Nub removal is the first real skill every Gunpla builder needs to master — and it makes more difference to your finished kit than almost anything else. If you’ve ever built a Gundam kit and ended up with those stubborn white stress marks, rough patches, or visible plastic chunks sticking out of your parts, that’s a nub removal problem. The good news? Getting clean, smooth parts is completely achievable once you know the right approach, and you don’t need expensive tools to start. This guide walks you through everything you need to know about nub removal as a Malaysian Gunpla beginner, from choosing your first pair of nippers to finishing up like a seasoned builder.
What Are Nubs and Why Do They Matter?
When Bandai moulds a Gunpla kit, all the individual parts are connected to plastic frames called runners via small injection points. When you cut a part free, the plastic left behind at that connection point is called a nub. On standard runners, nubs are typically 1–2 mm wide and slightly raised above the surface of the part.
Here’s the problem: if you cut directly at the part with standard nippers, the pressure of the blade causes the plastic to compress and then rebound — leaving a white stress mark called a nub mark. These marks are incredibly visible on coloured parts, especially red, yellow, and blue pieces where white patches stand out harshly. Even on grey and dark parts, nub marks catch the light and break the clean, uniform finish that makes a well-built kit look so satisfying.
The solution is a two-cut technique and the right tools — both of which we’ll cover in detail below.
The Tools You Need (And What to Skip for Now)
You do not need to spend thousands of ringgit on tools to remove nubs well. For beginners, here is what actually matters:
- A decent pair of Gunpla nippers (side cutters) — the single most important tool. Look for “hobby nippers” or “model nippers” with a thin blade. Popular budget options include the Tamiya 74035 or any reputable Japanese-made nipper. Avoid thick craft scissors or hardware-store wire cutters — these will crush the plastic.
- A sanding stick or sandpaper (400 grit, 600 grit, 800 grit) — for smoothing after cutting. A basic set of sanding sticks covers everything a beginner needs.
- A sharp hobby knife (optional but useful) — a Tamiya or NT cutter for shaving down any remaining nub flush before sanding.
That’s genuinely all you need to start. You can upgrade to single-edge blade (SEB) nippers later — these ultrasharp cutters leave almost no nub at all — but they’re not beginner-essential and they’re fragile if you use them on thick gates.
The Two-Cut Method: Step by Step
This is the technique that separates builders who get clean parts from those who end up with stress marks all over their kit. The two-cut method is simple, effective, and becomes second nature very quickly.
Cut 1 — The rough cut: Position your nipper blade about 2–3 mm away from the part surface, well back along the gate (the plastic sprue connecting the part to the runner). Cut here first. You’re not going for a clean finish yet — you’re just freeing the part safely from the runner. Because you’re cutting the thinner gate plastic away from the part, there’s very little stress transfer to the part itself at this stage.
Cut 2 — The close cut: Now you can position your nipper blade right at the surface of the part, flush with or just slightly above the plastic. Cut again. Because the part is now free-floating and there’s no tension from the runner pulling on it, this cut produces far less stress — and far less risk of a white mark. Aim to leave just the tiniest sliver of plastic above the surface rather than cutting into the part itself.
Sand to finish: Use your sanding stick (start with 400 grit, move to 600, then 800) to sand the remaining nub flush with the part surface. Work in one direction for flat surfaces. Light circular motions work well on curved parts. By the time you reach 800 grit, the surface should be smooth and nearly invisible.
For very visible surfaces — the front chest, face, shoulders — spend extra time at the 800 grit stage. For inner frame pieces and hidden areas, a quick rough sand is enough.
Dealing with Stubborn Nub Marks
Sometimes even careful two-cut technique leaves a faint white stress mark, especially on softer coloured plastics like red and yellow. Here’s how to handle them:
Burnishing: For very light stress marks, you can sometimes “burnish” the mark away — rub the back of your thumbnail (or the rounded edge of a toothpick) firmly over the mark in a circular motion. The friction and pressure can redistribute the stressed plastic molecules and reduce or eliminate the white appearance. It sounds unusual but it genuinely works on light marks.
Additional sanding: For more noticeable marks, sand deeper with 400 grit until the white completely disappears, then work back up through 600 and 800 grit to restore the surface. This takes more time but delivers a proper result.
Touch-up paint or Gundam markers: For worst-case scenario marks that persist after sanding, a touch-up paint pen or Gundam marker in the matching colour is your fastest fix. Bandai’s own Gundam markers come in many standard kit colours and apply easily with the marker tip.
One pro tip many Malaysian builders overlook: after applying top coat (either matte or semi-gloss), minor surface imperfections become far less visible under the uniform sheen. So don’t stress too much about microscopic marks — your finished, top-coated kit will look significantly cleaner than the raw parts stage suggests.
Nub Removal Tips Specific to Malaysian Builders
Building in Malaysia’s tropical climate adds a small but real consideration: humidity. On very humid days, freshly sanded plastic surfaces can sometimes look slightly milky or hazy. This usually disappears as the surface dries, but if you’re sanding extensively, work in a cooler, less humid environment if possible, or do your sanding in an air-conditioned room.
For tool care, keep your nippers clean and dry after use. Wipe the blades with a dry cloth and store them closed. Malaysian humidity can accelerate metal oxidation, so a light coating of tool oil on the pivot point every few months keeps your nippers cutting smoothly for years.
Finally, gate placement varies significantly between Gunpla grades. HG kits tend to have more gates in obvious positions (a legacy of older engineering), while newer MG and RG kits increasingly place gates on hidden surfaces or inner frame parts where nub marks are less critical. As a beginner, HG kits are excellent practice precisely because the gates push you to develop good nub removal habits from the start.
Building Your First Nub-Free Kit: What to Expect
The first time you apply the two-cut method consistently on a full HG kit, it will feel slow. You’ll be pausing on every part to double-cut and sand, and the build will take longer than a quick assembly session. That’s completely normal — and completely worth it.
By your third or fourth kit, the two-cut technique becomes muscle memory. Your hands naturally position the nippers at the right distance, your sanding becomes efficient, and your builds consistently look clean and polished. The early investment in proper technique pays dividends on every single kit you build after that.
If you’re looking for your next Gunpla kit to practise on, Entry Grade and HG kits at Gundam.my are excellent starting points — well-engineered, manageable part counts, and great for building core skills before moving up to MG or RG territory.
Final Tips Before You Start Cutting
A few last reminders to set you up for a great build:
- Never twist or pull parts off the runner — always cut them free cleanly.
- Work in good lighting so you can see exactly where each gate meets the part.
- Organise your parts as you cut them — a divided tray or small bowls by colour help prevent losing tiny pieces.
- Sand before assembling, not after — it’s much harder to sand inside assembled sections.
- Check your build manual first to understand which surfaces will be hidden and which will be highly visible — prioritise your effort accordingly.
Nub removal might seem like a small detail, but it’s the foundation everything else is built on — your panel lining, your top coat, your final display. Get this step right, and every other part of the build process becomes more rewarding.