How to Fight Against Nubs

You've just received your very first model kit, perhaps a superb Zaku or an adorable Rowlet. Excitement is at its peak! You open the box, sort the runners, and enthusiastically begin cutting and assembling. You carefully detach the first pieces and... oops! What's that ugly little mark, that tiny bit of plastic sticking out where the piece was attached to the sprue? Or worse, that little white mark that clashes with your beautiful dark piece?

Don't panic! You've just encountered the bane of the beginner modeler (and sometimes even the most experienced!): numbness . It's an extremely common problem, and the good news is that with the right tools and technique, you can eliminate it and achieve near-perfect finishes. We've all been there!

The Problem in Detail: What Does a "Nub" Look Like?

This minor imperfection can take two main forms:

1. A small excess of plastic: This is the most common problem. You didn't cut close enough to the part, and a small piece of the stem that connected it to the sprue remains. It feels sticky to the touch, and visually, it disrupts the line of the part.
   
   
2. A white stress mark: This one is more insidious. You cut very close to the part, perhaps even a little too close, or with an unsuitable tool. The plastic, under pressure or torsion, has "stressed" and whitened in that precise spot. It's particularly visible on dark plastics (black, navy blue, dark red, etc.), but much less noticeable on shades of white.

In both cases, the result is the same: it detracts from the final appearance of your model, especially on smooth armor pieces or curves. Bandai engineers do their best to ensure that the attachment points to be cut are located in discreet places once assembled. Some kits even use the undergate technique, where the part is attached to the runner from below to ensure that any trace of the nub is concealed.

Unfortunately, this isn't the case for all kits: some take the easy route and have parts molded from the sides in the traditional way. In that case, there's no choice but to do some work.

Why do these marks appear? The causes of the problem

Understanding where these brands come from helps to better avoid them:

• The Wrong Tool: Using kitchen scissors, nail clippers, or worse, trying to twist the piece by hand to detach it are the surest ways to get horrible nubs and stress marks. These tools crush or twist the plastic instead of cutting it cleanly, which tends to discolor it.
• The Wrong Technique (Even with the Right Tool): The initial instinct is often to want to cut the part perfectly flush with the cutting pliers. By making a single, very close cut, you put significant pressure on the plastic right at the base of the part, which almost always guarantees white marks.
• The Quality of the Pliers: Poor quality or dull model-making pliers will tend to pinch and stress the plastic rather than cut it cleanly. Don't worry, our tool ranges are not affected :)

The Solution: The Nub Hunt in Several Steps!

The goal is to achieve a perfectly smooth surface, as if the part had never been attached to a sprue. Here's the most recommended method, especially for beginners:

Use a pair of wire cutters (nippers)

Forget everything else, invest in a proper model cutter . They're designed to slice plastic cleanly. They're available at all price points, but even a basic, dedicated model cutter will be infinitely better than scissors. The best and most expensive ones often have a single, sharp blade (called a single blade) for an exceptionally clean cut.

The Double Cut Technique

• • First Cut (Away from the Part): Do NOT cut directly flush with the part! Place your pliers on the sprue , a few millimeters from the part itself, and cut. This detaches the part with a small piece of stem still attached. Cutting away reduces the pressure on the plastic of the part itself.
    
    
  • Second Cut (Near the Workpiece): Now, use your pliers to cut the remaining stem , this time much closer to the workpiece surface, but still leaving a tiny sliver (less than a millimeter). The goal is to remove most of the excess without directly touching the final workpiece surface with the pliers. If you are using really high-quality pliers, you can stop here.

The Finishing Touch: Eliminating the Last Residue

A very small, almost invisible bump remains. To eliminate it completely, several options (often combined) are available:

• • The Precision Cutter (Hobby Knife): This is the essential tool for this step. Be careful, the blade is very sharp! Place the blade flat on the surface of the piece and gently slide it to "shave" off the small excess of plastic, always cutting outwards (not towards your fingers!). Several very light passes are better than one heavy stroke.
    
    
  • Filing/Sanding: If using a craft knife intimidates you or if the result isn't perfect, use a fine model file or very fine-grit sandpaper (start around 600-800 grit, then move to 1000 or higher if needed). Gently rub the area, without applying too much pressure, until the surface feels smooth. Use sanding sticks or sponges for easier application. Gradually increase the grit to avoid scratching or discoloring the piece; ideally, you should stop at 2000 or even 4000 grit for excellent results.
    
    Tip: Lightly wet sanding on very fine grains gives an even smoother finish.
    
    
  • (Optional) Polishing: For purists or on very glossy/dark pieces, after very fine sanding (1500-2000+ grit), you can use polishing compounds and a soft cloth to restore a perfectly smooth and glossy finish to the area. This is an optional extra step, but the result is stunning.

Conclusion: Patience and Practice!

There you have it, you now have all the tools you need for a fantastic result! Don't get discouraged if your first attempts aren't perfect. As with everything in model making, practice and patience make all the difference. Every piece you cut and clean will make you better; that's what gaining experience is all about.

Take your time, learn to love the process, and admire the striking difference in your finished models. A perfectly smooth model is so much more rewarding!

Feel free to stop by the shop to see our tools, show us your progress, or ask for advice to get started. Happy building!