You can use 70% isopropyl alcohol on epoxy, but there are some considerations to keep in mind. Isopropyl alcohol is commonly used to clean and prep surfaces before applying epoxy, as it helps remove any contaminants that may affect the adhesion of the epoxy.
However, the water content in isopropyl alcohol can sometimes interfere with the curing process of epoxy. Epoxy cures through a chemical reaction between resin and hardener, and excessive moisture can slow down or prevent this reaction from occurring properly. This is why many people prefer to use higher concentrations of isopropyl alcohol, such as 91%, as it contains less water.
In most cases, using 70% isopropyl alcohol should work just fine without any issues. The water content is not significant enough to cause problems with the epoxy curing process. However, there may be instances where the epoxy remains tacky if the water content in the alcohol is too high or if the curing conditions are not ideal.
If you encounter this issue, it is advisable to switch to a higher concentration of isopropyl alcohol, such as 91% or even 99%, which contains even less water. By using a higher concentration, you can minimize the risk of the epoxy staying tacky and ensure proper curing.
It’s worth noting that the tackiness of epoxy can also be affected by other factors such as temperature, humidity, and the specific epoxy formulation being used. So, even when using higher concentrations of isopropyl alcohol, it’s important to follow the manufacturer’s instructions and recommendations for optimal curing.
In my personal experience, I have used both 70% and 91% isopropyl alcohol for cleaning epoxy surfaces, and I have not encountered any issues with tackiness. However, I have heard from other DIYers and professionals who have had instances where the epoxy remained tacky when using 70% alcohol. This is why I now always keep 90% or higher concentration isopropyl alcohol in my shop, as it provides added peace of mind and ensures consistent results.
To summarize, while 70% isopropyl alcohol is generally suitable for cleaning epoxy surfaces, there may be instances where it can contribute to the epoxy remaining tacky. If you encounter this issue, switching to a higher concentration of isopropyl alcohol, such as 91% or 99%, can help minimize the risk and ensure proper curing.