Hylomar blue is a polyester urethane based sealant which is
non-setting and non-hardening even at high temperatures.
The compound is resistant to a wide range of fluids
including all industrial fuels,oils,water and brine,air,
turbine and piston engine combustion products,
water,water/glycol and methanol mixtures, petroleum and synthetic diester
lubricating oils, gasoline and kerosene fluids(avtur and avcat) and fluorocarbon refrigerants.