How do I prepare and assemble miniatures before painting?

Everything you fail to do at this stage is permanently visible under paint. A mould line that looks like nothing on bare grey plastic becomes an obvious ridge running across a painted face, and release agent invisible on the surface makes the primer flake off six months later.

Safety

What you'll need

• A sharp hobby knife with fresh blades
• A mould line scraper or a needle file (optional)
• Clippers designed for miniatures
• Washing-up liquid, an old toothbrush and warm water
• Plastic cement for plastic, superglue for resin and metal

Step by step

1. Identify the material first, because everything else follows from it.Hard polystyrene plastic takes plastic cement and cleans up easily. Softer restic or PVC plastic does not respond to plastic cement and needs superglue. Resin is brittle, takes superglue, and must be wet sanded. White metal is soft, takes superglue or solder, and files easily.
2. Wash resin and metal miniatures before anything else.Resin castings carry mould release agent, which is engineered to stop things sticking and will do exactly that to your primer. Warm water, washing-up liquid, an old toothbrush, a thorough rinse and full drying. Plastic sprues benefit from it too.
3. Clip parts from the sprue leaving a small stub.Cut a couple of millimetres away from the part, then trim the stub flush with a knife. Clipping flush at the part pulls a divot out of the plastic that then has to be filled.
4. Scrape mould lines rather than sanding them.Hold the back edge of a knife blade at right angles to the surface and draw it along the line. It shaves the ridge off without rounding the detail either side, which is exactly what sandpaper does. A dedicated mould line remover does the same job more comfortably.
5. Check for mould lines in the awkward places.They run continuously round a figure, so they cross faces, cloaks, weapons and hands. Look under a good light from several angles — the ones on a curved surface are almost invisible until they are primed.
6. Dry fit before any glue.Especially with multi-part kits and resin, where warping is common. A resin part that does not sit right can often be softened in hot water and bent to fit, which is impossible once glued.
7. Decide your sub-assemblies before you build.The rule is simple: if you cannot get a brush to it once assembled, leave it separate. Heads, arms across the body, cloaks, shields and backpacks are the usual candidates. Pin them or leave the joint dry until after painting.
8. Fill the gaps that assembly leaves.Multi-part miniatures leave a gap at shoulders and waists. Fill with a modelling putty, smooth it with a wet tool, and sculpt in the texture of whatever surrounds it. A gap left unfilled reads as a crack in the figure once painted.
9. Pin heavy metal and resin joints.Drill a small hole in both faces and glue a short length of brass rod or paperclip in. Superglue alone on a heavy metal arm fails the first time the model is knocked, and it always breaks after it is painted.

Tips

• Fresh blades are the difference between scraping a mould line and tearing it. A blade is a consumable, not a tool — change it far more often than feels reasonable.
• A drop of superglue accelerator turns a slow fiddly joint into an instant one, but it makes the bond brittle and fogs the area white, so use it away from surfaces you will paint carefully.
• Keep the sprue offcuts. Stretched over a candle they make excellent thin rods for pinning, spears, aerials and repairs.

Common mistakes

• Skipping the wash on resin — Release agent is invisible and it is the reason a primer coat flakes or a paint job peels months later. It is the single most common cause of adhesion failure on resin, and it takes five minutes to prevent.
• Sanding a mould line on a detailed surface — The abrasive removes the sculpted detail either side faster than it removes the ridge, so you trade a thin line for a flat patch. Scrape instead.
• Assembling everything before painting — You then cannot reach the chest under an arm, the face under a hood, or the back under a cloak. The paint job is compromised before it starts, and no amount of skill recovers it.
• Dry sanding resin — The dust is a genuine respiratory irritant and it is very fine, so it stays airborne. Wet sanding produces a slurry instead and takes no longer.

If it doesn't work

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