While it's theoretically possible to clean the static mixer, it's probably more sensible to use a new one for each project. Another option is to bypass the static mixer altogether, squeeze the epoxy directly into a plastic cup, mix it with a stick, and apply. This is what I decided to do for my project, since I only needed a small amount of epoxy and I preferred to save the static mixer for the remaining 39' 10" of product. That may be the best thing about Six10-- you can use as little as you want and save the rest for later. West System includes a retaining nut and plug that keeps the resin and hardener separate and sealed for long-term storage. To be sure you don't cross pollenate, it's a good idea to mark the side of the plug that goes in the resin.