Protecting your vehicle's underbody from corrosion is a key maintenance procedure that is often overlooked. This problem is especially relevant for regions with aggressive climatic conditions: frequent temperature changes, high humidity and the treatment of roads with reagents. Cannon fat remains one of the most reliable and time-tested means for anti-corrosion treatment, despite the emergence of modern alternatives.
In this article we will look at why cannon fat (and not Movil or liquid plastic) is often chosen by professionals, how to properly prepare a car for processing, what tools are needed, and what mistakes lead to premature destruction of the protective layer. You will also learn how often you need to renew the coating and what nuances are important to consider when working with different types of bodies - from galvanized to aluminum.
The material has been prepared taking into account the current standards of 2026 and the recommendations of leading manufacturers of anti-corrosion compounds, such as Noxudol, Tectyl and Liqui Moly. If you plan to process the bottom yourself, these instructions will help you avoid common mistakes and maximize the service life of the metal.
Why cannon fat and not modern means?
There are dozens of compositions on the anti-corrosion materials market today: from bitumen mastics to polymer coatings with zinc. However cannon fat (aka PVC conservation lubricant) remains in demand due to its unique properties:
- 🔹 High adhesion — penetrates into microcracks and pores of the metal, displacing moisture.
- 🔹 Long service life — when applied correctly, protects for up to 3–5 years (versus 1–2 years for most aerosols).
- 🔹 Versatility - Suitable for steel, galvanized and aluminum surfaces.
- 🔹 Low price — a 1 kg jar costs 2–3 times cheaper than imported analogues.
In addition, cannon fat does not require a perfectly dry surface (unlike bitumen mastics) and does not lose properties at temperatures from –50°C to +50°C. This makes it the optimal choice for regions with harsh climates, such as Siberia or the Far East.
But there are also disadvantages: the complexity of application (heating is required), the need for thorough surface preparation and the risk contact with brake mechanisms or exhaust system, which may cause a fire. Therefore, it is better to carry out processing in a service center or strictly following the instructions.
Preparing the car: what needs to be done before processing
The quality of anti-corrosion protection depends 70% on surface preparation. If you skip this step, the lard will lie unevenly, quickly peel off, or will not penetrate into problem areas. Here mandatory checklist before processing:
High pressure underbody washing (minimum 100 bar)
Removing the old protective layer (with a scraper or solvent)
Treating rust with a converter (e.g. Tsinkar)
Drying the surface (with a compressor or in a warm box)
Taping brake discs, exhaust pipe and sensors with masking tape-->
Pay special attention hidden cavities: side members, sills and wheel arches. This is where moisture accumulates and corrosion begins. To clean hard-to-reach places, use steam generator or special nozzles for high pressure washing.
If there are already pockets of rust on the bottom, they must be removed mechanically (with a metal brush or sandblaster) and treated rust converter. Popular options: Hi-Gear Rust Treatment or domestic Chainmail. After this, the surface must be washed with water and dried.
⚠️ Attention: Do not use a hairdryer or open fire for drying - this may deform the plastic elements of the pendant. The best option: leave the car in a warm garage for 12–24 hours or use heat gun with a temperature not exceeding 60°C.
Which cannon lard to choose: review of the best brands
Not all preservative lubricants are equally effective. They are presented on the market as Soviet analogues (for example, PVK according to GOST 19537-83), as well as modern formulations with improved characteristics. The table below compares the most popular options:
| Brand | Temperature range | Protection period | Price per 1 kg (2026) | Features |
|---|---|---|---|---|
| Gun lard PVK (GOST) | –50°C to +50°C | 2–3 years | ~300 rub. | Classic composition, requires warming up before application. |
| Noxudol 700 | –40°C to +80°C | 3–5 years | ~800 rub. | Contains wax, easier to apply, does not drip. |
| Tectyl 506 | –30°C to +100°C | 4–6 years | ~1200 rub. | For professional use, high adhesion. |
| Liqui Moly Wachs-Konservierer | –40°C to +60°C | 3 years | ~900 rub. | Contains corrosion inhibitors, suitable for aluminum. |
For most passenger cars, the best choice would be Noxudol 700 or Liqui Moly - They are easier to apply and last longer. If the budget is limited, domestic is suitable PVK, but it will have to be heated and applied in 2-3 layers.
Important: avoid fakes! There is often “cannon fat” on the market from unknown manufacturers, which is actually melted technical fat. Such compounds do not protect against corrosion, but only clog drainage holes.
Before purchasing, check the certificate of conformity GOST 19537-83 or the technical data sheet of the product. The can should say "preservation lubricant" and not just "general purpose lubricant".
Step-by-step instructions: how to apply cannon lard
The bottom treatment process consists of several stages. If you are doing this for the first time, it is better to invite an assistant - some operations (for example, applying to wheel arches) are difficult to perform alone.
1. Warming up the lard
The cannon lard in the jar has a thick consistency, so it needs to be heated before applying. Optimal temperature - 60–80°C. To do this:
- 🔥 Place the jar in a bucket of hot water (not boiling water!).
- 🔥 Or use construction hair dryer at minimum power.
- 🔥 The services use special mastic warmers.
Do not heat lard over an open fire - it is a fire hazard!
2. Applying the first layer
To work use:
- 🖌️ Brush (width 5–10 cm) - for side members and thresholds.
- 🎨 Roller - for flat surfaces (for example, trunk floor).
- 🔧 Spray gun — for hard-to-reach places (only for heated lard!).
Apply the composition thin layer (1–2 mm), starting from the most vulnerable places: welds, panel joints and internal cavities. Avoid contact with:
- ❌ Brake pads and discs.
- ❌ Wheel bearings.
- ❌ ABS sensors and exhaust system.
3. Drying and second layer
After applying the first coat, leave the car for 2-3 hours to allow the grease to absorb. Then inspect the surface: if there are gaps or thin spots, apply a second coat. The total thickness of the coating should be 2–3 mm.
To check quality use thickness gauge or visually assess the uniformity of the layer. On smooth surfaces the lard should shine, and on seams it should completely fill the cracks.
What to do if grease gets on the brake discs?
If gun grease accidentally gets on your brakes, clean them immediately white spirit or a special brake cleaner (Brake Cleaner). Then wipe with a dry cloth and do a few test brakes at low speed. If the braking distance increases or a squeak appears, the pads need to be replaced!
Common mistakes and how to avoid them
Even experienced car owners sometimes make mistakes when processing the underbody. Here are the most common ones and ways to prevent them:
- Application on dirty or damp surfaces → The lard will not stick and will peel off quickly. Solution: thorough washing and drying.
- Too thick layer → Formation of “pockets” where moisture accumulates. Solution: Apply in 2 thin layers with intermediate drying.
- Ignoring hidden cavities → Corrosion continues to develop inside the side members. Solution: Use extended spray nozzles.
- Low temperature operation → The lard thickens and does not penetrate microcracks. Solution: process in a heated box or during the warm season.
Another common problem is clogged drain holes. Many car owners apply grease too much, which causes water to stop flowing from the sills. This leads to accumulation of condensate inside the doors and accelerated corrosion. To avoid this, clean the holes with wire or compressed air after processing.
⚠️ Attention: If after treatment the lard begins to flow down in large drops, you have overheated the composition or applied too much of it. Remove excess with a cloth soaked in white spirit, and repeat the procedure at the correct temperature.
How often should I update my protection?
The service life of cannon lard depends on the operating conditions of the vehicle:
- 🚗 City driving on asphalt - 3–4 years.
- 🚙 Regular driving on dirt/gravel roads - 2–3 years.
- 🏔️ Extreme conditions (salt, sand, high humidity) — 1–2 years.
It is recommended to check the condition of the coating every 6 months. The need for re-processing is indicated by:
- 🔍 Visible cracks or detachments of fat.
- 🔍 The appearance of rust in previously protected areas.
- 🔍 Change in coating color (darkening or fading).
If you operate your vehicle in a region with aggressive winter chemicals (for example, Moscow, St. Petersburg), it is better to repeat the treatment every autumn. To do this, it is not necessary to reapply lard - just rinse the bottom and restore the damaged areas.
Regular inspection of the bottom (at least once every six months) will allow you to detect damage to the protective layer in time and prevent corrosion at an early stage.
Alternatives to cannon lard: when it's not suitable
Despite its advantages, cannon lard is not always the best choice. In some cases it is better to use other means:
| Situation | Recommended remedy | Reason |
|---|---|---|
| Aluminum or magnesium body | Liqui Moly Aluminium-Schutz | Gun lard can cause galvanic corrosion. |
| Galvanized bottom | Tectyl Zinc 505 | Contains zinc for added protection. |
| Fast processing required | Movil in aerosol | No need to warm up, applied in 10-15 minutes. |
| Operation in high temperatures | Bitumen mastic with graphite | Does not melt when heated to +120°C. |
If you are in doubt about your choice, contact car passport — many manufacturers indicate recommended anti-corrosion agents. For example, for Volkswagen and Audi often advised Tectyl, and for Japanese brands (Toyota, Mitsubishi) — Noxudol.
FAQ: Frequently asked questions about treating the bottom with cannon tallow
Is it possible to apply gun lard to rust?
No, it's pointless. Lard creates a protective film, but does not stop corrosion that has already begun. First you need to remove the rust mechanically (brush, sandblast) or chemically (using a converter), and then apply protection.
How much lard is needed to treat a passenger car?
On average it is required 1–1.5 kg for sedan or hatchback and 1.5–2 kg for an SUV. The exact amount depends on the condition of the bottom and the number of layers.
Is it possible to treat wheel arches with gun fat?
Yes, but with caution. Avoid contact with brakes and bearings. For arches it is better to use special compounds with increased elasticity (for example, Noxudol 800), since they are less susceptible to chipping from flying stones.
How to wash gun grease off your hands or clothes?
Fresh stains are removed white spirit, kerosene or special cleaners (ABRO Masters Hand Cleaner). For dried stains use solvent 646, but it may damage the fabric.
Is it possible to paint over gun fat?
No, the paint will not lie flat. If you plan to paint, first remove the grease with a solvent, then degrease the surface and apply primer.