We all know how good Bondo is at restoring bodywork from scratches and dents. However, can it get wet when exposed to water?
According to 3M, Bondo is a waterproof resin. However, after going through the experiences car owners have had with Bondo, we can conclude that it is not 100% waterproof.
Bondo can get wet. This happens when it is exposed to water for a long time. Short-term exposure, which most Bondo fillers experience, has no lasting effect. But, when Bondo is continuously exposed to water, it will absorb it and gradually become wet.
What are the odds of Bondo becoming wet and getting damaged? This will rarely occur. Therefore, if you are worried that Bondo will get wet and damaged, you can confidently apply it to your car, knowing that it is safe.
Why Doesn’t Bondo Get Wet Easily?
Before we go any further in our review, allow us to clarify the following. Bondo does get wet. It isn’t 100% waterproof. This means that long-term exposure to water will leave Bondo wet.
However, if your Bondo work is only exposed to rain or car wash water, then it won’t get wet because this exposure isn’t continuous.
With the above in mind, let’s see why Bondo doesn’t get wet easily. The reason why Bondo doesn’t get wet easily is one of the ingredients used – plastic resin. This material doesn’t absorb water.
This, therefore, makes it hard for the Bondo to get wet. The way plastic resin is formulated, it absorbs water just like a sponge does. When squeezed, the resin emits water and dries up. This plastic resin is the reason why Bondo doesn’t get wet quickly.
Moving on to the other ingredient known as talc, this material is hygroscopic. It absorbs moisture from the air. Talc counters the ability of the plastic resin.
Therefore, these two ingredients work against each other. This ingredient is the reason why Bondo isn’t 100% waterproof. Because of its hygroscopic properties, Bondo can get wet when exposed to lots of water.
How Does Bondo Remain Dry?
It’s crucial you know how Bondo ingredients work. Despite talc being hygroscopic, how is it that Bondo remains dry for long periods?
First, we have the plastic resin to thank. It counters the hygroscopic properties of talc. Secondly, the heat from the sun does a great job of keeping Bondo dry.
Even after your Bondo work has been rained on, when the sun comes up, heat dries up any moisture that may have infiltrated the Bondo.
And that’s how it remains dry for long. If you live in an area that experiences minimal sunlight, you are more likely to experience wet Bondo. This will be because there is no source of heat.
Does Bondo Get Wet Over Time?
This, for a fact, is unavoidable. Bondo will get wet after some time, and this is something that can’t be avoided.
After a few months or years, water will leak through depending on how well the Bondo was prepared and applied. And once the water comes into the picture, that piece of Bondo will soon fall off.
For Bondo to hold on to a car, it must be dry. When it becomes wet, it loses its adhesion to metal, and that’s when problems start to arise. If this happens, you can remove the damaged Bondo and apply a new one.
What Happens When Bondo Gets Wet?
Two things will happen when Bondo gets wet. We will list them in the order they will occur.
1. The Bondo will get damaged. If your Bondo is fully soaked in water, then it becomes useless. Wet Bondo can fall off, easily revealing the dent or scratch it was used to conceal.
If you notice that some Bondo work on your car is wet, prepare to repair it as soon as possible.
2. The other thing that will follow is rust. If your Bondo is letting rust in, the metal beneath can rust. This is one of the main reasons some car owners are skeptical about using Bondo as an auto body filler.
Its inability to repel moisture is a disadvantage because it will cause rust development. If you are worried about rust or live in a rust-prone area, we would advise you to go for fiberglass instead of regular Bondo made using talc and plastic resin.
What If Bondo Gets Caught in the Rain?
There are certain scenarios where you may get caught up in the rain when applying Bondo. As you curse on how unlucky you are, you may be wondering if it rain will have any effect on unfinished Bondo.
As long as you have covered the dent or scratch, you shouldn’t be worried about the effects of rain as it will wash away on the surface of the Bondo. If it had already hardened, there is even a much lower risk involved.
The problem is if it rains when you are just applying the Bondo. In such a scenario, it may get wet because it has not fully hardened.
We would recommend starting the entire process from scratch once again. Alternatively, you can find a shed and finish up on the application. If some water had gone inside the Bondo, it would have evaporated when the sun came out.
Can You Expose Unfinished Bondo to the Rain?
When performing auto body repair, you may not get everything done in one day. For instance, you can apply Bondo today and paint the vehicle the next day. Is exposing unfinished Bondo risky? Well, that depends on several things.
If the Bondo has dried up, then there shouldn’t be much cause for concern. However, if it’s still wet, you should leave your car inside away from rain or water.
There are some preventative measures you can take when dealing with unfinished Bondo. Most car owners recommend spraying primer. Though useful, it won’t make the Bondo waterproof.
It would be best if you could opt for sealant. This will keep the contents of Bondo buried away.
Is Bondo Waterproof?
Bondo is far from being considered waterproof. We can refer to it as water-resistant. Original Bondo will get wet when exposed to water. On the other hand, Fiberglass Bondo stands a better chance of keeping water at bay.
If you are using Bondo for auto body repair, you must understand Bondo isn’t waterproof. This will help you avoid any issues in the future.
How Can I Prevent Bondo from Getting Wet?
For starters, you can completely avoid driving your car in the rain or washing it. These are all impossible. Any Bondo filler in your car will get wet from time to time. That is unavoidable.
What you can do is ensure that you mix it in the correct ratio with the hardener. Bondo that is too soft can be easily swept away by water. The other thing you can do is seal it or apply primer and then paint it.
Is Rain the Reason Why My Bondo Is Sticky?
Bondo dries up pretty fast, and it should be fully cured in a day or two. However, if you realize that the surface of the
Bondo is still sticky and it had rained previously, you may think the water is the cause. Water can’t cause Bondo to be sticky, not unless it gets rained on during application.
If your Bondo is still sticky days after application, you are either working with some low-quality filler or didn’t use enough hardener.
Irrespective of the cause, you should remove that Bondo right away and apply some new Bondo.
Why is My Bondo Not Drying?
The reason for this is because you didn’t use enough hardener. Bondo by itself won’t stick to metal. It is usually too soft. However, when mixed with hardener, it dries into a durable substance.
If you didn’t get enough hardener in the mixture, you will have to remove the Bondo and apply a fresh layer. Otherwise, the uncured Bondo will fall off, and it will leave a terrible mess behind.
Can Wetness Cause Bondo to Fall Off?
Bondo absorbs water in small amounts, which quickly dries off, leaving the Bondo intact. However, if it gets super wet, it will detach from the metal and fall off.
This is why you should try to the best of your abilities to prevent Bondo from becoming wet. It isn’t very common for Bondo to fall off because of being wet. However, improper application or use of too much or too little hardener can result in Bondo falling off.
Can You Apply Dry Bondo Over Wet Bondo?
You can apply Bondo over Bondo, but we wouldn’t advise you to seal wet Bondo. When you leave moisture trapped inside, it triggers rust and corrosion. If Bondo is compromised in any manner, you should remove and apply a fresh layer.
Is It Okay to Wash Over Bondo?
If it’s fully cured, then yes, you can wash over Bondo. But, if it’s still fresh, you should avoid doing so by all means. Similar to other fillers, Bondo needs time to dry before being exposed to various elements. It’s also a good idea for you to primer and paint before washing the car.