How to Fix Broken 3D Printed Parts – PLA, ABS, PETG, TPU
3D printing is great for creating parts, but with some models, we might end up with broken 3D printed parts. This can be due to weak points in the models, which sometimes can’t be avoided, but what we can do is learn to fix these broken parts.
You should glue broken 3D parts together with epoxy or superglue carefully, making sure the surfaces are cleaned up with sandpaper. You can also use a hot gun to melt materials like PLA then rejoin them, so the pieces bind together.
There are some key details that you’ll want to know when it comes to fix your broken 3D printed parts properly, so stick around and find out some extra tips.
How to Fix the Broken 3D Printed Parts
Fixing broken 3D printed parts isn’t too hard as long as you have the right information behind you. Sometimes it isn’t necessarily fixing broken parts either, where you just want to combine different parts of a larger 3D printed model.
Depending on what your situation is, you are going to want to use an adhesive substance to fix your broken 3D printed parts. There are other ways and materials that 3D printer users make use of when repairing parts, which will be described in this article.
The best ways to fix a broken 3D printed part is to:
- Prepare a flat, stable surface for you to work on
- Gather the broken 3D printed parts, along with an adhesive such as superglue or epoxy
- Sand down or remove rough pieces that may get in the way of bonding the main pieces together.
- Apply a small amount of your adhesive to the main part
- Connect the broken 3D printed part to the main part, then hold it together for around 20 seconds so it creates a bond.
- You should now be able to place the object down and let it cure over a short period of time.
One of the most common, and better options for fixing broken 3D printed parts is using superglue. It’s very cheap, easy-to-use and cures relatively quickly. You can easily get amazing results and a strong bond between two parts in a matter of seconds.
Many people wonder whether superglue works on PLA, and it does work very well.
The first thing you’ll need to do is clear the rougher surfaces of the printed parts which are getting bonded together. It’s a good idea to use sandpaper to get the surfaces
What you need to do is to clear the rough surface of the printer parts which are getting bonded with sandpaper to get them flat.
Clean the surface with alcohol, and let it rest and get dry. Then apply the superglue to the affected area where you want to bond the pieces.
You have to be careful and prepared with it as it cures faster, and you won’t get much time to relax after applying it. You can leave it on the printer parts for a couple of minutes, and then you are good to go.
This method is useful for rigid materials such as PLA, ABS & PETG, etc.
Superglue isn’t very effective for flexible materials like TPU, TPE & Nylon.
Weld the Gap with a Piece of Filament
- A piece of filament from same printed piece
- A soldering iron (chisel-tip)
- Some good steady hands!
The video below really illustrates this method, which is great if you have a large gap or crevice in your broken 3D printed part.
Some broken parts aren’t simply two pieces that need to be glued on, so in those cases, this method should really be helpful.
There is a little bit of a blemish on the finished part when you repair your broken model, but you can simply add extra melted filament to the part and sand it down in line with the rest of the model.
This method is mainly used for ABS, but some people have used it for other materials like PLA & HIPS (depending on the type and manufacturer). Acetone does a good job dissolving ABS, which is why it’s used to smooth it with vapor.
You can also use this dissolving to your advantage when fixing a broken 3D print.
The method to fix broken 3D printed parts with acetone is:
- Clean the surface of both 3D printed parts with sandpaper to flatten the surface
- Apply a thin layer of acetone to both surfaces with a brush or a cloth
- Now connect the two pieces with a clamp or even some tape and let it sit
- After drying out, your pieces should be nicely bonded back together
Disclaimer: Be very careful with acetone because it is a highly flammable liquid, which shouldn’t be used next to any open flames.
For HIPS, I would use limonene as your solvent as it works pretty well.
You can use plumber’s cement to join the two or more parts of the broken 3D print, especially for PLA, ABS and HIPS. It works as a solvent, similar to acetone or dichloromethane for PLA.
You have to clean the surface from grease and dirt, and you can use sandpaper to flatten the surface before applying it. After cleaning, apply the material on both parts, and you will get a strong bond in minutes.
However, the bonding will be visible because the cement comes in either red or yellow color.
Keep in mind that plumber’s cement won’t work with Nylon, PETG and similar filament.
The product is flammable, and you have to keep it away from sparks and flames while using it.
Epoxy is great when it comes to bonding but not so great when it comes to flexible bonding parts, and it actually makes them rigid after drying.
The best thing about epoxy is that you can use it for both bonding the two parts, and filling up the gaps between the parts.
A great epoxy that you can get from Amazon is the BSI Quik-Cure Epoxy. It’s made in the USA and does a great job of handling parts, with just a 5-minute working time.
This epoxy comes in two containers which contain two different materials, with simple instructions to follow to fix your broken 3D printed parts.
You have to combine both the materials and create a mixture of them for your purpose. You have to be sure that you are following a certain ration while mixing the two materials to create a solution for bonding.
After you have mixed them thoroughly, you can apply the mixture to the surfaces which you want to bond together. It will take some time to get dry, depending on the ration of the added materials.
You can use it in all kinds of materials but always read the manual to know about the mixing ratio, which you are required to use for a particular surface.
The AdTech 2-Temp Dual Temperature Hot Glue Gun provides strong bonding for virtually all materials, including your broken 3D prints.
This is an excellent alternative for gluing 3D printed parts together, and you can get a pretty good strong bond. However, the applied glue part will be visible to the naked eye.
It requires almost 2-3 mm in thickness for its adherence to the printed parts. Moreover, the hot glue after applying cools down in no time.
What you are required to do is clean the surface from the loose particles with sandpaper and then use the hot glue and apply it to the surface. Moreover, be careful with it, it is hot glue, so it’s going to be hot of course.
Best Glue/SuperGlue to Fix Broken Prints
The best superglue present in the market is Gorilla Glue XL Clear from Amazon. One of the best characteristics is how it has a no-run control gel formula, ideal for any vertical surfaces.
It also has an anti-clog cap, which helps in keeping the glue from drying out. It hardly takes 10-45 seconds to dry after applying, and your broken 3D printed parts can easily be bonded together.
I’ve used it plenty of times successfully, since thin parts of a 3D print can easily be broken when trying to remove those supports.
How to Fix Broken PLA 3D Printed Parts
So, as mentioned above, the easiest way to fix broken PLA 3D printed parts is to use a good quality superglue to bond the two pieces together. It isn’t a very complicated process and can be done very quickly.
Using the tips above, you should be able to follow along with the process and get your parts fixed nicely.
Here is another video that goes through gluing your 3D printed parts together which gets a little more detailed and precise.
Instead of just using superglue, the tutorial below uses:
- Rubber Bands
- Spray activator
- Paper towels
- Putty knife/Xacto knife
You can choose to use a filler and putty knife to smooth down the filler in line with your part. This is great if you are looking to paint your 3D printed parts.
How to Fix Broken ABS 3D Printer Parts
As described above, the best way to fix broken ABS parts is to apply acetone to both parts, and bind them together using a clamp, rubber bands or even tape.
This dissolves a small part of the ABS plastic and after curing, bonds the two pieces together.
How to Fix Broken TPU 3D Printer Parts
The video below shows a perfect illustration of using a heat gun to repair a broken TPU 3D printed part.
It shows a black TPU part which is going to absorb heat a little better than other colors, but 200°C was all that was needed.
You should make sure you use heat-resistant gloves and hold the two broken pieces together enough for it to cool down.
How to Fix Holes in 3D Prints
The gaps or holes which appear in the plain surface of the 3D print could be the cause of insufficient solid layer at the top, or your fill rate of the filament (under extrusion) was too low, or you might have provided insufficient material.
This phenomenon is called pillowing, which can usually be corrected by increasing number of ‘Top Layers’ or ‘Top Layer Thickness’ in your slicer settings.
Nozzle size during the printing and its height from the printing bed also cause under extrusion, which results in holes in the printer parts.
You can get your hands on a 3D pen to fill the gaps and holes you see after the printing process. Clean the surface from the loose particles, and before using the pen, make sure both the materials of 3D pen and printer parts are the same.
It covers all kinds of materials, and you can easily fill the holes and gaps present in the surface through it.