When SLiME repairs a puncture does the sealant actually harden?
No. The bright green liquid, synonymous with SLiME, is actually a delivery system for fibers, rubber particles and other sealing agents. As the liquid gets forced out through the puncture it carries along with it the larger puncture repairing ingredients which pack into and seal the hole, preventing air loss. The green dot that may be visible on the outside of your tire will not harden, but may congeal which results in a flexible seal.
