The three ways to glue 3D prints
Before looking at the material, it helps to know the three main methods. Read on to find out which one works best for each material.
Method 1: Super glue (CA glue) is what most people call "super glue." It cures in seconds and works on most filaments, especially if the surfaces are clean and lightly sanded. The bond becomes hard and relatively brittle, so it’s not the best choice for parts that vibrate, flex, or take a hit. A gel version is handy because it allows for more precise application.
Method 2: Epoxy consists of two components (resin and hardener) that you mix before use. Once cured, it creates a strong, tough bond that also fills small gaps. Epoxy takes time to cure, so you need to align and clamp the parts securely while they dry. It’s slower than super glue, but more reliable for parts that will be under stress.
Method 3: Solvent welding isn't glue in the traditional sense. You use a solvent that briefly dissolves the surface of both parts, causing them to fuse into one piece as they cure. This creates a virtually seamless, strong bond. This method only works on materials that dissolve in the specific solvent used, and it requires caution and good ventilation.
Gluing PLA
PLA is the easiest of all filaments to glue. For most connections, a good super glue (CA glue) is the fastest and most convenient choice, preferably a gel version for precision.
For parts that need to withstand more force, or where you want to fill small gaps, go with epoxy.
PLA is also suitable for solvent welding, although it's less common. Specific solvents like methyl acetate dissolve PLA and create a strong, seamless bond. Acetone has inconsistent results with PLA and doesn't dissolve it reliably, so don't count on it. Stick to super glue or epoxy for PLA, and you'll almost always be fine.
Gluing PETG
PETG requires a bit more preparation than PLA because the surface is smoother and sometimes slightly greasy. Always lightly sand the surfaces to be glued and degrease them with isopropyl alcohol before you start. If the glue doesn't stick well, it's almost always due to insufficient preparation.
Super glue works on PETG, but epoxy often adheres more reliably and provides a stronger bond. Important to know: solvent welding with acetone does NOT work on PETG. The material doesn't dissolve in acetone, so that method is out. For PETG, choose a roughened surface plus epoxy for the best results.
Gluing ABS
ABS is easy to glue and has one major advantage: it dissolves in acetone, making solvent welding an excellent option. By lightly dampening both surfaces with acetone and pressing them together, they fuse into a bond as strong as the material itself. This creates the cleanest, most seamless results on ABS.
Want to keep it simple? Super glue or epoxy also work great on ABS. Always work in a well-ventilated area when using acetone, as the fumes are harmful and flammable. By the way, that same acetone is also used to smooth out ABS surfaces, as you can read in how to smooth a 3D print.
How to glue two 3D prints together
Regardless of the glue you choose, the process is mostly the same. Good preparation determines whether the bond will hold.
- Make the surfaces fit. Check that the two parts line up properly. Sand down any imperfections so there are no gaps left.
- Lightly roughen. Lightly sand the surfaces to be glued with sandpaper (around 220 grit). A rough surface adheres better than a smooth one. This step is extra important for PETG.
- Degrease and clean. Wipe the surfaces with isopropyl alcohol to remove grease, dust, and support residue. Let them dry.
- Apply a thin layer of glue. Use as little glue as possible on one of the two surfaces. Too much glue will squeeze out along the seam and make a mess.
- Press and hold. Press the parts firmly together and align them well. With epoxy, clamp or tape the parts in place while they cure.
- Let it cure completely. Super glue grabs in seconds, but doesn't reach full strength for several hours. Epoxy and solvent welding often need overnight. Patience results in the strongest bond.
Wipe away excess glue immediately before it hardens. With super glue, too much glue can also leave a white haze around the seam.
Visible seam? Here’s how to hide it
Is a seam still visible after gluing? You can fill, sand, and paint it for a clean finish. You can read how to do that in our guides on smoothing a 3D print and painting a 3D printNever place a seam on functional parts at a critical contact surface or a fit.
Frequently asked questions about gluing 3D prints
What is the best glue for 3D prints?
For most prints, super glue (CA glue) is the quickest choice, while epoxy is the strongest. Super glue is ideal for small parts that aren't under heavy load, and epoxy is best for joints that need strength or gap filling. The best choice depends on your material and how much stress the part will be under.
Can you glue PLA with super glue?
Yes. PLA is excellent for gluing with super glue, especially a gel variant for precision. Lightly sand the surfaces and degrease them for the best bond. For parts under heavier loads, choose epoxy.
Which glue works on PETG?
Super glue works on PETG, but epoxy is often more reliable and stronger. Always lightly sand the smooth surface and degrease it, otherwise the bond will be weak. Gluing with acetone doesn't work on PETG because the material doesn't dissolve in it.
Can you glue ABS with acetone?
Yes. ABS dissolves in acetone, making solvent welding work well: lightly moisten both surfaces and press them together until they fuse. This creates a very strong, seamless bond. Always work in a well-ventilated area, as acetone vapors are harmful and flammable.
How strong is a glued 3D print?
That depends on the material, the glue, the preparation, and the load. A well-prepared epoxy or solvent bond can be almost as strong as the material itself. For heavily loaded parts, additional mechanical reinforcement, such as a screw or pin, is sometimes wise.
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