takes place as a result of heat applied to the liquid carrier by utilizing heat to cause solidification the invention particularly is useful for sealing cracks or holes in a combustion engine in its cooling system for example the invention is utilized for sealing cracked or warped heads or blown head gaskets in an engine or for sealing heating cores freeze plugs radiators or otherwise in the cooling system in one aspect the engine or cooling system is a gasoline or diesel type such as those used in vehicles such as cars trucks and boats in the present invention a liquid part of sealant is obtained by mixing sodium silicate and potassium silicate in liquid form to which is added a glycol and water in one aspect the liquid contains various coloring agents and preservatives in some applications the liquid contains particulates such as pumice or corrosion resistant metal filings the silicates of the present composition include potassium silicate and sodium silicate the silicates are high grade silicates and may be mixed in specific proportions for example sodium silicate may be present in 10 90 based on the total amount of the silicates more preferably 50 80 based on the total amount of silicates the balance of the silicates being comprised of potassium silicate the total amount.