How to Assemble a Multi-Part Resin Figure Kit

String tension resin pieces together into a finished figure is one of the most satisfying parts of the hobby, but it's also where a lot of kits go wrong before the paintbrush ever touches them. Multi-part resin figures — full-body kits with separate arms, heads, weapons, and bases — need a bit more care than a single-piece miniature. Get the assembly right and you'll have a clean, sturdy model ready for primer. Get it wrong and you'll be fighting gaps, misaligned joints, and snapped pins for the rest of the build. Here's a practical walkthrough for assembling a multi-part resin kit from the box to primer-ready.

What You'll Need Before You Start

Resin assembly rewards having the right tools on hand rather than improvising halfway through. At minimum, gather:

A hobby knife or resin-rated clippers for trimming casting flash

Fine files or wet/dry sandpaper (400–1000 grit) for cleaning mold lines

A pin vise with small drill bits (0.5mm–1.5mm is typical) for pinning

Brass rod or paperclip wire for pins

Cyanoacrylate (CA/super) glue, ideally both thin and gap-filling formulas

A CA accelerator or baking soda for instant bonds on larger joints

Two-part epoxy putty for gap filling

Nitrile gloves and a dust mask for sanding

Resin dust is fine and shouldn't be inhaled, so always sand or file over a damp paper towel or under light water to keep dust down.

Cleaning and Prepping the Parts

Every CastForge kit ships unpainted and unassembled in raw grey resin, straight from the mold, which means each piece will have some casting artifacts to clean up before it fits properly. Look for:

Mold lines — thin raised seams where the mold halves met. Scrape these off with a hobby knife or light sanding.

Flash — thin webs of excess resin, common around fingers, weapon edges, and folds in cloth.

Casting nubs — small stubs where the part was attached to the pour block. Cut these flush, then sand smooth.

Vents — tiny resin nibs from air release points, especially on undercuts and helmet crests.

Take your time here. A joint that looks fine with flash still attached will often not seat correctly once you start dry-fitting, so clean first, test-fit second.

Dry-Fit Everything Before Gluing

This is the step most beginners skip, and it's the one that saves the most frustration. Before any glue touches resin, assemble the whole figure loosely — hold arms in place, check how the head sits on the neck, see how a weapon rests in a hand. You're looking for:

Gaps that will need filling later

Parts that need trimming to sit flush

The natural pose the sculpt wants to hold, so you're not fighting the geometry

For larger kits with separate cloaks, packs, or weapon arms, it also helps to number or label parts with a pencil, since resin sprues rarely include a clear parts diagram the way plastic kits do. If you're building a figure meant to interact with terrain — kneeling behind cover, reaching for a doorway, or scaled to match a scenic base — this is also the point to test the pose against the piece it'll sit on. CastForge's terrain and diorama pieces are sculpted to work with full-body kits, so a quick dry-fit against the actual base or scenery avoids surprises after everything's glued.

Pinning for Strength

Resin is more brittle than plastic, and CA glue alone often isn't enough to hold weight-bearing joints like shoulders, waists, or long weapons at an angle. Pinning reinforces the joint with a length of wire running through both parts.

To pin a joint:

1. Mark the center point on both mating surfaces.

2. Drill a small hole into each part with your pin vise, matched to your wire's diameter.

3. Cut a short length of brass rod or wire, slightly longer than the combined hole depth.

4. Dry-fit the pin in one half first to check alignment before adding glue.

5. Apply a small amount of CA glue to the pin and both surfaces, then join the parts and hold until set.

Pinning is especially worth the extra few minutes on arms holding weapons out from the body, tall banners or standards, and any bust mounted on a separate plinth. If you're assembling a display bust rather than a full figure, the same pinning approach applies to attaching the sculpt to its base — worth checking CastForge's bust kits if you want a piece built specifically for that kind of display mount.

Gluing the Joints

With everything dry-fitted and pinned where needed, it's time to commit. A few rules of thumb for resin specifically:

Thin CA glue wicks into tight, well-fitted joints by capillary action — apply it to the seam after the parts are already held in position.

Gap-filling CA is better for joints with slightly uneven surfaces, since it won't run before it sets.

Accelerator speeds up cure time dramatically, which is useful for holding an arm in place without waiting minutes for it to set, but apply it sparingly since it can leave a slight white residue if overused.

Work in a ventilated space — resin and CA fumes together are more noticeable than either alone.

Assemble in a logical order: torso and legs first, then arms, then smaller details like weapons, packs, or loose cloth last. This gives you room to adjust angles before the model is too fragile to handle.

Filling Gaps and Final Cleanup

Even a well-prepped kit will usually have a few seams or small gaps left after gluing. Two-part epoxy putty is the standard fix — a small amount worked into the gap, smoothed with a wet tool or your finger, then left to cure before final sanding. For very fine seams, a thinned CA glue "skim coat" sanded back afterward works well too.

Once everything is filled and sanded smooth, give the whole model a final rinse to remove sanding dust and any mold-release residue left over from casting, then let it dry fully before priming.

Wrapping Up

Assembling a multi-part resin figure is really a sequence of small, careful steps: clean the parts, dry-fit everything, pin the joints that need it, glue in a sensible order, and fill what's left. None of it is difficult on its own, but rushing any one step tends to show up later in the paint job. Take the extra ten minutes at the dry-fit stage and your finished kit will thank you once the brush comes out.