The adhesive experts at Gluegun.com perform a variety of strength tests to ensure the quality of the products we recommend. Today we will test the widely-known JB Weld Kwikweld epoxy as well as Infinity Bond MMA 420. The results will show which adhesive is best for metal bonding applications.
About JB Weld Kwikweld Steel Reinforced Epoxy
JB Weld KwikWeld™ is a fast setting version of the original J-B Weld two-part epoxy cold weld system that provides strong, lasting repairs to metal and multiple other surface types. After mixing, it forms a permanent bond and can be shaped, tapped, filed, sanded and drilled after curing. KwikWeld™ has a 1:1 mixing ratio, sets in 6 minutes and is fully cured in 4-6 hours.
About Infinity Bond MMA 420 Toughened Impact Resistant MMA Adhesive
Infinity Bond MMA 420 is a perfect "jack-of-all-trades" Methyl Methacrylate Adhesive (MMA). It offers a fast set time (right around 5 minutes). Making it a great adhesive for high volume product assembly, smaller parts, or jobs you want to get done fast. MMA 420 offers strong, permanent bonds to difficult surfaces like metals, plastics, composites, and more. Like all of the Infinity Bond MMA adhesives, MMA 420 has great impact and weather resistance and requires little to no surface preparation. MMA 420 has a work time of around 5 minutes and reaches handling strength in about 15 minutes. Once fully cured, MMA 420 provides a strong, flexible bond that excels even under extreme hot or cold temperature ranges.
MMA vs. Epoxy for Bonding Metal
MMA (Methyl Methacrylate) Adhesives are a great choice for bonding metal substrates. Unlike other adhesives, minimal surface preparation is required to achieve optimum bonding on difficult substrates like metal, composite, and plastic. When using epoxy glues more abrasion, cleaning and priming is necessary to prepare substrates for bonding. Cutting out the preparation step makes production leaner and improves quality by avoiding potential priming errors. The adhesive experts at Gluegun.com regularly recommend MMA adhesives for bonding metal.
Testing Shear Strength
Aluminum samples were used to complete this strength test. Two 3x1 inch strips were used to create 2 samples for each adhesive. The adhesive was applied to a 1x1 inch area for continuity. Samples were allowed to set for 24 hours.
Our lab utilizes the Universal Testing Machine to measure peel strength, shear strength as well as tensile stress of an adhesive sample. For the purpose of this comparison, the shear strength of each adhesive was measured. The comparison values are measured in kilograms of force (kgf). The clamps were used to secure a sample from each side, and were secured by tightening the bolts attached. The machine was then instructed to apply a force in the vertical direction.
Shear strength is the ability of a material to resist lateral forces that cause the internal structure of the material to slide against itself. Adhesive shear strength tests are important for characterizing the structural integrity of a bond between two surfaces (substrates).
We recorded the force at break-point and calculate the corresponding shear stress. This test is important because if a material fails at lower strengths it may not be suitable for some applications.
Substrates Tested
- Aluminum
Adhesives Tested
- Infinity Bond MMA 420
- JB Weld Kwikweld Epoxy
Results
The force that each adhesive could withstand before failure was measured and recorded. The results of each adhesive sample and the force that it was able to withstand are shown below.
| Substrate | Infinity Bond MMA 420 | JB Weld Kwikweld |
| Aluminum to Aluminum | 462.585 kgf | 63.045 kgf |
Winner: Infinity Bond MMA 420
The results show that the Infinity Bond MMA 420 performed much better in this strength test. The aluminum samples bonded with Infinity Bond MMA 420 were able to withstand a higher level of force than the samples bonded with JB Weld Kwikweld adhesive.
Final Thoughts
Metal bonding can be a difficult task. Only the strongest adhesives will be up for the job. You should always thoroughly test any adhesive with your specific substrates. If you would like a personalized product recommendation or would like to have samples tested in our lab, please feel free to contact us.