This sequence of three images shows these weathered stone capitals before (showing carbon tarnish), during Torc cleaning, and after Torc cleaning.

They arrived in fairly poor condition, being heavily tarnished with carbon from airborne pollution over many years. The surfaces were also fairly fragile, so any aggressive cleaning techniques were out of the question.

The Torc system was chosen for this job as it cleans thoroughly yet gently, using a combination of air pressure, a little water and some granulate abrasives. The key to success is in choosing the right abrasive medium for the type of stone in question, from the options of calcite, dolomite and util.

As shown in the final (after image) the carbon has been effectively removed while retaining the patina of the stone.

If you face similar cleaning challenges and need to preserve the material to be cleaned, give our specialist team a call, or click in the header of any page to send us an email. We will be happy to quote for any or all of your building conservation needs.