It depends on how much epoxy and alcohol you have. The alcohol changes the chemical makeup of the epoxy when you thin it that way. If you have a lot of epoxy a couple of drops probably won't hurt. But if you only have a small bit of epoxy the alcohol will definitely make a big change. I prefer to thin epoxy by heating it if I can. Apply a small amount of epoxy to the area you are working in and use a heat gun to thin it out. Since heating shortens the curing time of the epoxy make sure you use 30 minute (or higher) epoxy

Hope this helps

Ken