Unprotected sills and hidden cavities of the body begin to rust from the inside after only 2-3 years of using the car in Russian winter conditions. It is at this moment that many car owners think about using cannon lard for cars, which has been proving its effectiveness for decades as a budget-friendly but reliable metal preservative. A thick, ointment-like substance based on petroleum oils thickened with solid hydrocarbons is able to penetrate microcracks and create an elastic film that is not washed off by rain and reagents.
The main task of this material is to displace moisture from hard-to-reach places and create a barrier to oxygen. Unlike bitumen mastics, which crack over time, cannon fat remains plastic at any temperature, which is critical for moving structural elements. Correct use of this composition allows you to extend the life of the body by 5-7 years, if the application technology was followed without violations.
Many people confuse this product with ordinary lithol or grease, but the chemical formula CPU-1 (this is how the composition is often labeled in catalogs) is designed specifically for the preservation of military equipment and metal products during long-term storage. The use of cannon lard for cars is justified in cases where reliable, durable and inexpensive protection of hidden cavities, arches and bottoms from an aggressive external environment is required.
Chemical composition and physical properties of the preservative
The base for production is petroleum oil, which undergoes an oxidation process with oxygen at high temperatures. As a result of the reaction, resinous substances are formed, giving the product its characteristic viscosity and stickiness. To improve anti-corrosion properties, add to the mass corrosion inhibitors and special additives that block the development of rust even in the presence of pockets under a layer of mastic.
- 🛡️ High adhesion to metal, allowing the composition to stay on vertical surfaces for years.
- 💧 Excellent water-repellent properties, eliminating contact of moisture with the body.
- 🌡️ Preservation of elasticity in the temperature range from -50 to +90 degrees Celsius.
- 🔋 Inert to most chemicals used by utilities.
It is important to note that the material does not contain volatile solvents that evaporate, leaving a dry film. On the contrary, it remains in a semi-liquid state, which allows it to “heal” minor damage to the coating. However, it is precisely this feature that requires caution when used in open areas subject to stone impacts, since the layer can be mechanically torn off.
⚠️ Attention: Cannon lard is not a paint and does not have decorative properties. If it gets on the paintwork of the body, it can dissolve some types of enamels or leave greasy stains that cannot be removed.
Preparing the car and necessary tools
Before starting work, the car must be thoroughly washed, especially in the area of the arches and underbody. Using a Karcher under high pressure will help dislodge old dirt from hidden cavities where you plan to apply protection. After washing the body must be completely dry, since applying a preservative to wet metal will seal the water inside, accelerating the corrosion process.
☑️ Checklist for anticorrosive preparation
The material will need to be heated to work, as at room temperature it is too thick to spray. It is optimal to use a hair dryer or water bath to heat the container with the composition to 60-80 degrees. You will also need a special spray gun with a flexible hose and a long nozzle to access the hidden cavities of the sills and side members.
Don't forget to prepare personal protective equipment. Vapors from heated petroleum products are toxic, so you should work in a respirator and a well-ventilated area. Clothing should cover all areas of the skin, since it is extremely difficult to wash off hot lard, and the risk of burns if handled carelessly is high.
Technology of application to hidden cavities and bottoms
The processing process begins with the internal cavities of the body. The flexible nozzle of the gun is inserted into the technological holes of thresholds, doors and pillars. Spraying produce evenly, rotating the tube 360 degrees so that the composition covers the entire inner surface. It is important not to overdo it: excess material will flow out through the drainage holes, staining the body.
Subtleties of door processing
In the doors, it is important not to clog the window lift mechanisms and locks with mastic. To do this, before processing, they are sealed with film, and after the composition has dried (after 2-3 hours), the excess in the area of the mechanical parts is carefully removed.
Processing the bottom requires a different approach. Here the material can be applied in a thicker layer, using a wide nozzle or even a brush for hard-to-reach corners. Movements must be progressive, ensuring overlap of the previous lane. Particular attention is paid to welds and places where units are attached, where most often it starts pitting corrosion.
- 🚗 Thresholds are processed from bottom to top through existing holes or removed plugs.
- 🚙 The spars are sprayed from the ends, moving towards the center of the car.
- 🚛 The wheel arches are covered with a double layer after installing the fender liners in place.
After completing the work, the car must be allowed to dry in a warm garage for 24 hours. Although the surface film forms quickly, complete structuring of the layer and final adhesion to the metal takes longer. It is not recommended to drive on the road or wash your car in the first 24 hours after treatment.
Comparison with modern anticorrosion agents and analogues
There are many modern compositions on the market based on bitumen, wax or polymer. To understand the place of cannon fat in this hierarchy, it is worth considering a comparative table of characteristics of various types of protection.
| Parameter | Cannon fat | Bitumen mastic | Wax anticorrosive | Polymer composition |
|---|---|---|---|---|
| Service life | 3-5 years | 2-3 years | 1-2 years | 5-7 years |
| Elasticity | High | Medium (cracks) | Low | Very high |
| Penetration | Excellent | Low | Average | Low |
| Price | Low | Average | High | Very high |
The main advantage of the material under discussion is its ability to remain alive and mobile. Bitumen mastics dry out over time and become covered with a network of microcracks into which moisture penetrates. Wax compounds are often washed off after the first active winter. Cannon lard combines low cost and high penetrating power, making it an ideal choice for older vehicles or budget conservation.
However, the material also has disadvantages. It does not have the mechanical strength of polymers (such as “liquid plastic”) that create armor on the bottom. Therefore, for open spaces exposed to gravel impacts, it is better to combine materials or use additional protective screens.
Typical mistakes when processing yourself
One of the most common mistakes is applying the composition to rust without first cleaning it. Although cannon lard has inhibitory properties, it does not convert rust. If you apply it over the red spots, the corrosion process will continue under a layer of ointment, and the owner will only know about it when the metal is completely eaten away.
Another mistake is ignoring the heating temperature. Insufficiently heated material forms lumps and does not penetrate into microcracks. An overheated composition may boil, losing some of its properties, or become too liquid, flowing off vertical surfaces instantly. It is necessary to strictly observe the temperature regime within 60-90 degrees.
Also often forgotten is the protection of rubber elements. Petroleum products have an aggressive effect on some types of rubber and plastic, causing them to swell or crack. Before starting work, all seals, silent blocks in the processing area and plastic covers must be insulated or removed.
⚠️ Attention: Do not apply a thick layer of material to the exhaust system elements. When the muffler is heated to high temperatures, the grease may ignite or create acrid smoke in the cabin.
Operation and service life of the coating
A correctly applied layer provides reliable protection for several years. However, regular visual inspection will not hurt. It is recommended once a year, before the winter season, to inspect the condition of the coating in arches and thresholds. If mechanical damage or washouts are noticed, it is enough to locally lubricate these places with a heated compound.
Key Point: Cannon fat does not require a complete upgrade. Local restoration of damaged areas is sufficient, which makes operation economical.
It is worth considering that the material can collect dust and dirt, forming a “porridge” on the bottom. This is a normal process that does not affect the protective properties, since the bottom layer adjacent to the metal remains sealed. It is not recommended to wash off this layer with aggressive chemicals, so as not to damage the preservative itself.
For owners of cars with high mileage, the use of gun fat is an excellent way to preserve the body before selling or long-term storage. It hides minor defects and prevents the appearance of new rust spots, maintaining the integrity of the metal.
Tip: To improve penetration in very cold seasons, you can add about 10-15% white spirit to the heated lard, but only if you plan to apply it inside closed cavities and not on the bottom.
Frequently asked questions (FAQ)
Is it possible to apply gun lard over old anticorrosive?
Yes, you can, but only if the old layer does not peel off and holds tightly. The surface must be cleaned of dirt, degreased and warmed up. If the old anticorrosive layer is swollen or cracked, it is better to remove it mechanically, otherwise the new layer will not stick and moisture will remain under it.
At what temperature does cannon lard freeze?
The material remains plastic even in severe frosts down to -50°C. It does not turn to stone like bitumen, so it does not crack due to vibrations and impacts. This is one of its main advantages over solid mastics.
Is gun lard harmful to rubber seals?
Prolonged contact with petroleum products can adversely affect some types of rubber. Therefore, when processing thresholds and doors, it is recommended to protect rubber seals with masking tape or pre-lubricate them with silicone grease to create a barrier layer.
How to dilute thickened cannon fat?
For dilution, it is best to use white spirit, kerosene or diesel fuel. They should be added to the heated mixture in small portions, stirring constantly, until the desired consistency is achieved. Gasoline is not recommended due to its high fire hazard and aggressiveness.
Do I need to remove the wheels to treat the arches?
Preferable, but not always required. Removing the wheels and plastic fender liners (lockers) gives 100% access to the arched space and allows for high-quality processing of the hidden cavities of the side members. Without removing the wheels, there is a high risk of leaving “blind spots” where corrosion will continue to develop.