For scale 3D models with thin wall thickness, cyanoacrylate (super glue) and plastic cement (e.g., polystyrene cement) are the top choices.
Cyanoacrylate dries quickly, forms a strong bond without adding bulk, and is perfect for delicate thin walls. Plastic cement melts plastic surfaces slightly to create a seamless, durable bond that keeps fine details intact—ideal for plastic scale models.
When working with very thin materials, test a small area first to prevent warping, and use a precision applicator (like a needle tip) for controlled glue application.