What Causes Fish Eyes In Paint? Discover The Common Culprits

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Have you ever finished painting a surface only to notice strange, crater-like imperfections on the finish? These tiny circular blemishes are known as “fish eyes” and can be quite frustrating for anyone attempting to achieve a smooth and flawless paint job.

While there are several factors that can contribute to fish eyes in paint, most of them revolve around one key issue: contamination. Whether it’s from oil, silicone, or other foreign substances, any type of impurity on the surface being painted can result in undesirable finish textures.

In this article, we’ll delve into some common culprits that cause fish eyes in paint. We’ll explore how each factor affects the final outcome and what steps you can take to prevent these annoying imperfections in your future projects. By understanding the root causes behind fish eyes, we hope to equip you with the knowledge needed to produce beautiful, high-quality finishes every time.

“Painting is just another way of keeping a diary.” -Pablo Picasso

So grab your brushes and let’s dive into discovering what causes fish eyes in paint!


Fish eyes in paint are a common problem that can occur when contamination is present during the painting process. This type of defect appears as small, circular craters or depressions on the painted surface and result from an interruption in the flow of the coating material. Understanding the various types of contaminants that could cause fish eyes in paint can help prevent these defects from occurring.

Presence of Dirt and Dust Particles

Dirt and dust particles are common culprits when it comes to causing fish eyes in paint. These tiny particles can easily find their way onto painting materials like brushes, rollers, and spray guns, potentially resulting in contaminated paint. Using cleaning solutions to thoroughly clean your tools before starting the painting process can help reduce the frequency of dirt and dust particle contamination issues.

Contamination from Chemicals or Solvents

A number of chemicals commonly used in painting products, such as solvents and thinners, can also lead to fish eye formation if they come into contact with other materials used in the painting process. This happens because certain chemicals react differently than others, leading to breaks and separations in the coating material. Be sure to read all product labels carefully and limit exposure of such substances to each other.

Bacterial Contamination

Bacteria can sometimes contaminate paint and cause fish eye defects to form. Bacteria thrive in warm and moist environments and may be introduced by using unclean containers for storing paint or leaving brushes soaked in water. Prevent this type of bacterial growth by making sure all containers used to store paint are tightly sealed – even if you only plan on taking a break between coats – and avoid submerging brushes stem-first into buckets of water.

Mold and Fungal Growth

In some cases, mold and fungal growth can also be the source of contamination that leads to fish eyes in paint. This type of mold is typically carried by spores that easily float through the air and attach themselves to surfaces. To prevent this issue, use paint with anti-mildew properties in spaces where high humidity levels persist or there has been a previous history of mildew issues.

  • Summary:
    • Fish eyes in paint are caused by interruptions during the coating process.
    • Dirt and dust particles on painting materials may cause contamination which results in an uneven surface finish when applied
    • Certain chemicals react differently to other materials used in the paint job to form breaks in the coating material.
    • Bacteria thrive in warm and moist environments and may find their way into paint coatings resulting in defects.
    • Mold and fungal growth produce spores that contaminate paint and cause problems with the final painted product.
“The best preparation for good work tomorrow is to do good work today.” –Elbert Hubbard

Inadequate Surface Preparation

One of the main causes of fish eyes in paint is inadequate surface preparation. This means that the surface was not properly cleaned, sanded, or prepared prior to painting.

Cleanliness: Insufficient cleaning can allow contaminants such as dust, oil, and grease to remain on the surface, which can cause fish eyes. It is important to use a high-quality degreaser to remove any dirt, oil, or grease from the surface before painting. Always rinse the surface thoroughly with clean water after cleaning.

Sanding or buffing: Lack of sanding or buffing can create an uneven surface that can lead to fish eyes. Ensure you have smoothed out any imperfections prior to applying the paint. Use a fine-grit sandpaper (e.g., 320 grit) for a proper scuffing result.

Removing old coatings: Failure to remove previous coating materials – especially if they’re incompatible – could generate issues later on and possibly provoke fish eye formation during the topcoat application stage regardless of correct preparation beforehand.

Drying time: Inadequate drying time can affect your results. If the surface has not fully dried before beginning painting, it can cause complications down the line, including fish eyes.

“Fish Eyes occur when there is a poor bond between the substrate and the new finish (for example, gloss paint over emulsion).”

Insufficient Cleaning

If the surface(s) aren’t adequately prepped before the paint goes on it will cause air pockets under the product that dries up leaving pinhole-type bubbles called fish-eyes due to insufficient clearing. Even minute accumulated residues left over can interfere with bonding property between the primer and top-coating material, leading to fisheyes.

The following tips will consider cleaning when avoid fish-eye formation on a new coat of paint:

  • First up is as simple but crucial delicacy – never cut corners when it comes to basic housekeeping like decluttering your workspace from trash or pet hair.
  • Solvents such as caustic chemicals must be safe for use immediately before painting onto surfaces, especially if they leave any residue that could interfere with bonding materials. Make sure to rinse thoroughly with clean water and wait long enough after rinsing before starting to prime/paint – typically 30-60 minutes at room temperature.
  • Specific chemical cleaners for removing rust inhibitors should also receive adequate drying time; otherwise, they may contribute to contamination on the newly painted surface and lead to air pockets under the finished product’s surface.

Lack of Sanding or Buffing

“The devil’s in the detail.” ~German proverb

The overall quality of industrial coatings heavily depends on the degree of cleanliness, initial preparation steps, and finishing intricacies you employ on the project. Therefore it’s not just about sanding off imperfections on visible areas shown during coating usage! Often unseen parts undergo excessive bubbling and take longer to smooth after metal treatment. An un-even or un-smooth result can lead to rough adherence and/or lack proper coverage execution by initiating air pocket buildup leading to fish eyes happening internally due to an unsatisfactory surface finish and resulting in ever-present fisheye problems.

An understandably tiresome approach towards preparing surfaces with fine-grit abrasives (220 to finer) prior to application could save many leftover hours fixing pesky interferences afterward.

Failure to Remove Old Coatings

Apply new coatings before getting rid of previous ones isn’t one of the best painting practices. Make sure that old layers of paint have been removed, especially when using an incompatible type or brand of coating.

If your paint coat points also include automotive, it’s convenient first and foremost to check for OEM compliance guidelines with aftermarket products being used. The number one complaint from any body shop is cheap materials affecting their quality standards in any soft- pastes or pre-cleaners exposing existing finished surfaces to serious contaminants causing fish eye reaction later during application stencil

Inadequate Drying Time

Rushing through the steps to get a job done quickly can cause mishaps like fish eyes, which distort the final outcome of any industrial process! As explained earlier, reaching sufficient surface finish dryness must be given plenty of time, especially after rinsing or cleaning delicate surfaces as they may leave unseen sticky buildups hindering bonding elements from ultimately adhering correctly.

Freshly painted areas should receive enough necessary temperature raise/ reduction until fully cured even if it takes longer than initial instructions suggest drying them out entirely so you don’t end up repeating all those dreadful steps around again.

“Another thing to keep in mind is whether the airflow has good circulation or not – humid environments slow down evaporation whilst drier conditions hasten eventual solidification.”

Temperature and Humidity

Extreme Heat or Cold

The temperature and humidity of a painting environment can greatly affect the quality of the result. One common issue that can occur is fish eyes in paint, which are circular craters that appear on painted surfaces.

One cause of fish eyes is extreme temperature changes during the application process, such as sudden drops or spikes in temperature. For example, if the surface being painted is too cold, it can cause moisture to form on the surface. When moisture mixes with paint, small holes or bubbles can form known as fish eyes.

Similarly, hot conditions can also cause fish eyes in paint. Rapid drying due to high temperatures can make it difficult for the paint to flow evenly across the surface, resulting in fish eyes.

High Humidity

Another factor that contributes to fish eyes in paint is high humidity levels in the air. When humidity is high, moisture can easily absorb into the paint film, causing tiny bubbles that then burst and create fish eyes. This occurs because humidity slows down the evaporation rate of solvents in the paint mixture. Additionally, if there is excessive moisture present in the painting area itself, this can aggravate the situation.

To avoid fish eyes caused by high humidity, it’s important to keep the painting environment at a consistent relative humidity level between 40-60%. This can be achieved through proper ventilation and dehumidification systems.

Low Humidity

On the other hand, low humidity can also lead to fish eyes in paint. Low humidity can cause the paint to dry too rapidly, forming surface tension on the top layer that repels any subsequent coats applied. If another coat is applied over this tensioned film, the solvent or thinner generates areas of stresses leading to separation and resulting in fish eyes.

One way to counteract low humidity is by spraying a light mist of water onto the surface being painted. This helps restore humidity levels around the paint film, allowing it to dry more evenly.

“It’s important not only to keep your workspace clean but also to control the temperature and humidity level during the painting process to prevent flaws like fisheyes from forming” -Richard J. Kinch, Woodworking

Maintaining proper temperature and humidity levels throughout the painting process can help minimize the occurrence of fish eyes in paint. Taking these precautions ensures that the end result is not compromised by environmental factors beyond an artist’s control.

Improper Mixing

Fish eyes in paint are a common problem faced by home decorators and professional painters alike. One of the main causes of this issue is improper mixing.

Inaccurate Proportions

When it comes to mixing paint, getting the right proportions is crucial. If you add too much thinner or hardener to the mixture, it can cause fish eyes in the final product. This is because an uneven distribution of these elements will prevent the paint from adhering properly to the surface and lead to crater-like formations on your painted surface.

According to Ryan Kletzien, a professional painter and owner of Paintline Painting in Madison, Wisconsin, “The most common reason for fish eyes appearing in acrylic enamels stems from incorrect mixing ratios, using too hot of water while mixing, or not allowing for adequate dry time between coats.”

This means that taking the time to measure out ingredients accurately and following manufacturer instructions is essential. Using the right tools, such as a measuring cup and a scale if necessary, can help achieve accurate proportions in your paint mixtures.

Mixing Too Quickly or Slowly

Another factor that can contribute to fish eye formation in paints is how quickly or slowly you stir the mixture.

If you mix too quickly, you may introduce air bubbles into the solution, leading to an uneven application and potential craters forming later on. On the other hand, if you mix too slowly, some ingredients may settle at the bottom of the container, leading to inconsistencies in the texture and quality of the paint.

A quote from the website of painting products company Purdy emphasizes the importance of careful mixing: “Slowly, but thoroughly mix coating material prior to use. A uniform consistency should be obtained before proceeding with the application. Stirring should continue throughout the use of the coating material.”

To avoid these problems, take your time when mixing paint and stir it continuously until you achieve a uniform consistency.

“Our team takes pride in our work and we understand that prep-work is essential for quality results. We ensure all damaged areas are properly primed and smoothed out before applying any paints or finishes,” says Eric Swartzentruber, founder of All Seasons Painting & Handyman Services in Portland, Oregon.

Fish eyes in paint can be frustrating to deal with, but by understanding what causes them – namely improper mixing – you can take steps to prevent this problem from arising. By following proper mixing techniques, such as using accurate proportions and slow and careful stirring, you’ll help ensure that your paint coats smoothly, ensuring lasting and professional results.

Application Technique

Fish eyes in paint can be a frustrating problem, especially when they ruin the finish of your project. Several factors contribute to this issue, and improper application techniques are among them.

Incorrect Spray Pattern

If you’re using a spray gun to apply paint, it’s essential to ensure that the pattern is correct. A poorly adjusted spray gun can cause fish eyes as the droplets do not bond correctly with the surface, leaving small craters. Make sure that you adjust both the fan and air pressure on your spray gun so that the pattern and flow rate are optimal for painting the material.

Failure to Follow Manufacturer’s Instructions

Using incompatible materials or mixing products incorrectly can lead to fish eyes. Always make sure to read the manufacturer’s instructions carefully before starting any painting project. It’s also vital to use compatible primers and paints if you want to achieve a smooth, consistent finish. Non-compatible products introduce silicons into the mix and prevent proper adhesion between layers leading to craters or bubbles forming (fish eyes).

Improper Brush or Roller Technique

Even if you’re using traditional brushes or rollers instead of sprays, it’s still possible to get fish eyes if you don’t use the right technique. Using too much force while brushing or rolling can push the paint away and create an uneven coat that does not stick. You might think applying more pressure will give you better coverage, but this would only bring about failure. Apply even strokes across the surface and let the paint dry well before moving onto other areas. Remember, a lighter touch gives you an impeccable finish and prevents errors like fish eyes.

Uneven Coating Thickness

Always start by sanding the entire surface thoroughly before painting. An uneven surface can cause coats to dry at different rates, trapping air and moisture underneath them creating bubbles or fisheyes. Using too much paint often obscures the grooves and lines on a surface, but it does not guarantee better results.

  • Start by preparing your brush or roller adequately before applying the first coat. Load up with just enough paint (don’t overload) that allows you to maintain control of your strokes.
  • Apply even pressure across the surface using light strokes so that you don’t end up with any missed areas. Don’t apply too heavy stroke as this will lift the previous layer and create an uneaven coating
  • For good bonding, remember to always let each coat dry before adding another. When layers dry out at different rates, they form lumps, and some of them may leave behind fish eyes when smoothed over later.
“Painting is about patience, persistence and perseverance.” -Lydia Jane Pugh

Frequently Asked Questions

What are fish eyes in paint?

Fish eyes in paint are small, crater-like imperfections that appear on a painted surface. They resemble the eyes of a fish, hence the name. These imperfections can be caused by a variety of factors including contamination, inadequate surface preparation, and application issues. Fish eyes can cause a rough and unattractive appearance to a painted surface and can be difficult to repair.

What causes fish eyes in paint?

Fish eyes in paint can be caused by a variety of factors. The most common cause is surface contamination, such as the presence of oil, grease, or silicone. Other causes can include inadequate surface preparation, such as failing to remove all dust and debris before painting, and application issues, such as using the wrong type of paint or applying the paint too thickly. Humidity and temperature can also contribute to the formation of fish eyes.

How can fish eyes in paint be prevented?

Fish eyes in paint can be prevented by following a few simple steps. First, ensure that the surface to be painted is clean and free of any contaminants. Use a degreaser or other cleaning agent to remove any oils, grease, or silicone. Next, make sure the surface is thoroughly dry and free of dust or debris. Use the correct type of paint for the surface and apply it according to the manufacturer’s instructions. Finally, avoid painting in high humidity or extreme temperatures.

What are some common sources of contamination that can lead to fish eyes in paint?

Common sources of contamination that can lead to fish eyes in paint include oils, grease, and silicone. These contaminants can come from a variety of sources, such as skin oils, cleaning agents, or lubricants. Dust and debris can also contribute to fish eyes, as can moisture or humidity in the air. It’s important to properly clean and prepare the surface before painting to avoid these contaminants.

What steps should be taken to remove fish eyes from painted surfaces?

To remove fish eyes from painted surfaces, first sand the affected area lightly to smooth out the surface. Then, clean the area with a degreaser or other cleaning agent to remove any contaminants. If the fish eyes are still visible, use a filler or putty to fill in the imperfections. Sand the area again, and then repaint the surface. It’s important to properly clean and prepare the surface before painting to prevent the formation of new fish eyes.

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