Fire damaged a second-floor workshop at a well-known Route 1 antiques shop and auction house in Newcastle on Monday morning, but firefighters prevented it from spreading to the first floor, where valuable antiques were stored.

Newcastle Fire Chief Clayton Huntley estimated the workshop, which is part of the Foster’s Antiques business, sustained about $10,000 in damage. Several hand tools were destroyed.

Huntley said a rag containing linseed oil spontaneously combusted, starting the fire. Linseed oil is used to refinish furniture. The rag had not been properly dried before it was it thrown into a trash can, according to the fire chief.

Huntley said crews from Newcastle, Damariscotta and Wiscasset quickly brought the fire, which was reported at 10:30 a.m., under control.

Foster’s Antiques and Auction House is owned and operated by Robert L. Foster. The company specializes in estates, individual consignments, fine antiques and art.