When used as directed, Chem-i-Weld will permanently repair existing cracks, flaws and porosity in automotive cylinder heads, blocks and other cooling system castings.
Chem-i-Weld is not a cure for overheating, as a result of coolant loss caused by cracks, flaws and porosities in castings
Chem-i-Weld will not cure oil-to-water leaks (oil in the water)
The development of cracks in castings is a type of stress relief, whether through overheating or ice formation in the coolant or as with flaws, poor design, metallurgy, or casting technique – porosity is usually age-related.Chem-i-Weld is effective on aluminium, cast iron, steel, brass, bronze and copper castings and works by hardening on exposure to air in a confined space. Head gaskets, irrespective of construction or material are joints, not castings – these and other cooling system joints may leak because of: corrosion on the surface clamping the gasket, and/or distortion of the surface clamping the gasket, and/or a reduction of the clamping force on the gasket, and/or deterioration of the gasket itself. Chem-i-Weld may cure head gasket leaks, but this cannot be guaranteed. Head gaskets, unlike castings, are subject to rapid deterioration and although the Chem-i-Weld may seal the immediate gasket leak, deterioration, or further deterioration, of the gasket or clamping surface may introduce a new leak around the initial seal. Chem-i-Weld will not cure leaks in flexible cooling system seals, e.g. wet cylinder sleeve ‘O’-rings, because these are subject to movement caused by heat/cold expansion and compression whilst Chem-i-Weld sets hard. It will not cure leaks in radiators because radiator tubes and tanks are too thin-sectioned for the Chem-i-Weld to effectively adhere to them, but it will attempt to seal the exposed end of a radiator tube – for this reason tubes must be kept submerged whilst Chem-i-Weld is being used. Boiling the water whilst Chem-i-Weld is being used may block radiator and heater core tubes, and small water galleries in engines. Note: For internal leaks into a combustion chamber – removing the spark plug in an affected cylinder (to reduce the cylinder pressure) for the first twenty minutes of Chem-i-Weld use was commonly done, but this practise is discouraged on vehicles with high energy ignition systems -.unless the correct procedure is used, damage to the system may result. Chem-i-Weld and oil do not mix – if it gets into an oil sump in quantity; i.e. a noticeable dipstick oil level increase or oil colour change, drain the sump, fill it with fresh oil and change the oil filter before proceeding Chem-i-Weld splash is best removed whilst still wet with hot water – there is no known solvent once it has set Chem-i-Weld on the skin or clothes should be washed off with soap and water Chem-i-Weld in the eyes should be flushed out with cold water