Car Paint Chipping or Bubbling? 8 Common Issues & Fixes

Car paint bubbling (and chipping) is a common problem among car owners. Knowing the most common issues to look for, and how to fix them, will keep your car paint from bubbling and chipping in the future.

Chipping and bubbling are two different categories of paint damage. Bubbling occurs because of an issue under or inside the paint while chipping occurs from an outside source damaging the paint.

We’ll look at these two categories separately to avoid confusion.

#1 – Your Car Was Painted In A Humid Area

Your car’s paint should be applied in a controlled area, which is why most professionals opt to use a paint booth that can keep a steady temperature and humidity level. High temperatures can cause paint to dry faster than expected, and high humidity can force moisture into the paint while it is drying.

This combination can trap moisture in a paint layer and cause a bubbling effect as the moisture expands as it cools.

As you probably know, a good paint job prevents rust on your car.

How to Fix It

Your best option to prevent moisture from being trapped by high temperatures and humidity is to use a controlled environment for painting. Each paint manufacturer has recommended temperature and humidity guidelines when using their products. If you find bubbling is starting to occur, the fix is to remove the paint until you reach the trapped moisture.

It must be allowed to evaporate and the paint reapplied correctly.

#2 – Too Much Paint Was Applied And Trapped Moisture

This is another case of moisture being trapped in the paint layers but for a different reason. If you have watched a professional painter work, they never stop moving the paint gun. Pausing in one area for too long can apply too much paint. You can also apply too much paint with an incorrect setting on the paint gun.

In either case, too much paint can trap moisture and solvents in the paint and cause bubbling later.

How to Fix It

Practice makes perfect with paint application.

A professional painter will practice applying paint to ensure the gun isn’t spraying more volume than required. A second reason to practice is to ensure a smooth steady path can be attained for continual paint application. If too much paint is applied, it needs to be removed before another layer is painted and traps moisture and solvent.

#3 – The Drying Process Took Too Long

Drying paint correctly involves the right temperature and humidity. For a given temperature and humidity level, paint is estimated to take a certain period of time for the best results. If that time is too long, there is a chance that moisture will be trapped inside the paint. This typically happens when the temperature is too low, and the paint doesn’t dry fast enough.

How to Fix It

The easiest way to prevent the paint from drying too fast or too slow is to only paint in the recommended temperature range from the manufacturer. If you are painting in an outdoor setting, only paint when the temperature is close to the manufacturer’s recommendation.

A paint booth is a better option as it should be easier to control the temperature in the surrounding air for proper drying time.

#4 – Bare Metal Was Left Exposed

Many times, a complete paint job will start from bare metal before applying filler or sealing materials.

Once bare metal is exposed to moisture in the air, the race is on to seal it before moisture and debris adhere to the bare metal surface. If a bare surface is allowed to sit for hours, there is a high likelihood that moisture and debris will cause bubbling paint later.

How to Fix It

The easiest way to fix this issue is to prevent it from happening. Don’t leave any bare metal surface exposed for long. One hour can be too long with the right temperature and humidity conditions that will promote corrosion. It’s best to immediately seal a bare metal surface and not allow moisture and debris to set in.

#5 – Your Painter Used Low-Quality Paint Thinner To Save Money

The paint on your car has to be thinned when it is applied. There are multiple brands of thinner available, but low-quality thinners will add cost rather than save money. These low-cost brands shouldn’t be used on high-quality paint as they create more problems with bubbling and poor paint adhesion.

How to Fix It

There are areas to save money on a paint job, but paint and thinner shouldn’t be included on that list. Spend money on quality paint and thinners that have a proven reputation for high-quality results.

#6 – Each Paint Layer Isn’t Allowed To Fully Dry

The last issue that causes bubbling to occur is not allowing each layer of paint to fully dry before spraying the next layer on. Paint jobs start with a sealing coat of primer that covers the bare metal before the paint color is applied. Layers of color are then applied one by one until all color layers are applied, and then a final layer of clear coat seals the paint. (Most cars have clear coat paint)

Each application layer of primer, color, and clear coat must be allowed to dry, or it will trap moisture. This moisture can freeze in low temperatures and will cause bubbling.

How to Fix It

Each layer of paint must dry before the next layer is applied.

Paint manufacturers have recommended drying times based on the temperature and humidity you are painting in. Follow the recommendations, and you should have a beautiful paint job when done.

#7 – Your Paint Is Chipped From Debris

Chipped paint happens from debris or another external source causing damage. This could be rocks on the road from another car’s tires, bugs, birds, deer, or UV exposure from the sun. Chips are usually very small, but they can create a lot of damage if left untreated.

How to Fix It

Chips happen in small, localized areas that can be repaired by removing the damaged paint and repainting the area. Some chips damage the paint layers down to the primer or bare metal. Others will just damage the top layers of the paint.

#8 – Your Paint Is Delaminating In Large Flakes

The last paint issue that occurs is delamination.

It’s not technically a bubbling under the surface or a chip from an external source, but delamination happens frequently. Delamination occurs because the sun’s ultraviolet (UV) rays begin to disintegrate or degrade the paint layers. They will slightly bubble and peel off in large pieces due to prolonged exposure to UV rays.

How to Fix It

Delamination can happen if the paint and clear coat aren’t fully cured before they are exposed to the sun’s UV rays and the environment. Most paint facilities will allow a car to sit in a warm area for a period of time to allow the paint layers to fully cure. This will ensure everything is dry.

If this step is cut short, it could later lead to delamination.

Beyond the curing of the paint, an ounce of prevention of the paint with a wax coating will protect the paint’s surface from UV rays and the environment. A wax or a coating can be applied on a frequent basis to prevent paint damage. There are also protective films that can be applied to the painted surface to prevent chips from road debris.

In all cases of bubbling paint, chipping, or delamination, the repair process is the same:

1. Remove the bubbling paint. This can be done by sanding or with a scraping tool.
2. Clean the surface with mineral spirits or a cleaning agent and allow it to fully dry before moving to step 3.
3. Apply a primer coat to seal the area affected and allow it to dry.
4. Apply a mixture of body filler and hardener as required to fill in small imperfections on the surface.
5. Smooth the surface by sanding the filler.
6. Apply paint and clear coat to complete the paint repair.

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