How to Choose the Right Sanding Sponge for Gunpla
By GUNNZO | Published: 2026-10-22
Category: Buying Guides
Learn how to pick the right sanding sponge grit for Gunpla. Compare Kamiyasu sanding sponge sets and get practical decision rules for plastic models.
Quick answer
For most Gunpla builds, start with a 2mm Kamiyasu sanding sponge set in #600–#1000 for seam lines and nub removal, then switch to a 5mm set for larger surfaces. Use ultra-fine #2000–#10000 sponges for final polishing.
Why thickness matters
Thickness affects how the sponge flexes. Thinner 2mm sponges give you more control on small parts and tight corners, while thicker 5mm sponges are better for broad, flat surfaces because they distribute pressure more evenly. If you work on a mix of parts, having both thicknesses in your kit is a practical advantage.
Grit ranges and when to use them
Coarse grits (#120–#400) remove material quickly and are useful for reshaping or heavy sanding, but they leave visible scratches. Medium grits (#600–#1000) are the workhorse range for smoothing nubs and seam lines after cutting. Fine grits (#2000 and above) are for polishing and restoring a glossy finish. You generally progress from coarse to fine, but you can skip coarse grits if you only need light cleanup.
Plastic-only limitation
These Kamiyasu sanding sponges are designed for plastic only. If you plan to sand resin, metal, or painted surfaces, you need a different abrasive. Stick to plastic model kits like Gunpla to get the best results without damaging the sponge or the part.
Decision rules for choosing your sanding sponge
- If you remove nubs and seam lines: Choose a 2mm set with #600–#1000 grits, like GH-KS2-A3B. The thin sponge gives you precision on small parts.
- If you sand large flat areas: Pick a 5mm set with #600–#1000 grits, like GH-KS5-A3B. The thicker sponge prevents uneven pressure. A 5mm sponge is also useful for curved surfaces where a flexible pad is needed.
- If you need heavy material removal: Go for a 5mm set with #120–#400 grits, like GH-KS5-A3A, for reshaping or aggressive sanding. Follow with a finer grit to remove the scratches left by coarse sanding.
- If you want a glossy finish: Use the ultra-fine 2mm set GH-KS2-KB with #2000–#10000 after all other sanding steps. This set is for polishing only, not for material removal.
Kamiyasu sanding sponge sets
- Kamiyasu Sanding Sponge 2mm Assortment Set B #600 #800 #1000 GH-KS2-A3B: 2mm thick, #600 x2, #800 x2, #1000 x1, 5 pieces total, for plastic only. This set covers the essential grits for nub removal and seam line cleanup on small Gunpla parts.
Kamiyasu Sanding Sponge 2mm Assortment Set B #600 #800 #1000 GH-KS2-A3B - Kamiyasu Sanding Sponge 5mm Assortment Set A #120 #240 #400 GH-KS5-A3A: 5mm thick, #120 x1, #240 x2, #400 x2, 5 pieces total, for plastic only. The coarser grits in this set are ideal for heavy sanding on large surfaces or when you need to reshape plastic.
Kamiyasu Sanding Sponge 5mm Assortment Set A #120 #240 #400 GH-KS5-A3A - Kamiyasu Sanding Sponge 5mm Assortment Set B #600 #800 #1000 GH-KS5-A3B: 5mm thick, #600 x2, #800 x2, #1000 x1, 5 pieces total, for plastic only. A thicker sponge with medium grits gives you even pressure on flat areas while still handling typical cleanup tasks.
- MIGAKI Kamiyasu Sanding Sponge 2mm Assortment Set #2000 #4000 #6000 #8000 #10000 GH-KS2-KB: 2mm thick, includes #2000, #4000, #6000, #8000, #10000, one of each, for shiny polishing. Use this set as the final step to bring back a glossy finish after coarser sanding.
Who should use which set
Best for
- Gunpla builders who need precise nub cleanup on small parts – choose the 2mm #600–#1000 set.
- Modelers working on large flat surfaces like shields or vehicle hulls – choose the 5mm #600–#1000 set.
Not for
- Sanding resin or metal parts – these sponges are for plastic only.
- Heavy reshaping tasks that require aggressive material removal – instead, start with the 5mm #120–#400 set.
