How to glue 3D printed parts
There is no single adhesive that is optimal for every filament and every load case. Bond performance depends on polymer, surface preparation, joint geometry, load direction and the adhesive itself. For functional parts, design the joint so that the adhesive does not have to carry the entire load by itself.
Prepare the surface
Common good practice:
- remove dust
- avoid grease
- keep surfaces clean
- lightly abrade if recommended by the adhesive manufacturer
PLA
Many cyanoacrylate and two-part systems can work on PLA. Suitability still depends on load, temperature and surface area.
PETG
PETG can be more difficult to bond reliably. Do not assume that a glue that works well on PLA will behave the same on PETG.
ASA / ABS
Some solvent-based methods can chemically soften these polymers. Only use appropriate products and follow safety information.
TPU
Flexible parts need a bond that can tolerate movement. A brittle adhesive may fail even if initial adhesion is good.
Better joint geometry
Prefer large overlap + mechanical guidance + adhesive, over small butt joint + adhesive carries everything.