This video tests the adhesion of various glues on PETG 3D printed parts. The creator bonds two PETG cubes with each adhesive, lets them cure, and then attempts to break the bond using a calibrated force gauge. Tested adhesives include super glue, epoxy, UV cure resin, and various specialized plastic glues. The video documents the force required to break each bond and declares a winner based on highest break strength.
This YouTube video, titled "The PETG adhesive test," meticulously documents a comprehensive experiment designed to evaluate the adhesion properties of various commercially available adhesives when bonding Polyethylene Terephthalate Glycol (PETG), a common 3D printing filament known for its strength and flexibility, to itself. The presenter begins by outlining the methodology of the test, emphasizing the controlled environment and consistent application techniques employed to ensure the reliability and repeatability of the results. He meticulously prepares identical PETG test pieces, ensuring consistent surface roughness and cleanliness, a critical factor in adhesive bonding.
The experiment involves bonding two PETG strips together, overlapping them by a predetermined and consistent amount, creating a standardized bond area. Each adhesive, carefully identified and presented to the viewer, is applied according to the manufacturer's instructions, ensuring uniform distribution and consistent bonding layer thickness. After a specified curing period, allowing each adhesive ample time to reach its maximum bonding strength, the presenter subjects each bonded pair of PETG strips to a destructive tensile strength test. This involves applying an increasing force perpendicular to the bonded area until the bond fails, meticulously recording the force required for failure.
The testing apparatus, which appears to be a digitally controlled tensile tester, provides precise measurements of the applied force, offering quantitative data for comparison. The video documents the failure point of each adhesive bond, visually demonstrating the mode of failure, whether it be cohesive (failure within the adhesive itself) or adhesive (failure at the interface between the adhesive and the PETG). Throughout the experiment, the presenter provides detailed commentary, explaining the nuances of each adhesive’s performance, highlighting any observed variations, and drawing preliminary conclusions based on the observed results. The video concludes with a summary of the findings, ranking the adhesives according to their measured bonding strength, effectively providing viewers with empirical data to inform their own adhesive selection when working with PETG. This allows viewers to make informed decisions about which adhesive is best suited for their particular application, considering factors such as required bond strength, environmental conditions, and material compatibility.
Summary of Comments ( 13 )
https://news.ycombinator.com/item?id=42883178
The Hacker News comments on the PETG adhesive test video largely discuss the efficacy of different adhesives for PETG, comparing the results shown in the video with their own experiences. Cyanoacrylate (super glue) is generally agreed to be unsuitable, while specialized PETG glues or more general-purpose plastics adhesives like MEK are favored. Some commenters debate the merits of different brands and application techniques, emphasizing the importance of surface preparation and clamping. Others offer alternative joining methods like solvent welding or mechanical fasteners, particularly for structural applications. A few comments also touch upon the video's production quality and presentation style, with some finding it overly long.
The Hacker News post "The PETG adhesive test [video]" discussing a YouTube video about testing adhesives for PETG plastic has a moderate number of comments, generating a discussion around various aspects of 3D printing and adhesive choices.
Several commenters discuss their preferred adhesives for PETG, with many mentioning CA (cyanoacrylate) glue, also known as super glue. Some specify certain varieties like Loctite gel control or specialized plastic glues, highlighting the importance of viscosity and control for specific applications. The quick setting time and strong bond of CA glue are praised, but some caution its brittleness, especially for parts under stress.
Alternatives to CA glue are also explored. A few users recommend two-part epoxy for its strength and gap-filling properties, particularly useful for structural bonds. Another commenter suggests methyl methacrylate (MMA) cement, noting its ability to chemically weld acrylics and some other plastics, but questioning its suitability for PETG specifically. One commenter specifically mentions using a product called "Plastimake," which they describe as being less brittle than CA glue while maintaining a strong bond.
The discussion also touches on surface preparation techniques to improve adhesion. Sanding the bonding surfaces is suggested to create a rougher surface for the glue to grip. Another commenter mentions using a chemical primer like acetone or isopropyl alcohol to clean the plastic and potentially enhance bonding, though another clarifies that isopropyl alcohol wouldn't dissolve PETG.
Beyond adhesive choices, the conversation delves into broader 3D printing practices. One user shares an anecdote about using a 3D-printed jig to aid in gluing parts together accurately. Another discusses the benefits of designing parts with integrated interlocking features to reduce reliance on adhesives altogether.
Finally, there's a short thread discussing the merits of PETG versus other 3D printing filaments like PLA, with one user mentioning PETG's superior layer adhesion and temperature resistance. Another challenges this, claiming their experience shows PLA to have comparable or even superior strength in certain scenarios.