While it is extremely important to make sure that you stir your resin and hardener mixture for 3 minutes, you really can’t overstir epoxy resin. If you stirred for 10, 12 ,15 minutes, it’s not going to do any harm. Just remember that you have a 45 minute window in which you need to pour before the resin will start to cure and become too thick to work with.
So when you stir, make sure you go slowly, methodically, and make sure that you scrape the sides and the bottom as you go. Try not to get in there and really whip the resin because that will just induce more bubbles than you need. If you do have a ton of bubbles in the end, you can simply torch them out with our Artist's Torch.
Remember, though, it’s always better to have more bubbles than less bubbles because that means that you did stir properly.
Learn how to use ArtResin as Glue.
ArtResin: Made For Artists, By Artists.