How to glue 3D prints: Getting started

Working with a 3D printer is a lot of fun. But the parts are often made of types of plastic which are not compatible with certain glues. Some designs are simply too big to 3D print in one piece, so to create bigger 3D printed models made of PLA, ABS, PVA or PC you need to know how to glue 3D printed parts together. 

Generally speaking, the best glues for 3D prints are super glue or epoxy resin as these form strong bonds with the plastics used. 

To decide which glue suits your needs, check what kind of plastic you’re working with. Epoxy and super glue are great for 3D printed parts made of PLA, PETG and ABS. Then assess how flexible the joints have to be. If the pieces are to be attached in a flexible way, you need a flexible super glue. If, on the other hand, you want to build a sturdier structure, an epoxy resin is the right choice. 

Unibond Repair Epoxy Plastic is a fast-setting epoxy – ideal for creating strong bonds and repairing most plastics. Not only can it be used to glue 3D printed parts together, it’s also ideal for gluing 3D prints to other common surfaces such as wood, leather, metal, glass and ceramics. Plus, you can fill in gaps or cracks in your models. 

Before you start to glue 3D printed parts together, you need to prepare your space and ensure that you have the following items at hand: 

• neoprene or nitrile gloves for handling 3D prints and solvents
• plastic sheet or other suitable covering to protect your workspace 
• a bowl of warm soapy water and a toothbrush for cleaning 3D parts
• clean cloths
• sandpaper
• Unibond Repair Epoxy Plastic
• solvent for cleaning up any spilled glue (make sure to adhere to the instructions)
• utility knife for cutting away any excess cured glue

Remember: Make sure your workspace is ventilated and wear gloves to protect your skin.

To ensure the best results with epoxy adhesive, take the following steps: 

1. Sand your printed pieces. If you’re fixing two large pieces together, sanding them with sandpaper creates a rougher texture and helps the adhesive form stronger bonds. 
2. Clean the surfaces thoroughly. Using warm, soapy water and a toothbrush, clean all the 3D parts of dust and dirt. 
3. Pre-fit the pieces. Before applying the glue, make sure that you know where and how the pieces will fit. 

Now that the 3D printed parts are prepared, you’re ready to start attaching them.

1. Prepare the epoxy adhesive. Unibond Repair Epoxy Plastic is a two-component epoxy adhesive that comes in a twin chamber syringe – all you have to do is cut the end of the nozzle and push the plunger to apply both the resin and hardener at the same time. Then mix it together. 
2. Apply the adhesive. For best results, apply the epoxy adhesive to one surface. 
3. Attach surfaces together. Using your hands or a clamp, stick the two surfaces together firmly and hold for 5 minutes. Then, either leave the pieces on a flat surface or in the clamp for a couple of hours or overnight. 
4. Clean up. Use a cloth dipped in some solvent (check the manufacturer’s instructions) to clean up any spilled adhesive or excess glue around your 3D prints. Once the glue has set, cut away any extra bits of glue with a utility knife.