Knowing the appropriate auto body fillers to use is extremely helpful while repairing dents and restoring cars' bodies. Ideally, the polyester resin in a filler helps repair dents, but all fillers are not created the same. Considering that no one would like a poor body repair job, we recommend using the best body filler for the best restoration jobs.
As such, we have prepared an informative guide on finding quality fillers for exemplary body repairs. Ranging from scratches and shallow dents to rusty bodies, there are fillers for everyone. However, before you decide to work for a low price, let's first understand the different filler types there are for an objective choice.
Types of Car Body Fillers
Body fillers are primarily categorized based on the consistency quality or reinforcing materials. Beyond this categorization, body fillers are also ranked based on other functionality features. For example, fillers are further categorized based on curing time and ease of use. Nonetheless, here are the most common types of fillers as per the primary criteria.
1. Standard-Grade Body Fillers
Standard-grade fillers spread easily and cure fast. Accordingly, they're applicable in repairing minor dents and body scratches. As the start point for fillers, this type offers the least stain resistance and minimal adhesion properties. Generally, these fillers are of low standard with low workability, thus low prices.
2. Medium-Grade Body Fillers
Even better, medium body fillers are more suitable for high-productivity works. Such fillers are commonly used in small repair shops since they adhere to many surfaces, sand easily and have better stain resistance.
3. Premium-Grade Body Fillers
On top of the ladder, premium fillers come with top-notch resins for superior adhesion and other top qualities. Some of the top qualities in this category include quick curing, high stain resistance, easy sanding, non-shrinking, non-clogging and high durability. Accordingly, these fillers are ideal for intensive body restoration and repairs. These fillers also come with a wide workability spectrum, matching their premium quality.
Reinforced fillers come with strands of carbon fiber, metal fiberglass or Kevlar. Unlike lightweight body fillers meant to fill pinholes and repair very small dents, the reinforced type is for major repairs. Additionally, the reinforced type is also harder to sand than regular fillers. Besides knowing reinforced filler, we offer wrecker services to move wrecked cars that require major restorations.
1. Metal Body Fillers
These fillers contain metal particles for strong bonding on metal bodywork. Also, metal body fillers don't shrink after curing, saving you the stress of reshaping painted surfaces. In addition, these fillers repair deep dents and last very long with a smooth finish, thanks to the metal reinforcements. However, any metal body filler comes at a hefty cost to cover for its premium qualities.
2. Fiberglass Body Fillers
Fiberglass fillers, on the other hand, contain metal and fiberglass particles. As a result, this mixture makes the best body filler workable on a wide range of surfaces. Accordingly, fiberglass body fillers are very tough and extremely durable.
Due to their quality, these fillers are used on large-scale repairs for outstanding outcomes. Additionally, a fiberglass filler is water-resistant and is effective on rusted areas. However, this type isn't the easiest to sand. Also, a fiberglass filler requires heat treatment to cure properly, thus requiring more input but eventually providing a smooth finish.
Which is the best body filler?
Buy on Amazon
1. Bondo Glass Reinforced Filler
- Ideal for repairing rust-out and rust hole repairs.
- Covers small (up to ½”) holes without the need for backing...
- Bondo Glass Reinforced Filler formula is stronger than...
- Ideal to repair metal, wood, concrete, masonry and fiberglass.
- Sandable in as little as 20 minutes for quick repairs
The best body filler on our list is the Bondo Glass Reinforced Filler. Matching its top ranking, this auto body filler provides premium performance when refilling and restoring damages on your car. In particular, this auto body filler can be used on rusted areas, repairing dents and as a foundation in a car's body holes. Read on to understand why this car body filler is the best.
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Functionally, this body filler is reinforced with short fiberglass strands that interlock for better filling strength. As such, this filler is twice stronger than other car body fillers due to its thickness and fast-drying feature. As a body repair kit, it also comes with a red Cream Hardener, compatible with this filler. Subsequently, you won't require backing cloths, fiberglass strips or resins as you repair holes.
In our firsthand experiences with this filler, it dries very fast, and you can sand it in under 25 minutes. More to its impressive performance, it's simple and convenient to mix. At all stages, you don't have to worry about messy car body-filling exercises. Notably, we realized it's more effective to apply this car body filler downwards or vertically for the best outcomes.
Overall, this exceptional filler fills up to 1/2 an inch of dents and is compatible with most paint systems of cars and boats. Additionally, it's also compatible with standard fiberglass repair tools complementing its ease of application. We recommend removing rust and paint as well as pulling dents before using this body filler to mask the affected areas. By all standards, this Bondo Glass Filler exceeds other fillers in the markets for repairs on vehicle exteriors.
2. Bondo Body Filler Original Formula
- Original formula for repairing dents, dings, holes, large rusted...
- Two-part lightweight compound mixes easily and spreads smoothly
- Spread easy and cures in only 20 minutes for same day repairs
- Formulated to be non-shrinking
- Suitable for wood, steel, aluminum, fiberglass, and concrete
Another great alternative to fill scratches, holes and dents is this original body filler by Bondo. Kidding you not, the manufacturer has created this filler to provide you with a captivating car's exterior post dents and scratches. As such, this body filler is ideal for repairing bare metal, wood and concrete surfaces as well as repairing fiberglass. To further understand how this filler restores the original beauty of your car's exterior, here are more details on its composition and action.
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To start with, this filler is made up of a two-part putty compound that contains a liquid hardener and premium resin-based filler. Ranking second is no easy feat for an auto repair product and thus its ability to repair virtually any type of car body damage. Also, as one of the best body fillers, this Bondo filler is non-shrinking and highly durable. Thanks to its effective filler compounds, it dries fast and takes the shape of the target area pretty quickly.
Furthermore, it's also compatible with a wide range of paint materials and application tools, making repair work easy. Finally, as a quality filler, it will allow you to apply your desired coats depending on the damaged being masked. Fortunately, it also comes with a guide on how effectively use it while leaving you with the discretion for different damages. Overall, this is an ideal filler with fast-acting compounds that effectively restore your car to new.
3. Permatex Liquid Metal Filler
- Works on metal, wood and concrete
- Excellent adhesion to galvanized metal
- Repairs cracks or porosity leaks in cast metal parts and fills...
- Resists water, oil and gasoline
- Suggested Applications: Oil pans, stake bed holes, door panels,...
Coming in third is the Permatex 25909 liquid metal filler, known for its outstanding damage masking qualities. Ideally, this auto body filler is versatile for bonding dents on different surfaces, including concrete, wood and galvanized metal. However, notwithstanding its versatility, it works perfectly on car bodies with a reliable adhesive. Here are specific details for a better perspective on this Permatex liquid metal filler.
Permatex 25909 liquid metal filler is a non-shrinking formula that is vacuum processed for smoothness. It is very adaptable during the application, meaning it easily takes the shape of the affected area, regardless of the damage in context. In most cases, it is used for repairing cracks and sealing leaks within a car's cast metal body. Once hardened, this filler is incompatible or resistant to gasoline oil and water, meaning it cannot be removed easily.
Image Credit: Permatex
Additionally, the 25909 Liquid Metal Filler is compatible with different paints and application materials. Nonetheless, before application, you must ensure your target surface is clean and free from oil and grease. Thereafter, you can make your target surface slightly coarse for best bonding outcomes. In the end, you can drill, fill, sand and paint the masked surface for an impressive restoration.
4. Bondo Body Repair Kit, 00312
- Do-it-yourself auto repair kit makes for durable same-day repairs
- Easy to use – includes step-by-step instructions
- Ideal for repairs from large holes and rust-outs to deep...
- Includes reliable materials for mixing and cleanup
- Featuring Bondo Body Filler, the original filler used by...
Next on our list is yet another Bondo body filler, the 00312 car body filler kit. Most impressively, this filler can be used on different surfaces, including galvanized metal, concrete and wood. As a popular choice by experts, you can be sure this filler will do an incredible restoration similar to the original build.
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Thanks to its outstanding ingredients, this car body filler is effective in repairing scratches, rust holes and dents, among others. Specifically, this kit comes with the original Bondo filler, Red Cream hardener, a self-adhesive patch for metal bodies and a spreader. Featuring such content, it's also easy to mix and apply, thanks to its step-by-step application instructions. Post application, this filler strongly bonds and easily takes shape, living up to its hype of impeccable masking.
In addition, this filler made it to our list of the best since you can apply it to both car's body and its panels. Eventually, this filler stays strong and lasts for long, if not permanently. Therefore, if you are looking for a filler with flawless outcomes, this car body filler is the right choice for you.
5. Evercoat Lite Weight Body Filler
- Auto Body Filler: Smooth spreading and easy sanding formula
- Superior Adhesion: Chemical bond to cold rolled and galvanized...
- Includes Blue Cream Hardener: Forms a nice consistency when mixed...
- Clog-Free Formula: Lightweight car body filler that does not...
- About Evercoat: We lead the industry in the use of “green”...
Last on our list is the Evercoat Lite weight body filler. Despite coming last, this product is a premium filler thanks to its top-notch quality. The manufacturer has made sure you will absolutely marvel at its stylish and outstanding outcomes. Subject to such a reputation, read on for its details.
Accordingly, this car body filler is effective in dealing with holes, scratches and rust. Nonetheless, it doesn't handle rust as well as other preceding fillers on this list, but it can still be adequate. That aside, it is effective for repair and restorations for eventual fanciful appearances. Fortunately, this exquisite filler is compatible with most car models and paint regimes.
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In addition to its unparalleled functionality, this is the best car body filler on our list for hobby projects. Its step-by-step guide leaves nothing to chance in providing satisfactory self-application outcomes. Even so, users should always ensure the filled surface is uniform, smooth and seamless before repainting.
In the end, this filler is strong, clog-free and durable. During application, it spreads easily and requires minimal sanding after drying. Even more, it cures fast with strong adhesive outcomes. Therefore, we recommend this product for the best car body filling outcomes.
How to Choose the Best Body Filler
With Your Car
The best body filler should be compatible with the car being repaired. Fortunately, most car body fillers are specifically made to bond with galvanized steel, fiberglass, Sheet Molding Compound (SMC) and aluminum, most common on car bodies. Bearing this in mind, some body fillers don't work well with metal surfaces. Therefore, top-rated car body fillers are compatible with multiple surfaces easing stress on the probing.
With Paint Systems
Also, a good body filler should work well with a wide range of paints. Moreover, your select filler should adhere properly to painted or sanded surfaces. Therefore, the best car body filler shouldn't peel off after drying and sanding. Alongside painting, a good body filler should bond well with plastic covers like bumpers without peeling off.
2. Ease of Use
The best car body filler should also be easy to use. Use in this case might refer to multiple processes, including mixing, spreading and sanding. By all standards, a good body filler is not ideal for use if it's not easy to use despite having the best formulation.
Whether using a one-part or a two-part body filler, always follow the manufacturer's instructions with the recommended ratio for a smooth consistency. Even so, a one-part body filler is less hectic to use but might be too lightweight for the intended use. After mixing a body filler, it should dry fast, moreso on a vertical surface.
Eventually, a good body filler should be easy to smoothen. Lightweight fillers are also easy to smoothen or sand and often require minimal sanding. Luckily, most filler kits come with mixing boards and equipment for mixing body filler ingredients effectively. In most cases, you can improve on the ease of use with more practice.
3. Curing Time
Moreover, a quality body filler should take less time to dry or cure. This feature ensures that car body repairs and restorations are done efficiently without wasting time between the processes. As such, the curing time should also be efficient on other metal surfaces besides a car's body, including fiberglass, concrete and wood.
In line with fast curing, a good car body filler should be able to provide strong bonding on its target surface. Therefore, it should be strong enough to reinforce its ability to cure fast. In the end, strong adhesion will facilitate efficient follow-up processes like sanding.
4. Stain-Resistant and Non-Shrinking
The best body fillers should also be stain-free to avoid ruining the paint repairs and restorations. Accordingly, we recommend using a filler that minimizes paint bleeds and provides consistent finishes. At best, adequate drying time ensures your filler remains resistant to stains. For classic car restorations, we offer flatbed towing for easy movement to restoration shops.
In addition to non-staining, the best filler for vehicle exteriors should come with a non-shrinking formula. This feature ensures that the putty contents will take and retain shape easily even after drying. Therefore, non-shrinking properties play a critical role in making a filler permanently durable.
Different fillers come in different quantities. As such, it goes down to the auto repairs at hand and how much filler they would require. It goes without saying that a small repair will require a small quantity while vice versa is true. In tight budget situations, you can go for a filler amount that will be enough for the job at hand.
For instance, if you are working on scratches on galvanized steel, you might require a few filler tubes. On the other hand, you might require filler cans when filling large holes and rusty areas. Nonetheless, buying a larger quantity is more economical in the long term as long as the filler has a long shelf-life. Overall, ensure you store your filler properly if it remains.
Tips and Tricks for Car Body Filler Use
- Always mix filler and hardener in the correct ratio as recommended by the manufacturer. This precaution will ensure you achieve the best consistency for the best repair outcomes. For instance, too little ratio will delay curing and hardening, while too much hardener will cause the mixture to crack when dry.
- Always remove rust before applying a filler. Applying filler over rust eventually causes the final results to pull away.
- Don't mix fillers on cardboard. Some filler components might have absorbent properties that might corrode the cardboard. Ideally, use a non-absorbing and hard surface for filler mixing.
- Always apply filler to a rough surface. A sanded surface provides a better grip and bonding depth for enhanced adhesion strength.
- While using glazing putty, always allow the filler to dry before sanding. You will know it has cured properly when it powders during sanding.
- As such, wear a dust mask while sanding and painting. This will prevent you from inhaling the harmful dust and paint.
- Always apply body filler to thicknesses of 1/4 inch. Even a high-quality filler will crack when dry if it goes beyond this thickness. In cases of deeper dents, you can first implement metal works before filling.
Frequently Asked Question on the Best Car Body Fillers
1. Is fiberglass stronger than Bondo?
Indeed, filler reinforced with fiberglass has more adhesion than the Bondo type. As such, the former is more durable than the latter. Nonetheless, fiberglass fillers always come at a hefty price.
2. Is fiberglass repair waterproof?
Indeed, fiberglass fillers are waterproof. Regardless of the fiberglass resin used in a filler, it should, at the minimum, be waterproof. Therefore, fiberglass fillers are better than ordinary water-resistant fillers.
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