Do-it-yourself repair of cracks in plastic bumpers - methods and technology. How to seal a plastic water barrel How to seal a plastic part

This post will be of interest to entertainment lovers " crazy hands" Anyone who thinks that repairing plastic is not something worth bothering with, and that you only need to buy new and only original plastic, can safely skip this post and not spoil your mood and my mood.

Preface

I ask you in advance not to judge strictly, because... I’m not an expert in this matter and I don’t have much experience, but what I have, in my opinion, may be valuable to someone. I also want to say that the plastic is NOT PAINTED at the current stage, but only its integrity is restored. There are plenty of articles on painting on the Internet, and doing it yourself in the garage is a collective farm. clean water(this statement does not apply to those who have experience and equipment for professional painting).
So where do we start? Let's start, as always, with the background. As I mentioned in my article, I initially bought the motorcycle seeing that the plastic was cracked and would either have to be replaced or restored. Naturally, changing this is not for me, otherwise you would not be reading this mini report. In fact, from the moment of purchase, I periodically scoured the Internet and collected information on methods for restoring ABS plastic. There weren’t that many of them, except for the “masters” who “repair” anything from hot melt glue to cold welding. The most “correct” way to repair plastic, according to the Internet, is considered to be soldering with a hair dryer with plastic electrodes, but for such work you need to have the hair dryer itself, electrodes and sufficient experience in using these tools. Since I didn’t have anything from the above list, especially experience, without which repairing plastic with a hairdryer could have ended with the purchase of new plastic, I decided to resort to a simpler but lower quality (again, according to the Internet community) method - namely soldering soldering iron But if soldering was only done with a soldering iron, then I probably wouldn’t write this post, because... There seems to be nothing new here, and besides, you can’t grow pieces of plastic that don’t exist with a soldering iron. Also on some forum I found a review of gluing plastic with the same plastic. It sounds strange but in essence it is true. Its essence is that the same plastic (abs) is taken and dissolved in 746 solvent (if I’m not mistaken with the number), and the plastic dissolves well, as my experience has shown, then the seam is filled with this “glue”. To be honest, there is something in this, but for the most part, vegetable oil is bullshit and a little later I will give reasons for my statement. I did not use gluing plastic with epoxy resin reinforced with fiberglass fabric, because... There is experience that in some cases this is not reliable enough and under strong vibrations the eboxy peels off from the plastic.

I’ll say right away: I haven’t made the plastic of the entire motorcycle yet; this weekend I only worked on three pieces that go “around the tank.” And one of these pieces had the most serious damage, in comparison with the rest of the plastic, therefore, using its example, I will tell you what I did and how, because the repair of the remaining pieces is actually only a part of the actions that were applied to this piece. Perhaps and only POSSIBLY, I will write another post closer to March-April where I will tell you what nuances there were in restoring the rest of the plastic and about painting it or covering it with vinyl.

Main roles

Well, we're done with the preface. So now let’s look at the main characters:
Plastic:

"displaced fractures"

a piece of the wall (it doubles as a stiffener) is missing

general view of the plastic part with inside, traces of repair with hot-melt adhesive are visible

detailed photo of the “hole” (it’s hard to call it a hole) for the cigarette lighter (obviously ripped out of some VAZ).

The “ear” into which the shaft that holds the glove compartment lid is inserted is also broken off

Patient review completed. Now a review of the “medical staff”:

Soldering iron 80 W

A Chinese straight grinder bought back in the summer for $10 along with a set of attachments purely to see if it would work (it did, but didn’t really make it into the frame).
Two-component putty for plastic (purchased at the auto department of Epicenter, I don’t include photos because it’s an advertisement for the company :) and it’s not a problem to find, there are many manufacturers)
A set of sandpaper with different grains (the smallest grain is 150 or 180, the largest is 80)

A brass mesh that was taken from the granaries of my grandfather’s homeland (also not included in the frame, below is a similar mesh, only mine has just wire vertically and cables horizontally).

Cyanoacrylate glue for temporary bonding of parts, you can easily do without it (I didn’t take a photo, any one you sell will do)

Steel wire 0.5-0.7mm

Let's start the renovation

Unfortunately, I don’t have any photos from each stage of the repair, because... Often your hands are dirty and your camera/phone is not always at hand.
Where did I start? I started by tearing off the hot-melt adhesive from my plastic with mats, for the most part it didn’t really stick, but in some places it stuck so much that it was problematic to tear it off. The part without this glue looked like this:

Then we had to completely break through the crack in order to be able to align the planes relative to each other. Simply breaking through was not enough, because... the one who repaired the plastic before me didn’t bother with this and soldered the plastic (apparently also with a soldering iron) “as it happened”, after which he filled the whole thing on top with hot glue. After the crack was broken, its inner edges had to be processed with a grinder to remove irregularities that were not allowing level the planes. After this matter was leveled, the position of the part was fixed with glue, and this glue was also poured into inaccessible places in the crack for a more reliable fixation during soldering. After this, a similar procedure was done with the remaining cracks, the only difference being that the cracks were not broken completely, but were sanded down to plastic and fixed in the “correct” position with glue. After all the cracks were processed, it was time for soldering. Because It was planned to paint the plastic later, so the cracks were soldered both from the outside and from the inside. Yes, I want to note that soldering is not just “sticking” a soldering iron tip into the plastic; you need to melt the plastic so that each time you melt the plastic, you partially weld it to the previous place where you melted it before.

Crack fixed with glue:

The same crack but already soldered (but not yet smoothed) with outside

After all the required seam was soldered, I smoothed out the crack with a soldering iron, actually leveling all the burrs left earlier, at the same time thoroughly warming up all the plastic under the soldering iron (my fingers got quite hot with reverse side details). Not like that in a cunning way All cracks on both sides of the part were sealed.

Now it's time to start making the missing pieces of plastic, or, as some call this process, artistic modeling, and I sculpted on the basis metal frame and two-component putty for plastic. In my case, it was restoring a piece of the wall with a stiffener + sealing the hole in the hole from the cigarette lighter. In the video that I will post at the end, it was recommended to use soldered wire to create a frame for the lost parts of the plastic. I tried this option (on another part) and I must say that this allows you to achieve the goal, but there is no convenience, because... the putty is quite “liquid” for such purposes, and tends to fall on one side or the other. Now, if I had worked with a mass resembling plasticine, then such a problem would not have arisen. Therefore I took advantage metal mesh. Its advantage is that:

firstly, it can be soldered over the entire contact area of the restored piece with the “original” plastic, and not just soldered 2 ends of the wire
secondly, the mesh can be immediately bent into a frame of the desired shape (in my case, stiffeners)
thirdly, the putty does not fall through the split so much and it can be applied more accurately, so as not to clean off a lot of excess later.

And so I cut the stack, soldered it along the entire fault line of the wall to which my piece adjoins, bent it as needed, cut off the excess. For the glove compartment with a hole with a cigarette lighter, a mesh patch with a diameter slightly larger than the hole itself was cut out and soldered into the roughness of the plastic (somewhere to the middle of the thickness of the plastic). After that, all the soldered pieces were sealed with putty + putty was added in those places where cracks had previously been soldered and too large unevenness resulted.

Wall with stiffener

glove compartment view from outside

glove compartment inside view

general view of the detail

The putty is very smelly and polymerizes quickly only at temperatures above about 20 degrees, so it is better to apply it outside and dry it anywhere but in the house. I did everything in the garage and dried it in front of the heater.

It takes about 8 minutes for the putty to harden according to the instructions, it took me more than an hour, because I dried it in the garage near the heater and the temperature there was far from +20 (as recommended). Once the putty has hardened, it can be safely processed, namely, cleaned off with coarse sandpaper.

A small retreat: don’t even think about cleaning it pointwise, because... If you draw and transfer the entire work again, or the edges of the part will float, which is not beautiful. Either make a flat long base for the emery (a banal wooden block on which the emery is stretched) or buy a ready-made mount for the emery in hardware store.

After the part has been given the desired shape, we sand the part with fine sandpaper until a completely smooth surface is obtained.

The mount for the glove compartment lid shaft was made from steel wire, which was soldered deeper into the plastic. It looks like this:

Now as for strengthening weak points. After everything was done, a “bending” test was carried out, which revealed the constructive weakness on a part, next to which there was previously a whole scattering of small cracks. Although all the other seams performed well, this was the area where there was a risk of breaking the part or getting new cracks. To strengthen this place, an overlay was made from the same mesh and soldered into the plastic with a soldering iron, but so that parts of the mesh were visible from above. Then the same dissolved plastic was poured onto the place with the mesh. As summer practice has shown (and in the summer I soldered a plow that broke on a stump in the forest), a mesh sealed and filled with the same solution holds very tightly, and despite the fact that I reached the asphalt very well with the plow a couple of times (I erased the bolts on the asphalt like this , that I couldn’t insert a screwdriver) not a single crack appeared in the places with the mesh, despite the decent load. So, the mesh and plastic filled with such “glue” represent a single whole. But if such “glue” is simply poured over the top of the sealed cracks, then nothing will work, because... the layer of glue turns out to be quite thin and while the solvent is evaporating, the layer of plastic under the glue does not have time to soften and properly contact the “glue”. In general, some of this “glue” had to be peeled off from my part. So I don’t recommend pouring it without a mesh.

In conclusion, I would like to ask you not to judge harshly.

Now a very useful video about repairing plastic, which helped me a lot:

You will need

- soldering iron or glue;
- acetone;
- sponge;
- emery;
- fiberglass;
- solder wire;
- clamp or masking tape;
- fittings;
- primer for plastic;
- dye;
- varnish

Instructions

Find out the composition of the plastic - its marking should be indicated on the back of the product (for example, PA - polyamide or PP -). It is important to study the properties of this material, since the type - gluing or welding - will depend on this. Thermoplastic polymers (plexiglass, polyethylene, polypropylene and others) are easy to recycle. But you won’t be able to melt the so-called thermosets (they contain phenol-formaldehyde, epoxy and other resins and fillers). You will need special glue.

Pick up at building material adhesive composition, epoxy for this type of plastic and consult with a competent seller. Follow the manufacturer's instructions exactly. Sand the surfaces to be glued, clean them of dirt and degrease with acetone. You can glue the crack directly along the seam, or pre-reinforce it with fiberglass.

To solder a leaky plastic part, use a solder wire of identical chemical composition. Process working parts sandpaper a centimeter from the edge, since the welded part will have to step on the left allowance for the strength of the seam. Collect the broken plastic into pieces and secure them with a clamp (fixing tool) or masking tape.

Start thin plastic from the “face” so that an unsightly bump does not appear on the visible surface. Plastic of a denser composition can be repaired immediately from the reverse side. Run the soldering iron along the crack; apply solder and fuse it into the thickness of the softened material. On the reverse side of the work, you can use thicker wire.

Some craftsmen combine plastic soldering with reinforcement (strengthening the structure). To do this, it is recommended to purchase a special brass or bronze mesh (about 0.2 mm in thickness). Cut the reinforcing material into strips the right size. Your task is to apply the amplifier to the inner surface of the chip and (heating the plastic with a soldering iron) drown it in the molten material.

Get ready for a plastic facelift. The glued or sealed surface must be washed, sanded with 1000 sandpaper and wiped with acetone.

Shake the can of plastic primer, shake it for 10 minutes and apply to the damaged part from a distance of 20 cm. If the packaging has other instructions, be sure to follow the manufacturer's instructions. Cover the plastic with 2-3 layers of primer (depending on the depth of the damage), let it dry and again go over the product with sandpaper and acetone.

The final stage of plastic repair will be spraying a special dye. Make sure it is designed specifically for the material. Apply the required amount decorative layers; Before each new coating, let the previous one dry for 15-20 minutes. If necessary, coat the product with varnish an hour after painting. You managed to repair the plastic, but until it dries completely it must be protected from dust and other contaminants.

Nowadays, there are a lot of mechanisms around us that use plastic gears. Moreover, it can be like toy cars, and quite serious things, for example, an antenna lift in a car, a spinning rod gearbox, etc. The reasons for gear failure can be different, of course, most of them are related to improper operation, but that’s not about that now. If you find yourself in such a situation and a couple of gear teeth are broken, then there is a way out: not to pay for an expensive part, but to restore it in a simple way.

Needed for recovery

Unnecessary toothbrush.
Detergent.
Two-component epoxy adhesive - cold welding for plastic.

Cold welding glue should be liquid, in tubes. Be sure to check the packaging to ensure it is suitable for gluing plastic and resin parts. This two-component adhesive can be purchased at either an auto parts store or a hardware store. If you have any difficulties and cannot find one, at the end of the article I will tell you how to make a similar analogue.

Restoring a plastic gear

Preparation

The first step is to prepare the surface of the gear. We wash it several times warm water With detergent, actively working with a toothbrush. Our task is to degrease and remove grease from all edges.
After degreasing is done, dry it dry.

Preparing the glue

Now let's prepare the glue. Mix the components on a small piece of cardboard in the proportions as in the instructions. Mix well.
In general, before opening the glue, I recommend that you carefully read its instructions, especially with the time of complete and partial hardening, since different manufacturers these data may differ radically.
If the consistency turns out to be liquid, let it stand for a while until it begins to harden.

Restoration of teeth

In my case, several teeth were ground down, the situation can be corrected. Apply glue to the place that needs to be restored. The glue should be very thick, but flexible.

We make such a peculiar tubercle.

We place the gear on an improvised stand so that the glue thickens even more. Again, everything is individual, I personally needed about 20 minutes for the consistency to noticeably thicken.

You can speed up the reaction and reduce the thickening time by heating. For example, take a hairdryer and start heating the glue on the gear.

Restoration of teeth

Now the most crucial moment is rolling the teeth. The unit where the gear was used, namely the other gear with which our broken one was in direct contact, must be generously lubricated with grease, grease or lithol.
We install the broken gear and roll it over the other one several times.

As a result, another gear will roll the track on the thick glue.

Now you understand that before rolling the teeth, the epoxy glue on the gear must cure to the consistency of hard clay.
Thanks to the lubrication, the glue will not stick to the other gear.

Hardening

Carefully remove the restored product from the mechanism and leave it for final hardening, usually for a day.

In this simple way, you can quite easily restore broken gears.

How to replace epoxy glue?

If you haven't found glue, I can recommend you to make a slightly similar composition.
For this you will need:

Epoxy resin with hardener.
The cement is dry.

We buy regular transparent or yellowish epoxy resin with hardener. These two components are often sold together.
In the proportion specified in the instructions, mix the components to obtain required quantity glue. Add cement. Not just cement-sand mixture, namely pure cement. The proportions are approximately two to one. That is, two parts glue and one part cement. And mix everything very thoroughly. The glue is ready, and then everything is as per the instructions above.

Plastic is different from plastic

First, let's figure out what plastic is and what it comes in. Plastics are commonly called materials that are a combination of synthetic (less often natural) polymers with organic impurities, which are added to impart various properties to the finished product during its formation from a viscous-flowing state to a solid.

Depending on their response to elevated temperatures, plastics are in turn divided into thermoplastic and thermosetting. When heated, thermoplastics change from a solid to an elastic state, and this change is reversible and can be repeated many times. Thermoplastics include polyethylene, polystyrene, polycarbonate, polyvinyl chloride, polypropylene, polymethyl methacrylate and polyamide.

Polypropylene is most often used in the automotive industry: it is excellent for the manufacture of bumpers and other parts that experience various shock loads and are the most frequently damaged. Polypropylene is very elastic and is able to restore its shape with light impacts, but this is not the only good thing about it. If damaged, polypropylene parts are easy to repair because this material perfectly tolerates such a popular plastic repair method as soldering.

Thermoset plastics have linear structure, being an infusible material that is destroyed as a result of heating and does not restore its original properties upon subsequent cooling. Such materials include polyurethane, polyester, urea and phenol-formaldehyde resins. The most widely used plastics in the automotive industry are those based on polyester resins. Unlike pliable polypropylene, parts made of polyester plastics have high rigidity, so this material is usually used for hoods, roofs and trunk lids. It must be remembered that when repairing such parts, using soldering is strictly unacceptable.

School repair

Restoration work on plastic parts is divided into two categories - deep structural repairs and cosmetic repairs. With a complete renovation, defects caused by damage to the structural integrity of a part or the loss of a part are eliminated, redecorating solves the problem of surface damage - eliminating chips, scratches and cracks.

A two-component polymer-captan-epoxy mixture is best suited for repairing surface defects in plastic parts. When hardened, this material not only provides the necessary strength to the repair area, but also retains elasticity. A part repaired using this mixture is able to fully restore its original properties and withstand design impact loads.

When working with propylene parts, the problem of lack of sufficient adhesion often arises. repair material to the surface of the plastic part being restored. This is explained by the low surface energy of propylene, which leads to weak intermolecular interactions. Simply put, one material cannot stick to another. In order to increase the adhesive ability, it is necessary to use a polyolefin activator containing polyolefins in its structure (polypropylene, polyethylene, ethylene-propylene rubbers).

To restore serious damage, you cannot do without a special two-component polyurethane-based adhesive. This composition is characterized by a high polymerization rate (drying time is only 30 seconds), which allows you to glue and restore lost parts of the plastic during operation. After the shape of the lost element is restored and the composition is completely polymerized, it can be processed (drilled, sanded) and painted. When using two-component glue, you can repair not only yourself plastic element, returning it to its original presentation, but also to its fastenings. For example, this applies to bumper mounts that have received minor damage - in this case, there is no need to replace an expensive part.

The material was prepared jointly with 3M

Sometimes, in his interviews with sports publications, the former Formula 1 pilot Joachim Stuck does comparative analysis two pilots. So this time, he tried to show the difference that exists between Heidfeld and Alonso, based on his experience and observations.

So the sports analyst warns the team BMW what should they replace Nick Heidfeld that the German pilot, although he can show excellent results in races, is not at all the one who can win the championship itself.

According to Stuck, the German team, wanting to get the title, should take on exactly Fernando Alonso, because only he is on this moment motivated more than other pilots and even Renault this season can work wonders.

A broken part of a tool, especially during work, can greatly spoil not only the work process itself, but also the mood for further work. It’s good if, with the breakdown of a minor part, the tool does not fail, and you can still work with it before replacing this most ill-fated part. In my case, for example, the pad between the frame and the container broke on a garden wheelbarrow.

The damage seems to be minor, and work can continue. But it's not that simple; under more or less serious load, the wheelbarrow begins to move in the direction from which the lining broke. This is very inconvenient when transporting heavy loads. Then I decided to remove the second overlay, for symmetry! I thought it would help.

It really helped - the car stopped moving to the side. But she started creaking like hell! Ears curl up! No amount of lubrication oil helps. I couldn’t stand it for a long time, and went to the nearest hardware store to get the part I needed, which, of course, wasn’t there. There was not the slightest desire to travel all over the city in search of the right thing. Then I decided to repair the broken thing myself. Today we will look at one of the options for how to put together a thin plastic lining split in half. This advice will greatly help those who find themselves in a similar situation. This may not necessarily be a wheelbarrow trim. This method can restore any plastic item or part. At least until the original one is purchased from the store.

You will need:

Pliers.
Pin.
Secondary glue.
Composite adhesive, “cold welding” type.
A drill, as thick as a prepared pin.
Bor machine or small drill.
Small grinding disc for machine bur.

Repairing a broken part

First, you need to check whether any other small pieces have fallen off and examine the repair object in more detail. If the part being repaired has stiffening ribs, then the longitudinal ones will have to be removed. This can be done using pliers and a bur machine with a small sanding disc.

Next, in the thickest places, using a two millimeter drill, you need to drill holes inside the part. Like this:

4-5 millimeters deep. We will need these holes to reinforce the part. For greater durability. Next, we take the prepared pin, straighten it, and break it (or bite it off with wire cutters - whatever suits you!) into eight-millimeter pieces.

Now, using a match or thin wire, we lubricate the holes on the drilled half of the broken part, and stick pins made from pins into the holes.

We do everything very quickly so that the glue does not set in the empty holes. Next, we drill holes in the second half of the broken part. Strictly opposite the pins protruding from the first half. If everything turned out as it should, lubricate both halves in the split place with second glue and stick them into each other.

It is necessary to compress the parts to be glued. At least for thirty seconds so that they stick.

Now it’s the turn of the composite glue. I use the “cold welding” type - very convenient glue. There is not as much fuss with it as, for example, with the liquid components of epoxy glue. Yes, and it hardens much faster, and in terms of reliability of fastening they are the same.

In general, we break off, or cut, from total mass the piece we need, spray our palms with water, and thoroughly stir and knead the glue in our palms. Until a homogeneous mass is obtained.

Next, lubricate with second glue inner surface the part being repaired, the one with which we broke out the longitudinal stiffeners. And we sculpt a cold weld onto the surface greased with glue.