How Do I Choose the Right Epoxy?
When considering which type of epoxy to choose, several obvious questions come to mind. Your first question is probably, “what substrates does it bond best?” Your next question likely tackles what environmental conditions your epoxy can withstand. But before you commit to an epoxy, don’t forget to consider the work-life. For a better understanding of structural adhesives check out another resource, here.
Not to be confused with pot life (which reveals how long an activated epoxy will last in your working tub before beginning to harden), work-life relates to cure time. Working life refers to how long your epoxy needs before it is hardened and dry. Although you can accelerate this process with certain epoxies by applying UV light or heat to the cured surface, choosing the right work-life can save you aggravation and possible damage to your substrates.
This is where the Goldilocks system comes in. Depending on your application, you need to choose an epoxy with a work-life that isn’t too short to complete your job and isn’t too long that your finished product is delayed. In other words: not too short, not too long, but just right. Understanding common applications for short, medium, and long epoxy cure times will help you determine the work-life that is best for your project.
Short Work-Life Epoxies
When referring to an epoxy adhesive with a short work life, you can expect to wait no more than three to ten minutes for the epoxy to set. Although some short work-life epoxies may not be fully cured for up to 24 hours, after that ten-minute mark, you will not be able to adjust your parts or make changes to the epoxied area. Short work-life epoxies such as the Infinity EP 100 General Purpose 5 Minute Epoxy (in black or clear) are ideal for quick repairs. They bond well with a variety of surfaces such as ceramics and plastics, so you can reinforce cracks, mend broken household parts, or repair leather and fabric fasteners. Thanks to the shorter work life, these epoxies can be helpful if you have a vertical application and need to hold your item in place with precision. Your arms get tired. Short work-life epoxy doesn’t.
Medium Work-Life Epoxies
Many commercial projects call for epoxy with medium work life. Because these epoxies begin to cure in 20 to 40 minutes, you have time to adjust your parts. This is especially important if you are using epoxy to reinforce joints and weight-bearing anchors, or need time to ensure your work is precise for water or airtight applications. The Infinity EP 420 High Peel and Shear Strength 25 Minute Epoxy is a two-part, general-purpose epoxy that fits the bill and is most commonly used to bond metals, ceramics, or glass. Medium work-life epoxies usually pack an extra punch and can withstand harsher external and environmental conditions, such as water, salt, and acid exposure. The Infinity EP 25 Minute Epoxy is a toughened epoxy adhesive giving it maximum impact, shock and vibration resistance.
Long Work-Life Epoxies
Long work life epoxies – the “papa bears” of the adhesive world – are critical for heavy-duty applications where precision is key. The longer open time gives you the most flexibility to adjust parts for precision and alignment. If your parts fit into an engineering system or work alongside other parts, the longer work life of epoxies such as the Infinity EP 190 Long Open Time Epoxy makes your job much easier. With about 60 minutes of work-life, these epoxies make metal and plastic bonding a breeze. Like many other epoxies, you can accelerate the cure by applying heat, so you can finish your project when you’re ready – not when your epoxy is.
Ready to Learn More?
Although other properties of your epoxy, such as viscosity or weight-bearing capabilities, may jump out first during your selection process, considering your epoxy work life is a necessary component to consider so you choose the most efficient materials for the job. Selecting an epoxy with an appropriate work-time can help make sure that you're able to effectively manage your time and result in a polished finished product with more ease.
At Gluegun.com, we have a great selection of epoxies for a variety of applications. If you need assistance finding the perfect epoxy or adhesive work-life for your application, contact us. Our knowledgeable team is happy to help.