Thank you for your question. I would suggest squirting some white vinegar into the screw area. You can also take a 50/50 or stronger mixture of tap (warm to hot) water and white vinegar:
Dip a rag into the solution, using tongs if necessary. Wrap the rag around the full handle. Leave the rag in place for 15 minutes or so to remove the calcium deposits that are preventing you from loosening the screw. Repeat if necessary up to 4 times, taking care to protect surfaces that may be damaged by vinegar. The white vinegar can stain porous stones like granite, limestone and marble.
Date published: 2018-05-07