Its normal because the materials dry out in dry heated houses.
This tutorial was extensive and detailed with the step by step instructions.
It would be nice to renew and repair the window sills so it looks brand new again.
Image by GGosforth Handyman via YouTube
After, wipe down the surface with a rag.
Continue to watchGosforth Handymanon YouTube for full instructions and details.
Prime the area you caulk, then use a gloss for the topcoat.
Although it might be tedious, it is simple.
