How to Fix Common Mistakes in Gunpla Building: Expert Tips for Perfect Models

Working on Gunpla models is a fun and rewarding hobby, but even experienced builders can make mistakes. Dent marks, whitish plastic tones, and mismatched parts are some of the most common issues faced by builders. These errors might seem discouraging, but they are usually easy to fix with the right techniques.

One frequent mistake is damaging the plastic when removing parts from the sprue. Using a sharp pair of nippers and cutting away from the part can prevent dents. If dents do appear, they can often be smoothed out with fine-grit sandpaper. Markers or paints can help cover any whitish marks caused by stress on the plastic.

Mixing up small parts is another common problem. A simple fix is to store unused parts in the original packaging to keep them organized. This reduces the chances of losing or confusing pieces, especially when building multiple kits. Following these tips can make building Gunpla models more enjoyable and less frustrating.

Understanding Gunpla Kits

Understanding the different grades and how to read the manual are crucial steps in building Gunpla kits, especially for beginners. Knowing the grades helps in selecting the right kit, while understanding the manual ensures a smooth assembly process.

Different Grades and Scales

Gunpla kits come in various grades, each indicating the level of detail and complexity. The main grades include High Grade (HG), Real Grade (RG), Master Grade (MG), and Perfect Grade (PG).

High Grade (HG) kits are the most common and are suitable for beginners. They are typically 1/144 scale, making them smaller and less detailed.

Real Grade (RG) kits offer more detail and complexity. They are usually 1/144 scale but have more parts and require careful assembly.

Master Grade (MG) kits are 1/100 scale and provide a lot of detail. They are more complex, making them better for intermediate to advanced builders.

Perfect Grade (PG) kits are the most detailed and complex. They are 1/60 scale and offer the highest level of detail, requiring advanced skills and tools.

Reading the Manual

Reading the manual is a key part of the building process. Before starting, familiarize yourself with the symbols and conventions used. The manual includes a parts list, showing every piece you need for the build.

Pay close attention to the assembly steps, which are often illustrated clearly. Look for specific symbols that indicate actions like gluing, painting, or using specific tools.

Keeping the manual handy during the build helps in avoiding mistakes and ensures each part is assembled correctly. Noting any special tips or warnings provided can also help in achieving the best results.

Essential Tools for Gunpla Building


Building a Gunpla model requires specific tools for cutting, sanding, and detailing. Knowing which tools to use can make the process smoother and improve the final look of your model.

Choosing the Right Nippers

Nippers are essential for removing parts from the sprue. Good nippers ensure clean cuts without damaging the parts. Find nippers that will provide you options for precision and ease of use.

Fine-Tuning with Files and Sandpaper

Sanding and filing are crucial for smoothing out rough edges and preparing parts for assembly and painting. Diamond files come in handy for detailed work on small parts. For sanding, a range of grits, from coarse to fine, is necessary. Start with 400-grit sandpaper for rough surfaces and move to 1000-grit for finer smoothing. Sanding sticks are also useful for reaching tight spots and ensuring even surfaces.

Detail Work with Tweezers and Markers

Tweezers are useful for handling small parts and applying decals. Precision tweezers with fine tips allow for better control and placement. Markers are used for panel lining and adding details. It’s also beneficial to have a set of fine-tipped permanent markers for adding intricate details and enhancing the overall look of your model.

Effective Parts Removal from Runners

Removing parts from runners properly is crucial to building a Gunpla kit that looks clean and professional. The key points are to use the right tools and techniques to avoid damaging the parts.

Proper Snipping Technique

Using side cutters is essential. These cutters allow for precise cuts close to the part without bending or snapping the plastic.

1. Positioning: Hold the side cutters flush against the piece and snip as close as possible to the part.

2. Second Cut: Leave a small nub when initially cutting. Then, make a second cut closer to the part to minimize the chance of stress marks.

3. Cleaning Nubs: After cutting, use a hobby knife to shave off any remaining nub. Be careful to shave in small layers to avoid gouging the part.

Avoiding Damage During Removal

1. Use Sharp Tools: Dull tools can crush or tear the plastic, leaving rough edges. Make sure your cutters and knives are sharp.

2. Sanding: Sand the area after cutting to smooth any rough spots. Start with a coarse grit and move to finer grit sandpaper for a polished finish.

3. Stability: Hold the runner securely but do not force parts out. Forcing can cause breaks or stress marks. If a part is stubborn, consider cutting it out in stages.

4. Lighting: Good lighting ensures you can see exactly where you are cutting, reducing mistakes.

Proper tools and careful techniques can prevent damage and ensure clean, precise parts for your Gunpla build.

Addressing Nub Marks and Sanding

Removing nub marks and sanding are crucial in making your Gunpla look polished. This process involves precise cutting and sanding techniques to achieve a smooth, clean finish.

Minimizing Nub Marks

One of the first steps is cutting the parts carefully from the sprue. Using a pair of sharp nippers, cut the part a bit away from the actual piece to avoid stress marks. Then, use a hobby knife to trim the remaining nub. Be careful and precise to minimize any damage to the surrounding plastic.

Next, apply light pressure while sanding. Start with a low-grit sandpaper like 400 grit to remove larger nubs. Gradually move up to finer grits such as 800 or 1000. Higher grits help smooth the cuts, making nub marks less visible.

To further hide any small nubs, use markers matching the plastic color. A good quality Gundam Marker can be used to color over any remaining nub marks, blending them into the plastic seamlessly.

Sanding Techniques for Smooth Finishes

Sanding is key to achieving a professional look on your Gunpla. Begin with lower grit sandpaper like 400 to remove the bulk of the nub. It’s important to sand evenly and in one direction to avoid scratches.

As you proceed, use higher grits like 600, then 800, and up to 1000 grit. The higher the grit, the finer the sandpaper. This makes the surface smoother. For dark-colored pieces, it’s helpful to finish with a 2000 grit wet sandpaper to polish the plastic.

When sanding, remember to use light, even strokes. Avoid putting too much pressure, as this can create deeper scratches. If you notice any stress marks, you can lightly sand them and then use a polishing kit for finishing.

Using a combination of these techniques ensures your Gunpla looks refined and professional.

Error-Free Assembly Tips

When assembling Gunpla, precision and patience are key. Follow these steps to avoid common mistakes and ensure a smooth build experience.

Following the Instructions

Read the Manual Thoroughly: Before starting, read the entire instruction manual. This helps understand the sequence of steps and prevents any surprises.

Sort Parts: Organize parts after removing them from the sprue. This prevents mixing up similar-looking parts and losing small pieces. Store them in small containers or the box the kit came in.

Step-by-Step: Don’t skip steps. Follow the instructions step by step for accurate assembly.

Check Fits: Dry fit parts before applying glue. This ensures that parts align correctly without gaps or misfit.

Tool Care: Use sharp tools for clean cuts. Dull tools can damage parts, making them harder to fit together.

Glue Application Best Practices

plastic cement

Choose the Right Glue: Use instant cement or similar plastic cement. They bond plastic without causing discoloration.

Apply Sparingly: A thin layer of glue is usually enough. Too much glue can cause excess mess and weaken the joints.

Join Quickly: After applying glue, join the parts quickly but carefully. This prevents the glue from drying out and ensures a strong bond.

Align Properly: Ensure that edges and joints align perfectly before allowing the glue to dry. Misalignment can lead to visible gaps and weakened structures.

Let It Dry: Allow enough time for the glue to dry completely. Rushing this process can lead to weak joints and may require reapplication.

By following these detailed tips, builders can minimize assembly errors and create sturdy and visually appealing models.

Enhancing Gunpla with Panel Lining

Panel lining is a key technique to bring out the intricate details in your Gunpla models. By choosing the right tools and using proper techniques, you can greatly enhance the visual appeal of your builds.

Choosing the Right Panel Line Tools

Gundam Decals

Gravis, Gunpla decal sheet, CC BY-SA 4.0

Selecting the right tools is essential for effective panel lining. Gundam markers are a popular choice. They come in various colors, perfect for different parts of the model. For light-colored pieces, a gray marker (GM02) works well, while a black marker stands out on darker surfaces. Some modelers prefer fine-tipped pens or even brushes with enamel paint for more precise control.

When picking a tool, consider the color of your model. The goal is to create contrast, making the lines look like shadows. This adds depth and realism. Additionally, having a good rubber eraser handy is crucial for cleaning up excess ink. Many enthusiasts recommend trying different tools to find what suits your style best.

Techniques for Clean Panel Lines

To achieve clean panel lines, it’s important to follow some simple steps. Start by running the panel line marker through the grooves carefully. Ensure that the ink flows into the recessed lines. If mistakes happen, use a rubber eraser to remove excess ink. It’s best to rub perpendicular to the line to avoid smudging.

Another helpful tip is to apply a gloss coat to the model before panel lining. This makes the surface smoother, allowing the ink to flow better and reducing the risk of damaging the paint. After applying the panel lines, let the ink dry overnight. This ensures it sets properly and gives a clean finish.

Practicing these techniques will help you enhance your Gunpla models with crisp, detailed panel lines, making each build look more refined and professional.

Application of Decals and Stickers

Applying decals and stickers to Gunpla models can enhance the appearance, adding fine details and realistic touches. The process involves specific techniques and careful placement to achieve the best results.

Decal Application Technique

Decals add intricate details to Gunpla models. They often come on a clear sheet and require soaking in water to release them.

Steps to apply decals:

  1. Cut the decal from the sheet using a sharp knife or scissors.
  2. Immerse the decal in water for about 10-15 seconds.
  3. Use tweezers to gently slide the decal onto the model’s surface.
  4. Position the decal carefully and smooth it out using a soft tool such as a brush.
  5. Press lightly to remove any air bubbles.
  6. Apply a clear topcoat to seal the decal and protect it from damage.

The technique requires precision and patience to ensure the decals look natural and adhere properly.

Sticker Placement for Maximum Effect

Stickers enhance the visual appeal by adding color and markings. Proper placement is crucial for achieving a realistic look.

Tips for sticker placement:

  1. Use Tools: Always use tweezers to place stickers, avoiding direct contact with fingers which can leave oils on the adhesive.
  2. Plan Ahead: Before applying, plan where each sticker will go to ensure balance and symmetry.
  3. Smooth Surface: Ensure the model’s surface is clean and smooth to help stickers adhere better.
  4. Alignment: Use tiny adjustments to align stickers perfectly. Misalignment can ruin the aesthetic.
  5. Press Firmly: Once in place, press the sticker firmly to secure it.

These methods ensure the stickers stay put and maintain their appearance during handling and display.

Painting for Customization

Painting your Gunpla is a key step in making it unique. Selecting the right type of paint, using proper techniques, and paying attention to small details can vastly improve the finished model.

Selecting Paints for Gunpla

Choosing the right paints is essential. Acrylic, enamel, and lacquer paints are the most common types. Each has its benefits. Acrylic paints are water-based and easy to clean. Enamel paints are durable and provide a glossy finish. Lacquer paints dry quickly and are tough.

Tamiya is a popular brand for all three types. It’s important to test the paint on scrap plastic first. Temperature and humidity can affect how paint adheres to the surface. High-quality paints lead to high-quality finishes.

Spray Painting Techniques

Using spray paint can provide a smooth, even coat. Shaking the can well before use is crucial. Hold the can about 6-12 inches away from the piece. Apply in light, even coats to avoid runs and drips. Multiple thin coats work better than one thick coat.

A primer is essential for good adhesion and a smooth finish. After priming, lightly sand the surface with fine-grit sandpaper. This helps the paint stick better. Tamiya spray paints are great for beginners and experienced builders alike.

Detail Painting Tips

Detail painting involves adding small touches to enhance features. Using fine-tipped brushes, it’s possible to paint small parts like eyes, panel lines, and other accents. Thinning paints slightly can make application easier and help avoid brush marks. Acrylic paints work well for detailing because they are easy to clean up.

For panel lining, use a fine brush or a panel line accent color.  These products flow into recessed lines, making details stand out. Using a magnifying glass or a work light can help see small details better. Patience and a steady hand are key to good detailing work.

Applying Top Coat for Protection and Finish

Applying a top coat to your Gunpla helps protect the model and enhances its appearance. It is important to choose the right type of top coat and understand how different finishes affect the final look.

Choosing the Right Top Coat

Choosing the correct top coat is critical for achieving the desired finish and protection. Gloss top coats give a shiny, vibrant look, making colors and details stand out. This finish is often used for more stylized models or to highlight certain features.

Matte top coats offer a non-glossy, realistic finish. They are perfect for military-style models or for those who prefer a more subdued look. Matte finishes help simulate a weathered or natural appearance.

Semi-gloss provides a middle ground between gloss and matte. It adds some shine without being too reflective. This option is useful for balanced looks where neither a full gloss nor a complete matte finish is desired.

Before applying any top coat, ensure the surface is clean and free of dust. This prevents blemishes that could ruin the finish.

Achieving Different Finishes

To get the best results, you should follow certain steps based on the type of finish you want. For a glossy finish, apply the top coat in thin, even layers. This can help to build up the shine without forming bubbles or streaks. Let each layer dry thoroughly before adding the next.

For a matte finish, apply the top coat in a well-ventilated area. Matte coats can sometimes appear misty if applied too thickly, so light, even layers are key. This non-reflective finish helps enhance realism and reduce glare.

A semi-gloss finish requires a careful balance. Apply layers evenly and let them dry completely. This finish works well for adding subtle highlights without making the model too reflective.

Top coating not only enhances appearance but also makes the model more durable. It helps protect against scratches, dust, and UV damage. By choosing the right top coat and applying it correctly, builders can achieve professional-looking results.

Final Touches and Pose Setting

Adding the final touches and setting the pose can make your Gunpla model stand out. This involves dynamic posing tips and adding details with inks and other finishing touches.

Dynamic Posing Tips

Dynamic posing brings your Gunpla to life. Start by deciding on the action or stance you want to capture. They can mimic real-life movements.

Ensure the legs are stable for balance. Adjust the arms and torso to create a natural S-curve. Bent knees and angled feet add realism.

Tilt the head slightly for character. Use tools like stands and posing rods for more complex poses. Taking photos from different angles helps visualize the best pose.

Adding Details with Inks and Finishing Touches

Inking your Gunpla gives depth. Panel lines are the main focus. Use a fine-tipped inking pen to trace these lines. Be precise to avoid smudging.

Add subtle weathering with ink washes. These bring a worn look to your model. Dry brushing with minimum paint on a stiff brush highlights edges.

Finish with a topcoat to protect the details. Matte or gloss, the choice depends on your desired finish. Customize with decals or stickers to complete the look.

Maintaining and Cleaning Gunpla

Regular upkeep is essential to keep your Gunpla models looking their best. This involves routine cleaning and using the correct tools for both general maintenance and specific tasks.

Routine Cleaning Methods

Regular cleaning helps maintain the look and integrity of your Gunpla. Dust can accumulate quickly, so using a soft brush to gently remove it is crucial. Brushes with fine bristles are ideal, as they can reach into small crevices where dust tends to settle.

For more stubborn grime, a Q-tip dipped in isopropyl alcohol can work wonders. Lightly dab and wipe affected areas. Be cautious, as too much pressure or alcohol can damage the paint.

Erasers can also be used to clean certain spots, especially to remove unwanted marks or light stains. Test erasers in a small hidden section first to ensure it won’t damage the finish.

Tools for Cleaning and Maintenance

Having the right tools can make a big difference in keeping Gunpla models in top shape. Soft brushes and Q-tips are basic essentials. They help clean dust and minor dirt without damaging the paint.

For deeper cleaning, isopropyl alcohol is a go-to solution, but always ensure it’s used sparingly. Small drops applied to Q-tips can clean hard-to-reach spots effectively.

Erasers are handy for removing light stains or marks. For parts that require tightening or repair, keep a set of precision screwdrivers and tweezers. These tools help maintain the assembly and ensure everything fits snugly.

Investing in a toolkit tailored for modeling can also be beneficial. Items like side cutters, sanding sticks, and glue applicators can be included to handle various maintenance needs.