Jacks Magic JMEXPOSURE&MAG640 5 gal Exposure Magic™ 640 Kit is a superior alternative to muriatic or sulfuric acid for exposing plastered pool finishes. It is non-hazardous and safer for crews and the environment. Works on quartz, pebble and more! Exposure Magic™ hangs on vertical surfaces for better finish exposure, has no limited surface contact tine and no oxidized pigments. Please Note: Avoid allowing the product to have prolonged contact with aluminum parts.