The most notable difference between these two compounds is their intended use. Epoxy coating resin is designed for surface coating applications, while casting resin is mainly used for jewelry, molds, or figurines. Epoxy is a specific type of two-part resin. Epoxy resins are the most commonly used type of resin for making crafts and creating resin art.
Because they are the easiest to measure and mix, epoxy resins are what I recommend for resin beginners. When it comes to forming strong bonds, both epoxy and resin glue can be strong, but epoxy is stronger. Epoxy resin systems can be custom-made to fit the unique needs of the project. Manufacturers use a variety of coreactants, including, for example, polyfunctional amines, phenols and alcohols, all of which produce slightly different results.
The type of base epoxy and the additives in the formula can also change the viscosity and intrinsic properties of the resin. Viscosity describes the degree of resistance of a liquid to flow. In the context of epoxy resin formulations, viscosity determines if the material will drip or spread evenly and if it should be poured, dipped, or painted onto the material. Viscosity also affects the amount of epoxy that pierces the substrate and the physical properties that are produced.
Low-viscosity epoxy resin is thin and works well for deep level penetration and filling small cavities. Consistency helps prevent air bubbles, making bonding easier between epoxy and substrate. You can use low-viscosity epoxy resin for encapsulation, sealing and potting. It is less permeable than low-viscosity formulas and offers greater mechanical strength.
The material can withstand moderately high temperatures and is often used for filament winding, vacuum bagging and tools. If you pour casting resin onto a surface instead of using a thin layer of coating resin, for example, the resin will run off the edges and take a long time to harden. This is not arbitrary, because when an epoxy resin is used, it takes less time to cure and the reaction is much more exothermic (i.e., releases heat) than the reaction of the cast resin. They are generally blended by volume with a particular amount of Part A (the resin) with a particular amount of Part B (the hardener).
These two resins are quite similar in some respects, but they are very different to work with and are intended for different uses. In general, there are two types of resin that are commonly used in home DIY projects: epoxy resin and casting resin. Many people use a casting resin, such as pourable plastic, when trying to enclose a souvenir product or piece, such as coins, dried flowers, marbles, glitter and sequins, or insects. Polyester resin tends to be used for quick fixes rather than long-term use because it is much more brittle and prone to cracking; however, it is completely UV-resistant (unlike epoxy resin) and cheaper to use than epoxy.
Excessive application of the thin casting resin could cause cracking of the epoxy because the curing process will proceed too quickly. Manufacturers can also produce aggregates, molded plastics, or electrical insulation with cast resin. For a casting resin, this means that you can pour a casting resin to a greater depth than an epoxy resin without damaging the bond within the resin. It is essential to read the instructions provided by the manufacturer you are using, as measuring accurately and mixing well is everything when it comes to resin.
As mentioned earlier, cast resin is also designed for projects that require thicker pouring, such as the ever-popular river tables that are usually several centimeters thick. The good news is that you can buy epoxy resin and cast resin that is designed to withstand much higher heat levels. Resin is used in a wide range of applications, including DIY projects, model making, art, surface finishing, adhesives and more. Polyester resins cure very hard, but they require you to know exactly how you will use them to know how much hardener to add.