Re: conflict in shelf life. The answer is chemical reality vs. business reality. We have resin and hardener from our first batches that still kick off and work fine. (We do occasionally test it just to see.) However, in today's society, it is better to offer a limited shelf life as we fully guarantee our product. We would rather have our distributors rotate their stock and offer fresh stock. If you have older product, do a test sample in a small cup. If it kicks off it's fine. Sometimes, depending on how and where people store the product when it's not in use, the resin can crystalize - like honey, but can be regenerated by placing in warm water, or become contaminated with oils or dirt/soot. We have no control on what they do after they buy it(storage etc.), so we give a limited shelf life.