Background: a 3 mm wide crack, about 5 cm long, centered on an exhaust system of an older Mazda to be sealed. First, I can edit with a wire brush the whole area intensively and carefully degreased with silicone remover and dry. Then the application is carried out exactly according to instructions. Also, the glass fiber mat was placed in the best possible and the engine was running for a while in the state to harden the sealant. Now, after a week (!), It will come back on the site to leaks. So it was an attempt that has failed. Pity!
