Severe Russian winters, reagents on the roads and high humidity create ideal conditions for the rapid development of corrosion on the car body. Rust can turn once proud metal into a sieve in just a few seasons if protective measures are not taken in time. One of the most reliable, decades-tested and affordable methods of preserving hidden cavities and bottoms is to use cannon fat. This material, originally developed to protect artillery barrels, has unique adhesion and the ability to displace water, remaining elastic even in severe frosts.
Many vehicle owners mistakenly believe that factory anti-corrosion treatment lasts forever and ignore the need for additional care. In fact, during operation the protective layer is damaged by gravel impacts, vibrations and thermal expansion of the metal. Cannon fat (or pushvacil) penetrates microcracks and forms a dense, non-drying film there, which blocks the access of oxygen and moisture to the metal. Processing this composition with your own hands is a labor-intensive process, but it is worth it, as it allows you to extend the life of the body by 5-7 years or more.
Before starting work, you must clearly understand that the quality of the result depends 90% on proper surface preparation. Applying a preservative to dirt or loose rust will only preserve the problem, allowing it to develop even more actively under a layer of fat. In this article we will analyze the application technology in detail, select the right equipment and discuss the nuances that newcomers to garage anticorrosion often miss.
What is cannon lard and how does it work?
Gun lard is a petroleum conservation lubricant, which is a thickened mixture of mineral oils, ceresin and petrolatum. Externally, it is a homogeneous mass from light yellow to dark brown, reminiscent of very thick technical Vaseline or paraffin. The key feature of the material is its thixotropy: when heated, it becomes liquid and flowing, and when cooled, it hardens again, without draining from vertical surfaces. It is this property that allows it to reliably stay on the bottom and in the arches even at high summer temperatures.
The protection mechanism is based on the creation of an impenetrable barrier. Unlike bitumen mastics, which can crack and peel over time, cannon lard remains plastic. It does not form a hard crust, but creates a “living” layer that heals minor scratches. The melting point of gun fat is about 90°C, making it resistant to heat from the exhaust system, but requiring preheating before application.
There are two main types of this material that can be found on sale: solid (in buckets) and liquid (preservatives based on it in aerosols or canisters). For garage processing, a solid composition in buckets is most often used, as it is more economical and allows you to control the degree of heating. Liquid analogs already contain solvents that make application easier, but can evaporate over time, leaving a thinner protective layer.
It is important to understand the chemical inertness of the material. It does not react with rubber, plastic or paintwork, so it is safe for all elements of the car. However, contact of heated grease with brake pads or discs is strictly unacceptable, as this will lead to loss of braking efficiency. Adhesion The (adhesion) with metal of cannon lard is phenomenal, which makes it one of the leaders in the niche of budget anticorrosion agents.
⚠️ Attention: Cannon lard is a flammable material. When heated by an open fire or overheated on an electric stove, the vapors may ignite. Never heat the composition until smoke or open fire appears - this will destroy its structure and create a fire hazard.
To test the quality of gun lard, drop a little heated material onto cold metal. If after cooling the drop remains translucent and elastic, without cracking when the metal is bent, the product is of high quality.
Necessary tools and composition preparation
High-quality machining of a machine is impossible without the right tools. Since cannon lard requires heating to a liquid state, you will need a heating container. An old bucket or metal can that you don’t mind getting damaged is ideal. You can heat it on a gas stove, a hair dryer (for a long time) or on a fire/burner, but the most controlled option is electric stove with a closed heating element.
To apply the material into hidden cavities and on the bottom, you will need a pneumatic gun for anticorrosion (the so-called “gun grease gun”) or a compressor with a suitable nozzle. Some craftsmen use a regular spray gun, but it can quickly clog when the mixture cools. You will also need brushes for treating hard-to-reach places, rags, degreaser (white spirit or Galosh gasoline) and personal protective equipment.
List of required equipment:
- 🔥 Warming container (bucket, tank) and heat source (stove, burner).
- 💨 Pneumatic gun for anticorrosion with a flexible hose and a set of nozzles.
- 🖌️ Brushes of different widths (synthetic so as not to shed) for local application.
- 🧤 Protective gloves, respirator and glasses (fumes from heated material are not good for breathing).
The process of preparing the composition takes time. Solid lard should be crumbled or cut into pieces, placed in a container and heated slowly. The mixture needs to be stirred periodically so that it heats up evenly. The consistency is ready to use when it resembles liquid sour cream or sunflower oil. If you make the mixture too thin, it will not stick well; if it is too thick, it will not penetrate into micropores.
Preparing the car for processing
The most important stage on which the final result depends is the preparation of the body. Treating a dirty car is a waste of money. The car must be thoroughly washed, paying special attention to the wheel arches and hidden cavities. It's best to use a pressure washer with active shampoo to remove all oil stains and road grime.
After washing, the body should be completely dry. Moisture under the preservative layer will lead to corrosion. To speed up the process, you can blow out hidden cavities with compressed air. Particular attention should be paid to areas of corrosion. If there is already rust on the bottom or in the arches, it must be cleaned mechanically (with a metal brush, a drill attachment) to bare metal or at least remove the loose layer.
Sequence of preparation:
- 🚿 Thorough washing of the body and arches under high pressure.
- 💨 Blowing out hidden cavities and drying with compressed air.
- 🔧 Removal of plastic fender liners, mudguards and engine protection (if any).
- 🧹 Mechanical cleaning of corrosion pockets and degreasing problem areas.
After cleaning, it is recommended to treat rusty areas rust converter based on orthophosphoric acid. This will stop the chemical oxidation reaction. After the converter has dried, the surface is degreased again. Only after this can you begin to apply the anticorrosive agent. Don’t be lazy to remove the plastic elements - they often hide the main areas of rotting, where the jet of a gun simply will not reach without dismantling.
⚠️ Attention: It is strictly forbidden to apply cannon lard to a wet surface or to residual water in hidden cavities. Water, once “sealed” in fat, will cause corrosion even more intensely due to the lack of oxygen access to passivate the metal.
Technology of applying anticorrosive coating to the bottom and arches
It is most convenient to apply heated gun lard at an ambient temperature of at least +10°C, although the material itself works even in cold weather. The work is carried out on an inspection pit or overpass. If there is no hole, you will have to partially dismantle the suspension elements or work lying down, which is extremely inconvenient. The prepared composition should be hot (about 80-90°C), but not boiling.
Processing should begin with the inner surfaces of the arches and hidden cavities of the thresholds. Using the flexible nozzle of the gun, go through all the service holes. Then move to the bottom. Movements should be smooth, the layer should be applied with a thickness of about 200-400 microns. Don’t try to apply a thick layer of everything at once - it’s better to apply two thin layers with a break for the first to cool.
Table of temperature conditions for working with cannon fat:
| Parameter | Meaning | Note |
|---|---|---|
| Melting point | ~90°C | Beginning of transition to liquid state |
| Operating temperature | 80-95°C | Optimal viscosity for spraying |
| Pour point | < 40°C | Beginning of layer polymerization |
| Critical temperature | > 120°C | Possible boiling and loss of properties |
It is important to evenly distribute the material along the welds and places where the elements are attached. It is in the gaps between metals that “pitting” corrosion most often begins. Hydrophobic properties lard allows it to displace remaining moisture from these joints. After treating the outer surfaces of the underbody and arches, let the car cool and check for bald spots. If necessary, apply a second coat with a brush in problem areas.
☑️ Control of anticorrosive application
Treatment of hidden cavities: doors, thresholds, side members
Hidden body cavities are the most vulnerable spot of a modern car. Moisture enters through drainage holes and remains inside due to poor ventilation. Rotting begins from the inside out, and once rust becomes visible from the outside, the process is often irreversible. Treating these areas with gun lard requires the use of special spray nozzles with a 360-degree spray angle.
The processing technology is simple in theory, but difficult to implement due to limited access. The doors, thresholds and side members are factory equipped with technological holes closed with rubber plugs. They must be carefully removed. Through these holes, a gun tube is inserted into the cavity. By rotating the tube, it is necessary to spray the composition evenly over all the inner walls.
The nuances of working with hidden cavities:
- 🚪 Remove the door trim to control the process and not stain the window lift mechanisms.
- 🌬️ Be sure to clean the drainage holes at the bottom of the doors before processing so that they don’t get clogged after the anticorrosive.
- 👀 Use a flashlight and mirror to visually inspect the coating inside the cavity.
After processing the insides of the doors and thresholds, put everything back together. It is better to remove excess material that gets on the mechanisms of locks or hinges, since over time dust can stick to them, turning into an abrasive paste. The spars are processed through existing holes or through holes for attaching the subframe. It is important here not to overdo it with pressure, so as not to damage the factory metal flanges.
What happens if you don't remove the door trim?
When spraying anticorrosive inside the door without removing the card (trimming), there is a high risk of staining the speakers, wiring and window lift mechanisms. In addition, you will not be able to visually check whether the stream has hit the lowest corners of the door, where moisture accumulates first.
Advantages, disadvantages and final recommendations
Using cannon lard has its pros and cons, which you need to know about before starting work. The main advantage is exceptional durability and low cost. The treated car can safely drive for 3-5 years without the need to repeat the procedure, even in an aggressive environment. The material is cheap, available at any auto chemical store and forgives errors in application.
However, there are also disadvantages. Cannon lard is a “dirty” anticorrosive agent. It stains clothes upon accidental contact, and dust and dirt stick to it in the first weeks after application. In addition, at very high temperatures (for example, at the muffler), it can drain. This is not a protective coating in an aesthetic sense, but purely functional protection.
Comparative characteristics:
- ✅ High penetrating ability and adhesion.
- ✅ Low cost compared to synthetic analogues.
- ❌ Long process of preparation and application.
- ❌ The need for special equipment (heating, gun).
As an alternative, you can consider modern synthetic wax-based anticorrosives, which are easier to apply and do not require heating, but their cost will be 3-5 times higher. For older vehicles or vehicles expected to operate in harsh conditions over a long period of time, lard remains the gold standard for cost-effective protection. The main thing is not to forget to renew the coating every few years and monitor the integrity of the layer.
⚠️ Attention: Do not apply grease to external visible body elements (fenders, hood, trunk) over paint unless you are prepared for the car to look “greasy” and collect all the road dust. This material is intended for hidden cavities and bottoms.
Gun lard is a choice for maximum protection and saving money, but at the expense of cleanliness and speed of application. For a long life of the body in Russian winter conditions, this is one of the best solutions.
Frequently asked questions (FAQ)
Is it possible to apply gun lard to rust without stripping it?
Technically it is possible, but it is pointless. The anticorrosive agent will create a film on top of the rust, but the oxidation process will continue underneath it, since moisture and oxygen remain in the pores of the rust. Rust must be cleaned down to metal and treated with a converter.
How to wash off gun fat from clothes or skin?
It is washed off the skin with warm water, soap and a brush; you may have to repeat the procedure. It is extremely difficult to remove it from clothes: you need to freeze the item (the lard will become brittle), scrape off the bulk, and remove the remaining residue with Galosh gasoline or white spirit, and then wash it intensively.
Do I need to dilute gun fat with a solvent?
When properly heated to 80-90°C, it becomes liquid enough to spray with a gun. You can add a solvent (gasoline, diesel) only if you apply it with a brush and want to make the layer thinner, but this will worsen the protective properties and increase the shrinkage of the layer when drying.
How often should the treatment be repeated?
Well-applied cannon lard lasts 3-5 years. It is recommended to carry out a visual inspection of the bottom and hidden cavities once a year. If the layer is intact and elastic, there is no need to repeat the treatment. If abrasions or material washes out in certain places, update locally.