How to fix a hole in a muffler without welding
Content
The elements of the car exhaust system are not always made of high-quality stainless and heat-resistant steel. Only manufacturers of the most expensive cars can afford such mufflers, and they are not very interested in this either. Therefore, the tightness of the exhaust is broken after a few years of operation, after which the malfunction is clearly visible by the noise and smell, sometimes penetrating into the cabin, which is unsafe.
Why do cracks and holes appear in the muffler
The working conditions of sheet structural steel, from which mass silencers, resonators and pipes are made, are very difficult.
Here everything is created for fast corrosion:
- high temperatures, reducing the resistance of the material;
- drops in the form of heating and cooling disrupt the structure of the sheet, especially in places that are already tense after stamping;
- the presence of corrosion concentrators in the form of welds and points;
- a high content of water vapor in exhaust gases at high temperatures, it is known that all chemical reactions are accelerated when heated;
- condensation in the mufflers after cooling, this water evaporates very slowly, and the access of oxygen from the atmosphere becomes free;
- fast external corrosion of parts, high temperatures are poorly tolerated by protective coatings, moreover, they are made of insufficiently high-quality means to save money.
There are also mechanical loads on structural elements, the exhaust system vibrates, is subjected to shock and shelling with sand and gravel. Worse conditions are difficult to imagine, so the exhaust suffers from rust in the first place.
Ways to repair the exhaust system without welding
Radical repair methods are the replacement of parts with new ones with severe corrosive wear or welding patches and welding of cracks, if, in general, iron allows this to be done.
But such procedures are time-consuming, costly and require experience from the performers. Alternatively, simpler sealing techniques can be used.
Cold welding
Cold welding is commonly referred to as two-component epoxy compounds that harden after mixing. Repair with their help has its own characteristics:
- small damages are subject to sealing, large defects cannot be reliably restored;
- it is undesirable to apply to highly heated parts close to the exhaust manifold, especially widespread compounds that can withstand no more than 150-200 degrees Celsius, there are high-temperature products, but they are also unreliable at 500-1000 degrees;
- the composition usually includes a filler in the form of a metal powder and other additives, which allows the use of a thick product that does not require additional strengthening before solidification;
- epoxy mixtures have good adhesion to metal, but it is also limited, therefore it is necessary to carefully clean the surfaces, but it is better to ensure mechanical engagement with the penetration of the mixture into the part;
- it will be optimal to use compounds specially designed for repairing mufflers, they have a temperature margin, increased strength, adhesion and durability, but the price is high.
According to the instructions, the components are mixed in the required proportions, after which they are kneaded with fingers in gloves moistened with water and applied to a cleaned and degreased crack.
You can reinforce the patch with fiberglass on self-tapping screws. The polymerization time is usually about an hour, and strength is gained in a day.
Ceramic Tape
Repair with a bandage made of a special fabric impregnated with silicone or other substances takes a little time, but allows you to eliminate large cracks and defects.
The tape is soaked with water or in another way specified in the instructions, then it is wound around the damaged pipe and tightened with clamps. After drying, a reliable, albeit temporary, bond is formed.
Other applications are possible, such as a metal patch with a tape-lined patch. Preferably with additional sealing by cold welding or high temperature sealant. Epoxy self-tapping screws are used as fasteners.
Sealant
Special exhaust sealants are available that have a high operating temperature. These are one-component compositions that polymerize in air.
They are suitable for sealing small defects, mainly according to the gasket principle, that is, either at the joints of parts, or with a metal or fabric patch preloaded. Such a sealant does not have the strength of cold welding.
We must carefully approach the choice. Ordinary silicone products can't withstand exhaust temperatures, no matter what degree number is on the label.
Sealant (exhaust system cement) should be from a reputable manufacturer, quite expensive and specifically designed for exhaust system repairs.
You can use cold welding, tape bandage and sealant in combination, it will not be worse, and the reliability of sealing increases.
Especially when using metal reinforcement, fasteners and protection. But in any case, these are temporary measures, only postponing the replacement of parts or welding procedures.
What to do so that in the future the muffler does not burn out
It is important to keep metal parts dry by removing wet dirt from them before storage. It is possible to update the protective coating with high-temperature anti-corrosion paint, but this is quite expensive and troublesome.
Sometimes a small hole is drilled in mufflers at the lowest point. This almost does not add noise during operation, but helps to remove condensate in a natural way. If there is such a hole, it must be cleaned periodically.
There are repair elements of the system made of stainless steel. It's expensive, but it allows you not to think about mufflers for a long time. In any case, early intervention when extraneous sounds appear will make it possible to reduce the cost of the upcoming repairs and fully use the resource of parts.
