The DeVilbiss DV191850 Automotive Refinishing QS-336 Oil Seal is a high-quality sealant designed to protect engine parts from oil and grease contamination. This sealant is a two-part system that requires no mixing and is ready to use right out of the bottle. The DeVilbiss DV191850 Automotive Refinishing QS-336 Oil Seal is a high-quality sealant designed to protect engine parts from oil and grease contamination. This sealant is a two-part system that requires no mixing and is ready to use right out of the bottle.