if the hole size does not exceed a matchbox. Otherwise, you really should rush to the master. So let's take a look.

We begin to eliminate the holes that have formed in the car. There are two ways to fix this problem.

You can disguise the hole using putty with the addition of fiberglass. This method is simple and fast, but not everyone can call it successful. Therefore, it is worth taking a closer look at the more complex and effective way car repair.

How to repair serious damage to a car body

Place a patch cut from any thin metal. From the same tin can. First, cut out a piece of metal the right size so that it completely covers the hole. Then take a powerful soldering iron and solder the patch to the body using an acidic rust converter as a flux.

Please note the following points:

Before soldering the patch, be sure to tin the edges of the patch with a soldering iron.
Don't forget to tin the surface to which the new piece of metal is soldered.
Solder the patch with a continuous seam so that there is not a single empty gap.
Then measure to see if the patch has formed a bubble over the hole. If this happens, then very carefully press the metal into place by tapping it with a hammer.
If a failure does occur, and this happens too often, then the patch will have to be removed using putty.

The thickness of the latter layer should not exceed 3 mm. If you can’t handle this delicate work, call someone else for help and don’t be shy: the appearance of the car is more expensive.

1. Take sandpaper with a grit size of 120. Determine by eye the surface area that should be filled, adding a few millimeters on each side of the patch.

2. Taking the adhesive line, apply it with soft, “cat-like” movements. This is necessary so that the putty sticks to the surface not by the “bare” metal, but by the material that provides good adhesion of the surfaces.

3. When the place for puttying is finally prepared, take a small rag, “White alcohol” and thoroughly treat the freshly sanded surfaces, cleaning them from dirt and dust and at the same time degreasing them.

4. Now you can move on to the most important step - preliminary priming of the patch. Please note that this work should be carried out immediately after treating the metal with alcohol, because within a couple of hours this part of the body will begin to rust.

5. First, apply the first coat of primer (phosphate or acid). It is better to dilute this two-component soil in glass jar or in any other plastic container. Another option is to use acidic soil, which is sold in aerosol cans.

6. Apply one thin coat of phosphate primer to the patch. The soil dries out quickly and can also cause smudges. After waiting 15 minutes, you can apply another thin layer. Provided that the room temperature is approximately 20 degrees Celsius.

7. After another 1-15 minutes, apply the final layer of two-component acrylic primer. The patch takes 2-3 hours to dry, after which it can shine as if it had just come from a salon. And all this - without outside help, with your own hands! If you don’t have time to wait, hurry up the patch using infrared heating.

Sometimes, before painting a car, having picked off another “bug”, we suddenly discover a through hole underneath it formed during the corrosion process. What to do in this case? Should I run to the bodybuilder with a welding machine, or solve this problem on my own, even without a welder?

Everything, of course, depends on general condition car, if it is only a local through hole, and not completely rotten body part, then we will begin to eliminate it.

To begin with, the corrosive area must be cleaned of rust. To do this, we use various brushes on the drill, or a special vinyl attachment on the drill.

Next, we begin to eliminate the holes formed as a result of stripping away the rust. At difficult cases, holes and openings of a large area, as already written above, of course, it is necessary to seek the help of welding and a body shop.

We will consider easier cases, where the size of the hole (hole) does not exceed the size of a matchbox. There are two ways to eliminate them.

Repairing a hole with fiberglass putty is not our method.

Some auto repairmen, either due to inexperience or simply not wanting to achieve quality work, try to seal the corroded hole with glass fiber putty. This is of course a very simple method, but it has one big drawback.

Let me explain, since putty is inherently hygroscopic, i.e. allows water to pass through, then on a freshly painted car, after a couple of days or after the first rain, an ugly bubble filled with water will appear on the new coating in the place of the former hole. You can easily verify this by piercing it with a needle. This option is laughable to chickens and we don’t need this method of repairing corrosion holes. That's why...

We solder the patch - and this is our method!

The principle of this method is quite simple - a patch.
We cut out a patch from a piece of metal (you can, for example, use cans of auto chemicals as a “donor”) that covers the hole in the body with its size, and solder it with a powerful soldering iron, using an acidic rust converter (orthophosphoric acid) as a flux, and of course tin solder.

All stages are shown in the picture below.

1 The edges of the patch must be tinned before soldering. (All areas treated with rust converter should be washed after soldering, following the instructions on the converter label).

2 We also tin the surface (edges of the hole) to which the patch will be soldered.
After soldering the patch (and it should be soldered with a continuous seam, without empty spaces), you need to measure whether it protrudes above the surface like a bubble. (We don't need cones!). This can be done with a metal ruler. If it protrudes, then use a light hammer and light blows to press the patch into place (see figure).

The resulting small gap will be smoothed out with putty.

Remember! The thickness of the putty layer should not exceed 2-3 mm, otherwise it may crack in the future.

Now that all the holes have been sealed and all the rust has been cleaned down to metal, we prepare the surface for puttying.

To do this, you need sandpaper with an abrasive size of 120 (manufacturers Mirka, 3M or similar).

We determine by eye the size of the places that should be matted. They should be slightly larger than the size of the area being puttied. And lungs in a circular motion We apply an adhesive mark. It is needed so that the putty has something to hold on to on the surface.

After preparing all the places for puttying, take a cloth, White Spirit and carefully treat all sanded surfaces to remove excess dust, dirt, and also degrease the surface.

And now we can move on to the important operation of preliminary priming. The cleaned metal surface rusts easily, so it is not recommended to leave the surface bare. protective coating more than an hour - a primer should be applied. To do this you will need two types of soil.

Prime with acid primer

The first layer of primer is phosphate, also known as acidic. As a rule, this is a two-component primer, diluted in glass or plastic containers, as it interacts with iron, removing water molecules from the surface. You can also use acidic soil in aerosol cans.

Phosphate primer is applied in one or two thin layers, directly to the bare metal. It dries quickly, is very liquid, so it can cause smudges, but in this case it’s okay, the smudges can be neglected. Within 10-15 minutes. (time is indicated at a temperature close to +20, at other temperatures make approximate adjustments) you can begin priming with acrylic primer.

Prime with acrylic primer

It should be applied in 2-3 layers with intermediate drying for 5-10 minutes.
You can use primer from aerosol cans, especially if you don't have a compressor. Then all this is dried for about three hours (when using forced infrared heating, the drying time can be reduced to 20-30 minutes).

I would like to note that personal experience that such patches last quite a long time. Let me say this, two years is not the limit!

Happy renovation!

It often happens that before painting a used car, we discover a through hole formed due to corrosion. What can be done in this case, if we leave the topic of professional body repair and high costs. Is it possible to fix the hole yourself, and if so, how to do it? All this will be discussed below.

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Of course, the possibility of carrying out independent body repairs is related to the level of damage to the car. For example, if a through hole is noticed in only one place, and the entire body or its part is not completely rotten, you can proceed to self-elimination. In other words, if there is a partial problem, and not a set of defects, it is 100% possible to do without specialists.

Note. In addition, it is important to eliminate through holes with your own hands only if they are not too large. Otherwise, you will have to order a professional service.

Filling holes in the body with putty

As a rule, holes most often appear on the bottom of the car. And in in this case everything around is thoroughly cleaned, car cosmetics (rust converter) and many other kits are used. Degreasing and priming are also required.

The technology of direct application of putty, without the use of a patch, implies application with reverse side lining area. In this way, it will be possible to significantly achieve maximum fixation of the composition. You can use a metal mesh instead of a lining as such. These are even sold in stores, you can make them yourself, etc.

The putty must be evenly distributed over the surface, filling the entire space of the hole. After the solution has dried, the area is treated with painting putty. Then, after drying, they paint and put on a protective film.

This option for eliminating a through hole in the body is the simplest. Experts, however, do not recommend using it, since the putty will begin to leak moisture over time and will collapse. This method is most suitable if restoration is urgently needed and there are no other alternatives.

Algorithm for carrying out the process of eliminating a through hole by applying a patch with a soldering iron

Here's what to do:

To begin with, it is recommended to thoroughly clean the rust from the corrosive area. You can use attachments and a drill (also another set of tools).
A patch is cut from a piece of metal sheet. An option is to use a can of auto chemicals, etc.

The patch must cover the entire hole on the vehicle frame element.

A powerful soldering iron is prepared, with which the patch is applied.

Now you need to tin the edges of the patch.

Particular attention is paid to the edges of the hole where the patch will be placed.

A piece of metal is soldered with a continuous seam.
It is checked by measuring whether the patch does not protrude above the surface of the body like a bubble.

You can diagnose the protrusion using a flexible ruler.

The protrusion (if detected) is recessed with gentle blows of the hammer.

Once the patch is recessed, there is bound to be a small gap. It will need to be leveled using putty. We must not forget that the thickness of the putty layer should not exceed 2-3 mm. Otherwise, the layer will crack easily after drying.

Before puttying, the surfaces are properly prepared: the rust is cleaned off with a metal brush, and then sanded.

It is better to use 120-grit sandpaper. We must not forget that the matting area should be larger than the area directly being puttied.

An abrasive mark is applied to the surface. This is done so that the putty has something to hold on to.
Now you need to treat all areas with a degreaser after sanding.
The surfaces must be primed first. This is done no later than an hour after sanding, since cleaned metal without paintwork quickly undergoes oxidation processes.

It is better to take a phosphate primer as the first layer. This type of primer is a 2-component composition that is easily diluted with water.

Attention. It is prohibited to dilute phosphate primer in a metal container. The fact is that phosphate tends to interact with iron, and this is not good. It is better to use a glass or plastic container.

If you can’t find a phosphate primer, aerosol KSL primer in cans is also an option.

As soon as 10-15 minutes have passed after applying the first primer, you must proceed to treating the surface with acrylic. This type The primer is applied in 2-3 layers. The gap between layers is maintained for about five minutes.

Note. Again, acrylic primer can successfully replace the composition of an AER spray can. This is especially true if there is no compressor.

Acrylic dries completely within 3-4 hours. If it is possible to use INFR heating, the drying period can be significantly reduced.

All that remains is to putty the surface, then sand and prime.

The method of sealing a through hole using a patch is considered the most rational for a number of reasons.

Soldered patches last much longer than just fiberglass putty.
The patch provides a more reliable connection.
You can close holes of almost any size (except for too large ones, when only the service of specialists is relevant).
Simplicity of technology. Even a beginner can handle the job.

Video on how to seal a through hole