Non-Setting Compounds Hylomar Limited manufactures the world’s leading range of high performance non-setting gasket and jointing compounds. The original product was developed in conjunction with Rolls-Royce and was used for sealing aircraft engines. Hylomar continues to manufacture Rolls-Royce approved products for sealing aeronautical turbines. Engine, compressor, electric motor, heavy industrial equipment, gearbox, defence industry component, turbine and many other original equipment manufacturers choose Hylomar non-setting compounds for their sealing and bonding applications.