When it comes to auto body work, body filler is by far the most misunderstood tool that technicians use. Its terrible reputation is no doubt due to countless past repairs by amateur auto mechanics and body shops who simply use way too much or try to do something they shouldn’t because they are cutting corners. That said, just because body filler (often generically referred to by trade name Bondo) has a negative association by uninformed consumers, there is no reason it should make you nervous when used properly.
The reality is that almost every good auto repair requires body filler to some degree. In fact, many cars come straight from the factory with a little bit of body filler here and there. Your car is made of metal, and metal deforms whether it’s the result of a car accident or an imperfection in the fabrication process. Once metal is deformed, it is nearly impossible to reform it and make its shape perfect again by hand. Don’t believe us? Go grab a paper clip and bend 4 or 5 times. We’ll wait…
Now unbend it and form it back into its original shape. We bet that no matter how close you come, you’ll still notice some imperfections. Guess what! Your quarter panels, door skins, front fenders, and bumpers on your car (if they are metal) behave the exact same way. When repairing a dent in a body panel, it is possible to get the shape pretty darn close, however you will still notice minor imperfections no matter how close you come. Fortunately, unlike the paper clip, when it comes to auto body work you can rely on body filler to smooth out any remaining imperfections to make a car look as good as new again!
What Is Body Filler?
Body filler is a general term for a series of products that are designed to smooth out small deformations and imperfections in auto body work. There are numerous different types that have different styles of application. In the past they were typically lead based however many of the more modern body fillers are plastic based and are easier to use. Some old school guys consider lead to be indicative of high end repairs, however in reality you won’t ever notice any difference after you have painted over either type. Body fillers are also tailored to interact well with the material they are intended to fill. Many auto body panels are made from steel, aluminum, and fiberglass. As such, the best body fillers are designed for specific panel materials so it’s important you understand what type of material you intend to fill.
Body filler comes in a variety of textures ranging from texture like mud to clay to paste to putty. There are a variety of tools used to apply it such as spatulas, squeegies, putty knives, spreaders etc. It also requires significant sanding using sanding blocks to blend and shape once it has cured.
The Best Body FIller
The best body fillers are the ones that are easiest to work with and are the most robust. The easier they are to work with, the better your end product is going to look. The more robust they are, the less issues you will encounter with the repair in the future. Below are our favorites to help guide your decision.
Evercoat Rage Body Filler
Our favorite line of body fillers is the Evercoat Rage line. This product line contains the 105 Premium Lightweight 105 Body Filler, the 120 Xtreme High Performance Body Filler, the Ultra Body Filler, and the Gold premium Lightweight Filler. These are all actually more similar than you’d expect; the main differences are various additives that change sanding and application characteristics a little bit. They also have differing likelihoods of drying issues such as voids and pinholes (although all of them are pretty good about this). All of them serve quite well and which you use is going to be ultimately decided mostly by budget and in part by preference.
Overall they are easy to work with, easy to apply, and easy to sand down after curing. Evercoat products are usable over fiberglass, steel, aluminum, and plastics. The usual sizes are either a quart or a gallon (which is a pretty considerable amount). As mentioned earlier in the article, less is more when it comes to body filler so you probably won’t need a whole gallon (and Lord help you if you do). As such, you can expect many repairs out of one can.
Bondo Autobody Filler
That’s right, Bondo. It’s legit. We know people have animosity against Bondo because people throw the word around when describing bad repairs. Don’t believe these people. Bondo is fine.
Bondo is an old standby in the automotive industry. It has been used for quite a long time. The reason that people refer to auto body filler as “Bondo” on occasion is because it is extremely widely used. Like the Evercoat, it is easy to spread and easy to work. It has high durability and you can count on it to last. It cures nicely with minimal shrinkage. You can also expect that you will avoid voids and pinholes similar to the Evercoat if you properly apply it.
Overall it’s a great product and will produce excellent results if you know what you are doing, just as well if not better than competitive products out there. So we repeat one last time, there is no reason to be afraid of using Bondo. It will do the job and do it well, trust us on this one.
So there you have it, we hope this guide has steered you in the right direction when it comes to picking the best body filler for automotive work. We should also note for posterity that body filler can be used for a variety of other applications around the home and is not just limited to cars, but that’s a topic for another article. While we have picked the best body fillers in our opinion, there are lots of options out there to choose from so we suggest you take a look at what the market has to offer by clicking here if you aren’t convinced that our suggestions are right for you. Thanks for reading and happy wrenching!