Causes of Caulk Yellowing and Solutions

What happens here

The discussion moves to why caulk yellows. Rob identifies several reasons: primarily, the type of polymer used (vinyl-based polymers tend to yellow with UV exposure, while acrylics are more durable); second, specific additives that can be incorporated to prevent yellowing; and third, the quality of the Titanium Dioxide (TiO2) used. For white sealants, lower-quality TiO2 can contain sulfur, which causes yellowing. Using higher-quality raw materials, including superior TiO2, is crucial to eliminate or minimize yellowing. Rob also advises that caulk, in general, is best painted to avoid tackiness and the collection of dust, although some high-quality, non-yellowing caulks like Tower Tech 2 can remain unpainted if regularly cleaned.

Goal: Understand the factors that lead to caulk yellowing and how it can be prevented.