Discoloration in sealant joints
Sealants are used in building and industrial applications in many places under various circumstances and on several substrates. It may occur that the sealant joints show discoloration after a couple of days or weeks. In general the joints can be considered as a reasonably colour stable product. The best colour stability can be achieved with the acetoxy curing silicone sealants and acrylic sealants. The neutrally curing Silicone sealants are more sensitive to yellowing, which in many cases is caused by contact with chemical vapours and fluids. In practice it seems that if discoloration of the sealant joint occurs, this most often is caused by local circumstances, which will be further illustrated below.