A Deep Dive into Structural Adhesives
In our post describing when to use structural adhesives, we introduced you to the three most common types: epoxy, acrylic, and urethane options. Because structural adhesives are stiffer than many alternatives and offer exceptional strength – even when bonding irregular surface areas or unprimed substrates – they are most popular in the transportation, automotive, and construction industries.
Let’s break down the two most popular types of structural adhesives and highlight some of these glues’ unique properties.
Epoxy for Strength
Epoxy brings strength to the table, making it ideal for gap filling or repairs in environmentally harsh conditions. Epoxy is best if your area may be prone to impact, abrasion, and other wear and tear.
The most popular epoxy is the ASI MP 5405BK Black 5 Minute Epoxy. This jack-of-all-trades begins to set in just three to five minutes and yields a rigid, tight bond. It’s easy to mix and easy to apply, making it a favorite for many general needs projects.
For a little more flexibility, we recommend the ASI MP 54750 Versatile & Resistant Epoxy. In addition to this adhesive’s clear color and longer work life, the low viscosity formula makes it easy to apply to a wide variety of substrates. The adhesive’s resistance to external forces such as acids, bases, and organic solvents makes it especially popular for projects at risk of elemental exposure.
Because epoxy shines for gap filling applications, we have to mention the ASI MP 54421 Gap Filling Epoxy. The ultra high viscosity formula (43,000 cps) and robust impact resistance makes this epoxy ideal for gap filling needs in heavily trafficked areas. Because the adhesive begins to set in just 20-30 minutes you can finish your repair and get on with it faster.
Acrylics for Flexibility
While epoxy’s claim to fame is strength, acrylic boasts extra versatility when bonding with difficult substrates such as plastics and metals. These characteristics make acrylics ideal for assembly and production needs more so than epoxy.
When using acrylic for prolonged periods of time (especially in tight quarters or along a production line), health conscientious adhesives, such as the 3M DP8805NS Low Odor Structural Acrylic Adhesive, are preferable. The low odor adhesive creates a more comfortable and healthy work environment while still boasting maximum productivity (think over 1,000 psi of shear strength), which is why this is our most popular acrylic adhesive.
For maximum substrate flexibility, the ASI MP 55350 Plastics, Composites & Metals Methacrylate (MMA) can’t be beat. Specifically designed to bond unlike surfaces, the MP 55350 also offers medium viscosity and medium work life, making it exceptionally versatile. We like the middle-of-the-road work life and viscosity because this allows you to use the adhesive on a wide variety of projects without needing to switch glues for every situation.
But if it’s strength you need – bump up to the 3M DP8410NS Structural Acrylic Adhesive.
While delivering many of the same benefits of other acrylics, the DP8410NS provides higher industrial-grade impact strength. This adhesive gives you the best of all worlds by rivaling epoxy’s strength, while harnessing acrylic’s traditional flexibility.
Structural adhesives give you great control over your finished product by delivering the type of bond you need, when you need it. Supported by a wide range of delivery tools and application systems, nozzles, and accessories – there is almost nothing structural adhesives can’t do when put in the right hands.