Glues for Scale Modelling
Glues for scale modelling
The correct adhesive depends on the materials, the size of the joint and the required working time. Plastic cement, cyanoacrylate, clear-parts adhesive, epoxy and UV-curing products behave differently and are not interchangeable.
Why glue choice matters
An unsuitable product may leave visible marks, craze a clear part, fail to bond resin or metal, or set before the parts are aligned. Always identify the materials and test the fit before applying adhesive. Follow the manufacturer's safety and ventilation instructions.
How plastic cement works
Plastic cement for polystyrene softens the mating surfaces so they fuse as the solvent evaporates. It therefore creates a welded joint rather than simply leaving a layer of glue between the parts. It is intended for compatible plastic and does not normally bond resin or metal.
Thin liquid plastic cement
Thin cement flows into a close-fitting joint by capillary action. Hold the parts together, touch the applicator to the seam and allow the liquid to travel along it.
Advantages
- Precise application on well-fitting joints.
- Little excess when used sparingly.
- Strong welded seams.
- A cured seam can usually be sanded.
Limitations
- Short working time.
- Excess can mark surrounding plastic.
- Touching softened plastic can leave fingerprints.
- It can damage paint and clear plastic.
Thicker plastic cement
Thicker cement stays where it is placed and gives more positioning time. It can be useful for large parts or joints that do not remain closed by themselves. It is easier to see during application, but excess is more likely to squeeze out and curing may take longer.
Cyanoacrylate glue
Cyanoacrylate, often called CA or super glue, bonds many materials and is commonly used for resin, photo-etched metal and mixed-material assemblies. It is available in thin, medium and gel forms.
Thin CA
Flows into narrow gaps and sets rapidly. It requires accurate positioning and very small quantities.
Gel CA
Stays in place, can fill a small gap and allows slightly more time for positioning. The cured joint may remain brittle under impact.
Important precautions
CA bonds skin and eyes extremely quickly. Its vapour can create a white bloom on surrounding surfaces and clear parts. Do not blow on the adhesive and use only with suitable ventilation and protection. Avoid using ordinary CA close to canopies unless the product is explicitly intended for clear parts.
Adhesives for canopies and clear parts
Dedicated clear-parts adhesives and some suitable water-based glues dry transparent and are less likely to attack or fog a canopy. They usually allow adjustment and clean-up with water before curing, but the bond is less structural and takes longer to set.
Epoxy adhesive
Two-part epoxy provides a strong bond and can fill gaps. It is useful for heavy resin parts, metal components and joints needing a longer adjustment time. The two components must be mixed in the specified ratio; excess is bulky and full curing can be slow.
UV-curing adhesive
UV products remain workable until exposed to the required light. They can be useful for small transparent details, controlled filling and some clear-part applications. The light must reach the adhesive, so they are unsuitable for every hidden joint. Follow the product's wavelength and safety directions.
Glue applicators
- Built-in fine brush for liquid cement.
- Microbrush or disposable applicator.
- Fine metal wire or needle for tiny dots.
- Toothpick for gel CA or epoxy.
- Dedicated precision nozzle.
Never return contaminated adhesive to its original container.
Choosing by project
| Material or task | Common choice |
|---|---|
| Close-fitting polystyrene parts | Thin liquid plastic cement |
| Large plastic assembly | Regular or thicker plastic cement |
| Photo-etched metal | Small amount of CA |
| Resin parts | CA or epoxy according to weight and fit |
| Clear canopy | Dedicated clear-parts adhesive |
| Heavy mixed-material joint | Two-part epoxy |
Common beginner mistakes
- Using too much adhesive.
- Gluing before dry-fitting and checking alignment.
- Handling plastic while solvent cement has softened it.
- Using ordinary CA on a clear canopy.
- Assuming plastic cement bonds resin or metal.
- Applying paint before the joint has fully cured.
Conclusion
Use plastic cement to weld compatible polystyrene, CA for small resin and metal parts, clear adhesive for canopies and epoxy for heavier assemblies. Good dry-fitting, precise application and adequate curing time produce stronger, cleaner joints.
