Cutting & Assembly

How to fix a broken Gunpla peg or snapped part

A peg sheared off in its hole, or a thin part snapped at the joint. It looks fatal, but a pin and a drop of glue usually brings it back.

Quick answer

A broken peg is repaired by clearing the stub from the hole, drilling a small centered hole in the break, and gluing in a short pin (brass or plastic rod) that bridges the two halves. Use cyanoacrylate (CA) or epoxy for the bond, let it fully set, then test the fit gently. Pinning is stronger than gluing the broken faces alone, because the break line is small and carries all the load.

TimeRescue: 20-40 minutes plus glue set time (longer for epoxy). Prevention: no extra time.
DifficultyIntermediate

Safety first

CA glue bonds skin in seconds; keep it away from fingers and eyes.
Ventilate when using CA glue; fumes irritate eyes and airways.
Never use CA accelerator on cotton cloth or tissue, which can heat quickly.
Wear eye protection when drilling or cutting small parts.

Is this your problem?

The peg broke off and the stub is stuck in the socketThis page: remove the stub, then pin or rebuild the peg.
The part is whole but the joint no longer holds and just flopsNot a break. See Gunpla loose joints.
A white line or whitened area appeared where you pulled or cut, but nothing snappedSee White stress marks and nub marks.
A glued joint came apart cleanly with no plastic tornThe glue was the weak point: clean both faces, scuff them lightly and re-glue, or see Plastic glue not working on resin or metal.
The plastic is brittle and snaps again as soon as you repair itPin it deeper and avoid stress on that spot; very old kits and some colors of plastic are more brittle.

You'll see

A peg or tab is missing from its part, or a stub of plastic is stuck in a hole and the part will no longer click together. Sometimes a thin arm, skirt or antenna snapped cleanly at a joint after being forced open.

Likely causes

Forcing a tight fitPegs are small and sit in snug sockets. Pulling a part off by one corner, or twisting it, puts shear load on the peg instead of lifting it straight out.
Thick paint or primer in the socketA coating adds thickness. The peg now fits tighter than designed and snaps on the next assembly attempt.
Prying with a bladeA knife tip used as a lever concentrates force on one point and can snap thin parts or shave the peg.
Repeated assembly cyclesPlastic can fatigue with repeated flexing, especially at thin pegs or thin armor tabs.
Thin parts under loadPosing a kit past its range puts leverage on small pegs, which are the weakest link.

What you need

Pin vise hand drill with fine bits
Brass rod or plastic rod of matching diameter
CA glue (and optionally accelerator) or two-part epoxy
Fine files or sanding stick
Hobby knife with a new blade
Clamps or reverse tweezers to hold the part
Parts separator for the next time

How to fix it

Clear the socket first. If a stub is stuck, push it out from the back with a pin, or carefully drill it out with a bit smaller than the hole. Go slowly so you do not widen the hole.
Test-fit the two parts dry to see where the broken peg sat and how long it needs to be.
Mark the center of the broken face and drill a small hole into the stub and its counterpart, about the diameter of your rod. Drill straight and in small steps, clearing plastic dust as you go.
Cut a short pin from brass or plastic rod. Roughen it slightly so glue can grip, and test it dry.
Put a tiny drop of CA glue or mixed epoxy in the holes and fit the pin. Join the faces together and hold or clamp until the glue grips. Keep glue off the surfaces that need to move.
Let the joint cure fully before testing. Epoxy usually needs longer than CA; follow the maker's instructions.
Trim any excess with a sharp blade and sand lightly. If paint was removed, touch up the area.
Assemble gently for the first time, supporting the repaired part and not pulling on the peg.

What to avoid

Gluing the broken faces without pinning when the contact area is tiny.
Using too much CA, which can leak into the joint and freeze it.
Forcing the part together to test before the glue has set.

Common wrong fixes

Hot-melting or heating a peg to reshape it, which can warp the surrounding plastic.
Packing a loose socket with extra glue instead of fixing the cause, which makes it impossible to open later.

Not worth fixing, or time to ask us

If you are not sure which joint is a poly cap and which is a hard peg, or the part is a hard-to-replace piece, ask us before gluing. We can help work out the least risky repair.

Send us a photo

By situation or hobby

Peg broke off inside a socket (stub stuck)

The stub often needs to be driven out from the opposite side. If it cannot be moved, drill a small centered hole through it and pull it out in pieces, then re-glue a new pin.

Thin armor tab or arm snapped

Pin across the break and fill any gap with epoxy putty if the ends do not meet cleanly. Epoxy putty can be sanded once cured.

Painted kit

Scrape paint from the glue faces before bonding. Glue on top of paint holds only as well as the paint holds to the plastic.

Polycap joints (soft inner parts)

These are soft plastic and should not be glued. If a polycap is damaged, treat it as a separate repair; do not use CA where it touches a polycap.

Already ruined?

If you have the broken piece, a pinned repair can be nearly as strong as the original. If the piece is lost or too crushed to match, rebuild it from plastic rod or epoxy putty, then sand and prime. If a thin part snapped in several places or the plastic crumbles, a pin will not hold and the part may need replacement.

Next time

Use a parts separator or a flat tool to open joints evenly and lift straight.
Do not pry with a hobby knife blade.
Keep paint out of sockets or sand it back before assembly.
Dry-fit after painting and before final assembly; adjust sockets slightly if needed.
Avoid posing past the joint's range.

Frequently asked questions

How do I fix a broken Gunpla peg?

Clear the stub, drill a small centered hole in each half of the break, glue in a short brass or plastic rod pin, and let it cure fully.

Can I glue a Gunpla peg back on without a pin?

You can, but the contact area is very small and a plain glued peg often breaks again. A pin gives the joint a much larger bonded area.

How do I remove a broken peg stuck in its hole?

Push it out from behind with a thin pin, or carefully drill a small hole in the stub and pull it out. Do not widen the socket.

What glue should I use on Gunpla?

CA glue and two-part epoxy bond broken plastic. Regular plastic cement works only where both faces are clean styrene and not painted. Never use CA near polycaps.

Is it safe to use CA glue on Gunpla?

Yes on hard plastic, but keep it off clear parts and polycaps, and use very little, because excess glue whitens nearby surfaces.

Jargon explained

Peg: A small pin on one part that clicks into a hole on another.
Polycap: A soft rubbery joint insert used inside Gunpla joints; not designed to be glued.
Pinning: Joining parts by drilling matching holes and gluing a rod across the join.

Tools that can help

UStar Precision Pin Vise Drill Set $39.95
Why it helps: A hand drill with a quick-change chuck and ten bits from 0.4 mm to 1.3 mm, described for pinning parts in plastic and resin.

How to use it
Drill a small centered hole in each half of the break for the pin.
502 Super Glue for Scale Models from $10.95
Why it helps: A thin, fast-setting 502 cyanoacrylate for plastic, metal, resin and wood.

How to use it
Place a small drop in the pin hole, press the pin in and hold the joint.
Cormake Parts Separators from $12.45
Why it helps: A parts separator with four heads, sharp enough to enter a joint and blunt enough not to damage the plastic.

How to use it
Open joints evenly next time so pegs are not stressed.
AB Epoxy Putty for Scale Modeling $16.95
Why it helps: A two-part epoxy putty for filling seams and repairing broken parts, in quick and slow-dry versions.

How to use it
Rebuild a missing tab or fill a gap around the pin, then sand once cured.