How to Fill Gaps on Figures (Scale Modeling Guide)

Filling gaps on figures—especially around arms, torsos, heads, and equipment—requires a slightly different approach than filling gaps on tanks or aircraft. Figures have organic shapes, curves, and skin textures, so the goal is to make the repair invisible without flattening or distorting anatomy.

Below is a complete, practical guide to doing it cleanly and confidently.

How to Fill Gaps on Figures (Scale Modeling Guide)

1. Choose the right filler for figures

Figures benefit from fillers that can be smoothed, sculpted, and blended into organic shapes.

Best options:

• Epoxy putty (Green Stuff, Milliput) - sculptable, ideal for muscles, folds, and organic shapes
• CA glue + talc/baking soda — great for small gaps, sands smooth
• Acrylic putty (AMMO A.MIG Arming Putty, Tamiya Light‑Curing) — easy to apply, good for shallow seams
• Sprue goo — good for plastic figures, bonds like real plastic

Rule of thumb: Use epoxy putty for anything that needs sculpting. Use CA glue for crisp, small gaps.

2. Prepare the surface

Before filling:

• Clean mold lines
• Test‑fit the parts
• Glue with liquid cement (for plastic) or CA glue (for resin/metal)
• Let the joint fully cure

A well‑aligned joint means less filling later.

3. Apply the filler based on gap size

A. Small gaps (hairline seams)

Use:

• Thin CA glue
• Acrylic putty

How:

1. Apply a tiny bead along the seam
2. Smooth with a damp finger or silicone sculpting tool
3. Sand lightly once cured

B. Medium gaps (0.5–1 mm)

Use:

• CA glue + talc
• Milliput (Standard or Fine)
• Green Stuff

How:

1. Press filler into the gap
2. Slightly overfill
3. Smooth with water (Milliput) or Vaseline (Green Stuff)
4. Let cure
5. Sand or sculpt as needed

C. Large gaps or missing detail

Use:

• Milliput or Green Stuff
• Sculpting tools
• Reference photos

How:

1. Build up the area with putty
2. Sculpt folds, muscles, or armor edges
3. Blend into surrounding anatomy
4. Let cure fully (4–24 hours depending on putty)

Epoxy putty shines here because it can be shaped before it hardens.

4. Blend and sculpt the repair

This is the most important step for figure work.

Techniques:

• Wet sculpting: Smooth epoxy putty with water or saliva
• Feathering: Use a silicone shaper to blend edges
• Texturing:
• Stipple with a stiff brush for skin
• Drag a toothpick for cloth folds
• Press fabric or sandpaper for subtle texture

The goal is to make the repair look like it was always part of the figure.

5. Sand carefully (or not at all)

Figures have curves—sanding can flatten them if you’re not careful.

When sanding is OK:

• Hard armor plates
• Boots
• Weapons
• Smooth surfaces

When to avoid sanding:

• Faces
• Hands
• Muscles
• Clothing folds

For delicate areas, sculpt and smooth the putty before it cures so sanding isn’t needed.

6. Prime to check your work

A thin coat of primer reveals:

• Remaining gaps
• Texture mismatches
• Fingerprints in putty
• Over‑sanding

If flaws appear, repeat the fill‑smooth‑prime cycle. This is normal—even pros do it.

Common Mistakes to Avoid

• Using too much putty
• Over‑sanding organic shapes
• Not smoothing epoxy putty before it cures
• Filling gaps before aligning parts properly
• Forgetting to texture the repair