How to Produce a Consistent Fire Door Mastic Bead Around a Frame

A consistent fire-door mastic bead is not created by relying on a finishing tool to rescue an uneven application. The consistency has to start at the gun. Prepare the route Before applying anything, identify the full run you are going to seal. Check where the joint changes width, where access tightens, and where you are likely to stop and restart. The more often you stop, the harder it becomes to produce a continuous appearance. More importantly, stop-start working makes it easier to miss sections of the intended joint. Set the nozzle for control Sika's current instructions tell the installer to cut the nozzle to the desired bead size and to apply into the joint while avoiding air entrapment and achieving full contact. That is the correct starting point for consistency: make the outlet suit the line, not the other way…