Best Glue for 3D Printing - How to bond PLA, ABS, PETG & Co.

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Martin has a M.Sc. in physics and has gained many years of experience in industry as a lab manager and quality assurance manager. He has now tested dozens of 3D printers and is happy to share the collected experience with each new article.

Superglue

For most 3D projects, cyanoacrylate or superglue* is the easiest way for gluing individual parts together. Handling is uncomplicated and the adhesive hardens within a very short time. You will get great results and a smooth seam between the glued objects.

However, before using super glue you should know exactly which parts you want to join together and how, because the glue really cures in seconds. Therefore, align the parts correctly before curing and hold them together for some time (depending on the super glue). In order for the glue to cure completely, you should fix the individual objects for a few more minutes to be on the safe side.

Superglue is suitable for bonding most 3D printing materials, with the exception of flexible plastics. The reason is that these type of glues form a thin, rigid layer during curing, which can easily break when applied to elastic materials. So you should only use superglue on rigid plastics such as ABS*, PLA* or PETG*.

If the surfaces of the glued pieces are too rough, you should use fine sandpaper to prepare them and make them sufficiently flat. Additionally, clean the surface with rubbing alcohol. THe surfaces you want to glue together should be completely free of dirt and fluids and oils like fingerprints.

Since superglue cures exceptionally fast, you should avoid skin contact at all times. To protect the work surface from damage, you should carefully cover it with old newspapers.

Acetone

If you want to bond ABS*, PLA* or HIPS*, you can use acetone* or an paint thinner*. In general, any acetone-soluble material is suitable for bonding to this material. With acetone, you will achieve a very strong bond and also get a nearly invisible seam.

To bond two individual parts with acetone, first, apply a thin layer to both surfaces to be bonded. You can use a small brush or fabric soaked in acetone. But be careful with the acetone because too much of it can cause damage to your 3D printed part.

This is especially true if the objects are very thin. The acetone melts the top layer of your 3D prints. If you press two parts together, their top layers will mix together.

During the drying time, it is advisable to fix the parts to be glued with adhesive tape or with the help of staples. Depending on the size of the parts and the amount of acetone used, this evaporates within a few minutes or hours and a strong and compact plastic layer is formed.

This is the best way to connect two parts made of PLA, ABS or HIPS. This is a very strong gluing method and if you do it correctly, the seam between the parts is almost invisible.

Be careful with acetone – it can ruin your 3D print if used incorrectly! (source: reddit)

Make sure that both surfaces are free of both grease and dirt before you apply the acetone. It is best to use some sandpaper to smooth out the corresponding areas.

Acetone is a flammable liquid. Never use it near fire, sparks or hot surfaces. Since acetone is also a toxic liquid, you should only work with it in a well-ventilated area or outdoors. If you experience dizziness or lightheadedness during use, get out into the fresh air immediately.

Pipe Cement

You can also use Pipe cement* for bonding PLA, ABS and HIPS. This is a solvent-based adhesive that reacts with plastic like acetone. The cement makes the bond extremly strong. Otherwise, the same properties apply to cement as to acetone. Plumber’s cement is not suitable for use on PETG*, nylon* or similar filaments.

Before gluing, make sure that the affected surfaces are free of grease and dirt and smooth them down with the help of some sandpaper.

Pipe cement is a dense and flammable liquid. So keep it away from fire, hot surfaces or flying sparks. You should also only use plumber’s cement in a well-ventilated area or outdoors. If you get dizzy during use, get out into the fresh air immediately.

Epoxy

Gluing with Epoxy* is also a good way to connect two plastic parts together. It is compatible with most filaments. However, epoxy hardens as it cures and may not be the best option for flexible materials*. These are also bonded together, but end up with a rigid area on the surface.

A positive feature of epoxy is that you can use it as both an adhesive and a filler. If your 3D printed object has a gap, you can fill it with epoxy. When comparing epoxy to other methods of bonding 3D printed objects, it takes more work to get a good bond. Usually, the delivery is done in two separate containers, the contents of which have to be mixed together before gluing. One container contains epoxy resin, the other container contains a hardener. These components must be mixed in a certain ratio. Once you have done this, the mixture is applied to the surfaces to be bonded.

Then you connect the individual parts. Depending on the mixing ratio and type of epoxy, curing can take from a few minutes to several hours. Once the epoxy resin has cured, you can sand or even paint it.

If you use epoxy to bond 3D printed parts, the surfaces do not need to be completely flat. It is no problem to apply the epoxy even in a relatively thick layer.

Since some types of epoxy develop very high temperatures during mixing, you should adhere to the manual and the safety instructions!

Polyurethane and Silicone Adhesives

Both polyurethane and silicone adhesives* allow you to create a very strong bond between two parts very quickly. However, both adhesives have the disadvantage that they require a layer of a minimum of a few millimeters for a sufficiently strong connection.

This circumstance makes it difficult to hide the adhesive seams. The silicone adhesive needs a few hours to cure completely. Some types of polyurethane adhesives, however, cure within seconds.

Since there are lots of polyurethane and silicone adhesives with different properties available, you should test your chosen product before applying it to the 3D printed parts you are going to produce.

To prepare the adhesive surface optimally, you should clean both pieces thoroughly. Also with this adhesive, it is important to avoid skin contact at all costs.

Hot Glue

The classic hot-melt adhesive* is a simple alternative to all the other solutions. The bond produced is usually very strong, but hot melt adhesive requires a thickness of two to three millimeters. This makes it difficult to hide the seams, which you should consider when designing your 3D printed model. A big advantage of this adhesive is that it is ready in seconds, so you don’t have to fix the pieces as they dry.

Before applying the adhesive, carefully clean only the affected surfaces from loose particles. Hot melt adhesive can be applied to all rigid materials such as ABS, PLA or PETG. As the name suggests, hot melt adhesive is very hot. Therefore, take care not to burn yourself while working with it.

3D Printing Pen

You can get a beautiful result with 3D pens*. Bonded parts look like they were printed in one piece because the adhesive uses the same filament you used to print the parts. Unfortunately, the bond is not very strong, so you can only use this technique on models that are not to be actively used. You should also note that the 3D printed model must be made from the same filament as the 3D printing pen.

Before applying the adhesive mass, you should remove loose particles from both surfaces. The filament emerging from the 3D pen is also a hot adhesive, so be careful during the gluing process.

PLA Hot Glue Gun

A great idea is to just use a Hot Glue Gun* with PLA sticks! This method of joining two parts together creates a very strong bond. You also have the ability to customize both color and material.

Before applying the hot filament you should again clean both surfaces thoroughly. As with the hot glue gun, caution is required – the escaping material is hot and should therefore not come into contact with the skin.

Glue Stick for Better Printing Bed Adhesion

You now know how to join individual 3D-printed parts together using various adhesives. Often, however, a special glue stick for 3D printing* is used during the 3D printing process.

This can help 3D printing adhere better to the print bed. A high-quality printout also requires optimal print bed adhesion. Poor adhesion, however, can lead to faulty prints. There are many different ways to ensure that your 3D printed model adheres properly to the printing bed. These include painter’s tape, hairspray or a glass printing bed. However, the traditional glue stick has proven to be one of the easiest and most commonly used methods.

Advantages of the glue stick, as opposed to other options for fixing the print model on the printing bed, are

Easy cleaning:
Many glue sticks are water-soluble, which makes cleaning quick and easy. The use of adhesive tape can leave residue on the printing bed, which makes removal a challenge.
Easy to use:
Unlike sprays, glue sticks are applied directly to the printing bed to prevent the area around the printing bed from sticking. In the case of adhesive tapes, the correct alignment and application is a particular challenge.
Easy removal of the print:
In contrast to other methods, the glue stick allows the printed model to simply chip off when the printing bed cools down. This is a great and practical advantage for you as a user. In addition, the use of some types of filaments, such as PETG, can lead to permanent adhesion to a glass bed. However, glue sticks prevent this.

The most popular glue sticks for the optimal preparation of the printing bed are

Elmer’s disappearing purple glue stick

Elmer’s is one of the most productive glue manufacturers and has been producing innovative glues for over 65 years. The disappearing purple glue stick* is especially characterized by the color change effect.

It is purple when applied, but becomes transparent after drying. If you want to ensure effective coverage of your printing bed, this glue stick with its harder consistency is a good help when applying a thin layer. Possible gaps in the adhesive cover are very easy to detect due to its color.

UHU pen

As early as 1931, the UHU company created the first copy of the well-known all-purpose adhesive*. This is not only suitable for paper or cardboard, but also very useful in the field of 3D printing.

Due to the soft consistency of the glue stick, you can easily apply a thin layer on your printing bed. In addition, the comfortable handle allows you to adjust exactly how much glue should be exposed. The practical screw cap guarantees that the glue stick never dries out.

Magigoo

Magigoo is a specially formulated adhesive manufactured by Thought3D. It is a liquid adhesive in a pen, which is deposited through a felt membrane.

The pen applicator is especially popular with the 3D printing community because the consistency of the fluid it contains is optimal for smooth application to the printing bed. Once the heated print bed cools, the adhesive is automatically deactivated. This allows you to easily remove the 3D printed object once it is finished.

Scotch Purple Glue Stick

Scotch is an own brand of the company 3M and is known for the transparent adhesive tape, which is produced since 1930. In addition to the adhesive tape, the company also produces decorative articles and adhesives. Similar to other glue sticks, the Scotch glue stick* is easy to apply because the adhesive has a firmer consistency.

The biggest advantage, however, is that the adhesive – like the glue stick from Elmer’s – is applied in purple and becomes transparent during drying. This makes it easier for you to see if you have forgotten individual areas on the printing bed. To clean a 3D glass printing bed, simply use a mild soap and a little water.

LAYERNEER Bed Weld

There is even a new product on the market that reduces warping and other negative side effects of bad adhesion: the Bed Weld from LAYERNEER*:

Best Glue for 3D Printing – How to bond PLA, ABS, PETG & Co.