Have you ever walked out to your car and wondered what that funny little thing was on the rocker panel?
Then discover that it’s rust?
Your first instinct may be to buy a new car. Then you look at new car prices.
Your next thought is probably a body filler.
All brands and types are often erroneously referred to as Bondo. It’s a popular way to make small repairs without suffering through the expense of replacing an entire panel.
There are pages and pages of online jokes about “Bondo.” The truth is that it’s a great solution to small problems. Why pay to replace the entire rocker panel and a paint job for a small one square inch of rust?
Of course, you want to make sure that you use the best possible product and apply it correctly.
I may not be able to explain all the different ways to apply and use body filler in such a short space. But I can recommend some of the best body fillers.
Maybe you need a body filler for a rusty panel or even a wood application. Perhaps you have a fiberglass body or a marine application that’s waterproof. I’ll give you the low-down on body fillers and which will work best for each application.
What body filler do the pros use?
This is difficult to pin down. It’s like asking 100 different people which car model or even which car make is best! Everyone has an opinion depending on the application.
Ask professionals and one name you are bound to hear over and over is Bondo. Whether it’s Bondo 261 or the Bondo Hair with Long Fiberglass Fibers, these names come up over and over again.
If you speak to those who work in boatyards, you might hear the name Duraglas. It is the best nearly waterproof body filler.
Evercoat products are also commonly mentioned.
The product that is the best will depend on the application you want it for and your own draw to a certain brand.
If you read carefully, you will surely find the best product for whatever it is that you are working on.
What is the strongest body filler?
Evercoat Everglass Reinforced Filler is the strongest and hardest body filler around.
It’s reinforced with the same product used in body armor, Kevlar. This is still a lightweight body filler that is, well, hard as a rock! Try it once and you will see what I mean!
If fiberglass reinforced fillers are stronger than regular plastic-based fillers, then a Kevlar fiber embedded filler must really be extra strong.
Don’t get me wrong, fiberglass fibers are excellent since they do not absorb water. Technically Kevlar fibers will absorb some water, but only if they are exposed. Once they are embedded into the filler, they are every bit as waterproof as fiberglass.
Many boats and kayaks today are made from a sandwich of fiberglass and kevlar and held together with resin.
Kevlar is the stronger material and it’s lighter than fiberglass pound for pound.
But since Kevlar is stronger, this means it is the devil to sand and smooth. You should work in very small batches and try to smooth the product out before it hardens.
Kevlar is also more expensive than fiberglass. The best always costs more, right?
Don’t forget to wear the proper protective gear when sanding! Dust from body fillers, whether they are plastic, fiberglass, or Kevlar, is not good for the lungs.
Is Bondo body filler any good?
Yes, Bondo is an excellent product.
The problem with the Bondo name is that it is commonly used to refer to all types and brands of body filler. Even whether it is a Bondo product or not.
This means that even the cheapest junk body filler will be called Bondo. This unfortunately means that the Bondo name gets dragged through the proverbial mud when the product fails.
This is similar to the way that cotton swabs are all called Q-Tips and tissues are often called Kleenex. Q-Tip and Kleenex are brand names, not the name of the actual product.
Of course, you might find some who don’t happen to like the Bondo brand of products. That’s their opinion and they are entitled to it.
But if you find a better product than Bondo, you should use it.
Bondo was introduced in 1955. The original formula, 00261, is still the number one, best-selling body filler today.
That’s nearly 70 years of being number one. Bondo must have something going for it!
Does body filler last long?
This is another difficult question. Does a pair of shoes last long? That would depend on what they were used for, what they were made from, and how well they were taken care of, correct?
The same is true of body filler.
Making body filler last longer depends on the application and how it was applied. For example, body repair on a classic car that mostly sits or a water tank that is left outside in extreme temperatures. One will last longer than the other.
Prepping the surface is of the utmost importance. A surface that is dirty, rusty, or contains contaminants won’t allow the filler to stick properly.
It can last for decades when the surface is properly prepared. The filler must be added in a sufficient amount but not to excess. It should be properly sanded, primed, and painted. That’s how you get it to last a long time.
Also, the quality of the filler will matter. Shoes from the dollar store won’t last more than a few outings right?
The same is true with fillers. A super cheap filler with no name or an unknown name will give you unsatisfactory results.
A poor job in any of the above workmanship areas can give bad results. It can mean that the filler will crack or even have small chunks fall off, in a matter of months.
How do you apply body filler smoothly?
This is something that takes practice. But if you are careful, even a beginner can pull off a basic body repair.
Make sure that the surface is well-prepped. Be sure that your surface is clean of dust and grease, and that it is fairly flat. Use a straightedge if you must.
Apply a base coat of epoxy primer and then use fine sandpaper to feather out the edges of the paint.
How much of the product you will mix will depend on the size of the repair and how fast the product cures. For an average-sized repair, try mixing up an amount that would equal a typical sandwich on white bread.
Applying the filler smoothly is something like icing a cake. You should wipe or sweep from side to side, don’t dab at it or slap on a big glob.
Unfortunately, you don’t have a great deal of time to play with most products, so put it on and get to work fast!
Body Filler Tips
Body filler isn’t nearly as complicated as it sounds. Do your prep work, pick a quality product, and you will be surprised at how well your project turns out!