Bondo For Concrete Cracks (A Comprehensive Guide)

Cracks in concrete are inevitable. No matter how careful you are, cracks will always develop on concrete surfaces. What you can do is learn how to repair these cracks, whenever they occur.

Now, Bondo is mostly associated with automotive repairs. But did you know that it can also be used on other materials like wood, aluminum, fiberglass, stone, and concrete?

Today, I will be taking you through the methods of how to use Bondo for concrete repairs. I will also leave you with some tips and alternative methods of fixing cracks in concrete.


Can You Use Bondo for Concrete Cracks?

Bondo can indeed be used to repair small cracks in concrete. This two-part epoxy putty can penetrate the tiny cracks in your concrete and fill them in as it dries.

Bondo adheres perfectly well to concrete as it does to metal. What I love about Bondo is that it can also be painted to match the finish of existing concrete. Therefore, besides sealing cracks, it can also make your concrete floors or walls look better.

How to Use Bondo for Concrete Crack Repair?

When it comes to filling concrete cracks with bondo, it’s a relatively easy process. Here is a step-by-step guide that is approved by professionals;

Step 1 – Thoroughly Clean the Concrete Crack

Depending on how long the crack has been there, it may have lots of dirt and impurities. The presence of such contaminants can affect bondo’s adhesion to concrete.

Start by running a high-pressure water spray on the cracks. That will remove dirt particles and loose concrete. After cleaning a concrete crack, don’t rush to apply the Bondo. Wait for it to dry first.

Step 2 – Mix the Bondo

Because it’s a two-part epoxy, Bondo has to be mixed with a hardener. Make sure that you use the ratios recommended by the manufacturer. If you use too much hardener, the Bondo may not work effectively, and vice versa.

Step 3 – Fill the Bondo into the Crack Using a Putty Knife

Grab a putty knife and start stuffing the Bondo into the concrete crack. Because bondo turns into a smooth paste after being mixed, it should be easy to spread. Ensure that it gets as deep as possible into the crack.

Step 4 – Let It Dry

Give the bondo enough time to dry. The environment will determine how long this takes. If it’s too humid, it might take longer for the Bondo to cure.

Step 5 – Touch Up the Bondo

After it dries, you can now touch up the surface so that it resembles that of the concrete. This entails sanding and painting the surface to make it look better. With a few touch-ups, the crack should be completely sealed and repaired.

Why Use Bondo for Concrete Crack Repairs?

As you may already know, there are plenty of other products that you can use to repair concrete cracks. I will discuss these alternatives later on. But for now, let’s focus on the benefits of using bondo for concrete crack repairs;

The application process is effortless. From the method described above, you can confirm that the application of Bondo on concrete cracks is relatively easy. You don’t need any special skills, tools, or knowledge.

Bondo is extremely durable. When you fill a concrete crack with Bondo, it can last for years. This is unlike other products that can chip easily when exposed to the elements.

Bondo also dries pretty quickly when applied to concrete cracks. After filling in the cracks, bondo dries within a few hours and the affected area can be opened up for traffic.

You can use Bondo to repair cracks on both interior and exterior concrete surfaces. This versatility makes it a top choice for property owners dealing with cracks on the inside and outside.

Using bondo to repair cracks on concrete is quite affordable. Bondo itself is an inexpensive product. Also, the fact that you don’t need to hire an expert to apply it for you reduces the repair costs significantly.

Bondo can be painted and finished to match the existing concrete. This comes in handy as it ensures the repairs look more aesthetically pleasing.

Are There Drawbacks of Using Bondo for Concrete Cracks?

Unfortunately, there are a couple of drawbacks associated with using bondo for concrete cracks. Familiarizing yourself with these drawbacks is crucial.

Bondo only works for smaller concrete cracks. If you are dealing with a huge concrete crack, look for other alternatives.

The other issue is that bondo is rigid when it dries. Concrete experiences a lot of movements. Due to Bondo’s rigidity, it may crack when exposed to excessive movements.

If your concrete is finely polished, bondo may not properly adhere to it. To be guaranteed sufficient adhesion, only use bondo on rough concrete.

Using Bondo for concrete cracks isn’t a long-term solution. Compare to seeking professional repair services, Bondo is more of a quick fix that won’t last for the next few years.

How Does Bondo Compare to Other Concrete Crack Repair Methods?

Earlier, I mentioned that Bondo isn’t the only product you can use to repair cracks in concrete. There are plenty of other products and methods out there. So, here are the top alternatives to using bondo for concrete crack repairs;

• Injecting Epoxy – When you approach a licensed concrete company, this is the method they will use to fix the cracks on your concrete floors.

This method entails injecting an epoxy resin into the cracks. This resin bonds firmly to concrete and can last for decades.

• Concrete Crack Sealants – There are special sealants out there that are formulated for use in cracked concrete. These sealants are available in silicone or polyurethane. Unlike bondo, these sealants can flex to accommodate the structural movements of concrete.

• Concrete Patching Compounds – These are just like sealants but they are available in cement, polymer, and latex. What makes concrete patching compounds stand out is that they offer unrivaled adhesion.

Each of these methods has its pros and cons. You should take the time to evaluate which one seems more ideal for you.

Bondo is a cheaper and quicker repair solution for concrete cracks. However, an epoxy injection is more durable and long-lasting. Whereas sealants offer better adhesion.

What Types of Concrete Cracks Are Suitable for Bondo Repair?

Bondo wasn’t formulated to fix all types of cracks. It’s only effective for narrow, shallow, and smaller cracks. You can use Bondo to fix non-structural cracks, surface cracks, hairline cracks, and minor chips on concrete. As for large cracks, you will need to explore professional repair methods.

How Long Will Bondo Last on Concrete Cracks?

A well-applied bondo epoxy can last for years on concrete cracks. To emphasize what I mentioned earlier, Bondo is highly durable and it can withstand bad weather. But you have to understand that it’s not bulletproof.

Movements within the concrete can widen the crack thus making the bondo ineffective. Also, if a concrete surface is constantly exposed to bad weather and high traffic, it will eventually collapse.

The other factor that can shorten the lifespan of Bondo on concrete cracks is poor application. Mistakes such as not adequately filling the concrete crack or not preparing the bondo correctly can result in premature failure.

To prolong the life of Bondo on concrete cracks, you can consider covering it with a special sealant.

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