How Many Cans of Fluid Film to Undercoat Car | Veintone Professional Guide
XIEBINRONGWith the increasing awareness of rust prevention, more and more car owners are choosing Fluid Film as the protective coating for the chassis. A common question is: "How many cans of Fluid Film should be used for undercoating the car?" If the estimation is insufficient, it may result in an incomplete protective layer; if the amount is excessive, it will cause unnecessary waste. Therefore, knowing the correct dosage range is crucial for both DIY users and car owners seeking professional installation.
In this blog, we will thoroughly analyze the "number of Fluid Films required for chassis protection." We will also provide practical reference standards based on different vehicle models, usage environments, and construction methods. At the same time, we will share some construction tips to help you complete the protection work more efficiently, ensuring that your car remains in the best condition during daily use and in harsh environments.
What is Fluid Film?
"Fluid Film" is a rust-preventing spray developed based on "Lanolin". It is different from traditional rust coatings as it does not contain solvents or harmful substances and is an environmentally friendly and non-toxic product. Its principle is to form a persistent protective film on the metal surface, blocking oxygen and moisture, thereby preventing metal oxidation and corrosion.
In the automotive field, Fluid Film has a wide range of applications. It is commonly used in positions that are prone to moisture and salt erosion, such as the chassis, suspension system, interior of the car doors, and wheel arches. Due to its strong permeability, it can penetrate into metal gaps and welding points, providing comprehensive protection. It is particularly suitable for use in areas with heavy rainfall and snowfall or where salt is frequently applied on the roads.
Compared with traditional paint or asphalt chassis armor, Fluid Film has the characteristics of being waterproof, rust-proof, highly permeable and easy to apply. Moreover, it does not harden, crack or peel off, has a longer maintenance period, and can be easily re-applied during cleaning. For car owners who want to extend the lifespan of their vehicles and reduce rust problems, this is an efficient and economical protection solution.
Factors That Determine How Many Cans You Need
When using Fluid Film for vehicle rust prevention, the main concern for many car owners is: How many cans are needed? In fact, there is no fixed answer to this quantity; it depends on several key factors.
🚘 Vehicle Size
The size of the vehicle directly determines the protective area.
- Compact car: Usually requires 3 - 4 tanks to cover the entire chassis.
- SUV / Mid-size pickup truck: Generally needs 4 - 6 tanks.
- Full-size pickup truck or commercial vehicle: May require 6 - 10 tanks, or even more.
The larger the vehicle is, the wider the coverage area will be, and the greater the required amount will be.
📏 Coverage Area
Not every vehicle requires full chassis painting.
- Full chassis coverage: Includes the chassis, fenders, crossbeams, weld points, providing more comprehensive protection, but with a higher material usage.
- Local protection: Only targeted at areas prone to rust (such as weld points on the chassis, around the exhaust pipes), usually allowing for a 30% - 50% reduction in material usage.
🔧 Is the wheel arch / suspension system to be sprayed
Many car owners will take extra measures to deal with exposed metal parts such as wheel arches, suspension arms, and shock absorber mounts. These areas come into frequent contact with the road surface and are prone to being affected by moisture and salt. If these areas are included in the spraying range, at least an additional 1-2 cans will be required
🛠️ Application Method
The use of different tools also affects the coverage efficiency:
- Pneumatic Spray Gun: It can produce fine mist-like spraying, with uniform coverage and high efficiency. It usually can save 10% - 20% of the material usage.
- Spray Can (Aerosol Can): Suitable for DIY use, but has a limited coverage range and is prone to repeated spraying, resulting in an increase in overall material usage.
How Many Cans Do You Need?
Fluid Film Usage Reference Chart
| Vehicle Type | Recommended Aerosol Cans (11.75oz / 355ml) | Recommended Gallon (with Spray Gun) | Notes |
|---|---|---|---|
| Small Sedan | 3–4 cans | 0.5–0.75 gallon | Undercarriage & partial protection |
| SUV / Crossover | 4–6 cans | 0.75–1 gallon | Undercarriage + wheel wells |
| Pickup / Large SUV | 6–8 cans | 1–1.5 gallons | Full undercarriage + suspension |
| Van / Commercial Vehicle | 8–12 cans | 1.5–2 gallons | Larger coverage area |
👉 Tip: Aerosol cans are less efficient and provide uneven coverage. For large-scale applications, use gallon containers with a spray gun for better results.
How to Spray Fluid Film Correctly？
The correct construction method can enable the Fluid Film to achieve the maximum anti-rust effect. If the spraying is improper, it not only fails to cover evenly but may also affect the normal operation of vehicle components. Therefore, when operating, pay attention to the following points.
🧼 Cleaning Preparation
Before spraying, the chassis and wheel arches must be thoroughly cleaned. Remove sand, oil stains and salt to avoid impurities affecting adhesion. It is recommended to dry the vehicle completely after washing to ensure there is no water accumulation on the surface.
🎯 Spraying Procedure
When spraying, there should be a sequence and no omissions should be allowed. Proceed from the front of the vehicle to the rear, advancing in sections. Use the partition spraying method to ensure that every solder joint, crossbeam and corner area is covered. It is recommended to combine with an extended nozzle to enhance the coverage effect of the deep cavities.
📏 Thickness Recommendations
When spraying, it should be done in a thin and even manner. If you spray too thickly at once, it is likely to run and the coverage effect will be poor. The correct approach is to stack multiple layers and repeat the spraying after a few minutes of interval. This method can form a more stable and long-lasting protective layer.
🔧 Critical Areas
Some areas are particularly prone to moisture or corrosion and require special attention:
- The inner side of the wheel arches: The most vulnerable to erosion by sand, stones and salt.
- The welding points of the chassis: The structural connection points are prone to water accumulation and rusting.
- The suspension arms and brackets: Exposed for a long time, they bear significant impacts.
- The brake lines: Metal pipelines in contact with a humid environment for a long time are prone to rusting.
⚠️ Safety Warning
During spraying, be sure to avoid spraying onto the following areas: Brake discs and brake pads: May affect braking performance. Exhaust pipes and hot components: Likely to produce smoke or unpleasant odors.
DIY vs Professional Application
When using the Fluid Film anti-rust product, car owners often struggle with the decision: should they do it themselves or entrust it to a professional shop? Both have their own advantages and disadvantages, and the key lies in the budget, tools, and the requirements for the construction effect.
🛠️ DIY Advantages:
Advantages:
Saving money: Just one spray can is needed to get started, and the overall cost is lower than that of professional installation. Flexibility: The owner can carry out local reapplication at any time as needed. Operation is simple: No complex equipment is required. It is suitable for mild rust protection or for trial use.
Disadvantages:
Inconsistent coverage: The pressure of the spray can is limited, which can lead to uneven atomization or missed areas. More consumables: Compared to the spray gun, the spray can is less efficient and the overall usage may increase by 20% - 30%. Easy to overlook blind spots: Such as the interior of the frame, welding points, and the deep recesses of the wheel arches. These critical areas may not be adequately protected.
👨🔧 Professional Application
Professional stores usually use gallon-sized Fluid Film in combination with a high-pressure sprayer.
Advantages:
- Even coverage: The high-pressure atomization effect is excellent, able to penetrate cavities and welding areas, providing more thorough protection.
- More precise dosage: Avoid unnecessary re-spraying or excessive accumulation, resulting in higher overall material utilization.
- Time-saving: The complete construction usually only takes 1-2 hours, which is more efficient than DIY by the car owner.
- Longer-lasting: Professional construction stores will focus on handling high-risk areas and provide re-spraying suggestions, ensuring a more reliable effect.
Deficiency:
- Higher cost: The cost of a full vehicle repair is often several times higher than DIY materials.
- Low flexibility: It requires an appointment and cannot be done by oneself at any time for re-painting.
FAQ
Q1: How long can a single application of Fluid Film last?
Under normal conditions, the validity period of Fluid Film is approximately one year. If the vehicle is driven frequently in areas that are cold, snowy or where roads are frequently salted, it is recommended to reapply it once a year to maintain the best protective effect.
Q2: Can it be sprayed on the car paint surface?
It is not recommended to spray it directly on the exterior paint surface. The main application of Fluid Film is for hidden or easily corroded areas such as the chassis, wheel arches, door cavities, and suspension systems. If sprayed on the exterior paint, it will not damage the paint but will form an oil film, affecting the appearance.
Q3: Will there be any problems if I spray multiple times?
Excessive spraying will not damage the vehicle body, but it will cause dust and impurities to adhere more easily, thus affecting the cleaning effect. The correct approach is to apply thin and even layers and build them up, rather than applying a thick coat all at once.
Q4: What is the difference between Fluid Film and Rubberized Undercoating?
Fluid Film belongs to penetrating protection, which can penetrate into the crevices of metals and form an oily protective layer, and it also has a certain "self-repairing" feature, without cracking or peeling off. Rubberized Undercoating, a type of hard coating, provides good initial coverage. However, it is prone to cracking and peeling when subjected to long-term impacts or temperature fluctuations. Once damaged, it may even accelerate the spread of rust.
Veintone Expert Insights
In the daily construction of Veintone, we have accumulated a lot of practical experience regarding the application of Fluid Film anti-rust spray. Generally speaking, the amount of Fluid Film used is closely related to the size of the vehicle model. For ordinary sedans, 3 to 4 cans of spray-type Fluid Film are sufficient to cover the chassis and key parts; while for SUVs and crossover models, usually 4 to 5 cans are needed to achieve comprehensive protection.
For pickups, commercial vehicles, or those that frequently travel on salt-alkali roads and in snowy areas, we recommend a full underbody spray for the vehicle and an annual maintenance touch-up. This ensures that high-risk areas such as weld points, suspension systems, and wheel arches remain effectively protected, thereby preventing the spread of rust.
In terms of construction methods, we have found that many DIY users often underestimate the amount needed when using spray cans, and it is easy to cause uneven coverage. However, professional stores use gallon containers with high-pressure spray guns, which can not only more accurately control the amount used, but also save at least 20% of materials within the same range. This is why many car owners, after making comparisons, tend to choose professional construction.
In chassis protection, Veintone has always recommended the combination of Fluid Film + regular inspection. Through professional spraying and subsequent maintenance, we can help vehicles remain rust-free for 5 to 10 years of use, significantly extending the lifespan of the chassis and reducing the cost of later repairs.
Protect Your Vehicle with the Right Fluid Film Application
An ordinary sedan usually requires 3 to 4 tanks, an SUV about 4 to 6 tanks, a pickup truck is around 6 to 8 tanks, and large commercial vehicles may need 8 to 12 tanks. The exact amount also depends on the construction method - using a spray can is more suitable for DIY, while a professional sprayer can achieve a more even application and save materials. Overall, Fluid Film is a cost-effective undercarriage protection solution. It can effectively prevent rust and is also easy to maintain and reapply.
👉 Not sure how much material your vehicle requires? Contact the Veintone professional team, we will provide you with an accurate quantity estimation and professional installation services, helping your vehicle stay free from rust problems for the next 5 to 10 years.
Reference
how many cans of fluid film should I get?