How to Permanently Build Legos

If you're wondering how can I permanently build LEGO models? you're not alone. Many LEGO enthusiasts, artists, and public exhibit curators face this question when they want their creations to stay intact over time. Gluing LEGO bricks together is a common and effective method for making permanent builds. This is especially useful for display pieces, installations, or models in public spaces where the bricks need to stay together despite frequent handling or exposure to different environments. In this blog, we’ll guide you through the process of permanently bonding LEGO models and offer tips on the best adhesives to use for your builds.

1. Understand the Goal and Consider Alternatives

Permanently Bonding LEGO

When we talk about permanently bonding LEGO, we mean that the pieces will no longer be able to come apart without causing some damage. This process is ideal for models that need to stay intact over a long period of time, such as display models, installations, or public exhibits. If you're creating something that will be handled frequently or is meant to be a permanent part of a display, gluing is a good solution. It ensures that your LEGO creation remains stable and tamper-proof, even if it’s being touched or moved around by others.

This approach is great for those who want to make sure their LEGO creations remain surdy and intact without the risk of them falling apart during handling or display.

Alternatives

If you only need to keep a model together temporarily—for example, for storage, transport, or a temporary display—gluing may not be the best option. Instead, consider alternatives like carefully boxing or wrapping the model in plastic to keep it intact without making it permanent. This allows for easy disassembly later on if needed.

Remember, gluing LEGO bricks is irreversible and reduces the reusability of the pieces. Once glued, your bricks cannot be easily taken apart and reused for other builds. This makes gluing less suitable for casual builds or situations where you might want to take apart your creation and rebuild it later.

2. Best Adhesives for Permanent LEGO Builds

a. Solvent-Based Glues (Professional Method)

MEK (Methyl Ethyl Ketone) / Butanone:

• MEK is the preferred adhesive used by professional LEGO builders and at LEGOLAND parks, and it's known for creating a seamless and extremely strong bond.

• MEK works by chemically melting the surface of the ABS plastic that LEGO is made from, which allows the bricks to fuse together at a molecular level. This creates an incredibly durable bond that ensures your model stays together permanently.

Application:

• Use a fine-tipped applicator or brush to apply a small amount of MEK to the connecting surfaces between bricks. Press the bricks together for about 30 seconds, allowing them to bond securely.

• Let the model cure for at least 24 hours in a well-ventilated area to ensure the bond sets properly.

Safety:

• MEK is a hazardous chemical, so it's essential to take safety precautions when using it. Always wear gloves, goggles, and work in a well-ventilated area (preferably outdoors). Avoid direct skin and eye contact, and never inhale the fumes.

b. Plastic Model Glues

ABS/Polystyrene Cement:

• These glues are specifically designed for bonding ABS plastics, which is the material LEGO bricks are made from. While they create a strong bond, they are less aggressive than MEK, making them a good option for home use.

Brands:

• Look for model-making adhesives such as UHU Allplast, Pattex PXSM1, or similar products that are designed for ABS or polystyrene bonding.

Application:

• Apply the glue sparingly to clean surfaces, then press the bricks together. Allow the model to cure as per the manufacturer's recommendations for the best bond.

c. Cyanoacrylate (Super Glue) and Epoxy

Super Glue (Cyanoacrylate):

• Super glue is known for its fast-setting, strong bond. However, it's more suited for smaller applications or quick fixes, as it can leave visible residue on the bricks and isn’t as durable for large builds.

Warnings:

• Super glue can bond skin instantly, so use caution when handling it. It's also difficult to work with in larger quantities, and it might not hold up well over time in large models.

Epoxy Glue:

• Epoxy is an excellent adhesive for creating a very strong bond, and it’s ideal for specific applications where a stronger hold is needed, such as heavy-duty or gap-filling areas.

Application:

• Epoxy glue requires mixing before application, and it tends to be a bit messier than other adhesives. Be cautious, as it can fill gaps and affect the overall aesthetic of the model.

Curing:

• Epoxy requires a longer curing time compared to other adhesives, so ensure you let your model sit undisturbed for the full curing period.

3. Step-by-Step Instructions

Clean the Bricks
Before starting the gluing process, make sure that all LEGO bricks are clean and free from any dust, oil, or residue. Cleaning the bricks ensures the best possible bond between the pieces. Use a dry cloth or a soft brush to remove any debris. For tougher grime, you can use a gentle cleaning solution, but ensure the bricks are completely dry before applying any adhesive.

Test the Adhesive
Before gluing your entire model, it’s important to test the chosen adhesive on a spare or hidden brick. This step allows you to check for any unwanted discoloration, residue, or negative effects the glue might have on the plastic. Testing also ensures that the adhesive bonds well and does not cause any damage to the bricks.

Apply the Adhesive
Using a fine applicator or brush, apply a small amount of glue to the contact points between the LEGO bricks. It’s crucial to use only a tiny amount of adhesive—too much can damage the bricks or cause the glue to seep out from the sides, making a mess. A small amount is sufficient to form a strong bond between the pieces. Make sure to apply the glue only where the bricks will connect to avoid excess spreading.

Join the Bricks
Once the adhesive is applied, press the LEGO pieces together firmly. For most adhesives, hold the bricks together for the recommended time—usually about 30 seconds for solvent-based glues. For epoxies, it may take longer. Ensure the pieces stay aligned as the adhesive sets. This is the key step in ensuring a strong bond.

Cure the Model
After pressing the bricks together, it’s essential to let the model sit undisturbed for the full curing time—typically 24 hours—depending on the type of glue used. During this time, the adhesive will bond the pieces securely, ensuring that the model stays together permanently. Always leave the model in a well-ventilated area during the curing process to allow the glue to fully set.

Clean Up
If any adhesive seeps out from the joints while the pieces are pressed together, carefully remove it with a suitable solvent before it dries. Once dried, excess adhesive can be difficult to clean, potentially damaging the appearance of your model. Be sure to clean any visible glue immediately to maintain the pristine look of your LEGO creation.

4. Important Safety and Practical Tips

Ventilation: Always work in a well-ventilated area, especially when using strong solvents like MEK or acetone. These chemicals emit fumes that can be harmful if inhaled for prolonged periods.

Protective Gear: When working with potentially hazardous chemicals like MEK or super glue, wear gloves and goggles to protect your skin and eyes from irritation or injury.

Avoid Transparent Elements: It’s important to avoid gluing transparent LEGO elements. The solvents used in adhesives can cause clouding or permanent damage to clear plastic, ruining the aesthetics of your model.

No Spray Adhesives: While spray adhesives may seem convenient, they don’t penetrate the studs and sockets of the LEGO bricks effectively, resulting in a weak bond. Additionally, they can make the application process messier and harder to control.

Permanent Bonds: Remember that once you glue LEGO bricks together, they cannot be easily separated without causing damage. Make sure you are certain that the model is final before committing to gluing it, as you will not be able to reuse the pieces without altering their integrity.